Anterior segment ischemia: a complication of retinal detachment repair in a patient with sickle cell trait. Anterior segment ischemia (ASI) is a dreaded complication of retinal detachment surgery particularly in patients with predisposing factors such as sickle cell disease. We report a case of ASI after scleral buckling in an otherwise healthy black patient with sickle cell trait. Conditions of relative hypoxia intraoperatively from either anesthesia or surgical manipulation may precipitate vasoocclusive phenomena in these normally asymptomatic patients. Since the incidence of sickle cell trait in the black population in the United States is 8.5%, we recommend these patients have a preoperative sickle test followed by hemoglobin electrophoresis with quantification if positive. The presence of sickle cell trait should alert the surgeon to the risk of ASI, and factors predisposing to hypoxia should be minimized when possible. 