Case 4: Ischemic Branch Retinal Vein Occlusion
An 81-year-old man noticed a sudden painless loss of vision in his right eye. His vision had been relatively good up to this point, ever since he had his cataracts removed 5 years earlier.
He had mild hypertension for which he was taking hydrochlorothiazide(Drug information on hydrochlorothiazide). His other medications were aspirin(Drug information on aspirin), 81 mg/d, and a daily multivitamin supplement. His previous eye examination 1 year earlier was unremarkable except for bilateral pseudophakia.
Visual acuity was 20/100 in the right eye and 20/25 in the left eye. There was no afferent pupillary defect. The rest of his ocular examination was unremarkable except for the dilated funduscopic evaluation of the right eye. This showed a wedge-shaped area of intraretinal hemorrhages extending peripherally from a junction of a branch retinal artery that crossed over a corresponding branch retinal vein. The hemorrhages involved the macula. Numerous yellow-white lesions (cotton-wool spots) were present in the superficial retina.
This patient had a branch retinal vein occlusion. Because the macula was involved, his vision was significantly decreased. The cotton-wool spots are coagulated exudates of plasma and fibrin; they represent focal areas of hypoxia and are signs of retinal ischemia. Patients with cotton-wool spots need to be monitored closely (every month until the lesions resolve) because they are at increased risk for retinal neovascularization.
Patients with macular involvement are usually observed for 3 months to see whether the macular hemorrhages and edema resolve on their own. If macular edema persists after this period, focal laser treatment may be indicated.
This patient’s blood pressure was elevated (142/92 mm Hg). He was referred back to his family physician for reevaluation of his antihypertensive therapy. He is being monitored monthly with ophthalmological examinations.