This test allows your retina specialist to assess the blood flow of the retina. Often this test is required for accurate diagnosis and treatment of a wide range of retinal diseases. The test requires the patient’s eyes to be dilated. Your doctor will then inject a small amount of a water-based dye into an arm vein, similar to having blood drawn. Photographs are then taken by a photographer using a special retinal camera. The results of the photographs are then reviewed with the patient by a retina specialist.