Fundus manifestations simulating Coats disease in a case of retinitis pigmentosa

Purpose: To report a case of retinitis pigmentosa who showed fundus changes simulating Coats disease with vitreous hemorrhage. Case: A 61-yaer-old male presented with impaired visual acuity in his left eye. He had had night blindness at the age of 13 and been diagnosed with retinitis pigmentosa at the age of 17 years. Retinitis pigmentosa was present in his two brothers and one cousin. He had received cataract surgery in both eyes 4 years before and had visual acuity of 0.04 in either eye. Findings: His corrected visual acuity was 0.03 right and counting fingers left. The right eye showed findings compatible with retinitis pigmentosa. The left eye showed vitreous hemorrhage and proliferative membrane in the superior hemisphere. During vitrectomy, the left eye showed organized proliferative membrane, newly formed vessels, and tortuous retinal vessels. Visual acuity improved to 0.03 in either eye one year after surgery. Conclusion: This case illustrates that retinitis pigmentosa may manifest neovascularization, vasodilatation and proliferative membrane in the retina simulating Coats disease. Vitreous surgery was effective for the fundus lesions.