A 67-year-old smoker comes to the office with a 2-week history of decreased vision in his right eye that he describes as "blurry" and "distorted." The patient has been having vision problems over the past year, and these have made it more difficult to drive and require that he use a bright light to read the newspaper. He has no history of diabetes mellitus or hypertension. The patient uses an albuterol inhaler for occasional wheezing and shortness of breath. Ophthalmologic examination of the right eye shows a grayish discoloration of the macula with areas of adjacent hemorrhage. Which of the following should be specifically targeted in treatment of this patient's condition?
This patient likely has age-related macular degeneration (AMD), the leading cause of blindness in industrialized countries. AMD occurs in genetically predisposed individuals as a result of advancing age and environmental factors (eg, smoking) and is classified into dry and wet subtypes. Dry AMD is characterized by gradual vision loss in one or both eyes and can cause difficulty with driving/reading. The condition likely results from chronic oxidative damage to the retinal pigment epithelium and choriocapillaris, leading to subretinal inflammation with abnormal extracellular matrix formation (eg, confluent drusen, basement membrane thickening). These changes appear on funduscopy as subretinal drusen deposits with pigment abnormalities.
Progressive extracellular matrix accumulation can eventually result in retinal hypoxia, which stimulates local vascular endothelial growth factor (VEGF) production and causes subretinal neovascularization with formation of leaky vessels. This condition is termed wet AMD and presents with acute vision loss (days to weeks) with metamorphopsia (distortion of straight lines). Funduscopy shows a grayish-green subretinal discoloration with adjacent fluid/hemorrhage.
Patients with dry or wet AMD may benefit from antioxidant vitamins and zinc, and smokers should receive smoking cessation counseling to prevent disease progression. Wet AMD usually requires specific treatment with VEGF inhibitors (eg, ranibizumab, bevacizumab).
(Choice A) Therapy against the CD20 glycoprotein on B cells (eg, the monoclonal antibody rituximab) is used to treat various lymphomas and active rheumatoid arthritis.
(Choice B) Epidermal growth factor receptor inhibitors (eg, erlotinib, gefitinib) are used to treat advanced non-small cell lung cancer.
(Choice C) Anti-interleukin-2 therapy is primarily used for immunosuppression in organ transplant patients and in conditions such as graft versus host disease.
(Choice D) Inhibitors of tumor necrosis factor-alpha are used in many inflammatory autoimmune conditions, such as rheumatoid arthritis, inflammatory bowel disease, and seronegative spondyloarthropathies.
Educational objective:
Wet age-related macular degeneration is characterized by retinal neovascularization due to increased vascular endothelial growth factor (VEGF) levels. Patients typically have acute vision loss and metamorphopsia with funduscopy showing a grayish-green subretinal membrane and/or subretinal hemorrhage. Treatment includes smoking cessation and VEGF inhibitor therapy (eg, ranibizumab, bevacizumab).