A 55-year-old woman, who had fairly well-controlled type 2 diabetes for 15 years, noticed a slow, progressive decrease in the visual acuity of her right eye during the past 6 to 8 weeks.
Funduscopic examination revealed changes characteristic of nonproliferative diabetic retinopathy, including dot-blot hemorrhages that originate in the middle layers of the retina. Also seen were flame-shaped hemorrhages, which develop from the more superficial precapillary arterioles and follow the course of the retinal nerve fiber layer (A). A fluorescein angiogram revealed macular edema, caused by generalized leakage from dilated capillaries, which impaired this patient's retinal function and resulted in visual loss.
Focal argon laser photocoagulation guided by the fluorescein angiogram was applied to the right eye. This procedure stabilized the patient's condition and improved her vision.
Nearly 17 months later, the patient again complained of blurred vision. More advanced nonproliferative diabetic retinopathy changes were found; fluorescein angiography confirmed the recurrence of macular edema. Funduscopic examination showed dot-blot and flame-shaped hemorrhages. Hard exudates composed of lipid and protein deposits were seen along the supratemporal arcade; a single soft exudate, or cotton-wool spot (nerve fiber layer infarct), was noted along the infratemporal arcade. Hypopigmented and hyperpigmented areas in the macula were residual changes from the earlier laser application (B). The patient was again treated with focal laser photocoagulation.
About 3 years later, the patient reported difficulty with her near vision when reading. Moderate nonproliferative retinopathy changes were found, but there was no macular swelling (C). The patient's new visual problems were attributed to ischemic changes and the expansion of laser scars. No laser or other treatment (except tight blood glucose control) is indicated for ischemic maculopathic changes.
The patient's vision has stabilized, but the potential for further deterioration exists. Her ocular history is typical of the often relentless and progressive course of diabetic retinopathy in which maculopathy is the most common cause of visual impairment.