Board Review Questions in Ophthalmology

Tommy S. Korn, MD, FACS, Assistant Clinical Professor of Ophthalmology, Sharp Rees-Stealy Surgical Eye Consultants, University of California-San Diego, San Diego, Ca

1. An 84-year-old man with recent onset of headache and fatigue presents to the emergency department with sudden vision loss. Examination reveals a visual acuity of "light perception only" in the right eye and 20/20 in the left eye. An afferent pupillary defect (Marcus Gunn pupil) is seen in the right eye. Examination by direct ophthalmoscope reveals a diffusely appearing pale retina except for a bright red spot in the fovea (Figure 1). What is the most likely diagnosis?

1. amaurosis fugax
2. central retinal artery occlusion
3. optic neuritis
4. subarachnoid hemorrhage from a ruptured intracranial aneurysm

2. Which of the following tests should be ordered immediately for the patient in question 1, even before the ophthalmologist's arrival?

1. brain magnetic resonance imaging (MRI) with gadolinium enhancement
2. head computed tomography (CT) scan
3. erythrocyte sedimentation rate (ESR)
4. carotid Doppler ultrasound

3. A 31-year-old woman presents to the urgent care clinic with 12 hours of significant purulent discharge in her left eye. She does not wear contact lenses and has not suffered any ocular trauma. The right eye appears normal, but the left eye reveals copious yellow, purulent discharge and severely injected conjunctiva with chemosis. The left eyelid is mildly swollen. The cornea appears normal in both eyes. The left preauricular lymph node is very tender and enlarged. What would a Gram stain and a Giemsa smear of the discharge reveal?

1. gram-positive cocci
2. cytoplasmic inclusion bodies
3. intracellular gram-negative diplococci
4. gram-negative rods

4. A 72-year-old man presents to the emergency department with a 3-day history of discharge, pain, and redness in his left eye. He states that his ophthalmologist surgically placed a "filter" in this eye 5 years ago to control his glaucoma. Visual acuity is 20/200 in this eye. Inspection reveals a very injected and swollen eye. You also note a very milky layer of fluid accumulating in the anterior chamber (Figure 2). What is the most likely diagnosis?

1. bacterial keratitis (corneal ulcer)
2. anterior uveitis
3. hyperacute bacterial conjunctivitis caused by Neisseria gonorrhea
4. bacterial endophthalmitis

5. A 39-year-old woman with diabetes presents with an acute onset of severe headache; a droopy right eyelid; and an inability to elevate, adduct, and depress the right eye. The right pupil appears dilated compared with the left pupil. The left eye shows no motility deficits. What is the most likely diagnosis?

1. acute third-nerve palsy secondary to intracranial aneurysm
2. acute third-nerve palsy secondary to diabetic microvascular infarct
3. ophthalmic migraine
4. cavernous sinus thrombosis

6. A 46-year-old man presents with a 3-week history of redness, light sensitivity, and episodic pain in the right eye. The patient has been using topical gentamicin (eg, Garamycin, Genoptic, Gentacidin) eye drops for 7 days, which has not relieved any of his symptoms. His past medical history is significant for sarcoidosis. What is the most likely diagnosis?

1. acute angle-closure glaucoma
2. anterior uveitis
3. episcleritis
4. toxic conjunctivitis secondary to gentamicin use

7. A 19-year-old college student presents to the urgent care clinic complaining of pain and redness in the right eye on awakening. He has no history of any sexually transmitted diseases. The patient admits to regularly wearing his soft contact lens while sleeping. Slit lamp examination reveals significant conjunctival injection and discharge. Fluorescein staining shows a large oval defect in the central cornea with an underlying white haze (Figure 3). What is the most likely diagnosis?

1. herpes simplex keratitis
2. corneal abrasion
3. bacterial keratitis (corneal ulcer)
4. giant pupillary conjunctivitis

8. A 65-year-old Asian woman awakens in the middle of the night with severe left eye pain associated with nausea and vomiting. On presentation to the emergency department, visual acuity is noted to be "counting fingers at 1 foot" in the left eye and 20/40 in the right eye. The left eye is very injected and the cornea appears hazy. The left pupil shows minimal reaction to light and appears slightly dilated. The right eye is completely normal. What is the most likely diagnosis?

1. acute angle-closure glaucoma
2. acute uveitis
3. corneal abrasion secondary to recurrent corneal erosion
4. orbital cellulitis

9. A 33-year-old woman presents with a 3-day history of seeing "spots" floating around in her right eye. Today, she notes streaks of light in the same eye accompanied by a "shadow" in her peripheral vision that moves when looking up and down. Her medical history is significant for migraine headaches; however, she has never had such visual symptoms with her headaches. What is the most likely diagnosis?

1. ophthalmic migraine
2. malingering
3. retinal detachment
4. amaurosis fugax

10. What is the most common cause of legal blindness in the United States in patients over the age of 65?

1. senile cataracts
2. primary open-angle glaucoma
3. age-related macular degeneration
4. diabetic retinopathy

ANSWERS

1?B. This is a classic presentation of central retinal artery occlusion. In an elderly patient, temporal (giant cell) arteritis may be associated with central retinal artery occlusion. The diagnosis of temporal arteritis is considered an ophthalmic emergency because severe, irreversible vision loss can rapidly occur in the other eye.¹ (See also answer to question 2.)

Reference

J Clin Neuroophthalmol.

1. Mohan K, Gupta A, Jain IS, et al. Bilateral central retinal artery occlusion in occult temporal arteritis. 1989;4:270-272.

2?C. With a diagnosis of temporal arteritis (see answer to question 1), an ESR measurement should be ordered immediately. If the ESR is normal but the patient has constitutional symptoms highly suggestive of temporal arteritis (ie, fever, weight loss, jaw pain, myalgias), C-reactive protein concentration should be measured.¹ The diagnosis is confirmed by temporal artery biopsy. Systemic corticosteroid treatment should be started immediately and not delayed pending the biopsy because of the high risk of visual loss in the other eye. Biopsy should be performed within 1 week of starting corticosteroid treatment to decrease the possibility of a false-negative result.²

References

Ann Rheum Dis

1. Kyle V, Cawston TE, Hazleman BL. Erythrocyte sedimentation rate and C reactive protein in the assessment of polymyalgia rheumatica/giant cell arteritis on presentation and during follow up.. 1989;48:667-671.

Arch Ophthalmol

2. Hedges TR III, Gieger GL, Albert DM. The clinical value of negative temporal artery biopsy specimens. . 1983;101:1251-1254.

Neisseria gonorrhea

3?C. The presentation of hyperacute purulent conjunctivitis is another ophthalmic emergency. The history is typical of gonococcal conjunctivitis. can rapidly penetrate an intact cornea and infect the eye.¹ If left untreated, the risk of corneal perforation is high. Gram stain of the discharge would reveal gram-negative intracellular diplococci. Treatment is different from that for routine bacterial conjunctivitis; systemic antibiotics are required in addition to topical antibiotics. The patient should also receive systemic treatment for chlamydial conjunctivitis because of the high rate of coinfection with gonorrhea exposure.

Reference

Surv Ophthalmol.

1. Ullman S, Roussel TJ, Forster RK. Gonococcal keratoconjunctivitis. 1987;32:199-208.

4?D. When any patient who has undergone an intraocular surgical procedure such as cataract or glaucoma surgery presents with a red and painful eye, infection should be ruled out. Any microbial infection within the eye is called endophthalmitis. The appearance of a "milky" white layer in the anterior chamber is called a hypopyon, which consists of many packed inflammatory white blood cells. This severe intraocular inflammation is suggestive of endophthalmitis. Postoperative endophthalmitis can occur days, weeks, months, or even years after eye surgery. Surgical glaucoma procedures carry an increased risk for intraocular infection.^1,2 The diagnosis of endophthalmitis constitutes an ophthalmic emergency. Treatment consists of broad-spectrum topical and intraocular antibiotics and, possibly, surgical vitrectomy.³

References

Ophthalmology

1. Lamping K, Bellows AR, Hutchinson BT, et al. Long-term evaluation of initial filtration surgery. . 1986;93:91-101.

Ophthalmology

2. Ciulla TA, Beck AD, Topping TM, et al. Blebitis, early endophthalmitis, and late endophthalmitis after glaucoma-filtering surgery. . 1997;104:986-995.

Arch Ophthalmology

3. Brown RH, Yang LH, Walker SD, et al. Treatment of bleb infection after glaucoma. . 1994;112:57-61.

5?A. This is the classic presentation of an acute third-nerve palsy secondary to an intracranial aneurysm, which constitutes a medical emergency. A neurosurgery consultation and arteriogram are urgently required. The pupil is dilated because the parasympathetic fibers that cause pupil constriction travel on the outside sheath of the third cranial nerve and are highly susceptible to compression by an adjacent aneurysm. A microvascular infarct (eg, in a patient with diabetes or hypertension) affects the inner fibers of the third cranial nerve and does not result in pupil dilation. Nevertheless, there have been reported cases of a progressing intracranial aneurysm in patients with a third nerve palsy but no pupil dilation.^1-3 Such patients should be monitored closely for the possibility of underlying intracranial aneurysm if an imaging procedure is not performed.

References

Surg Neurol

1. Arle JE, Abrahams JM, Zager EL, et al. Pupil-sparing third nerve palsy with preoperative improvement from a posterior communicating artery aneurysm. . 2002;57(6):423-426.

Neurology

2. Ikeda K, Tamura M, Iwasaki Y, et al. Relative pupil-sparing third nerve palsy: etiology and clinical variables predictive of a mass.. 2001;57(9):1741-1742.

Clin Neurol Neurosurg

3. Ranganadham P, Dinakar I, Mohandas S, et al. A rare presentation of posterior communicating artery aneurysm. . 1992;94(3):225-227.

6?B. Anterior uveitis should be suspected in any patient with persistent red eye with photophobia, pain, and no response to topical antibiotics. Uveitis refers to inflammation of the iris, ciliary body, and uveal tissue. Typically, the inflammation is characterized by the presence of inflammatory cells circulating in the anterior chamber. The conjunctiva is always injected and the eye is sensitive to light because constriction and dilation of the pupil cause pain in the iris and ciliary body. From 20% to 50% of patients with systemic sarcoidosis develop anterior uveitis.^1-2 Treatment requires topical corticosteroids to control the intraocular inflammation. Topical cycloplegic agents also help dilate the pupil and prevent further iris and ciliary body spasm. A systemic workup for uveitis is indicated in recurrent and atypical bilateral cases.

References

Am J Ophthalmology

1. Obenauf CD, Shaw HE, Sydnor CF, et al. Sarcoidosis and its ophthalmic manifestations. . 1978;86:648- 655.

Vasc Diffuse Lung Dis

2. Usui Y, Kaiser ED, See RF, et al. Update of ocular manifestations in sarcoidosis. Sarcoidosis . 2002;19(3): 167-75.

7?C. Any corneal epithelial defect with an underlying white "opacity" is considered a corneal ulcer. This is another ophthalmic emergency. There is a high incidence of gramnegative corneal ulcers in patients who sleep while wearing their contact lenses.¹ Treatment includes discontinuing use of the contact lens and beginning hourly application of topical fortified broad-spectrum antibiotics. If not properly diagnosed and treated, the risk of developing visually debilitating corneal scars or a corneal perforation is high because the microbial enzymes can rapidly melt the cornea.^2-3 Topical corticosteroids are contraindicated in the presence of infectious corneal ulcers as they may accelerate further melting of the cornea.

References

N Engl J Med

1. Schein OD, Glynn RJ, Poggio EC, et al, for the Microbial Keratitis Study Group. The relative risk of ulcerative keratitis among users of daily-wear and extended-wear soft contact lenses. A case-control study. . 1989;321:773-778.

Invest Ophthalmol

2. Brown SI, Bloomfield SE, Tam W. The cornea-destroying enzyme of Pseudomonas aeruginosa. . 1974;13:174-180.

Ophthalmol Clin North Am

3. Ma JJ, Dohlman CH. Mechanisms of corneal ulceration. . 2002;15:27-33.

8?A. The history is typical of acute angle-closure glaucoma. The raised intraocular pressure stimulates nausea and vomiting. This condition is an ophthalmic emergency because the optic nerve is at risk for damage from the prolonged, elevated eye pressure. Initial treatment consists of topical and/or systemic glaucoma medications to lower the pressure. Once the pressure is medically controlled, a laser iridotomy is required to relieve the "block" at the iris?lens pupil boundary. The laser creates a new passageway through the iris for the aqueous humor to drain into the trabecular meshwork angle. Alaskan natives and Asians are at high risk for an acute attack of angle- closure glaucoma because their smaller eyes have narrow anterior chambers, resulting in anatomical "crowding" of the iris and lens.¹

Reference

Surv Ophthalmol

1. Congdon N, Wang F, Tielsch JM. Issues in the epidemiology and population-based screening of primary angle-closure glaucoma. . 1992;36:411-23.

9?C. The history suggests retinal detachment. As people age, the vitreous begins to detach from the retina and can cause the perception of "floaters," which represent vitreous condensation. In certain eyes, the normal process of the vitreous detaching from the retina may cause a peripheral "horseshoe" tear in susceptible areas of the retina. The tear allows fluid within the vitreous to accumulate under the retina and cause a detachment. When the retina is partially detached and the eye moves, the patient may notice a "shadow" that corresponds to the torn retina. A retinal detachment is considered an ophthalmic emergency because the detachment can progress to the fovea and threaten central vision. When any patient complains of the new appearance of flashes of light or floaters, a dilated retinal examination should be performed by an ophthalmologist to rule out retinal tear or detachment.¹

Reference

Am J Ophthalmol

1. Hikichi T, Trempe CL. Relationship between floaters, light flashes, or both, and complications of posterior vitreous detachment. . 1994;117:593-598.

10?C. By far, age-related macular degeneration is the leading cause of blindness in developed Western countries.¹ The disease is characterized by age-dependent structural deterioration of the central retina known as the macula or fovea (Figure 4).

Reference

Surv Ophthalmol.

1. Leibowitz HM, Krueger DE, Maunder LR, et al. The Framingham Eye Study monograph: an ophthalmological and epidemiological study of cataract, glaucoma, diabetic retinopathy, macular degeneration, and visual acuity in a general population of 2631 adults, 1973-1975. 1980;24(suppl):335-610.