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A 25-year-old man complains of moderate discomfort, burning, redness, serousdischarge, and slightly impaired vision in his right eye; he also has mild photophobia.His symptoms began suddenly about 36 hours earlier, and the discomforthas increased steadily since that time. The left eye is unaffected.
A 25-year-old man complains of moderate discomfort, burning, redness, serousdischarge, and slightly impaired vision in his right eye; he also has mild photophobia.His symptoms began suddenly about 36 hours earlier, and the discomforthas increased steadily since that time. The left eye is unaffected.HISTORY
The patient is in good health and takes no medications. He has had norecent illnesses or injuries.EXAMINATION
Visual acuity is 20/25 in the right eye and 20/20 in the left. Extraocularmovements are intact. There is 2+ injection of both the bulbar and palpebralconjunctivae in the right eye. Results of a funduscopic examination are normal.Fluorescein staining reveals a linear stain in the inferior cornea consistentwith a dendrite pattern. The corneal stain appears to be superficial; it demonstratesend bulbs throughout. The left eye is normal.Which of the following is the most likely cause of this patient'ssymptoms? A. Herpes simplex keratitis. B. Intracerebral (berry) aneurysm.C. Amaurosis fugax.D. Bacterial conjunctivitis.CORRECT ANSWER: A
This patient has herpes simplex keratitis (choice A). Inthe United States, herpes simplex is responsible for morethan 1.5 million cases of blindness each year and is one ofthe leading infectious causes of blindness.A herpes simplex viral infection may be a primary infection(transmitted by a symptomatic or an asymptomaticcarrier) or a recurrence (incited by trauma, fever, corticosteroiduse, exposure to sunlight, extreme hot or coldtemperatures, or a systemic infectious disease). The infectionrecurs in 28% of affected eyes.1 These recurrencescan cause significant tissue destruction and inflammatoryeffects in the stroma and deeper levels of the cornea as aresult of the immune response.The dendritic corneal epithelial lesion seen in this patientis a classic finding in recurrences of corneal herpessimplex. The acute onset, unilateral nature of the symptoms,and painful loss of vision are also very typical of keratitisin general-and even more common in herpes simplexkeratitis.Initial treatment of herpes simplex keratitis consistsof 1 drop of 1% trifluridine ophthalmic solution instilledinto the conjunctival cul-de-sac of the affected eye every 2hours while the patient is awake (to a maximum dailydose of 9 drops), until the corneal ulcer has completely reepithelialized.Following re-epithelialization, treatment iscontinued for an additional 7 days, at a dosage of 1 dropevery 4 hours while the patient is awake (with a minimumdaily dose of 5 drops). Warn patients of the dangers associatedwith recurrence, and instruct them to seek medicalattention immediately if symptoms reappear.This patient's history and ocular findings are not consistentwith bacterial conjunctivitis (choice D), which iscaused by a wide range of organisms (mainly gram-positive).Although bacterial conjunctivitis has a sudden, initiallyuniocular onset-as seen here-vision changes ordisturbances, significant ocular pain, and corneal abnormalitiesare not typical of this entity.Intracerebral (berry) aneurysm (choice B) can causechanges in the eye. Pressure on the cranial nerves thattraverse the cavernous sinus can produce a variety of ocularpalsies. The history typically includes diplopia (whichpatients may misinterpret as blurred vision) or visionchange, and examination reveals extraocular movements.When subarachnoid hemorrhage occurs, blood can beseen behind the retina (subhyaloid hemorrhage). None ofthese findings are present here.Amaurosis fugax (choice C) is another cause of suddenvision change or loss (again, sometimes misinterpretedby patients as blurred vision). Typically, this is a complicationof atherosclerosis obliterans that involves an extracranialor intracranial carotid artery. In amaurosisfugax, the ocular examination does not reveal inflammatorychanges; however, afferent papillary defects and vascularfindings (eg, cherry red spots, refractile [Hollenhorst]plaques) are typically seen in the retina. This patient is 25years old, which is far younger than the typical age foratherosclerosis. Moreover, he has none of the ophthalmicfindings of occlusive disease.Outcome of this case. The patient responded well totherapy and has been asymptomatic for 1 year. He waswarned about the danger of recurrence and was instructedto seek medical attention immediately if the symptomsreappeared.
Wilhelmus KR, Beck R, Moke PS, et al. Acyclovir for the prevention of recurrentherpes simplex virus eye disease.
N Engl J Med.
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