“Did the loss of vision occur suddenly?”

“Is the eye painful?”

“Can you describe the pain?”

“Did the pain come on suddenly?”

“Does the light bother your eye?”

“Do you have pain when you blink?”

“Do you have the sensation of something in the eye?”

“Do you have headaches?”

“Do you have pain on movement of the eye?”

“Do you have pain over the brow on the same side?”

“Do you wear contact lenses?”

• Dryness

• Eye pain

• Stinging or burning sensation

• Stringy discharge from the eye

• Light sensitivity

• Heavy eyelids

• Foreign body sensation

• Sand in the eye; a gritty feeling

• Itching

• Redness

• Blurring of vision

• Decreased tolerance of reading, working on the computer, or any activity that requires sustained visual attention

Age: Dry eye is a part of the natural aging process. The majority of people older than age 65 experience some symptoms of dry eyes.

Gender: Women are more likely to develop dry eyes because of hormonal changes and menopause.

Medications: Certain medicines, including antihistamines, decongestants, statins, beta-blockers, diuretics, analgesics, and antidepressants can cause dry eyes.

Medical conditions: Persons with rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis, diabetes, and thyroid problems may develop dry eyes. Patients who have suffered with Stevens-Johnson syndrome (also known as erythema multiforme) may develop severe dry eyes. Also, problems with inflammation of the eyelids (blepharitis), inflammation of the surfaces of the eye, or the inward or outward turning of eyelids (entropion or ectropion, respectively) can cause dry eyes.

Environmental conditions: Exposure to pollutants such as smoke, exhaust, and smog, and arid and windy conditions can increase tear evaporation, resulting in dry eye symptoms. Failure to blink regularly, such as when staring at a computer screen for long periods, can also contribute to the dry eye syndrome. Excessive alcohol consumption is also associated with the dry eye syndrome.

Other factors: Long-term use of contact lenses can be a factor in the development of dry eyes. Refractive eye surgeries, such as laser-assisted in situ keratomileusis (LASIK),² can cause decreased tear production and dry eyes.

“Have you had any injury to the eye?”

“Does anyone else in the family have a red eye?”

“Have you had any recent coughing spells? Vomiting?”

“Have you had any associated eye pain?”

“Does light bother your eyes?”

“Is there any associated discharge?”

“Do you wear contact lenses?”

Using the Standard Snellen Chart

If a standard Snellen eye chart is available, the patient should stand 20 feet from the chart. If the patient wears glasses for distance, he or she should wear them for the examination. The patient is asked to cover one eye with the palm⁴ or an index card and read the smallest line possible. If the best he or she can see is the 20/200 line, the patient’s vision in that eye is 20/200; this means that at 20 feet, the patient can see what a person with normal vision can see at 200 feet. This can also be explained as 10% of normal vision in that eye. If a patient at 20 feet cannot see the 20/200 line, he or she is moved closer until the letters are recognized. If the patient can read these letters at 5 feet, the patient’s visual acuity in that eye is 5/200.

Using a Pocket Visual Acuity Card

If the standard Snellen chart is not available, a pocket visual acuity card is helpful. This is viewed at 14 inches (35.6 cm). The patient is again asked to read the smallest line possible. If neither eye chart is available, any printed material may be used. The examiner should remember that most patients older than 40 years require reading glasses. Although visual acuity cannot be quantified, the examiner can certainly determine whether the patient has any vision. In such a case, the patient is asked to cover an eye and read the smallest line possible on a given printed page.

Evaluation of Patients with Poor Vision

Patients with poor vision who are unable to read any lines of print should be tested for finger-counting ability. This crude measurement of visual acuity is obtained by the examiner’s holding up fingers in front of one of the patient’s eyes with the other eye covered. The patient is then asked how many fingers are seen. If the patient is still unable to see, the next step would be to evaluate whether he or she has any light perception. This is performed by covering one eye and directing a light at the eye in question. The examiner asks the patient whether he or she can see when the light is on and off. No light perception is the term used when a person cannot perceive light.

Evaluation of Patients Who Cannot Read

For individuals who cannot read, such as young children or illiterate patients, the use of the letter “E” in different sizes and directions is helpful. The examiner asks the patient to point in the direction of the letter: up, down, right, left.

The examiner stands or sits 3 feet in front of and at eye level with the patient. The patient is asked to close the right eye while the examiner closes his or her own left eye, each fixating on the other’s nose. The examiner holds up fists with the palms facing him or her. The examiner then shows one or two fingers on each hand simultaneously and asks the patient how many fingers he or she sees. The hands are moved from the upper to the lower quadrants, and the examination is repeated. The examination is then repeated, with the other eye of the patient and that of examiner. The fingers should be seen by both patient and examiner simultaneously. To position the patient to better advantage, the hands are held up slightly closer to the examiner. This provides a wider field for the patient. If the examiner can see the fingers, the patient can see them unless he or she has a field deficit. This technique for examining the patient’s left eye is shown in Figure 7-10.

Because lesions along the visual pathway develop insidiously, the patient may not be aware of any changes in visual fields until late in the course of the disease. Confrontation fields, performed by the internist, may provide the first objective evidence that the patient has a lesion involving the visual pathway. An area of depressed vision is called a scotoma.

The normal central vision extends approximately 30 degrees in all directions of central fixation. The blind spot is the physiologic scotoma located approximately 15 to 20 degrees temporal to central fixation, corresponding to the optic nerve head. No sensory elements such as the rods or cones are located on the nerve head.

Assess Visual Field Abnormalities

Pathologic scotomata may be appreciated on visual field testing. Scotomata may result from primary ocular disease, such as glaucoma, or from lesions in the central nervous system, such as tumors. Figure 7-11 illustrates some of the common defects.

Total loss of vision in one eye constitutes a blind eye, resulting from a disease of the eye or a lesion of its optic nerve.

Hemianopsia refers to absence of half of a visual field. A defect in both temporal fields is termed bitemporal hemianopsia. It results from a lesion involving the optic nerves at the level of the optic chiasm. Pituitary tumors are common causes.

A homonymous hemianopsia results from damage to the optic tract, optic radiation, or occipital cortex. The term homonymous indicates that the visual loss is in similar fields. A patient with a left homonymous hemianopsia is unable to see the left half of the fields of both eyes. This defect occurs with damage to the right optic tract. Homonymous hemianopsia is the most common form of field loss and occurs frequently in patients with strokes.

A quadrantanopsia is a field loss in one quadrant, also known as a “pie in the sky” lesion. A patient with a left upper homonymous quadrantanopsia has damage to the right lower optic radiations or the right lower occipital region. Tunnel vision may occur in advanced glaucoma. However, the visual fields enlarge with increasing testing distance, in contrast to hysterical blindness, in which the field size typically remains the same at all times, regardless of the testing distance.

Assess Optokinetic Nystagmus

On occasion, a patient may feign blindness. They may be trying to qualify for disability insurance or some other issue of secondary gain. Alternately, they may have psychological issues. A useful test for ruling out such malingering involves optokinetic nystagmus (OKN). OKN is the rapid alternating motion of the eyes that occurs when the eyes try to fixate on a moving target. For example, observe the eyes of a person riding a train as it enters the station. The eyes move rapidly back and forth as the person tries to fixate on a station sign. The presence of OKN indicates physiologic continuity of the optic pathways from the retina to the occipital cortex. OKN may be elicited in the examining room by having the patient fixate on the numbers on a tape measure while you rapidly pull out the tape. Because OKN is involuntary, a positive response⁵ provides excellent verification that the patient is feigning blindness.

The condition of a deviated, or crossed, eye is called strabismus, or tropia. Strabismus is the nonalignment of the eyes in such a way that the object being observed is not projected simultaneously on the fovea of each eye. Esotropia is deviation of an eye nasally; exotropia is deviation of an eye temporally; hypertropia is deviation upward. An alternating tropia is the term used to describe the condition in which either eye deviates. Figure 7-12 shows a patient with a left exotropia.

Perform the Cover Test

The cover test is useful for determining whether the eyes are aligned (if a deviated eye is present). The patient is instructed to look at a distant target. One eye is covered with a 3 × 5 inch (7.6 × 12.7 cm) card. The examiner should observe the uncovered eye. If the uncovered eye moves to take up fixation of the distant point, that eye was not straight before the other eye was covered. If the eye did not move, it was straight. The test is then repeated with the other eye.

Evaluate the Six Diagnostic Cardinal Positions of Gaze

Because the rotational actions of the oblique and vertical rectus muscles cannot be easily assessed, the eye must be moved into six diagnostic gaze positions that best isolate the vertical actions of these muscles to test their innervations. The oblique muscles are tested in adduction to maximize their vertical action. In contrast, the vertical rectus muscles are tested in abduction; in these positions, the superior rectus acts now as a pure elevator and the inferior rectus as a pure depressor. These diagnostic cardinal positions of gaze are the testing positions for the muscles, and the abduction and adduction testing movements are different from the normal actions of the muscles as indicated in Table 7-1.

Hold the patient’s chin steady with your left hand, and ask the patient to follow your right hand as it traces a large H in the air. Hold your right index finger approximately 15 to 18 inches (38 to 46 cm) from the patient’s nose. From the midline, move your finger approximately 12 inches (30 cm) to the patient’s left and pause; then up approximately 8 inches (20 cm) and pause, as shown in Figure 7-13; down approximately 16 inches (40 cm) and pause; up approximately 8 inches (20 cm); and then slowly back to the midline. Switch your hands, now holding the patient’s chin with your right hand. Cross the midline and repeat the finger movements on the other side. These are the six diagnostic cardinal positions of gaze. Observe the movement of both eyes, which should follow the finger smoothly. Look for the parallel movements of the eyes in all directions.

On occasion, when looking to the extreme side, the eyes develop a rhythmic motion called end-point nystagmus. There is a quick motion in the direction of gaze, which is followed by a slow return. This test differentiates end-point nystagmus from pathologic nystagmus, in which the quick movement is always in the same direction, regardless of gaze.

If the eye and eyelid do not move together, lid lag is present.

The six diagnostic cardinal positions of gaze, with the related muscles, are illustrated in Figure 7-14, and Table 7-6 summarizes the abnormalities in ocular motility that are caused by paretic muscles.

The images projected on the retina may be interpreted by the brain in one of three ways: fusion, diplopia, or suppression. Fusion and diplopia have already been discussed. In children, strabismus leads to diplopia, which leads to confusion and then suppression of the image and finally to amblyopia. Amblyopia is the loss of visual acuity secondary to suppression. Amblyopia is reversible until the retinas are fully developed, at approximately the age of 7 years. Amblyopia is a phenomenon that occurs only in children. An adult who acquires strabismus secondary to a stroke, for example, cannot suppress the deviated eye’s image and will experience diplopia, which is intolerable.

Evaluate the Pupillary Light Reflex

Evaluate the Near Reflex

The near reflex is tested by having the patient look first at some distant target and then at a target placed approximately 5 inches (13 cm) away from his or her nose. When the patient focuses on the near target, the eyes should converge, and the pupils should constrict.

• Orbits and eyelids

• Lacrimal apparatus

• Conjunctiva

• Sclera

• Cornea

• Pupils

• Iris

• Anterior chamber

• Lens

Are the globes present in the orbits? An enucleation of his left eye is pictured in Figure 7-15. The removal of the entire globe from the orbit may be caused by trauma, surgery (as in the case of a ruptured globe), or self-induced injury by a psychotic person. Rarely one may see a case of congenital anophthalmos.

Examine the eyelids for evidence of drooping, infection, erythema, swelling, crusting, masses, or other abnormalities. Have the patient open and close the eyelids. The motion should be smooth and symmetric. Do the eyes close completely?

Note the position of the eyelids. When the eye is open, the upper eyelid normally covers only the upper margin of the iris. When the eye is closed, the eyelids should approximate each other completely. The space between the upper and lower lids is the palpebral fissure. Drooping of the eyelid is known as blepharoptosis, or ptosis. Figure 7-16 depicts marked bilateral ptosis, causing narrowing of the palpebral fissure that resulted from a muscle-weakening disorder, myasthenia gravis.

Figure 7-17 shows a patient with Kearns-Sayre syndrome, also known as chronic progressive external ophthalmoplegia. In this autosomal-dominant condition, there is a slowly progressive, symmetric ptosis and symmetric external ophthalmoplegia (weakness of the external eye muscles). The syndrome also is associated with retinal pigmentary degeneration and cardiac conduction defects such as complete heart block. Affected patients are frequently of short stature and may be deaf. In the patient shown in Figure 7-17, notice the arching of the brows in an effort to lift the eyelids to reduce the ptosis.

Lagophthalmos is a condition, pictured in Figure 7-18, in which there is an inability to close the eyelids completely. It is seen in thyroid disease secondary to orbital infiltration caused by inflammation, as a result of autonomic stimulation, or as a consequence of ocular surgery. The name comes from the Greek word lagos, meaning “hare,” an animal believed to sleep with its eyes open.

Figure 7-19 shows a patient with an entropion. An entropion is a turning inward of the lid margin in such a way that the eyelashes abrade the cornea and globe. An ectropion is a turning outward of the eyelid margin. An ectropion is pictured in Figure 7-20. Both entropions and ectropions may be seen as involutional changes associated with aging and may be associated with the dry eye syndrome.

A common benign lesion of the eyelid is a marginal intradermal nevus, shown in Figure 7-21. Such lesions are well differentiated, and hairs commonly grow from them. One of the associated problems is that these hairs may scratch the cornea, causing corneal abrasions like those caused by entropions.

A cutaneous horn is a clinical diagnosis referring to a conical projection above the surface of the skin that resembles a miniature horn. The base of the horn may be flat, nodular, or crateriform. The horn is composed of compacted keratin. Cutaneous horns usually arise on sun-exposed skin but can occur even in sun-protected areas. More than half of all cutaneous horns are benign. Malignancy at the base of the horn, however, is present in up to 20% of cases, with squamous cell carcinoma being the most common type. No clinical features reliably distinguish between benign and malignant lesions. Tenderness at the base and lesions of larger size favor malignancy. Figure 7-22A shows a patient with a cutaneous horn on the medial aspect of the left upper eyelid. Figure 7-22B shows a close-up of the cutaneous horn. Figure 7-23 shows another patient with a cutaneous horn above her left eyebrow.

Molluscum contagiosum is a viral infection, caused by a member of the poxvirus family, that causes raised, pearl-like, umbilicated (dimpled) papules on the skin. In most people, the growths range from about the size of a pinhead to as large as a pencil eraser (2 to 5 mm in diameter). This is a common infection in children and occurs when a child comes into direct contact with a lesion. It is frequently seen on the face, neck, armpit, arms, and hands but may occur anywhere on the body except the palms and soles. The virus can spread through contact with contaminated objects, such as towels, clothing, or toys. The virus also spreads by sexual contact. Early lesions on the genitalia⁶ may be mistaken for herpes or warts but, unlike herpes, these lesions are painless. Persons with an impaired immune system, such as patients with acquired immune deficiency syndrome (AIDS), may have a significantly worse case of molluscum contagiosum. Figure 7-24 shows a patient with molluscum contagiosum around the eye. Note the umbilicated lesions in this figure as well as in Figure 15-37.

A common ocular occurrence of aging is herniation of the orbital fat, caused by progressive thinning of the orbital septum, allowing orbital fat to move forward and resulting in puffy areas around the globe. Figure 7-25 shows an example of herniated orbital fat. Note the unrelated old corneal scars and the arcus senilis, discussed later in this chapter.

Figure 7-26 depicts a small hemangioma of the lower eyelid. Sturge-Weber syndrome is a congenital condition recognizable by a characteristic port wine stain, or nevus flammeus, on one side of the face that follows the distribution of one or more of the divisions of the trigeminal nerve. Hemangiomas may develop on the episclera, iris, ciliary body, and choroid. Unilateral glaucoma develops frequently on the affected side if there is extensive involvement of the eye with a uveal hemangioma. These patients should be screened for glaucoma early. Figure 7-27 shows a patient with Sturge-Weber syndrome. Notice the sharply demarcated patch of the hemangioma with the involvement of the ophthalmic and maxillary divisions of the left trigeminal nerve. The lesion, which does not blanch on pressure, tends to darken with age from red to purple (see also Fig. 21-7).

A chalazion is a granulomatous reaction to inspissated secretions of the meibomian glands in the eyelid. It is caused by a blocked duct in one of the glands. These glands are aligned vertically in the eyelids perpendicular to the lid margin. The openings of these glands are located on the eyelid margin directly behind the eyelashes. The glands, which number approximately 30 in the upper lid and 20 in the lower lid, produce a thin, oily fluid that lubricates the eye. A chalazion may appear as a localized mass on the eyelid near the orifice of the gland, painful at first, but usually painless when chronic. Figure 7-28A shows a patient with a chalazion; Figure 7-28B illustrates the position of the meibomian glands on the lids. Figure 7-29 shows a patient with bilateral chalazions. A chalazion will often disappear without treatment within a month or so. The initial treatment is to place very hot, but not burning,⁷ compresses over the eyelid for 10 to 15 minutes at least 4 times a day. This tends to soften the hardened oils blocking the duct, and promote drainage and healing. Figure 7-30A shows another patient with a chalazion; Figure 7-30B shows the same patient with the lid everted. Note the chalazion distorting the lid margin and the granuloma formed on the lower inner eyelid at the proximal end of the meibomian gland.

In herpes zoster ophthalmicus, rows of vesicles, ulcers, and crusted scabs are scattered along the course of one or more of the branches of the ophthalmic division of the trigeminal nerve. The vesicles contain clear fluid. These rupture, leaving ulcers that can become infected secondarily and form crusts. The eyelids become edematous and red. Pain can be excruciating. Ophthalmoplegia secondary to involvement of the extraocular muscles may also occur. Figure 7-31 shows a patient with AIDS and herpes zoster ophthalmicus at different stages of evolution (fresh and crusted vesicles) in the ophthalmic division of the trigeminal nerve. Treatment with antivirals will dramatically reduce the symptoms.

Is orbital discoloration present? One type of orbital pigmentation known as raccoon eyes is an important sign of a basilar skull fracture. This discoloration is caused by extravasated blood from the fracture of the base of the brain. This is an important sign to recognize, especially in an unconscious patient, when a history is not available. Figure 7-32 shows a patient with a basilar skull fracture. Notice also the subconjunctival hemorrhages on the lateral aspects.

Inspect the eyelids for xanthelasma. Although not specific for hypercholesterolemia, these yellowish plaques are commonly associated with lipid abnormalities and are caused by lipid deposition in the periorbital skin. Xanthelasma is shown in Figure 7-33.

A stye, or acute external hordeolum, is a localized abscess in an eyelash follicle and is caused by a staphylococcal infection. It is a painful, red infection that looks like a pimple pointing on the lid margin where the hair follicle of the eye lash or cilia is situated. Figure 7-34 depicts a stye. Blepharitis is a chronic inflammation of the eyelid margins. The most common form is associated with small white scales around the lid margin and the eyelashes, which stick together and may fall out. There are several annoying symptoms: itching, tearing, and redness. The condition is frequently associated with seborrheic dermatitis and acne rosacea. Figure 7-35 shows a patient with blepharitis.

Malignant tumors of the eyelids are not uncommon. Characteristics suggesting malignancy include:

Carcinoma of the eyelids has the highest incidence of any malignant ocular tumor. Men are more commonly affected than women; the average age at onset is 50 to 60 years. Of all eyelid carcinomas, 95% are of the basal cell type. The location of basal cell carcinomas are on the lower eyelid (50–60%), medial canthus (25–30%), upper eyelid (15%), and lateral canthus (5%). Figure 7-36 shows a basal cell carcinoma of the lower lid. The lesion begins growing slowly and painlessly, eventually forming the typical rodent ulcer with a raised border and an indurated base. The tumor erodes the surrounding area, forming the ulcer. Note the raised border of the lesion in Figure 7-36.

The remaining 5% consist of squamous cell carcinomas and meibomian gland carcinomas. Squamous cell carcinomas are 40 times less common than basal cell carcinomas and tend to be on the upper eyelid and grow faster than basal cell carcinomas. Early ulceration is common. A squamous cell carcinoma of the eyelid is shown in Figure 7-37. The base and edges of the ulcer are hard and hyperemic.

Malignant melanomas are less then 1% of all malignant tumors of the eyelid.

The most common ocular manifestation of AIDS affecting the eyelids is lesions of Kaposi’s sarcoma. The initial manifestation may be subtle and may be mistaken for blepharitis or a chalazion. Refer to Figure 5-100C, which shows a patient with AIDS and Kaposi’s sarcoma of the eyelid.

Inspect the Lacrimal Apparatus

In general, there is little to be seen of the lacrimal apparatus, with the exception of the punctum. If tearing, also known as epiphora, is present, there may be some obstruction to flow through the punctum. If excessive moisture is present, check for a blockage of the nasolacrimal duct by pressing the lacrimal sac gently against the inner orbital rim. If a blockage is present, material may be expressed through the punctum. Figure 7-38 shows massive lacrimal gland enlargement as a result of sarcoidosis.

Figure 7-39 shows marked bilateral proptosis of the globe in a patient with hyperthyroidism. Note the massive lacrimal gland enlargement.

Dacryocystitis is a term describing the inflammation of the lower lacrimal passages usually seen in infants or older individuals. The causes include congenital anomalies, infection, and stenosis of the lacrimal duct. Chronic dacryocystitis, seen in Figure 7-40, is a common disorder and almost always arises secondary to ductal obstruction.

Inspect the Conjunctiva

The conjunctivae should be examined for signs of inflammation (i.e., injection caused by dilatation of its blood vessels), pallor, unusual pigmentation, swelling, masses, and hemorrhage.

The tarsal conjunctiva may be seen by everting the eyelid. Ask the patient to keep the eyes open and look downward. Grasp gently some of the eyelashes of the upper lid. Pull the eyelid away from the globe, and press the tip of an applicator stick against the upper border of the tarsal plate. Then quickly turn the tarsal plate over the applicator stick, using it as a fulcrum. Your thumb can now be used for holding the everted lid, and the applicator stick can be removed. After inspection of the tarsal conjunctiva, have the patient look up to return the lid to its normal position.

The normal conjunctiva is transparent. Note the number of blood vessels. Normally, only a small number of vessels are seen. Ask the patient to look up, while you pull down on the lower eyelids. Compare the vascularity in the two eyes.

Conjunctivitis is the most common of all eye diseases in the Western hemisphere. The causes are numerous: bacterial, viral, chlamydial, fungal, parasitic, spirochetal, allergic, traumatic, chemical, and idiopathic. Bacterial conjunctivitis is the most frequent type and is self-limited, lasting 10 to 14 days. Figure 7-41 shows acute hemorrhagic conjunctivitis. This highly contagious ocular infection, often bilateral, is caused by the enteroviruses (members of the picornavirus family), Pneumococcus organisms, and Haemophilus influenzae. Giant papillary conjunctivitis is an ocular syndrome consisting of excessive secretion of conjunctival mucus, itching, and the development of giant papillae (1 mm or more in diameter) on the tarsal conjunctiva. This syndrome occurs mostly in patients who wear soft contact lenses, but it can occur in patients with ocular prostheses or other foreign bodies in the eye. Figure 7-42 shows a patient with giant papillary conjunctivitis.

Figure 7-43 shows a large subconjunctival hemorrhage. This common condition may occur spontaneously, usually in only one eye, in any age group. Because of its sudden appearance and bright red color, the patient may become alarmed. The hemorrhage is usually caused by a rupture of a small conjunctival vessel after a bout of severe coughing or sneezing. Occasionally, a subconjunctival hemorrhage may occur as a consequence of elevated blood pressure. There is no treatment, and the hemorrhage resolves within 1 to 2 weeks.

The conjunctiva is attached to the episclera by loose connections. This potential space can easily be filled with fluids such as blood or serum. Chemosis is the presence of fluid in this space. Trauma, allergies, and chronic exposure, as seen in proptosis of hyperthyroidism and neurologic deficits, are important causes of chemosis. Figure 7-44 shows chemosis secondary to hay fever. An example of hemorrhagic chemosis is pictured in Figure 7-45. The patient, a 42-year-old man, had a 7-year history of progressive proptosis secondary to a melanoma.

Two common benign growths on the conjunctiva are the pinguecula and pterygium. A pinguecula is a whitish-yellow, triangular, nodular growth on the bulbar conjunctiva adjacent to the corneal-scleral junction (limbus), as seen in Figure 7-46; it does not cross on to the cornea. A pterygium is a more vascular growth on the bulbar conjunctiva that begins at the medial canthus and extends beyond the corneal-scleral junction to the cornea. This typically triangle-shaped fibrovascular connective tissue may cause astigmatism or even decreased vision if it extends toward or occludes the pupillary margin. The cause of the pterygium is thought to be chronic dry eyes because its frequency is higher among people living near the equator. Figure 7-47A shows a pterygium; Figure 7-47B is a close-up photograph of a pterygium in another patient. Notice the vascularity and their positions across the limbus.

Primary acquired melanosis is a unilateral condition in which melanotic pigmentation develops in the conjunctival or corneal epithelium. It starts insidiously during middle age. A biopsy is often needed to rule out a malignant melanoma. Figure 7-48 shows primary acquired melanosis. Primary acquired melanosis of the plica semilunaris in another patient is seen in Figure 7-49.

A benign pigmented tumor of the conjunctiva may be a conjunctival nevus. This is a solitary, well-defined, slightly elevated lesion. Nevi have a predilection for the limbus, plica semilunaris, caruncle, and lid margin. Most nevi are tan or brown, and many have zones of clearing within known as lacunae. Figure 7-50 shows a patient with a conjunctival nevus.

A dermolipoma of the conjunctiva is a common congenital tumor, often bilateral, that usually appears as a smoothly rounded growth in the superotemporal quadrant of the bulbar conjunctiva near the lateral canthus. Figure 7-51A shows bilateral dermolipomas of the conjunctiva. A close-up of the lesion in the right eye is shown in Figure 7-51B. The yellowish color is secondary to the increased fatty deposits in the lesion. Often, fine hairs may protrude from its surface. Treatment is usually not indicated.

Inspect the Sclera

The sclera is examined for nodules, hyperemia, and discoloration. The normal sclera is white. In dark-skinned individuals, the sclera may be slightly brownish in color because of pigment migration.

Jaundice, or icterus, is a yellowish discoloration of the sclera, skin, and mucous membranes, and is caused by retention of bilirubin or its products of metabolism. Jaundice is more easily seen in the sclera of white individuals and may be missed in people of color or in dim light. Ingestion of too much carotene-containing foods, carotenoids, may cause yellowing of the skin but not of the sclera (see Fig. 14-5). Many foods are associated with high levels of carotenoids; these include carrots, sweet potatoes, tomatoes, asparagus, yellow corn, cheese, mustard, oranges, papayas, peaches, pineapple, pumpkin, and many more.

The sclera may appear bluish, normally in infants or pathologically in osteogenesis imperfecta. Osteogenesis imperfecta is a group of hereditary disorders with bone fragility. Individuals with these disorders may suffer bone fractures after mild trauma. The autosomal dominant form is most widely recognized. In this form, the sclerae are very thin and take on a blue hue because the uveal pigment shows through the sclera. Deafness is also seen in this form of the disorder. Figure 7-52 shows blue sclerae in a patient with osteogenesis imperfecta.

Episcleritis is a benign, usually painless, commonly recurring disorder frequently affecting both eyes of young adults, more commonly women. It is a noninfectious inflammation that is subconjunctival and yet superficial to the underlying sclera. The affected area may be either flat and diffuse or localized and nodular (1 to 4 mm in diameter). Although the cause in most cases is unclear, episcleritis also occurs in patients with inflammatory bowel disease, herpes zoster, collagen vascular disease, gout, syphilis, and rheumatoid arthritis. Figure 7-53 shows the classic features of episcleritis.

Scleritis is a painful, often bilateral, recurrent disorder, less common than episcleritis, that affects older age groups and occurs in women more often than in men. There is inflammation of the sclera with possible involvement of the cornea, uveal tract (i.e., iris, choroid, and ciliary body), or retina. Photophobia is common. Scleritis is usually related to a systemic disorder. It occurs much more commonly in patients with connective tissue disorders. It may be diffuse or localized and nodular. Nodular scleritis is marked by dark localized blue patches in the anterior portion of the sclera; these are seen because the choroid is visible through the translucent sclera. The condition may resolve spontaneously. Figure 7-54 shows nodular scleritis.

Scleromalacia perforans is an uncommon, painless scleral condition characterized by the appearance of one or more dehiscences in the sclera in the absence of inflammatory changes. This necrotizing scleritis without inflammation is classically seen in patients with long-standing rheumatoid arthritis. The underlying uvea is often visible, and it may bulge out, as shown in Figure 7-55. Another example of scleromalacia perforans is shown in Figure 7-56. Notice the thinning of the sclera and the underlying dark uvea, as well as the irregular border of the iris. Anterior synechiae are present, holding the iris down to the lens and causing the scalloped appearance of the iris. There is corneal disease as well.

Inspect the Cornea

The cornea should be clear and without cloudiness, ulceration, or opacities.

A whitish ring at the perimeter of the cornea is probably an arcus senilis. In patients older than 40 years, this finding is usually a normal phenomenon. Although there are many false-positive findings, patients younger than 40 years may have hypercholesterolemia. An arcus senilis is seen in Figures 7-57 and 7-58.

An abnormal golden to greenish-brown ring near the limbus, most evident superiorly and inferiorly, is a Kayser-Fleischer ring. This ring is a specific and sensitive sign of Wilson’s disease, which is hepatolenticular degeneration as a result of an inherited disorder of copper metabolism. Approximately 95% of patients with Wilson’s disease who present with neurologic signs will have a Keyser-Fleischer ring. This ring is caused by deposition of copper in Descemet’s membrane of the peripheral cornea. Figure 7-59 shows a Kayser-Fleischer ring. Notice that the ring is most prominent in the vertical meridian.

Corneal ulcers are extremely painful lesions caused by loss of substance from the cornea by progressive erosion and necrosis of tissue. These ulcers may be caused by a variety of agents, including bacteria, viruses, fungi, and hypersensitivity reactions. Pneumococcus organisms are common bacteria associated with corneal ulceration. Pseudomonas infection is less common but is associated with a rapid spread and corneal perforation. Herpes simplex virus (HSV) is another common cause of corneal ulceration and is the most common cause of corneal-related blindness. It is almost always unilateral and may affect any age group. The keratitis (inflammation of the cornea) is commonly accompanied by conjunctival hyperemia, tearing, and photophobia. Recurrent attacks may be less painful to painless as generalized corneal anesthesia develops. Patients with AIDS or other immunosuppressive conditions are very susceptible to this recurring infection. Figure 7-60 shows a corneal ulceration secondary to HSV infection. Marked blepharospasm is common with corneal ulceration. The most common characteristic finding of HSV-related keratitis is the dendritic ulcer on the cornea. This ulcer is the result of active viral replication in the corneal epithelial cells. Figure 7-61 shows HSV-related keratitis. The eye has been stained with rose Bengal. The devitalized, swollen cells laden with the replicating virus stain brightly with this substance. Figure 7-62 shows corneal scarring in another patient as a result of a previous herpes zoster infection. Note the discrete areas of infiltrates in the cornea, as well as the darkening of the skin on the ipsilateral side from the nose to the forehead.

Keratoconus is an acquired abnormality of the shape of the cornea. It has a gradual onset. It is usually bilateral but asymmetric. It is estimated to occur in 1 per 20,000 individuals. The cornea protrudes as a cone, with the apex becoming thin and scarred. Affected patients experience slow visual deterioration. When the patient is asked to look downward, the cone can become quite obvious, deforming the lower lid to a pointy shape as seen in Figure 7-63. This is known as Munson’s sign.

Patients with keratoconus or corneal scarring from other causes may require corneal transplantation. A recent corneal transplant is shown in a patient in Figure 7-64. Note the sutures and the mild edema. In recent years, a new treatment, corneal cross-linking, has been developed to prevent the need for corneal transplantation; corneal cross-linking causes the cornea to harden, and the cornea can then be reshaped with laser correction.

Figure 7-65 shows a patient with a dermolipoma of the corneal limbus. It is a smoothly rounded, yellowish, benign growth (see also Fig. 7-51).

Inspect the Pupils

The pupils should be equal in size, round, and reactive to light and accommodation. In approximately 5% of normal individuals, pupillary size is not equal; this is called anisocoria. Anisocoria may be an indication of neurologic disease. Pupillary enlargement, or mydriasis, is associated with ingestion of sympathomimetic agents or with administration of dilating drops. A sluggish, mid-dilated pupil may be present with acute angle-closure glaucoma. Pupillary constriction, or miosis, occurs with ingestion of parasympathomimetic drugs, with inflammation of the iris, and with drug treatment for glaucoma. Many medications can cause anisocoria. It is therefore important to ascertain whether the patient has used any eye drops or has taken any medications.

Pupillary abnormalities may be markers of neurologic disease. The Argyll Robertson pupil is a pupil constricted 1 to 2 mm that reacts to accommodation but is nonreactive to light. It occurs in association with neurosyphilis. Horner’s syndrome is sympathetic paralysis of the eye that is caused by interruption of the cervical sympathetic chain. In addition to miosis and ptosis, anhidrosis⁸ is also present. A benign condition known as Adie’s tonic pupil is a pupil dilated 3 to 6 mm that constricts little in response to light and accommodation. This pupil is often associated with diminished to absent deep tendon reflexes in the extremities. It occurs more commonly in women 25 to 45 years of age, and the cause is unknown. There are no serious clinical implications. Table 7-7 lists features of these significant pupillary abnormalities.

Inspect the Iris

The iris is evaluated for its shape, color, presence of nodules, and vascularity. Normally, iris blood vessels cannot be seen unless the eye is observed with magnification.

An iris coloboma is a notch or gap in the iris. It results from failure of fusion of the embryonic tissue. The typical iris coloboma is usually part of a choroidal coloboma, which is an autosomal dominant trait. It is often bilateral, is usually located inferiorly, and involves the iris, choroid, or overlying retina (see Fig. 7-146). Visual acuity may be normal if the macula and optic nerve head are spared. Figure 7-66 shows a patient with an iris coloboma involving the ciliary body and the choroid.

Inflammation of the iris, known as iritis or iridocyclitis, is associated with severe pain, photophobia, tearing, decreased vision, and circumcorneal congestion. This congestion is caused by injection of the deep episcleral vessels (known as ciliary flush). The dilation of the iris vessels leads to transudation of protein into the aqueous humor and deposition of inflammatory cells on the corneal endothelium, known as keratic precipitates. As a result of this deposition, the iris becomes blurred and loses its distinctive radial appearance (a “muddy iris”). There are many causes of iritis, including exogenous infection from perforating injuries; secondary infection from the cornea, sclera, or retina; endogenous infection such as tuberculosis, gonorrhea, syphilis, and viral and mycotic infections; and systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, Reiter’s disease, Behçet’s syndrome, and relapsing polychondritis. Figure 7-67 shows the classic features of an extremely severe case of acute iritis. Most of the time iritis is not visible to the naked eye and requires examination using the slit lamp.

As a result of the inflammatory reaction of the iris, the iris may adhere to the cornea, forming anterior synechiae; posterior synechiae are adhesions between the iris and lens. Glaucoma is a well-known sequela of iritis and synechiae formation. Visualization of synechiae requires slit lamp examination.

Inspect the Anterior Chamber

Is the anterior chamber clear? If not, is it filled with pus or blood? Figure 7-68A shows pus in the anterior chamber, known as a hypopyon, in a patient with HSV keratitis. Another example of hypopyon, a large hypopyon together with severe conjunctival injection, is shown in Figure 7-68B.

Is there blood in the anterior chamber? This condition, known as a hyphema, is illustrated in Figure 7-69. Note the subconjunctival hemorrhage also in the patient in Figure 7-69A. A hyphema can occur as a result of significant blunt trauma to that eye causing bleeding within the eyeball. This bleeding comes from the anterior chamber angle or the iris, and therefore pupillary abnormalities are common. A hyphema can occur spontaneously also, not related to trauma. The presence of neovascularization of the iris, as can be seen in severe diabetes mellitus or after a central retinal vein occlusion, predisposes for a spontaneous hyphema. Figure 7-70 depicts an example of a “candy cane” hyphema resulting from neovascularization of the iris as a consequence of a central retinal vein occlusion. The photograph shows blood breakdown products intermingled with fresh blood.

Assess the depth of the anterior chamber. By shining a light obliquely across the eye, you can estimate the depth of the chamber. If a crescentic shadow on the far portion of the iris is visible, the anterior chamber may be shallow. Shadowing of the anterior chamber refers to the decreased space between the iris and the cornea. The technique for estimating the depth of the anterior chamber is illustrated in Figure 7-71.

The presence of a shallow anterior chamber predisposes an individual to a condition called narrow-angle glaucoma. The term glaucoma refers to a symptom complex that occurs in a variety of disease states. The characteristic finding in all types of glaucoma is an increased intraocular pressure. The Schiotz tonometer, which is a small, portable instrument, can be used for the quantitative assessment of intraocular pressure. There is more up-to-date equipment now to measure intraocular pressure. Palpation of the globe to determine intraocular pressure is a technique of low sensitivity. Palpation, if performed incorrectly, may be deleterious, because a retinal detachment may result. If the patient has had recent trauma to the eye, palpation of the globe may result in extrusion of ocular content in the case of a ruptured globe. Therefore palpation of the eye should never be performed.

Inspect the Lens

With oblique lighting, inspect the lens. Is the lens clear? Note any opacity that may be visible through the pupil.

The most commonly observed abnormality of the lens is opacification; the most common cause of opacification is aging. Slow, gradual vision loss is the symptom. Other causes include hereditary diseases, such as Down’s syndrome and cretinism; ocular diseases, such as high myopia, iritis, and retinal dystrophy; systemic disease, such as diabetes and hypoparathyroidism; medications, such as steroids; and trauma, such as a penetrating eye wound.

A cataract is any opacification of the lens that causes reduced visual acuity and interferes with the patient’s everyday life. Figure 7-72A shows a dense cataract of the left eye. Note the leukocoria⁹ related to the cataract. Figure 7-72B shows a dense nuclear, or central cataract of the left eye in another patient. Figure 7-73 is a close-up view of a dense nuclear cataract with anterior cortical spokes (opacification of the anterior cortex of the lens). The red reflex, described in the following section, “Ophthalmoscopic Examination,” is absent in all of these patients.

Is the lens in the normal position, or is it dislocated? The lens may be dislocated anteriorly, pressing the iris against the posterior cornea and blocking aqueous humor outflow, or it may be dislocated posteriorly. Secondary glaucoma may result. Marfan’s syndrome is an autosomal dominant condition, often with incomplete expression, in which there is increased length of the long bones; ocular complications include dislocation, or subluxation, of the lens, usually superiorly and nasally. Figure 7-74 shows a subluxated lens secondary to Marfan’s syndrome. This is the pupil of the patient’s left eye. Note the lower edge of the lens and the attached zonules that are apparent from the 3 o’clock to 7 o’clock positions (white lines). The red behind these lines is the red reflex of the retina in the background.

Patients now receive intraocular lens implants after cataract surgery. Figure 7-75 shows a dislocated intraocular lens implant. Note the dislocated wire attachment.

The Ophthalmoscope

Before the examination of the optic fundus is discussed, a few words about the ophthalmoscope are in order. The ophthalmoscope is an instrument with a mirror optical system for viewing the interior anatomy of the eye. There are two dials on the ophthalmoscope: one adjusts the light apertures and filters, and the other changes the lenses to correct for the refractive errors of both the examiner and the patient.

The most important apertures and filters are the small aperture, the large aperture, and the red-free (green) filter. The small aperture is for an undilated pupil, the large aperture is for a dilated pupil, and the red-free filter excludes rays of red light and is designed for visualization of blood vessels¹⁰ and hemorrhages. With this filter, the retina appears gray, the disc appears white, the macula appears yellow, and blood appears black.

Using the Ophthalmoscope

Hold the ophthalmoscope in your right hand in front of your right eye to examine the patient’s right eye. Ask the patient to look straight ahead and fixate on a distant target. If you wear glasses, remove them for better visualization of the retina. The ophthalmoscope light is turned on, and the aperture is switched to the small aperture. Start with the lens diopter¹¹ dial set to 0 if you do not use glasses. The myopic examiner should start with “minus” lenses, which are indicated by red numbers; the hyperopic examiner needs “plus” lenses, which are indicated by black numbers. Your index finger remains on the dial to enable easy focusing.

Place the ophthalmoscope against your forehead while your left thumb gently elevates the patient’s right upper eyelid gently against the superior orbital rim. The ophthalmoscope and your head should function as one unit. While looking through the ophthalmoscope, approach the patient at eye level from about 15 inches (38 cm) away at an angle of approximately 15 to 20 degrees lateral from center, as shown in Figure 7-76. The light should shine on the pupil. A red glow, the red reflex, can be seen in the pupil if the path of light is not obstructed by an opaque lens. Note any opacity in the cornea or lens. Because the macula is temporal to the optic disc, by shining the light 15 to 20 degrees lateral from center, little light will fall directly on the macula, and the patient will not find the light beam uncomfortable.

By moving in toward the patient along the same 15 to 20 degree line, you begin to see the blood vessels of the retina. Move in close to the patient, bringing your hand holding the ophthalmoscope against the patient’s cheek. As contact is made with the patient, the optic disc or vessels are visible. By rotating the diopter wheel with the index finger, you bring these structures into sharp focus. Figure 7-77 shows the correct position of the examiner and patient for viewing the retina; Figure 7-78A shows a normal optic fundus in the right eye and Figure 7-78B in the left eye. Notice that the macula is temporal to the optic disc.

After the right eye is examined, hold the ophthalmoscope in your left hand and use your left eye to examine the patient’s left eye.

Careful assessment of the optic fundus is important for several reasons. The optic fundus is the only area where the blood vessels can be seen in vivo; it can provide an excellent picture of the state of the vasculature of other organs. In addition, the optic fundus is frequently involved with manifestations of systemic disease such as AIDS, infective endocarditis, hypertension, and diabetes; a thorough evaluation of the fundus can provide valuable clues to their diagnosis. Finally, because the eye is an extension of the central nervous system, evaluation of the optic fundus can provide information about many neurologic disorders.

The optic fundus must be assessed methodically, starting at the optic disc, tracing the retinal vessels emerging from it, inspecting the macula, and evaluating the rest of the retina.

Inspect the Optic Disc

The most conspicuous landmark of the retina is the optic disc (Fig. 7-79). The optic disc is the intraocular portion of the optic nerve and is seen with the ophthalmoscope. Its margins, color, and cup-disc ratio should be determined. The disc should be round or slightly oval with the long axis usually vertical and with sharp borders. The nasal border is normally slightly blurred. The disc is pinkish in light-skinned individuals and yellowish-orange in darker-skinned individuals. The relative pallor of the optic disc is caused by the reflection of light from the myelin sheaths of the optic nerve. In the center of the normal optic disc, there is a funnel-shaped depression known as the physiologic cup. The cup is the portion of the disc that is central, lighter in color, and penetrated by the retinal vessels. The normal ratio of the cup diameter to disc diameter varies from 0.1 to 0.5. The examiner should check the cup-disc ratio in both eyes for symmetry. Asymmetry of the physiologic cups is not typical, and the patient should be evaluated for possible early glaucoma.

The benign condition myelinated, or medullated, nerve fibers is seen in 0.3% to 0.6% of all individuals. In this condition, the nerve fiber layer continues to myelinate into the retina. The fibers appear as white patches with feathery borders that radiate from the optic disc and obscure the retinal vessels over which they pass. The condition can be seen soon after birth, does not change, and usually causes no visual impairment. Figure 7-80 shows the retina of a patient with myelinated nerve fibers. Another dramatic example of myelinated nerve fibers at the disc is shown in Figure 7-81. Figure 7-82 shows myelinated nerve fibers in the peripheral retina.

An optic pit is a congenital anomaly of the optic disc. It is a small depression, located temporally in 75% of cases, in the optic nerve and is usually gray or yellow. In 85% of cases, it is unilateral. Figure 7-83A shows an optic pit. Retinal tears and detachment can occur in 50% of patients with an optic pit, as shown in Figure 7-83B; this patient has an optic pit and a retinal tear involving the macula of the left eye.

Inspect the Retinal Vessels

The normal vessel wall is invisible with its thin light reflex. In hypertension, the vessel may have focal or generalized areas of narrowing or spasm, causing the light reflex to be narrowed. With time, the vessel wall becomes thickened and sclerotic, and there is a widening of the light reflex to greater than half of the diameter of the column of blood. The light reflex develops an orange metallic appearance called copper wiring (Figure 7-84A). When such an artery crosses over a vein, there appears to be a discontinuity of the venous column as a result of the widened, but invisible, arterial wall. This is termed arteriovenous nicking (Figures 7-84B and 7-84C). It has been postulated that, because the arteriole and venule share a common sheath, the arteriole’s thicker walls push against those of the venule forcing the venule to collapse. This makes the venule form an hourglass shape (nicking) around the arteriole.

Follow the vessels in all four directions: superior temporal, superior nasal, inferior nasal, and inferior temporal. Remember to move your head and the ophthalmoscope as one unit.

Inspect the Macula

When the ophthalmoscope is kept level with the disc and moved temporally approximately 1.5 to 2 disc diameters, the macula is seen. This appears as an avascular area with a pinpoint reflective center, the fovea. If the examiner has difficulty in seeing the macula, the patient can be instructed to look directly into the light; the fovea is then visible. The red-free filter is also helpful in locating the macula. Figure 7-85 shows a normal macula of the right eye.

Figure 7-86 shows a patient with a macular hole of the left eye; notice the punched-out appearance at the macula. Macular holes can be seen in patients with high myopia.

Describe Any Retinal Lesions

When a lesion is seen, its color and shape are important in determining its cause. Is it red, black, gray, or whitish? Red lesions are usually hemorrhages. They can be located best by using the green (red-free) filter of the ophthalmoscope. Linear, or flame-shaped, hemorrhages occur in the nerve fiber layer of the retina (Fig. 7-87), whereas round hemorrhages are located in deeper intraretinal layers. Are the borders of the lesions sharp or blurred?

A common benign retinal finding is congenital hypertrophy of the RPE. This appears as a round, dramatically dark pigmented lesion, often one to several disc diameters in size. The surface is flat, and the edges are very sharp. Several small, punched-out holes are commonly present within. The retinal vessels appear normal. This is an asymptomatic lesion and is usually unilateral; it may occur in any position in the retina. Its recognition is important and should not be misdiagnosed as a malignant melanoma. Figure 7-88 shows a retina with congenital hypertrophy of the RPE.

Black lesions that are shaped like bone spicules are associated with retinitis pigmentosa (RP). In this condition, melanin tends to unsheathe the retinal vessels (see Fig. 7-148 and a discussion of this condition at the end of this chapter). A doughnut-shaped lesion is often found in chronic inactive toxoplasmosis chorioretinitis (see Figs. 7-131 and 7-132). A pigmented, raised, disc-shaped lesion is suggestive of a melanoma (see Fig. 7-145). Diffuse spotting of the retina is often a degenerative state. Flat, gray lesions are usually benign choroidal nevi (see Fig. 7-144).

White lesions may appear soft, as in cotton-wool spots, or dense, as in drusen. Soft, cotton-wool spots or exudations are caused by retinal nerve fiber layer microinfarcts (see Figs. 7-84A and 7-87). Infarcted retinal ganglion cell axons extrude their axoplasm and form these yellowish-white spots. These spots are commonly arrayed around the optic disc and along the temporal vascular arcades. Cotton-wool spots are frequently associated with hypertension or diabetes. Drusen appear in normal aging, but they may also be found in other pathologic conditions, as is discussed later in this chapter.¹² The differentiation of white lesions of the retina is summarized in Table 7-8 and is discussed later in this chapter under “Clinicopathologic Correlations.”

Difficulties in Using the Ophthalmoscope

Frequently, difficulties arise in the use of the ophthalmoscope. These include the following:

The examiner should use one drop of tropicamide (Mydriacyl) in each eye. Care should be taken to place the drop on the inside of the lower lid by pulling the lower eyelid away from the eye to make a space. The patient should be told that the drop will sting slightly and will result in everything appearing much brighter, especially if it is a sunny day. Often a drop of proparacaine hydrochloride 0.5% is instilled beforehand to cut down on the sting of the tropicamide. The duration of the mydriatic action depends primarily on the patient’s sensitivity to the medication: a more heavily pigmented iris requires more time to achieve mydriasis. The cycloplegic¹³ action lasts for approximately 3 to 4 hours. These drops should not be used in patients wearing contact lenses; patients need to remove the lenses first. Atropine should be avoided because its effect lasts for up to 2 weeks. The large aperture of the ophthalmoscope is used when the pupil is dilated. Record in the chart that the patient’s pupil or pupils were dilated and which medications were used.

The room should be darkened as much as possible for the easiest evaluation of the retina. Another common problem is corneal reflection. Often, light is reflected from the cornea, which makes the examination more difficult. Use of the small aperture or a polarizing filter, which many ophthalmoscopes include, may be helpful.

Patients with myopia provide the most problems for the novice examiner. In myopic eyes, the retinal image is enlarged, making it difficult sometimes to visualize the retina adequately. If the patient is severely myopic, it may be necessary for the patient to wear corrective lenses while being examined.

A mature, or advanced, cataract may not allow adequate visualization of the retina.