Retinal detachment

Incidence of rhegmatogenous retinal detachment (RD) (Fig. 31.2) in the general population is 0.02%6. The risk for development of RD increases with myopia due to higher degree of retinal and vitreous degenerations, posterior vitreous detachment, and retinal hole formation7. Phacoemulsification also increases the risk of RD and, as shown in Table 31.2, the combination of both myopia and phacoemulsification markedly enhances this risk. Intraoperative complications such as rupture of the capsular bag or vitreous loss elevate the risk up to 8.0%, even in the general population. Published data on the incidence of RD after phacoemulsification in myopes vary greatly depending on the particular study; from 0 to 8.1% in one single study as shown in Table 31.3, which includes a meta-analysis of publications from 1994 to 2008 dealing with this issue8. The majority of these publications are studies with a retrospective design. Considering the given incidences in Table 31.3, one must note the wide variation concerning the different particular operative techniques (e.g. ICCE, ECCE), the degree of myopia, and the length of follow-up between the studies. In addition, microincisional surgery and IOL with sharp optic edge design were not available until recently. The incidence of PCO was consequently higher in the young patient collectives and Nd:YAG-capsulotomy had to be performed more often. There is an overall tendency that all studies with a RD rate of 0 % embrace a follow-up of less than 4 years and studies with a longer follow-up indicate higher rates of RD. In order to estimate the real cumulative incidence of RD after RLE, an adequate long-term follow-up is mandatory as it has been shown that the cumulative risk of RD after lens surgery increases in a linear fashion over time9. Therefore, one should consider the cumulative risk of RD for young myopes that undergo RLE to be somewhat higher with respect to their significantly longer life expectancy.

Fig. 31.2 Biomicroscopical appearance of multiple retinal holes with retinal detachment in a young high myopic patient.

Table 31.2 Incidences of rhegmatogenous retinal detachment

Deductively, identifiable risk factors for RD after RLE are high axial length, age >50 years, male gender, Caucasian race, existence of peripheral retinal degenerations, intraoperative complications such as rupture of the capsule with vitreous loss, and postoperative application of laser capsulotomy for treatment of PCO.

There is a completely different risk profile for RD after hyperopic RLE. Hyperopic eyes exhibit a short axial length and do not display any intrinsic retinal pathology. Thus, published data of several retrospective studies have not shown a single case of RD after hyperopic RLE during a follow-up of up to 6 years.

Role of retinal photocoagulation to prevent rhegmatogenous retinal detachment

The debate over the role of prophylactic peripheral retinal photocoagulation in myopes in order to prevent RD after lens surgery is a lengthy and ongoing one in the ophthalmic community. It is noteworthy that retinal hole formation may also emerge in clinically unsuspicious areas. The main arguments against a prophylactic retinal photocoagulation are the facts that an unnecessary and non-evidence-based therapy is inefficient, expensive, and may cause later complications. These complications constitute a higher incidence of macular pucker, macular edema, and posterior vitreous detachment. Finally, the question of a benefit of prophylactic peripheral retinal photocoagulation in the high myope cannot be answered today based on the heterogeneity of the current, mostly retrospective published data. Indication is therefore still based on an individual consideration of the patient`s age, grade of myopia, existing retinal degenerations, state of the vitreous body, and complication profile of the lens surgery.

PCO after RLE

Independent of the type of implanted IOL, RLE causes an increased rate of posterior capsule opacification (PCO) (Fig. 31.3) due to the younger age of the patients. Thus, only IOL with sharp edge design should be used in RLE. IOL should be centered in the capsular bag and anterior capsulorrhexis should overlap the IOL (Fig. 31.4). Avoiding PCO is important in order to reduce complications associated with Nd:YAG capsulotomy such as elevation of IOP, iritis, vitreous prolapse, posterior vitreous detachment, cystoid macular edema, or RD. Published data concerning the incidence of RD after lens surgery and subsequent laser capsulotomy vary between 0 and 4%10,13. It is noteworthy that some authors postulate the incidence of RD after laser capsulotomy is not due to the application of the energy of the laser, but rather to the opening of the posterior capsule itself11. A direct correlation of mode, configuration, point of time after lens surgery, or level of applied energy of laser capsulotomy has not yet been substantiated in any study. However, the risk of RD after laser capsulotomy increases significantly with the degree in high myopia. Therefore after RLE, one should carefully weigh the risks of laser capsulotomy in eyes with beginning PCO and an axial length of more than 24 mm against the benefit of some gain in visual acuity12. In some cases it may be advisable to perform surgical polishing of the posterior capsule instead of using the laser in order to avoid opening of the posterior capsule.

Fig. 31.3 Biomicroscopical appearance of posterior capsular opacification after IOL implantation into the capsular bag.

Fig. 31.4 Intraoperative appearance of a circular curvilinear capsulorrhexis with an intact capsular bag. Note, that the anterior capsule circularly overlaps the optic of the IOL (AMO, AR40e).

Refractive surprise after surgery

In case of a postoperative refractive surprise that might occur despite thorough preoperative clinical examination and application of the correct IOL formula, several approaches are available: explantation and reimplantation of the correct IOL power, implantation of an add-on-IOL, or excimer laser procedure. The choice of treatment depends on the amount of refractive error and the time of the second surgery. If secondary surgery is performed late it may be preferable not to operate on fibrotic intraocular structures, which carry a higher risk for capsular bag trauma and IOL complications.