The macula is the area of the retina responsible for central vision tasks, such as reading or watching television. The wet form of age related macular degeneration is caused by the rapid growth of abnormal new blood vessels under the macula. These small blood vessels leak fluid and blood, which can cause a rapid loss of central vision. This condition can occasionally be treated with a photodynamic therapy that calls for the injection of a medication, called Visudyne, into a vein in the arm. Once the medication reaches the retina, it is activated by laser light to close the abnormal vessels.

Diabetes leads to the formation of abnormal blood vessels on the retina. These vessels rupture easily, giving rise to haemorrhages that result in reduced vision. Complications caused by diabetic retinopathy can be treated using laser photocoagulation to close the abnormal vessels.

This test consists of injecting a fluorescent dye through a vein in the arm. The dye quickly travels to the blood vessels in the eye. A special camera is used to take pictures of the blood vessels in order to help identify any abnormalities and treat them with laser.