Hyphema

Traumatic hyphema, or anterior chamber hemorrhage, can often manifest after blunt trauma. Most hyphemas clear spontaneously and do not cause residual visual impairment. However, permanent visual impairment can arise from complications of hyphema. These complications include: (1) corneal blood staining;⁶ (2) ghost cell glaucoma as a result of blocked outflow from clogging of the trabecular meshwork by erythrocytes;⁷ or (3) central retinal artery occlusion from elevated intraocular pressure.⁸ All these complications are more common when secondary bleeding occurs, usually 48–72 hours after the injury.

The laboratory workup for traumatic hyphema is tailored to the specific patient. While laboratory evaluation is not indicated in most patients with a hyphema, blood coagulation tests (partial thromboplastin time, prothrombin time, bleeding time, platelet counts, and liver function tests) should be considered in patients with a known bleeding diathesis or pertinent review of systems. African American patients should be questioned about a family or personal history of sickle cell disease or trait. If unknown, a sickle preparation or hemoglobin electrophoresis should be obtained. Patients with sickle cell hemoglobinopathies and traumatic hyphema present special problems because of their decreased ability to tolerate modest rises in intraocular pressure. Goldberg⁹ reported four patients with sickle cell hyphemas who developed optic atrophy with elevated pressure for short periods. This presumably is due to decreased perfusion pressure, sludging and sickling of erythrocytes and subsequent infarction. In addition, because of its lower likelihood to cause systemic acidosis that promotes sickling, methazolamide (Neptazane) rather than acetazolamide (Diamox) should be used to decrease intraocular pressure in these patients. Mannitol should be used only once to avoid hemoconcentration and the subsequent erythrocyte sludging and vascular obstruction.

Primary management of traumatic hyphema is directed at prevention of rebleeding, which is a significant risk factor for the development of glaucoma.¹⁰ Rebleeding has been reported to complicate up to 35% of cases¹¹; the wide range in reported incidence likely relates to variability in patient ethnicity, treatment, and severity of injury. Previous clinical studies have demonstrated the benefits of shielding the injured eye to prevent accidental repeat trauma, using atropine for cycloplegia, and daily checking of visual acuity, corneal status, and intraocular pressure.^12,13 On the other hand, no benefit in the prevention of rebleeding has been proven for hospitalization with enforced bed rest or for bilateral patching to reduce eye movement.¹⁴

Several pharmacologic measures have been used to prevent rebleeding. Corticosteroids, both topical (prednisolone acetate 1% q.i.d.) and systemic (prednisone 0.5–1.0 mg/kg per day), reduce iritis and ciliary spasm, increase patient comfort, and theoretically stabilize the clot formation, thereby decreasing the rate of rebleed.¹⁵ Clinical trials have demonstrated the efficacy of oral epsilon-aminocaproic acid, both systemic (Amicar, Lederle Laboratories, Pearl River NY, given 50 mg/kg every 4 hours for 5 days) and topical (Caprogel, ISTA Pharmaceuticals Irvine, CA, given every 6 hours for 5 days) and tranexamic acid (Cyklokapron, Pfizer, New York, NY) in reducing the incidence of secondary bleeding.^16,17 These antifibrinolytic agents reduce clot degradation from traumatized blood vessels by inhibiting the conversion of plasminogen to plasmin, the protein responsible for clot breakdown.

A recent review and meta-analysis examined the use of antifibrinolytic agents, corticosteroids, cycloplegics, miotics, aspirin, conjugated estrogens, unilateral or bilateral patching, elevation of the head, and bed rest. No intervention had a significant effect on visual acuity, whether measured at ≤2 weeks after the trauma or at later time points. All antifibrinolytic agents significantly reduced the incidence of recurrent hemorrhage. The evidence to support an associated reduction in the risk of complications from secondary hemorrhage (i.e., corneal blood staining, peripheral anterior synechiae, elevated intraocular pressure, and development of optic atrophy) by antifibrinolytics was limited by the small number of these events. Use of aminocaproic acid was associated with increased nausea, vomiting, and other adverse events compared with placebo. There was no difference in the number of adverse events with the use of systemic versus topical aminocaproic acid or with standard versus lower drug dose.¹⁸

In most cases the hyphema improves with medical management. However, empiric criteria for surgical evaluation have been developed^13,19,20: (1) intractably elevated intraocular pressure (IOP) despite medical therapy (>60 mmHg for 2 days in sickle-negative patients; or >24 mmHg for more than 1 day in sickle patients); (2) total hyphema for more than 5 days with IOP >25 mmHg; (3) corneal bloodstaining; (4) persistence of hyphema occupying at least one-half of the anterior chamber volume. Several surgical techniques have been suggested to manage this problem, including paracentesis, anterior chamber washout with a one-needle irrigation or irrigation–aspiration technique,²¹ washout with a two-needle technique, clot evacuation with a forceps or cryoprobe through a large limbal incision,²² or clot evacuation associated with a trabeculectomy filtering operation.²³

A two-instrument bimanual technique using vitrectomy instrumentation inserted through limbal incisions permits controlled removal of anterior chamber hemorrhage (Fig. 110.1).^24,25 The surgeon inserts through one incision a blunt infusion cannula (20-gauge (G), or smaller) or a bent needle (typically 23G) connected to balanced salt solution and a vitrectomy instrument through the other. Using both the aspiration and cutting functions of the instrument, as much of the clot and free blood is removed as possible. Care is taken to avoid damaging the crystalline lens and corneal endothelium. It is not uncommon to leave some residual blood at the end of the procedure. The incisions are closed with “X-type” sutures using 9–0 or 10–0 monofilament nylon with knots buried in the incision. However, this technique may also now be performed with the newer small-gauge vitrectomy instruments. By using a 23G or 25G approach, self-sealing incisions may be possible.

Fig. 110.1 A two-instrument bimanual technique permits controlled removal of anterior chamber hemorrhage. An angled, blunt, 20G infusion cannula is inserted through a nasal limbal incision, and the vitrectomy instrument is inserted temporally. Careful aspiration and cutting are used to evacuate the clot. The instruments can be transposed to reach hemorrhage inaccessible in the primary position. Alternatively, smaller gauge infusion and vitrectomy instrumentation can be used for the same procedure.

Lens subluxation and dislocation

Blunt trauma can lead to either subluxation or dislocation of the crystalline lens. In lens subluxation, zonular filaments are broken, and the lens is no longer held securely in place but remains in the pupillary aperture. Lens dislocation occurs following complete disruption of the zonular filaments and displacement of the lens from the pupil. Trauma is the leading cause of lens dislocation.²⁶

The dislocation or subluxation is not a problem in itself. Patients can have 20/20 vision with a totally dislocated lens and aphakic correction. However, the contusive impact can lead to cataract formation. Special considerations and techniques are required when extracting a subluxated or dislocated cataractous lens.

In the evaluation of a patient with a cataractous lens after blunt trauma, it is important to remember that the lens may be subluxated. During the slit-lamp examination, evidence of iridodonesis or phacodonesis must be sought. This usually is more apparent in the undilated state, when the remaining intact zonular filaments are under less tension. Phacodonesis can be detected by having the patient look quickly from side to side or up and down, or by jarring the slit-lamp table. If an associated iridodialysis is present, the absence of zonular fibers can be identified by looking through the area of absent iris (Fig. 110.2). In addition, vitreous sometimes can be identified extending around the lens, either through the pupil or through the iridodialysis. Presence of vitreous in the anterior chamber is proof of zonular rupture and probable lens subluxation.

Fig. 110.2 This 13-year-old boy suffered an iridodialysis and subluxated lens with zonular rupture from a nonpenetrating BB pellet injury. A cataract developed within 2 weeks of the injury.

Extraction of a subluxated or dislocated cataractous lens should be considered only when the cataract is causing significant visual impairment. Urgent intervention is indicated for cases of pupillary block glaucoma, intractable uveitis, or lens–corneal touch leading to corneal decompensation. In children, the possibility of development of amblyopia must be remembered and may necessitate surgery. Lens extraction also may be necessary if visualization of the fundus is impaired and ultrasonography is equivocal with regard to retinal status. When surgery is planned for a subluxated or dislocated cataractous lens, vitreous loss is likely, and the success of surgery most likely depends on the care with which the vitreous is managed.

For cases with minimal lens instability, the traditional phacoemulsification techniques through a corneal limbal or scleral tunnel incision may be used, with a thorough hydrodissection and care to minimize the stress on the zonule and vitreous during all steps of the procedure. A capsular support device may increase the safety and ease of phacoemulsification by stabilizing the capsular bag. Alternatively, a larger capsulorrhexis may be used, and the lens may be prolapsed into the anterior chamber for phacoemulsification. Of great concern is vitreous prolapse through the cataract wound, and if vitreous is pulled on, traction transmitted to the vitreous base can cause retinal tears, giant retinal tear, and retinal detachment.²⁷ Consequently, the surgeon must recognize that vitreous prolapse through the wound is probable and be prepared for its management.

A pars plana approach using vitreoretinal instrumentation avoids many of the risks associated with limbal extraction (Fig. 110.3). Using a two- or three-port system, a myringotomy blade or a bent 21G or 23G butterfly intravenous needle connected to irrigation is inserted through the pars plana into the lens for fixation, and either a vitrectomy or a phacofragmentation instrument is inserted through the opposite pars plana to digest the lens. If the lens is soft, as in children and young adults (the most frequent victims of trauma), the entire lensectomy can be performed with the vitreous cutter. Vitreous around the lens can be managed with high-speed cutting to prevent traction on the vitreous base. Should the lens nucleus be harder and require phacofragmentation, care should be taken to perform either a limited vitrectomy around the lens before introduction of the phacofragmatome or to use the phacofragmatome only when inside the lens capsule. This avoids unintentional aspiration pressure on the vitreous that could lead to retinal damage.

Fig. 110.3 Technique for pars plana lensectomy for subluxated cataractous lens. (A) A pars plana infusion cannula is sutured in place in the inferotemporal quadrant, and the lens is fixated with a myringotomy blade inserted through a pars plana sclerotomy. A vitrectomy instrument (if the lens is soft) or phacofragmentation instrument (if the lens nucleus is harder) is inserted into the lens through the opposite pars plana. (B) If any lens material falls posteriorly, a fiberoptic probe is inserted in place of the myringotomy blade, and the lens material is removed using standard two-hand vitrectomy techniques. (C) Residual peripheral lens material is removed with the use of careful scleral indentation to bring the pars plicata area into view.

If any lens fragments fall posteriorly, a fiberoptic probe can be inserted through a sclerotomy and the lens material removed using standard vitrectomy techniques. In order to minimize vitreous traction during manipulation, all vitreous surrounding the lens must first be carefully removed. Lens material on the retinal surface should then be brought into the middle or anterior vitreous cavity before fragmentation. Residual peripheral lens material can be removed by having an assistant perform gentle scleral depression to bring the pars plicata area into view. Vitrectomy should be as complete as possible. However, if there is no evidence of posterior segment injury and no posterior vitreous detachment (PVD) is present, the surgeon usually should not risk retinal damage in an attempt to create a vitreous separation to remove all vitreous.

If enough zonular filaments remain intact to support a sulcus-fixated intraocular lens (IOL), primary placement of an IOL can be considered. If minimal capsular support remains, the residual capsule should be removed, as this may increase the risk of late postoperative anterior fibrous proliferation and traction on the ciliary body and retina. Complete capsular removal is most easily performed using a two-handed technique: in one hand, an end-grasping microforceps engages the capsule, gently pulling it centrally, and in the other hand a vitrector aspirates and cuts the residual capsule and zonular filaments. An open-loop flexible anterior chamber intraocular lens (AC-IOL) or iris-fixated lens can be placed, or the eye may be kept aphakic with the intention of attempting refractive correction with a contact lens.

Pars plana vitrectomy and pars plana lensectomy (PPV/PPL) with implantation of IOL can be used for cases of subluxated traumatic cataract with extensive zonular damage. Kazemi et al. reported on nine such eyes, in which an anterior chamber IOL was placed. Complications included retinal detachment in one patient, transient limbal wound leak in one patient, and cystoid macular edema in three patients. All of the complications were managed successfully. Best-corrected visual acuity of better than 20/40 was achieved in six of the nine eyes, and the etiology of poor visual acuity in the remaining three eyes was attributed to the original injury.²⁸

Kodjikian et al. reported on nine consecutive cases of traumatic cataract with zonular dialysis of at least 180° and visual acuity of 20/100 or worse. Following PPV/PPL and implantation of an iris-fixated Artisan IOL, all patients achieved best-corrected visual acuity of 20/30 or better. Postoperative complications included one instance each of iris incarceration into the corneal wound and anterior uveitis, which was medically managed.²⁹ Other authors have reported similar results using PPV/PPL and sutured sulcus IOLs.³⁰ A consistent finding in these studies is that the primary cause of poor visual acuity postoperatively is posterior segment pathology related to the original injury.³¹

Should an iridodialysis be present, it can be repaired at the end of the case using a 10–0 Prolene suture introduced through the cornea in a modification of the technique described by McCannel³² to fixate IOLs to the pars plana (Fig. 110.4). At the end of the procedure, the peripheral retina should be carefully inspected with scleral depression to identify retinal breaks, dialyses, or areas of retinal detachment. Inspection can be performed either with binocular indirect ophthalmoscopy or through the microscope equipped with wide-field viewing. Should retinal breaks or detachment be present, they should be treated immediately with retinopexy and, if necessary, scleral buckling and endotamponade.

Fig. 110.4 An iridodialysis can be repaired with a modification of the McCannel suture technique. A curved needle attached to a 10–0 Prolene suture is introduced through the limbus. With the iris grasped with a microforceps and pushed back into place, the needle is passed through the iris and back out through the limbus. The needle is then tied, reapproximating the iris in its original position.

Vitreous hemorrhage

Vitreous hemorrhage may result from damage to blood vessels in the ciliary body, retina, or choroid. Vitreous hemorrhage from blunt trauma may be associated with a retinal tear, and indirect ophthalmoscopy with scleral depression should be performed with great care in attempting to identify retinal abnormalities. Vitreous hemorrhage often is limited immediately after injury, with the initial fundus examination allowing best visualization of retinal detail. Subsequent diffusion of the hemorrhage or further bleeding may compromise later examinations. If the physician suspects an occult scleral rupture, scleral depression should be deferred.

If vitreous hemorrhage obscures examination of the retina, ultrasonography plays a critical role in decision-making. With combined contact A-scan and B-scan techniques, many details of the posterior segment can be determined, including presence of retinal detachment, posterior vitreous detachment, occult scleral rupture, hemorrhagic or serous choroidal detachment, and giant retinal tear (Fig. 110.5). For example, if ultrasound demonstrates vitreous strands emanating from an equatorial location, an occult scleral rupture with vitreous incarcerated in the wound can be inferred, requiring conjunctival peritomy and exploration.

Fig. 110.5 In the presence of vitreous hemorrhage, contact B-scan ultrasonography can demonstrate a retinal detachment and can sometimes also identify the causative retinal tear.

In general, patients with a nonpenetrating ocular injury and a vitreous hemorrhage without associated retinal tear or detachment should be observed. In cases of minimal diffuse hemorrhage, indirect ophthalmoscopy may be sufficient to establish retinal attachment. However, if the blood does not settle, the patient should be followed every few weeks with ultrasonography repeated to confirm retinal attachment. If retinal detachment is seen or suspected on ultrasonography, pars plana vitrectomy should be performed.

If pars plana vitrectomy is performed for a nonclearing vitreous hemorrhage caused by nonpenetrating trauma, we recommend a standard three-port technique. After the infusion cannula is sutured in place and confirmed to be in the vitreous cavity, a core vitrectomy should be performed to remove hemorrhagic vitreous. In most cases a PVD will have developed in the interim between injury and surgery. After one cuts through the detached posterior hyaloid face with the vitrectomy instrument, subhyaloid blood can be aspirated from the preretinal space. A blunt cannula connected either to the vitrectomy system for powered extrusion or to a fluted handle for passive extrusion will allow controlled removal of the blood. Residual vitreous, including posterior hyaloid, is then excised with the vitrectomy instrument. The retinal periphery should be examined carefully to identify retinal tears or dialyses that could have led to the original vitreous hemorrhage.

If a PVD is not present, the surgeon should attempt to create one, by using gentle suction from the vitrectomy instrument. If this is not successful, the posterior hyaloid can be engaged with a powered soft-tipped extrusion cannula. The vitreous detachment can be extended using an illuminated vitreoretinal pick while the hyaloid is elevated with either the extrusion cannula or vitrectomy instrument. Other techniques include using a vitreoretinal pick or carefully incising the posterior hyaloid with a myringotomy blade over the periphery of the optic nerve. If the posterior hyaloid remains adherent in certain locations, it should be freed from surrounding vitreous so that all localized vitreoretinal traction is relieved. Residual posterior cortical vitreous can be easily visualized by instilling triamcinolone (either full-strength or diluted 20% in balanced salt solution) following core vitrectomy. If traction persists, it may be necessary to place a local scleral buckle. Areas of persistent vitreoretinal traction should be scrutinized carefully because they may represent sites of occult scleral rupture where the vitreous became incarcerated in the laceration.

Smaller-gauge vitrectomy instrumentation can be used successfully for cases of traumatic vitreous hemorrhage, especially those without associated retinal detachment, proliferative vitreoretinopathy, and with some visualization of the retinal periphery. The surgeon should remember several aspects of transconjunctival small-gauge surgery that are especially relevant to traumatized eyes. First, since the infusion cannula is not sutured in place, it may slip backwards into the suprachoroidal space, even after being well-visualized at initial placement. This risk is higher in eyes with choroidal hemorrhage, choroidal congestion, or dense accumulation of blood or fibrin at the anterior vitreous base. This risk can be minimized by preoperative ultrasonographic confirmation of an absence of choroidal detachment, by choosing a quadrant of the eye with a relatively clearer periphery, and by selecting the longest infusion cannula available. Second, smaller-gauge vitreous cutters (especially earlier-generation 25G cutters) may become clogged with dense hemorrhage or vitreous debris. Third, additional instrumentation (such as intraocular forceps, scissors, lighted instruments, or equipment for oil infusion) may be required for treatment of associated vitreoretinal pathology. The surgeon must have as much information regarding the ocular anatomy as possible and have readily available the surgical instruments that may be required.

The visual prognosis for eyes with vitreous hemorrhage associated with nonpenetrating trauma depends on associated macular damage (from choroidal rupture, traumatic macular hole, Berlin’s edema, or macular contusion), retinal dysfunction from associated retinal detachment, and occlusional amblyopia in young children. In a study of 33 eyes with severe vitreous hemorrhage associated with closed-globe injury, best-corrected visual acuity following resolution and/or treatment of hemorrhage was <20/200 in 54%. The most common cause of poor visual outcome was macular scar. Poor prognostic factors included presenting visual acuity of light perception or worse, hyphema, traumatic cataract, and age 55 years or younger.³³

“Commotio retinae”, avulsion of the vitreous base, and retinal tears

Blunt trauma can damage the retina in many ways, ranging from retinal edema to retinal detachment. “Commotio retinae” is commonly seen after a contusive injury to the globe and appears ophthalmoscopically as retinal whitening. Edema involving the macula (termed Berlin’s edema) can impart an appearance similar to a cherry-red spot. The reasons for this retinal opacification are disputed, with some attributing it to extracellular edema³⁴; however, experimental and histopathologic studies have shown that disruption of the photoreceptor cell outer segment and damage to the retinal pigment epithelium accounts for the retinal whitening.^35,36 Vision can be markedly decreased with commotio retinae, but vision most often improves as the swelling resolves over a 3–4-week period. However, the macula can develop an atrophic appearance with granular hyperpigmentation associated with decreased vision. In addition, the cystoid areas can coalesce to form a large cyst, which can lead to macular hole.

Blunt trauma can also lead to large areas of irregular, jagged retinal holes. These breaks have been observed almost immediately after the contusive injury and are believed to be the result of mechanical disruption and fragmentation of the retina. Similar-appearing breaks have been produced in an experimental model of concussive injury to the globe.³⁷ This syndrome has been given a variety of names, including “acute retinal necrosis”³⁸ and “chorioretinitis sclopetaria.”³⁹ We prefer the latter term to avoid confusion with the acute retinal necrosis inflammatory syndrome of herpetic viral origin.

In eyes with chorioretinitis sclopetaria, it is tempting to intervene in some way because of the frightening size and often posterior location of the retinal breaks (Fig. 110.6). However, the retina rarely detaches in this situation, presumably because of the inflammation at the edges of the necrotic retina that leads to a firm chorioretinal adhesion. If a retinal detachment occurs, it is usually from another site. Therefore, it is not necessary to perform prophylactic cryopexy or photocoagulation. Patients with this syndrome often have poor visual acuity because of the effects of the severe blunt force on the macula.

Fig. 110.6 (A) Color fundus montage showing inferior retinal detachment caused by a giant retinal tear (GRT) along the inferior arcade with overlying vitreous hemorrhage. The inferior peripheral retina is white from presumed infarction arising from arteriolar transection. Posterior segment injuries often result from contrecoup forces and vitreoretinal traction, and the most common retinal break following blunt closed-globe trauma is a retinal dialysis. As the vitreous was forcefully separated from the retina, abnormally strong perivascular vitreous traction over the post-equatorial may have contributed to the unique location of the GRT in this case. (B) Color montage taken 10 months following vitrectomy, scleral buckling, endolaser and gas endotamponade.

Blunt trauma also can cause retinal breaks by transmission of the force to the vitreous, leading to acute severe vitreoretinal traction. Rapid displacement of the vitreous can tear the retina in various ways, including retinal dialysis with or without avulsion of the vitreous base, operculated retinal tear, macular hole, and horseshoe-shaped retinal tears at the posterior margin of the vitreous base, at the edge of a meridional fold, or at the equator.^40,41 A study by Cox³⁷ concluded that the different forms of retinal abnormalities are a result of the point of impact of blunt trauma.

The most common retinal break from trauma is a retinal dialysis. This is seen most commonly in the superonasal and inferotemporal quadrants because of blunt trauma frequently striking the globe inferotemporally.^42,43 The blunt force causes equatorial stretching of the globe, leading to traction on the vitreous base at the site of impact and diametrically opposite. Cox et al.⁴⁰ reviewed 160 patients with retinal detachment caused by contusion. Retinal dialyses larger than one oral bay were found to be the most common retinal break.

It is important to perform careful indirect ophthalmoscopy with scleral depression on all patients with a history of blunt trauma. The authors recommend prophylactic cryopexy or photocoagulation to any retinal dialyses or tears that are identified, in the hope of decreasing the likelihood of subsequent retinal detachment.

Retinal detachment and macular hole

It is uncommon for a patient to develop an acute rhegmatogenous retinal detachment after blunt trauma. Most trauma victims are young with solid vitreous, providing internal tamponade to the retina despite retinal tears or dialyses. However, with time the vitreous liquefies, allowing fluid to form in the vitreous cavity, which can pass through the retinal breaks and detach the retina. By careful examination of the retina shortly after the injury and treatment of areas of retinal damage, detachment can be prevented in many cases.

In treating a retinal detachment in a patient with a history of ocular contusion, the surgeon must remember the types of retinal breaks that are most common in this setting, specifically retinal dialysis. Most traumatic retinal detachments can be treated with conventional scleral buckling techniques. Because of the potential for retinal damage 180° from the impact site, an encircling element is recommended. The selection of chorioretinal adhesive procedure and determination of the need to drain subretinal fluid should be made by the surgeon using the same principles as for nontraumatic detachments. Johnston⁴⁴ reported 77 eyes with retinal breaks after contusive injury; 65 developed rhegmatogenous detachment. Surgical treatment restored or maintained retinal apposition in 96% of the eyes.

In rare cases, blunt trauma may cause a rhegmatogenous retinal detachment from a giant retinal tear or a macular hole. Although these detachments have been repaired successfully in the past with a variety of scleral buckling techniques, modern vitreoretinal surgery has significantly increased the rate of anatomic reattachment. A giant retinal tear is defined as a retinal tear of greater than 3 clock-hours. Vitreous surgery allows mobilization of the flap by excising adherent vitreous. With the aid of surgical adjuvants, such as perfluorocarbon liquids, and current surgical techniques (as described in Chapter 105, Optimal procedures for retinal detachment repair), the rate of successful retinal reattachment for such cases has greatly improved.

Traumatic macular hole formation is uncommon. Like idiopathic macular holes, traumatic holes can be rehabilitated with vitrectomy. However, a significant number of traumatic macular holes may close spontaneously. In a consecutive series of 18 such cases, spontaneous closure and accompanying visual improvement were seen in eight (44%) and occurred between 1 week and 4 months following injury.⁴⁵ Although the visual outcome may be limited by associated macular damage (such as a macular choroidal rupture), there are encouraging reports of successful anatomic and functional outcomes with vitrectomy. Since patients with traumatic macular hole are typically younger and phakic, we elect to use long-acting gas endotamponade with 14% perfluoropropane to optimize the chance of hole closure. It has been suggested that surgical adjuvants such as autologous plasmin enzyme⁴⁶ or removal of internal limiting membrane^47,48 may improve the rate of anatomic success. Improvement in visual acuity of at least 2 Snellen lines has been reported in 69–94% of cases.^47–49

Preoperative evaluation

It is important to obtain a history from any patient being evaluated for a possible eye injury. Although many trauma patients will be poor historians because of associated shock, intoxication, or neurologic problems, the history can give important clues about the ocular damage. For instance, if a patient felt something flying into his or her eye while hammering a nail but did not note any visual disturbance, the physician must carefully search for evidence of an intraocular foreign body (IOFB), even if there is no evidence of obvious ocular laceration. Furthermore, since many of the medical malpractice cases brought against vitreoretinal specialists involve trauma, careful documentation of the details surrounding the injury may prove valuable in case of litigation later on.⁵⁰

Careful evaluation is important not only for appropriate management, but can also be helpful in prognostication of visual outcome, when used according to the ocular trauma score (OTS). The OTS was developed by Kuhn et al. following review of over 2500 registered cases of ocular trauma. The OTS provides a single probability estimate that an eye trauma patient will obtain visual acuity within a specific visual range by 6 months after injury.⁵¹ In the OTS, a numerical score is derived by adding or subtracting points on the basis of initial visual acuity, presence of rupture, endophthalmitis, globe perforation, retinal detachment, or afferent pupillary defect. Higher OTS scores are associated with a better visual prognosis.⁵¹ The OTS can thus be used as an aid in patient counseling and can assist in identifying severe ocular injuries with a poor visual prognosis.

The initial step in examination is determination of visual acuity (VA) with either a near vision card or a Snellen acuity chart. When a retrospective review of penetrating injury patients was subjected to multivariate analysis, VA was the most important determinant of final visual outcome. Patients with initial VA of 5/200 or better had a 28 times greater chance of salvaging acuity at this level than those with vision worse than 5/200.⁵² Two subsequent prospective studies of penetrating injuries have confirmed this finding. In the first of these series, 94% of patients with initial VA of 20/200 or better achieved a final VA of 20/200 or better.⁵³ In the second series, multivariate analysis revealed that presenting visual acuity of 5/200 or worse was the most important factor contributing to poor visual outcome; statistically insignificant factors were time since injury, cataract, and presence of IOFB.⁵⁴ In one review of 167 open-globe injuries, only 3% of eyes presenting with vision better than light perception ultimately underwent enucleation, as compared with 39% of eyes presenting with light perception and 89% of eyes presenting with no light perception.⁵⁵

Others have demonstrated that the presence or absence of an afferent pupillary defect (APD) is a strong predictor of outcome.^56,57 A multivariate analysis of 240 traumatized eyes found 69% of eyes without an APD obtained a final VA of 20/200 or better, as compared with 34% of eyes with an APD (P < 0.00001).⁵⁶

On rare occasions, the surgeon may contemplate primary enucleation when encountering a totally disorganized globe with prolapse of intraocular contents, including retina. In these cases it is important to determine carefully whether the patient can perceive light. This is best done with the uninjured eye covered, with the indirect ophthalmoscope light at maximal intensity, and with the light held at sufficient distance so that the patient cannot perceive the heat of the ophthalmoscope light. Unfortunately, since many patients with injuries of this severity often are either intoxicated or have other injuries affecting their mental status, determination of light perception is questionable. Additionally, there have been rare reports of eyes with preoperative measurement of no light perception achieving visual acuity of light perception or better following reconstructive ocular surgery.^51,58 For these reasons, primary enucleation is rarely performed.

It is important to perform an examination sufficient to determine the extent of injury but not so extensive as to cause further damage to the globe. Pressure on the globe that could cause further prolapse of ocular contents must be avoided. Lid retractors may be used with care when lid swelling precludes visualization of the globe. If the history is highly suggestive of a penetrating injury and the examination is inconclusive, possibly because of poor cooperation, an examination under anesthesia should be performed, at which time repair can be performed if needed.

Occasionally, a scleral rupture can be occult (hidden under conjunctiva, Tenon’s capsule, or rectus muscles). Diffuse chemosis or subconjunctival hemorrhage suggests the presence of occult rupture. An open globe often has low IOP, but normal or elevated IOP does not rule out the possibility of a rupture. On occasion, slit-lamp biomicroscopy of the anterior vitreous can be useful, demonstrating vitreous strands directed toward a hidden scleral rupture site (Fig. 110.7). Similarly, ultrasonography can detect this finding. Computed tomography (CT) has also been reported to show occult rupture, with flattening of the posterior contour of the sclera (the “flat tire” sign).⁵⁹

Fig. 110.7 In cases of occult scleral rupture, slit-lamp biomicroscopy can demonstrate vitreous strands directed toward the rupture site.

Confirming the presence or absence of a retained IOFB is critical to determining management of a patient with trauma. In many cases, the IOFB can be identified by slit-lamp biomicroscopy or indirect ophthalmoscopy (Fig. 110.8). However, if the ocular media are clouded by corneal damage, hyphema, cataract, or vitreous hemorrhage, ancillary techniques are necessary. For many years, the standard technique of localizing foreign bodies involved special applications of conventional radiographic imaging; however, these methods often were inaccurate and cumbersome, could cause iatrogenic damage to the globe, and were useless in cases involving radiolucent foreign bodies. Consequently, radiographic localization of IOFBs has been replaced by ultrasonography and CT. Ultrasonography can accurately localize foreign bodies, particularly with a systematic approach providing transverse and longitudinal views in all meridians (Fig. 110.9). When the globe is open, however, the resolution of ultrasound may be limited, as the examination often must be performed gently through closed lids. The usefulness of echography is also limited by shadowing caused by highly reflective surfaces such as air, reverberation artifacts created by some IOFBs, and by the user’s skill and familiarity with ocular pathology.⁶⁰

Fig. 110.8 This patient suffered an intravitreal foreign body while shooting at a rifle range. The intraocular foreign body was nonmagnetic and was successfully removed via vitrectomy with foreign body forceps.

Fig. 110.9 Contact B-scan ultrasonography can demonstrate a metallic intraocular foreign body. The foreign body has a characteristic triangular shape because of its absorbance of the sound waves and the resultant trail of artifact behind it. The foreign body is highly reflective and remains visible even at low gain.

CT has emerged as the imaging technique of choice in the evaluation of IOFBs. It is a noninvasive technique requiring minimal patient cooperation and can be used to image radiolucent and radiopaque foreign bodies (Fig. 110.10). By assembling many consecutive orbital slices that demonstrate the ocular anatomy and by using computer-generated reconstructions in three dimensions, the presence and location of an IOFB can be determined. In an experimental study to determine the size of CT cuts required to detect small IOFBs, Dass et al. concluded that with modern spiral CT scanning both 3 mm and 1 mm cuts were effective (100% sensitivity) in detecting a 0.5 mm metallic, glass, or stone IOFB.⁶¹ The absorption characteristics of the foreign body are quantitated in Hounsfield units and can be compared with the absorptions of various materials already determined experimentally. Zinreich et al.⁶² have shown that wood is the least dense of the nonmetallic foreign bodies, followed by plastic and then glass. Unfortunately, all metallic foreign bodies have the same absorptions and are impossible to differentiate. CT scanning does have limitations, in that metallic IOFBs often create significant scattering artifact that may obscure their precise location. This can be particularly bothersome when attempting to determine whether a foreign body is intraretinal or intrascleral. In addition, identifying some of the lower-density foreign bodies, such as wood, may be difficult with CT scanning.⁶³

Fig. 110.10 This computed tomography (CT) scan demonstrates an intraretinal shotgun pellet in the patient’s left eye.

Magnetic resonance imaging (MRI) has proved useful for imaging intraocular tumors and other lesions. However, the magnetic fields and heat generated during MRI scanning preclude examination of patients with potential intraocular or intraorbital metallic foreign bodies. Investigators have shown that ferromagnetic foreign bodies implanted in animal eyes can move 7–8 mm in the suprachoroidal space and up to 10 mm in the vitreous space when subjected to the torsional forces of MRI.⁶⁴ Furthermore, retained intraocular ferromagnetic foreign bodies cause surrounding image distortion, making the globe itself difficult to visualize. Image distortion can similarly occur from the paramagnetic effects in granite, solder, and mascara. Another disadvantage of MRI is its inability to image bone. MRI’s principal advantage over CT is that it can accurately and safely detect wood and plastic IOFBs.

The possibility of intraocular infection must also be addressed during the initial evaluation. Endophthalmitis is a devastating complication of penetrating injuries, and its prognosis is related to a number of factors, including time to diagnosis. Classically, eyes with endophthalmitis will be painful and have swollen conjunctiva and marked intraocular inflammation, including hypopyon. However, these signs may be more difficult to identify in an already traumatized globe. This diagnosis can be made only if the physician remembers it as a possibility. Traumatic endophthalmitis is discussed in greater detail later in this chapter.

Repair of laceration

Principles guiding the repair of a laceration or rupture of the globe are the same whether confronting a straightforward corneal laceration or a complex corneoscleral laceration with prolapse of ocular contents. First, the structural integrity of the globe must be restored, providing a watertight closure of all wounds and restoration of normal IOP. Second, iatrogenic damage to the eye must be avoided. Efforts should be made to protect the visual axis but not if this sacrifices the previous principles.

Before repair of a laceration, it is critical to determine the extent of the injury. If a corneal laceration extends to the limbus, a limited conjunctival peritomy is necessary to evaluate for any scleral extension. After the extent of injury is established, the presence or absence of iris or vitreous incarceration needs to be determined.

A simple corneal laceration without tissue incarceration should be closed with interrupted 10–0 nylon sutures. Tissue bites should be placed into the deep stroma at equal depths on either side of the laceration. Various techniques have been suggested on how to proceed with the closure, such as starting at one end and working to the other, starting at both ends and working toward the center, or starting at the middle and continually bisecting the laceration until the wound is watertight. We prefer the last approach. It is often necessary to replace some of the earlier sutures if they become loose as the wound is pulled together more tightly. In some cases it may be helpful to use larger sutures during initial approximation of the wound, similar to the way cardinal sutures are used for penetrating keratoplasty surgery. Placement of cardinal sutures may be particularly helpful in repair of jagged lacerations. If the edges of the corneal wound are edematous, the suture bites need to be placed at a greater distance from the wound edge. After tying the knots, the surgeon should try to bury them, but this may not be possible when the cornea is edematous.

A watertight closure can be difficult to achieve with stellate lacerations. In some cases the wound leaks even with multiple sutures criss-crossing the laceration. A purse-string closure may help in these cases. The suture is placed in a circle through the various portions of the cornea involved in the laceration and then tied to itself with the knot buried in the laceration. If this technique does not work, corneal tissue may have been lost. In these situations, use of cyanoacrylate tissue adhesive can seal the leakage site.⁶⁵ When there is too much tissue loss for glue to work, a corneal patch graft can be used.

When iris is incarcerated in the corneal wound, it can be reposited in most cases. We advocate excision of uveal tissue only if it looks extremely necrotic, usually having been externalized for more than 24 hours. Reposition of incarcerated iris usually can be accomplished with introduction of an iris or cyclodialysis spatula or a 27G cannula connected to viscoelastic through a limbal stab incision made about 90° away from the laceration. This maneuver is best done after the corneal integrity has been partially restored by the first few sutures and the anterior chamber has been reformed with balanced salt solution, air, or hyaluronic acid.⁶⁶ When there is positive pressure or in the presence of a hyphema, the surgeon may be helped by having the assistant reposit incarcerated iris while the surgeon places the suture.

Whereas the location and extent of corneal lacerations are obvious, scleral lacerations require deliberate exploration. Therefore, good exposure is important. Lid sutures can be useful for lid retraction without putting excessive pressure on the globe. A conjunctival peritomy should be performed for 360°, followed by sharp dissection of the conjunctiva and Tenon’s fascia from the sclera in the four quadrants to avoid undue pressure on the globe.

Scleral lacerations should be repaired with 8–0 or 7–0 nonabsorbable sutures. We prefer spatulated needles similar to those used for placement of sutures for scleral buckling. In general, we use interrupted sutures to close the laceration, working from anterior to posterior. If a scleral laceration is well delineated, a running shoe-string suture can provide a watertight closure.

In some cases, a scleral laceration may either be located under the rectus muscles or extend under the muscles. In these cases, the area under the muscle can be exposed by gently passing a muscle hook under the muscle and using the hook to lift it out of the way. If this is unsuccessful or is causing too much pressure on the globe, the muscle should be isolated on a 6–0 Vicryl suture and cut from the globe. After repair of the laceration, the muscle is resutured to its original insertion. If a scleral rupture has resulted in extensive loss of tissue, such as with large missile injuries, it may be necessary to use a scleral patch graft.

Uveal tissue is often extruded through scleral lacerations. In most cases this tissue can be reposited by the assistant while the surgeon closes the overlying sclera. Even when the tissue appears necrotic, cutting the tissue can cause significant bleeding; rarely should extruded tissue be excised if the repair is performed within 24 hours of the injury.

If vitreous has extruded through the laceration, it should be cut with a sharp scissors flush with the sclera. A vitrectomy instrument should not be inserted into the eye through a scleral laceration to clean-up extruded vitreous because of the potential for damaging the retina. If the surgeon suspects extrusion of retina, every attempt should be made to reposit the retina, avoiding excision or incarceration if possible.

In some cases, the scleral laceration extends posterior to the ora serrata and may have an associated retinal laceration. Because of associated vitreous hemorrhage, it is rare to be able to identify a retinal laceration at the time of primary repair. Cryopexy should not be performed prophylactically unless a specific retinal tear can be visualized, since cryotherapy may cause excessive inflammation that may promote the development of later traction retinal detachment.⁶⁷

In cases of lacerations involving both the cornea and sclera, the extent of the laceration must be determined first. In an effort to restore structural integrity, the limbus is the best place to start, as it provides a recognizable anatomic landmark. Limbal wounds are closed using 9–0 nylon sutures (Fig. 110.11). After the limbal portion of the laceration is closed, it is easier to repair the corneal laceration first, then the scleral laceration. The same techniques and principles described for lacerations limited to the cornea or sclera should be employed.

Fig. 110.11 Repair of a complex corneoscleral laceration begins with exploration of the globe to determine the extent of the injury. (A) The limbus is then reapproximated with 9–0 nylon sutures. (B) The corneal laceration is then repaired with 10–0 nylon sutures. (C) Subsequently, the scleral portion is sutured with nonabsorbable interrupted sutures.

In some cases, a hyphema or cataract is identified at the time of laceration repair. Because of the possibility of causing additional damage to the eye by attempting significant intraocular manipulations at the time of primary repair, we generally advocate deferring the anterior chamber washout or lensectomy to a secondary procedure. These issues are discussed in greater detail below.

The value of scleral buckling at the time of primary open-globe repair has been revisited by two retrospective studies.^68,69 The justification for prophylactic scleral buckling (typically only considered in eyes with lacerations extending >5 mm posterior to the limbus) is that support of the vitreous base may reduce vitreoretinal traction and subsequent retinal tears or detachment, which occurs in up to two-thirds of cases.⁷⁰ Placement of a buckling element at the time of primary repair, however, is easier because the rectus muscles are often already isolated during exploration of the open globe, and there is no scarring of the wound, Tenon’s fascia, or conjunctiva. In one comparison of 18 eyes treated with prophylactic placement of a 3.5 or 4 mm encircling band and 33 eyes treated without buckling, the rate of subsequent retinal detachment (30–39%) and mean final VA (20/200–20/400) were statistically similar. Importantly, a worse outcome was seen in eyes with opaque media at presentation, independent of primary treatment.⁶⁸ This institutional study was limited, however, by small sample size and selection bias, since more severely injured eyes may have been more likely to receive prophylactic buckling. Arroyo et al. employed a matched cohort study from two institutions and found significantly better visual and anatomic outcomes in eyes treated with prophylactic buckling than in matched controls. These results may be explained by a trend toward a lower incidence of retinal detachment in prophylactically treated eyes (26% compared with 53%).⁶⁹

Management of intraocular foreign body

In general, we recommend removal of an IOFB at the time of repair of the entry site or soon afterwards. In certain cases, IOFB removal must be delayed, because of inaccessibility to appropriate specialized resources or because of systemic medical instability. Because of the inflammation caused by IOFBs, they often are rapidly surrounded by a fibrous capsule that can make delayed surgical removal more difficult. Foreign bodies may contain copper, which can cause immediate severe inflammatory changes, or iron, which can cause chronic siderotic damage to the eye.⁷¹ In addition, traumatic endophthalmitis, particularly associated with the Bacillus cereus, is more commonly seen with IOFBs than with other forms of penetrating injuries.^66,72 Traditionally, IOFB removal within 24 hours of injury has been advocated because of the increased risk of endophthalmitis.^73,74 In these series, however, it was not clear that systemic antibiotics were administered. By contrast, in a recent report of military soldiers sustaining ocular trauma with IOFB, none of 79 eyes developed endophthalmitis despite a median delay of 38 days in IOFB removal. Since 97% of patients received antibiotics (most commonly by systemic administration, and most commonly levofloxacin), the authors contended that prompt antibiotic use was helpful in reducing the chance of endophthalmitis.⁷⁵

In cases involving a metallic IOFB, it helps to determine whether the object is magnetic before surgery. If it is not known whether the IOFB is magnetic, the surgeon may attempt to extract the foreign body with the magnet. If the foreign body does not move when the magnet is turned on, an alternative approach must be used.

Three instruments are commonly available for IOFB extraction: external magnets, intraocular forceps, and intraocular magnets. External magnets are best reserved for cases in which extraction can be performed immediately (success rates fall when the IOFB becomes encapsulated⁷⁶) and when there is good fundus visualization with minimal associated posterior segment injury. (In a study of eyes with comparable damage, significantly better anatomical and functional results were achieved in eyes managed with vitrectomy and intraocular magnet.⁷⁷)

Our surgical approach to IOFBs is summarized in Table 110.2. When a magnetic intravitreal foreign body can be well visualized, extraction with an external electromagnet is usually effective (Fig. 110.12). This should be done through a pars plana sclerotomy after repair of the entry site. It is important to make the sclerotomy large enough so that the foreign body can pass out of the globe without becoming incarcerated in the pars plana. If the scleral laceration site is used for extraction, then it should be enlarged, since the elastic sclera and ocular tissues will have stretched after initial IOFB entry and made the wound smaller than the longest dimension of the IOFB. A magnetic extraction is best performed with an assistant holding the magnet over the sclerotomy while the surgeon visualizes the IOFB with indirect ophthalmoscopy and controls the magnet’s foot pedal. If a large sclerotomy is needed, it is helpful to pre-place a mattress suture so that it can be closed quickly after removal of the IOFB to decrease the period of hypotony. We do not advocate prophylactic cryopexy or scleral buckle in these patients.

Table 110.2 Management of intraocular foreign bodies

REM, rare earth magnet.

Fig. 110.12 Management of magnetic intravitreal foreign body. (A) Suturing of entry site. (B) Creation of a pars plana sclerotomy with a preplaced mattress suture. (C) The external magnet is held over the sclerotomy while the surgeon visualizes the foreign body with indirect ophthalmoscopy and controls the magnet’s foot pedal. (D) Occasionally, the foreign body must be grasped at the sclerotomy site with a forceps and pulled out.

When the magnetic intravitreal foreign body is poorly visualized because of cataract or vitreous hemorrhage, a pars plana vitrectomy and/or lensectomy needs to be performed (Fig. 110.13). The foreign body can then be removed by a number of techniques. The IOFB can be removed with greatest control using IOFB forceps inserted through the pars plana sclerotomy site or with the rare earth intraocular magnet.⁷⁸ If the intraocular magnet is used to grasp the foreign body and bring it into the anterior vitreous, it often helps to transfer the IOFB to foreign body forceps to pull it through the sclerotomy.

Fig. 110.13 Management of magnetic IOFB in the presence of vitreous hemorrhage. (A) A pars plana vitrectomy is performed to remove the vitreous hemorrhage in order to visualize and mobilize the foreign body. (B) The foreign body is grasped with the intraocular rare earth magnet and brought into the anterior vitreous. (C) The foreign body is transferred to a foreign body forceps and removed through a sclerotomy.

The surgeon must have the foreign body grasped firmly when removing it through the sclerotomy. If the foreign body is dropped, it will likely strike the macula and bring about poor visual consequences. Injection of liquid perfluorocarbon has been recommended as a means to protect the macula in this setting. However, experimental studies suggest that these heavier-than-water agents will not support a metallic foreign body.

Removal of intraretinal foreign bodies is more difficult and more hazardous because of the risk of retinal detachment (Fig. 110.14). If the ocular media are clear and the IOFB can be localized by indirect ophthalmoscopy, it can be removed by a transscleral approach (Fig. 110.15). A trapdoor scleral flap is created, the choroidal bed is treated with external diathermy, the choroid is incised, and the foreign body is removed with either forceps or an external magnet. If retinal incarceration occurs, the area can be treated with a localized scleral buckle. Because the surrounding area has already been treated with diathermy, it is unnecessary to add cryopexy.

Fig. 110.14 This patient was striking a chisel with a hammer when he suffered a penetrating ocular injury. The metallic IOFB is located within the retina. Inflammatory retinal whitening developed within 6 hours of the injury.

Fig. 110.15 Transscleral approach to intraretinal foreign bodies. (A) The intraretinal IOFB is localized with indirect ophthalmoscopy. (B) A trap-door scleral flap is created. (C) The choroidal bed is treated with external diathermy and the choroid incised. (D) The foreign body is removed with either forceps or an external magnet.

Intraretinal foreign bodies can also be removed via a transvitreal approach, particularly when they cannot be well visualized (Fig. 110.16). After a pars plana vitrectomy is performed, the foreign body should be gently mobilized with the foreign body forceps. In many cases the foreign body will be somewhat adherent to the retina or choroid. If the IOFB has been surrounded by a fibrous capsule, the capsule may be incised with a myringotomy blade before removal. All these manipulations are made to avoid further tearing of the retina. After the IOFB is freed, it can then be removed with either the forceps or intraocular magnet using the method described above.

Fig. 110.16 Management of an intraretinal foreign body in the presence of vitreous hemorrhage. (A) A pars plana vitrectomy is performed removing vitreous blood. (B) If a posterior vitreous detachment is not present, one is created by gently aspirating the posterior hyaloid with suction or a vitreoretinal pick. (C) The foreign body is grasped with the foreign body forceps and removed from the eye.

When it is necessary to perform a vitrectomy to remove an intraretinal foreign body, it is important to remove the posterior hyaloid overlying the incarceration site. In some cases a PVD will be present; otherwise one must be created using powered suction either with a soft-tipped extrusion cannula or the vitrectomy instrument. After the posterior hyaloid is engaged, a pick can be inserted between the hyaloid and retina, and hyaloid is gently lifted off the retina. If the posterior hyaloid is left, there is potential for the postoperative development of vitreoretinal traction or formation of epiretinal proliferation along the posterior hyaloid (Fig. 110.17). In an early report describing the use of pars plana surgical techniques for removal of intraretinal foreign bodies, 90% of eyes developed either macular pucker or proliferative vitreoretinopathy.⁷⁹ The authors believe the frequency of this complication can be decreased by careful attention to removal of the posterior hyaloid.

Fig. 110.17 This 19-year-old man suffered a perforating injury from hammering metal. A metallic intraocular foreign body was lodged in the inferior sclera (A). Following placement of an encircling band, the foreign body was extracted from the exit wound (B,C), which was then closed and supported by the scleral buckle. Vitrectomy, endolaser photocoagulation, and silicone oil infusion were then performed to repair the inferior retinal detachment. Postoperative photograph taken 3 months later following removal of silicone oil shows retinal reattachment and the old exit wound inferiorly (D).

There has also been controversy over the optimal management of a retinal tear caused by the foreign body. Some surgeons emphasize the necessity of creating a chorioretinal adhesion at this site with either cryopexy or photocoagulation. In our experience the inflammation caused by the foreign body impaction has been adequate to prevent retinal detachment, particularly if the surgeon pays close attention to proper management of the posterior hyaloid. There has also been discussion of the need to place photocoagulation around the intraretinal foreign body preoperatively to decrease the risk of retinal detachment at the time of foreign body removal. Again, it has been our experience that this is unnecessary. Ambler and Meyers⁸⁰ reported five eyes with intraretinal foreign bodies managed without retinopexy or fluid–air exchange without developing retinal detachment or preretinal fibrosis. If, however, a retinal detachment does occur at the time of extraction, it is particularly important to attempt removal of adherent posterior cortical vitreous before fluid–gas exchange to reattach the retina. In these cases, endophotocoagulation should be placed around the retinal break. If the surgeon is unable to remove all adherent vitreous, then the retinal tear should be supported on a scleral buckle. We perform prophylactic encircling scleral buckles in all eyes receiving vitrectomy for management of penetrating injuries, as discussed later in this chapter.

Nonmagnetic intravitreal foreign bodies require extraction with intraocular forceps whether they are well visualized or partially hidden by vitreous hemorrhage or cataract.^81,82 In these cases, we perform a vitrectomy with or without a lensectomy, depending on the lens clarity. The foreign body is grasped with the IOFB forceps and removed through the pars plana sclerotomy site. Some nonmagnetic foreign bodies may be quite inert, such as glass or plastic, and can be observed without immediate removal. However, it is difficult to know whether they are infected, and with rare exceptions, we advocate immediate removal of IOFBs, regardless of their type.

Extremely large foreign bodies can pose great difficulty for the surgeon attempting removal by way of a pars plana approach. The foreign body forceps designed to pass through the 20G or 19G sclerotomy sites, is unable to grasp large IOFBs, such as BB pellets. When they can be grasped, they are too large to be removed through the sclerotomy and must be removed through a second incision created at the limbus. When one suspects that a foreign body cannot be removed by way of pars plana surgery, a scleral tunnel, a limbal opening, or an open-sky approach should be considered. In many of these cases, there is severe corneal damage with a stellate laceration that makes visualization of the posterior structures difficult. By removing a corneal button and performing an open-sky vitrectomy, one can identify and remove the foreign body.

Intralenticular foreign bodies usually must be removed in concert with lens extraction. However, if the anterior capsule tear is small and the foreign body is composed of a nontoxic material, the capsular wound may fibrose, resulting in a localized, visually insignificant cataract that can be observed.⁸³ If cataract formation has occurred, or if the object is metallic, then lens and foreign body extraction should be performed using standard extracapsular cataract extraction methods. We also recommend lensectomy for small capsular defects when endophthalmitis is suspected or if the foreign body was dirty (e.g., rural trauma).

Overall, patients with IOFBs can have an excellent outcome, with approximately one-half of eyes achieving visual acuity of 20/50 or better. Worse outcomes are typically associated with IOFBs of greater mass, uveal prolapse, and injury with a BB or pellet.^84,85

Perforating injury

Perforating injuries represent a small subset of ocular trauma, occurring in only 4.4% of lacerated globes.⁸⁶ Until the introduction of vitreoretinal surgery, these eyes had a uniformly poor prognosis because of ingrowth of fibrovascular tissue through the posterior exit site, leading to severe retinal detachment. Our current management of this type of injury results from the experimental studies of Topping et al.⁸⁷ They reported that by day 7 after an experimental perforating injury, the scleral wounds had self-sealed. The degree of transvitreal proliferation increased dramatically after day 7. Contraction of the transvitreal proliferation can lead to tractional retinal detachment. Pars plana vitrectomy is performed to intercede in this process, removing the scaffold for proliferation and contraction.⁸⁸

Ideally, vitrectomy would be performed early enough to prevent transvitreal proliferation. However, vitrectomy is impossible unless the scleral rupture sites are sealed. The entry site can be repaired by the surgeon using standard techniques described earlier in this chapter. However, attempts to close posterior rupture sites can be difficult as well as hazardous, causing excessive traction on the globe and optic nerve and possibly leading to extrusion of intraocular contents. Having learned from the experimental studies that the scleral wounds seal by day 7, we routinely delay vitrectomy until this time or later. We do advocate suturing the anterior “entry site” promptly after injury (see Chapter 98, Pathophysiology of trauma).

We employ the standard three-port technique for vitrectomy, proceeding from anterior to posterior, clearing vitreous opacities (Fig. 110.18). As in vitrectomies for penetrating injuries, it is important to identify the posterior hyaloid and, if it is still adherent to the retina, create a PVD. The stump of proliferation growing through the exit site should be reduced but not eliminated, so that the posterior exit site is not reopened. Retinal breaks are managed with air–fluid exchange and endophotocoagulation or scleral buckling with cryopexy. We routinely advocate an encircling scleral buckle, even in eyes without retinal detachment.

Fig. 110.18 Perforating injuries are managed with primary repair of the entry site. At 7–10 days later, pars plana vitrectomy is performed with removal of the posterior hyaloid. The proliferation growing through the exit site should be reduced to a stump but not eliminated.

Overall, the prognosis for these eyes appears to be improved by this management (Fig. 110.19). In a case–control study of penetrating injuries, a beneficial trend was demonstrated for those eyes managed with vitrectomy.⁸⁹ Martin et al.⁹⁰ achieved anatomic success in 41 of 51 eyes, with functional success (visual acuity better than 5/200) in 32 eyes (63%). Although the authors of these series have investigated a number of factors that may correlate with prognosis, the location of the exit site has profound influence on the final visual acuity. If the exit site is through the macula or optic nerve, the final vision is obviously limited. The location of the exit site also affects the surgeon’s ability to complete removal of the posterior hyaloid. This is more easily achieved when the exit site is located posterior to the vitreous base.

Fig. 110.19 This child suffered a perforating injury with a whittling knife. Following emergent repair of the corneal laceration (A), lensectomy and vitrectomy were subsequently performed. He returned 2 months later with (B) tractional retinal detachment associated with fibrous ingrowth at the exit site.

More recently, it has been demonstrated that chorioretinectomy (removal of the choroid and/or retina at the impact or perforation site) may improve final visual acuity and increase the chance of globe salvage.⁹¹ In this technique, first advanced by Zivojnovic nearly three decades ago,⁹² any retinal or uveal tissue incarcerated into the perforation site is removed using the vitrector, with diathermy destruction of the retina/choroid in a 1 mm ring around the exit wound/impact site. High cutting speeds (2500 cpm) with low vacuum are typically used. Bleeding, though uncommon from necrotic incarcerated tissue, is controlled with endodiathermy or transient elevation of infusion pressure. In a small pilot series of such a “proactive technique” reported by Kuhn et al. in 2004, chorioretinectomy was performed in five consecutive eyes within 100 hours of perforating globe injury. Their strategy involved limited vitrectomy (performed while looking through the binocular indirect ophthalmoscope) at the time of primary repair, intensive topical corticosteroid therapy, and complete vitrectomy, localized retinectomy, evacuation of subretinal blood, laser retinopexy, and placement of silicone oil 3 days later.⁹³ While no substantive conclusions or definitive management recommendations can be made on the basis of a small uncontrolled series, the absence of proliferative vitreoretinopathy or traction retinal detachment in this series suggests proof of concept. Such a technique should only be considered, however, by surgeons with the requisite experience and in cases with adequate visualization of the posterior segment and confirmation that there is minimal retinal or choroidal detachment.

Vitreous hemorrhage and retinal detachment

Despite advances in the management of eyes with penetrating injuries, a large group of patients still have a poor prognosis. These more severe injuries most often have posterior segment involvement. A seminal study evaluating the outcome of penetrating ocular injuries identified several factors other than initial visual acuity that correlate with a poor final visual outcome. These include presence of an afferent pupillary defect, wounds involving the sclera or extending posterior to the insertion of rectus muscles, wounds >10 mm, and vitreous hemorrhage.⁵⁷ The study emphasized that the prognosis after a penetrating injury is strongly influenced by the nature of the injury and the location and extent of initial damage. Functional loss of these eyes is caused by either inoperable retinal detachment or damage to ciliary body function. These changes, in most cases, result from intravitreal fibrovascular and fibroglial proliferation, which leads to traction on the ciliary body and the retina. This proliferation seems to occur more commonly in injuries with lacerations of the ciliary body and retina and in injuries with vitreous hemorrhage. These initial conclusions were recently corroborated in a prospective observational study of 69 eyes with penetrating injury.⁵⁴

Beginning in 1979, Cleary and Ryan⁹⁴ published a series of papers in which they described an experimental model for penetrating ocular injury with vitreous hemorrhage. Invariably, a traction retinal detachment resulted, appearing similar to the retinal detachment seen clinically after penetrating ocular injuries. In subsequent studies, they demonstrated that vitrectomy performed 1–14 days after injury could significantly reduce the risk of traction retinal detachment.⁹⁵ Although several previous studies suggested the efficacy of vitreous surgery in management of severe penetrating ocular injury,⁹⁶ Cleary and Ryan’s experimental studies supported the clinical impression that by removing the scaffold for intraocular proliferation, vitrectomy may reduce the incidence of severe visual loss after penetrating injuries. However, the precise role and timing of vitrectomy in penetrating injuries has not been clarified.

In eyes with vitreous hemorrhage secondary to penetrating injury, vitrectomy has been suggested to minimize intraocular fibrous proliferation and progressive vitreoretinal traction, as well as to provide visualization of the retina for identification and treatment of possible retinal detachment. A series of patients with severe penetrating ocular injury with vitreous hemorrhage and no retinal detachment treated with vitrectomy had an 82% functional success rate.⁹⁷ This uses the Ryan and Allen⁹⁸ definition of functional success. However, only 17 of 33 (52%) eyes with vitreous hemorrhage and concurrent retinal detachment were successfully repaired using vitrectomy.

Vitreous surgery should be performed in all eyes with light perception vision, lacerations involving the sclera, and moderate to severe vitreous hemorrhage. There is considerable disagreement about the appropriate timing of surgery. Some experienced surgeons favor operating within the first 48–72 hours, and others prefer delaying surgery up to 14 days after injury.

Vitrectomy for penetrating ocular trauma was first advocated by Coles and Haik⁹⁹ in 1972 when, on examining several eyes enucleated after trauma, they noted fibroblastic tissue in areas of vitreous hemorrhage within several hours of injury. Primary vitrectomy at the time of closure is thought to decrease the risk of this intraocular proliferation. Coleman,¹⁰⁰ re-expressing this rationale for early vitrectomy, speculated that development of severe inflammatory changes may be prevented by performing vitrectomy within 72 hours of injury. At the same time, the surgeon can decrease the risk of fibroblastic proliferation. Faulborn et al.¹⁰¹ also advocated early surgery, suggesting primary vitrectomy (albeit open-sky) at the time of primary repair of the corneoscleral laceration. They believed that this approach improves visual prognosis by permitting examination of the fundus and immediate retinal surgery when indicated. In addition, it prevents the complications from vitreous incarceration in the laceration. Another consideration favoring early vitrectomy is that it can be combined with primary wound repair, thereby obviating the need for a second hospitalization and second operation.

Delaying vitreous surgery beyond 72 hours after the injury permits further diagnostic evaluation, including ultrasonography and electrophysiology. It also permits the operation to be performed under conditions more favorable than emergency circumstances. Furthermore, spontaneous separation of the posterior hyaloid surface may occur during the waiting period, making excision of the posterior cortical vitreous (a critical step in the vitrectomy) easier and less hazardous.

In addition, several authors have noted the problem of severe hemorrhage when attempting early vitrectomy,^96,98,102 presumably secondary to uveal congestion associated with acute penetrating injury. Certainly, hemorrhagic choroidal detachment can accompany a penetrating injury, making it extremely difficult to insert an infusion cannula or other vitrectomy instruments properly without damaging the retina. Delaying surgery may decrease the risk of uncontrollable intraoperative hemorrhage, as well as allow choroidals to recede or to be drained more easily.

Most authors believe that vitrectomy for severe penetrating injuries should not be delayed beyond 14 days.^98,101 First, if the vitrectomy is unsuccessful, these eyes may be at risk for developing sympathetic ophthalmia and require enucleation to prevent its development. Evidence suggests that the risk of sympathetic ophthalmia may be significantly reduced if enucleation is performed within 14 days of injury. Second, histologic studies of penetrating eye injuries show intraocular cellular proliferation within 1 week of injury with membrane formation already occurring by 2 weeks.¹⁰³

Once the decision has been made to perform a vitrectomy, the surgeon has the following goals: (1) to clear the ocular media through removal of cataractous lens or vitreous hemorrhage; (2) to remove the vitreous scaffold from the scleral laceration site; (3) to remove the posterior hyaloid that could provide a future scaffold for epiretinal membrane formation and vitreoretinal traction, and (4) to identify and treat retinal breaks and detachment.

In most cases, general anesthesia with endotracheal intubation is employed for vitrectomy following trauma. Peribulbar or retrobulbar anesthesia has the risk of increasing orbital pressure leading to extrusion of intraocular contents, but has been used successfully in selected patients, typically those with short corneal or limbal wounds and a formed anterior chamber.¹⁰⁴ Conventional wisdom has it that succinylcholine chloride should be avoided during induction. However, in an experimental study, succinylcholine administration resulted only in forward displacement of the iris and lens without extrusion of intraocular contents, suggesting that some of the historical fears of its use may be unwarranted.¹⁰⁵ In most cases, the wound will have been closed prior to vitrectomy, but the globe should be inspected, and open or leaking wounds should be resutured to make the eye watertight.

At the onset of surgery, the surgeon must make several critical decisions that can have profound influence on the procedure’s outcome. First, the presence or absence of hemorrhagic choroidal detachment must be determined. This can best be done by preoperative ultrasonography. If present, the blood can often be drained through scleral incisions while simultaneously infusing air or balanced salt solution through a cannula inserted through the limbus in aphakic eyes and pars plana in phakic eyes to maintain normal IOP (Fig. 110.20). After drainage of the choroidal hemorrhage, a long pars plana infusion cannula (6 mm) should be inserted, but infusion should not be turned on until the cannula tip can be visualized in the vitreous cavity. It is essential that all sclerotomies be deep enough to ensure penetration through the uveal tissue.

Fig. 110.20 Vitrectomy for vitreous hemorrhage with hemorrhagic choroidals after penetrating injury. (A) Scleral cutdown incisions are made to drain choroidal blood while air is infused into the eye through a cannula inserted through the limbus. (B) After drainage, a 6 mm pars plana infusion cannula is inserted and infusion started only when the cannula can be visualized within the vitreous cavity.

Second, the surgeon must decide whether surgery can begin through the pars plana or whether it must be started through limbal incisions. For instance, in the presence of total hyphema, where the status of the retina is unknown, the hyphema can be evacuated through a limbal incision with an irrigating infusion needle inserted through a second incision (Fig. 110.21). On the other hand, the same problem can be managed in aphakic eyes by inserting a long irrigating infusion needle through a pars plana incision into the anterior chamber where it can be visualized and then turned on. Similarly, the vitrectomy instrument can be inserted through the pars plana and brought anteriorly to evacuate the hyphema.

Fig. 110.21 When anterior chamber hemorrhage precludes visualization of the infusion cannula at the beginning of a vitrectomy for vitreous hemorrhage after penetrating injury, a blunt 20G infusion needle can be inserted through the pars plana, maneuvered into the anterior chamber where it can be visualized through the cornea, and infusion turned on. The vitrectomy instrument can be brought into the anterior chamber in a similar manner to remove the hyphema and begin the vitrectomy. When the anterior chamber hemorrhage has been cleared to adequately visualize the pars plana infusion cannula, the blunt infusion needle can be removed and replaced with a fiberoptic probe.

Third, a decision must be made on the necessity of lens removal. Often, the lens has been lost at the time of the injury. In other instances, the lens will have become opacified, subluxed, or dislocated and will need to be removed. If the lens interferes with visualization of the posterior segment from cataract or blood on its anterior or posterior surface, it must be removed. In cases with cyclitic membranes, transvitreal sheets extending to an anterior injury site or to anterior hyaloid hemorrhage, the lens must be removed to achieve the mechanical objectives of the procedures. In most cases the lens is removed through the pars plana using either the vitrectomy probe or an ultrasonic fragmenting device.

After the anterior segment is cleared, the vitrectomy can be performed, proceeding from anterior to posterior. It is critical to remove the posterior cortical vitreous (Fig. 110.22). This is easily achieved in the presence of a PVD, which is present in many eyes with vitreous hemorrhage by 10 days after the injury. If the cortical vitreous is adherent to the retina, a soft-tipped extrusion cannula or pic should be used to create a PVD. This can be quite difficult and, possibly, hazardous, in areas of detached retina. In recent years, the introduction of smaller-gauge instrumentation has resulted in a significant percentage of vitreoretinal procedures being performed with 23G or 25G instruments. However, due to the complexity of trauma cases and the likelihood of unanticipated intraoperative findings, we still perform the majority of these procedures using the conventional 20G instruments.

Fig. 110.22 When a vitrectomy is performed for ocular trauma, it is critical to remove the posterior cortical vitreous. When a posterior vitreous detachment is not present, one can be created by either suction, a vitreoretinal pic, or carefully incising the posterior hyaloid with a myringotomy blade, and then lifting it with the pic.

After the vitrectomy is completed, the retina is carefully inspected for retinal tears and detachment. If no retinal problems are present, we routinely place a 3.5 mm or 4 mm encircling band prophylactically to decrease the risk of subsequent retinal detachment.

When retinal tears are identified, they are treated by endophotocoagulation. In the absence of retinal detachment, placement of a posterior radial scleral buckle is recommended in cases with persistent traction adjacent to a posterior retinal tear. Similarly, it is recommended that peripheral retinal breaks be buckled either with an encircling band or additional elements if needed.

When retinal detachment is present, it is essential that all tangential and anteroposterior vitreoretinal traction on the retinal break be relieved either by membrane peeling, delamination, or segmentation. If this traction cannot be relieved, it will be necessary to place a scleral buckle to support the break or to perform a relaxing retinectomy. Subretinal fluid usually is drained transvitreally during a fluid–gas exchange either through a posterior retinal break or through a posterior retinotomy created superonasal to the optic nerve in an area free of traction. In some cases, extrusion can be used to flatten the retina by drainage of posterior subretinal fluid through a peripheral retinal break. Long-acting gases, such as sulfur hexafluoride or perfluoropropane, can be injected to provide a longer-lasting internal tamponade to the detached retina. In selected cases, silicone oil may be used in primary vitrectomies for trauma.¹⁰⁶

Retinal incarceration in the scleral laceration site can produce difficult retinal detachments. In many cases, this situation can be managed with vitrectomy and scleral buckling, particularly when the incarceration is located anteriorly. However, when the incarceration is more posterior, scleral buckling is more difficult, and retinotomy may be necessary. Han et al.¹⁰⁷ reviewed their experience with this problem and recommended retinectomy when a scleral buckle is insufficient to relieve the traction or when the incarceration is located too posteriorly to be treated with a scleral buckle. In the former situation, they performed a circumferential relaxing retinectomy. In the latter situation, they performed retinotomies circumscribing the retinal incarceration site. Endodiathermy was placed to provide hemostasis before the retinotomy. With these techniques, they achieved anatomic success in 11 of 15 eyes (73%), but only six eyes regained visual acuity of 5/200 or better. Eyes with traumatic retinal detachment associated with retinal incarceration appear to carry a poor prognosis even when managed aggressively.

Intraocular bleeding can be a frequent intraoperative hazard of vitrectomy for penetrating injuries. Massive uncontrollable intraoperative hemorrhage has been noted as a significant problem precluding successful vitrectomy in some eyes injured by trauma. This complication was noted, however, in only two of 106 vitrectomies for trauma reported by Brinton et al.⁷⁰ Intraoperative bleeding can be managed by a number of maneuvers, including raising the infusion pressure to increase the IOP and endodiathermy to areas of active hemorrhage. In some cases, a fluid–air exchange can help tamponade active bleeding. If all of these maneuvers fail, control of bleeding by infusion of a thrombin solution at a concentration of 100 U/mL may be attempted.¹⁰⁸

Visualization of the posterior structures can be a problem for reasons other than bleeding. When the cornea becomes cloudy because of epithelial edema, the epithelium can be carefully removed with a surgical blade. Folds in Descemet’s membrane can be overcome by coating the corneal endothelial surface with sodium hyaluronate.¹⁰⁹ In some cases, visualization through a scarred cornea can be improved with the use of a wide-angle viewing system. In cases in which the cornea is grossly edematous, markedly distorted by a stellate laceration with multiple sutures, or damaged with tissue loss requiring a patch graft, vitreoretinal surgery can be performed with a temporary keratoprosthesis. The first temporary keratoprosthesis, the Landers–Foulks device, is a clear cylindrical polymethylmethacrylate lens that fits into a trephinated corneal bed and permits excellent visualization of the vitreous and retina without an additional contact lens.¹¹⁰ Though a great advance, this keratoprosthesis has a concave lens that minimizes the retinal image and a long optical cylinder that obstructs visualization of the anterior retina and vitreous base where much of the significant pathology in traumatized eyes exists. Many of these limitations were eliminated with the Eckardt keratoprosthesis.¹¹¹ This device has normal magnification and a short optical cylinder, allowing anterior vitreoretinal dissections and better visualization of posterior segment pathology. In a series of 11 traumatized eyes surgically rehabilitated with the aid of an Eckardt keratoprosthesis, five (45%) obtained a visual acuity of 20/400 or better.¹¹²

Penetrating keratoplasty (PKP) can be combined with vitrectomy and temporary keratoprosthesis to reconstruct severely traumatized eyes. However, functional outcomes are usually disappointing, due in large part to graft failure and hypotony from ciliary body dysfunction. In a recent series of 34 eyes managed with combined PKP and vitrectomy, fewer than one-third achieved vision of better than hand motions at any time postoperatively, and fewer than 15% of grafts remained clear more than 1 year postoperatively.¹¹³

An alternative to temporary keratoprosthesis in eyes with impaired visualization due to corneal opacity, is endoscopy.¹¹⁴ This approach may be particularly useful in cases in which a donor graft or corneal surgeon may not be readily available or in cases in which silicone oil placement is planned and there is concern of corneal graft failure. Disadvantages of endoscopy include the need for specialized equipment, mandatory additional surgery for corneal transplantation, and a steep learning curve.

No prospective controlled study to date has evaluated the efficacy of vitrectomy in penetrating ocular injury. Large series of patients treated with vitrectomy have been published, with the comment that favorable results would not have been possible without vitreoretinal surgical techniques. The frequency of obtaining functional visual acuity of 5/200 or better ranged from 52% (in the series of 106 patients of Brinton et al.⁷⁰) to 78% (in the 112-patient series of Coleman).¹⁰⁰ Most results from other authors were also in this range. ^98,101,102 A 1984 case–control study matched eyes managed with vitrectomy with similar eyes that did not undergo vitrectomy.⁸⁹ When visual results were compared, no statistical advantage from vitrectomy was found. However, a beneficial trend was demonstrated in severe injuries in which initial visual acuity was worse than 5/200. Further analysis of data from this study demonstrates that case–control matching was not done according to preoperative visual acuity and that significantly more patients had poor vision in the vitrectomy group than in the nonvitrectomy group. The shift in the distribution of visual acuity indicated a greater benefit for vitrectomy in the group with preoperative visual acuity worse than 5/200.

Endophthalmitis

Endophthalmitis is an uncommon feature of a penetrating injury and occurs in 1–7% of penetrating injuries.^115,116

Ocular signs associated with traumatic endophthalmitis are similar to those with a postoperative infection: aqueous cell and flare, hypopyon, and vitreous cell and flare exceeding that expected from the injury itself. Aqueous or vitreous fluff balls are characteristic of fungal infections. However, the initial diagnosis of posttraumatic endophthalmitis can be difficult because the significant postoperative inflammation and pain that commonly occur in these eyes can obscure infectious endophthalmitis. The consequent delay, compounded by the virulent bacteria involved in these cases, makes the prognosis for recovery particularly grim.

In one retrospective investigation, risk factors for endophthalmitis after penetrating ocular trauma were subjected to univariate and multivariate analysis.¹¹⁷ Factors such as scleral wounds, hyphema, uveal prolapse, retinal detachment, suprachoroidal and vitreous hemorrhage, lens rupture, and IOFB were investigated. Only lens rupture was independently significant for the development of endophthalmitis, carrying a relative risk of infection of 15.8. In a more recent comparative cohort study, patients developing post-traumatic endophthalmitis were ascertained prospectively and compared with historical controls of patients with open globe injury. Delay in primary repair, ruptured lens capsule, and dirty wound were each independently associated with the development of post-traumatic endophthalmitis.¹¹⁸ The presence of an IOFB had a relative risk of infection of 1.9, but this did not reach statistical significance. The National Eye Trauma Study found a statistically significant increased incidence of endophthalmitis for eyes with retained IOFBs, particularly if surgical intervention occurred more than 24 hours after the injury (13.4% versus 3.5%, P < 0.0001).^119,120

Two recent series have reported lower rates of endophthalmitis, and the authors attributed this reduction in part to the systematic use of antibiotics.^116,121 In the series from the Massachusetts Eye and Ear Infirmary, intravenous vancomycin (or clindamycin if allergic) and ceftazidime (or a fluoroquinolone if allergic) were administered promptly and continued for at least 48 hours.¹¹⁶

While the majority of cases of postoperative endophthalmitis are caused by less virulent coagulase-negative staphylococci, post-traumatic endophthalmitis is frequently caused by virulent organisms such as Bacillus, Streptococcus, and Gram-negative organisms. Bacillus cereus is most commonly associated with penetrating ocular injuries that occur in rural areas and, while rarely seen in postoperative endophthalmitis, accounts for 25-46% of cases of posttraumatic endophthalmitis.¹²¹ The multiple enzymes and exotoxins elaborated by this organism lead to blindness or enucleation in the vast majority of eyes.¹²¹ Several cases of retained useful vision have been reported after successful management of B. cereus endophthalmitis.¹²² Gram-negative bacteria are responsible for up to 20% of cases of posttraumatic endophthalmitis.⁷² Similarly, these cases also carry a poor prognosis, with one-third of eyes ending in no light perception or enucleation.¹²³

Management of traumatic endophthalmitis parallels that described for postoperative endophthalmitis. Cultures of the aqueous and vitreous are obtained, any retained foreign body is removed, and antibiotic therapy is administered. Cultures should include blood agar, chocolate agar, and thioglycolate broth incubated at 37°C for bacteria, and Sabouraud agar incubated at 25°C for fungi. Gram stains should also be obtained, and may provide useful information for antibiotic selection.

We recommend antibiotic delivery via systemic, subconjunctival, intraocular, and topical routes. Although the Endophthalmitis Vitrectomy Study (EVS) did not show a benefit to using intravenous ceftazidime or aminoglycosides, it should be noted that the EVS studied only patients with acute endophthalmitis following cataract extraction or lens exchange.¹²⁴ In post-traumatic endophthalmitis, we still consider systemic antibiotic use the standard of care. We prefer a third- or fourth-generation fluoroquinolone (levofloxacin 500–750 mg or moxifloxacin 400 mg daily for 5 days) because of its broad coverage of most likely pathogens and its excellent vitreous penetration following intravenous or oral administration.

Intraocular antibiotics in cases of suspected endophthalmitis should target a broad range of Gram-positive and Gram-negative organisms, and intraocular toxicity must be negligible. Vancomycin is active against Gram-positive bacteria, is bactericidal, rarely promotes resistance, and is well tolerated by the eye in efficacious dosages (1.0 mg delivered in 0.1 cc intraocularly). Ceftazidime is a β-lactamase stable third-generation cephalosporin with excellent activity against most Gram-negative bacteria, including Neisseria, Haemophilus, Pseudomonas, Acinetobacter, and most Enterobacteriaceae. Furthermore, it has activity against some Gram-positive bacteria, including penicillinase-producing Staphylococcus aureus. Alternative intraocular antibiotics include clindamycin phosphate (1 mg in 0.1 cc) and amikacin (400 µg in 0.1 cc).

Prophylactic intraocular injection of antibiotics to prevent endophthalmitis in patients with penetrating injury is controversial. However, in settings where there is high suspicion of injury from a contaminated foreign body, or early signs of endophthalmitis are present (e.g., significant anterior chamber cells, perivascular retinal sheathing), prophylactic treatment with intravitreal antibiotics should be considered. In a prospective study of eyes with penetrating injury, patients were randomized to receive either intraocular injection of antibiotics (40 µg of gentamicin sulfate and 45 µg of clindamycin sulfate) or balanced saline solution. The rate of endophthalmitis within 2 weeks was significantly lower in the group treated with antibiotics (2.3% versus 0.3%), but this difference was driven by the high incidence of infection in eyes with IOFB (28% in the control group versus 0% in the antibiotic group).¹²⁵

Prognostication for cases of traumatic endophthalmitis is difficult because of the compounding effect of the penetrating injury. Prognosis also relates to the specific organism and to the interval to diagnosis. Overall, Brinton et al.¹¹⁵ reported 42% of cases obtaining final VA of 20/300 or better and 26% with 20/30 or better. Affeldt et al.¹²⁶ showed only 22% of their patients with 20/400 or better. Lieb et al. reported final VA of 20/400 or better in only 50% of open globes with a positive bacterial culture and overt signs of endophthalmitis.¹²⁷

Cataract

Management of cataract after penetrating injury is controversial. Determination of the presence of a cataract at that time can be difficult, as fibrin in the anterior chamber almost immediately after the injury can simultaneously obscure visualization of the lens and give the appearance of a cataract. In such settings, the authors rarely perform a lensectomy at the time of repair of the corneal laceration. In some cases, however, a rent can be identified in the anterior lens capsule accompanying an opacified lens. It is in this situation that cataract extraction at the time of primary repair of the laceration may be considered to reduce the chance of postoperative inflammation and infection.

When the decision has been made to perform a primary lensectomy, the surgeon should first repair the laceration using the techniques and principles described earlier in this chapter. At that point, it must be decided whether the cataract extraction can be performed through a limbal incision or whether a pars plana approach is necessary. When the laceration is limited to the cornea and the posterior lens capsule is believed to be intact, a limbal incision should be created and lens aspiration, phacoemulsification, or standard extracapsular cataract surgery performed. If, during the course of the surgery, it becomes apparent that the posterior capsule has been damaged, it is critical to manage the vitreous loss properly, making sure there is no vitreous incarcerated in either the laceration site or the limbal incision. Primary placement of an IOL has been shown to be well tolerated in selected cases and does not appear to increase the risk of endophthalmitis or other postoperative complications. However, the IOL power selection may be inaccurate and the surgeon may misjudge the intactness of the posterior capsule. In one series, 64% of patients who underwent lensectomy and IOL implantation at the time of primary repair of a penetrating ocular injury obtained 20/40 or better visual acuity.¹²⁸ Therefore, if capsular support allows, one can proceed with IOL placement. If too little capsule remains, an anterior chamber IOL, or sutured posterior chamber IOL should be deferred as a second procedure. Implantation of an IOL in children has also become an accepted means of visual rehabilitation. In children 4–17 years of age, up to 87% of penetrating ocular injuries primarily managed with lens aspiration and IOL implantation obtained 20/40 or better visual acuity.¹²⁹ IOL implantation in infants, however, is still controversial and should probably be deferred to a secondary procedure.

Although a second procedure is required, cataract surgery is more easily performed following primary repair. Deferral of surgery permits clearing of fibrin and intraocular inflammation and allows proper determination of the extent of the cataract, position of the lens, capsular integrity, and IOL power.

When cataract surgery is planned, the choice between a limbal or a pars plana approach depends on the extent of zonular support. If the lens is in place with no signs of iridodonesis or phacodonesis, standard cataract surgery through a limbal or clear corneal incision can be performed. If the lens is believed to be dislocated or subluxated, the surgery should be performed through the pars plana with vitrectomy instrumentation as described for cataracts associated with nonpenetrating injuries. Because of the high incidence of damage to anterior chamber angle structures in eyes with penetrating injuries, we routinely do not advocate anterior chamber IOL implantation when pars plana lensectomy has been performed. However, the evolution of techniques for sulcus fixation of posterior chamber IOLs presents a potentially acceptable alternative to contact lens fitting for the aphakic patient.

Late complications of penetrating injury

Despite excellent repair of corneoscleral lacerations and proper vitreoretinal surgery for vitreous hemorrhage, cataract, and other immediate complications of penetrating injuries, a variety of late complications can arise.

Fibrotic membranes result from organization of residual lens material after a traumatic cataract. In this situation, the material is often quite difficult to cut with the vitrectomy instrument alone (Fig. 110.23). However, after segmentation with a myringotomy blade or scissors, the material may be more easily removed with the vitrectomy probe. When this fails, the segments of tissue can be grasped with intraocular microforceps, cut with microscissors, and removed from the eye through the sclerotomy. If the tissue has become vascularized, it may be necessary to use endodiathermy for hemostasis. With these techniques, a clear pupillary space can be achieved in nearly all cases. Final vision depends on the status of the remainder of the eye, as well as amblyopia in children.

Fig. 110.23 Residual lens material can cause an opaque pupil. This material can be difficult to remove with vitrectomy instrumentation. In these cases the material is incised (A) and then grasped with a microforceps held in one hand and cut with an intraocular scissors (B) or vitrectomy instrument held in the other hand.

Some aphakic eyes develop an occluded pupil (Fig. 110.24). This often is caused by residual lens material but can also result from contraction of a vitreous sheet incarcerated in a corneal or limbal laceration. In the latter situation, the pupillary space can be recreated by freeing the vitreous from the wound and excising it, although cutting of the iris with the vitrectomy instrument may be necessary in some instances.

Fig. 110.24 This patient developed an occluded pupil after an extensive corneal laceration with extrusion of the lens.

Pupillary membranes can occur after penetrating injury in the absence of residual lens material. These presumably develop either from proliferation through an anterior scleral laceration that grows in the retropupillary space or from proliferation of tissues as a result of the inflammation associated with a penetrating injury. Although some of these membranes simply impair visualization of posterior structures, more advanced cyclitic membranes can cause ciliary body detachment and hypotony.

In general, we advocate surgery through the pars plana for these membranes, using techniques similar to those described for residual lens material. However, if one suspects a cyclitic membrane, care must be taken to avoid infusing into the subretinal or suprachoroidal space. Surgery should be performed with a bent infusing needle until the sutured pars plana infusion cannula can be visualized. The use of a smaller-gauge vitrectomy instrument may be contemplated in these cases; however the larger 20G probe is likely more effective in cutting and ingesting the often thick cyclitic membranes.

Macular pucker can develop after penetrating injuries and is managed in an identical manner to an idiopathic macular pucker. Retinal detachment, either traction or rhegmatogenous, can also be a late complication of a penetrating injury. Pars plana vitrectomy and prophylactic scleral buckling have been described as decreasing the risk of this complication. However, even in eyes with ocular lacerations without vitreous hemorrhage, retinal detachments can be seen in a higher percentage than in uninjured eyes,¹³⁰ since vitreous is incarcerated in the wound site in virtually all cases of scleral laceration. Repair of late retinal detachments in patients with a history of penetrating trauma should be managed similar to nontraumatic detachments. However, additional care should be taken when one is performing the conjunctival peritomy and isolating the rectus muscle because of the possibility of areas of scleral thinning associated with the laceration.