The examination takes a few minutes. If the blood vessel growth is normal, Dr. Coats checks again every week or so until the retina matures and the child is no longer at risk. In the past, ophthalmologists relied on written notes and their memories in following the progress of development. Now Dr. Coats sets a special camera made by the Massie Research Company in Dublin, Calif., on top of the baby's eye and obtains photographs that are about the same quality as what he sees through an ophthalmoscope. Treatment is recommended when the ophthalmologist sees abnormal growth of blood vessels in at least five contiguous, or eight non-contiguous, hour zones.
Doctors can choose between two therapies, either a laser or freezing technique.
Neither treatment is aimed at the abnormal blood vessels, but at the retina that has not yet developed a blood supply. Each procedure takes from 45 to 00 minutes. It can be done by the bedside or in the operating room under general anesthesia. Using a laser, Dr. Coats flashes the retina from 500 to 2,000 times in each eye, depending on the severity of the condition. The laser beam is directed in a full circle at the peripheral retina with the hope of stopping production of the chemical growth factor.