Diabetic Retinopathy is the leading cause of acquired blindness among the people under the age of 65. The great majority of this blindness can be prevented with proper examination and treatment by ophthalmologists. Ther are 4 imp. Studies guiding the treatment, the Diabetes Control and Complications Trial (DCCT), the Diabetic Retinopathy Study (DRS), the Early Treatment Diabetic Retinopathy Study (ETDRS), and the Diabetic Retinopathy Vitrectomy Study (DRVS).

Background Diabetic Retinopathy

Background diabetic retinopathy (BDR) may occur at any point in time after the onset of diabetes. In general, this is the first "stage" of diabetic retinopathy and, therefore, the least concerning.

In general, patients are not typically treated with laser photocoagulation of the retina for background retinopathy..

Clinically Significant Macular Edema

Clinically significant macular edema (CSME) is a condition of swelling of the macula related to the development of leaky capillaries and microaneurysms. Ophthalmologists use rather strict criteria to determine whether a patient should be treated with focal laser photocoagulation for this condition. These criteria were set forth by the studies mentioned above.

Patients with CSME are generally recommended to undergo focal laser photocoagulation. This entails a fluorescein angiogram to guide treatment and utilization of a laser to help "dry up" the localized swelling (macular edema). Ophthalmologists apply laser treatment to the macula of the eye, avoiding the fovea where central acuity resides, in a grid-pattern or directly to leaking microaneurysms. It is important to realize that laser treatment does not usually improve vision, but is aimed at prevention of further visual loss.
Most patients with CSME require 3 to 4 different focal laser sessions, two to four months apart, to resolve the swelling.

Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) carries the greatest risk of visual loss of the conditions discussed thus far. The condition is characterized by the development of neovascularization (new, abnormal vessel growth) on or adjacent to the optic nerve and vitreous or pre-retinal hemorrhage (hemorrhage in the vitreous humor or in front of the retina).

Patients with PDR should receive scatter laser photocoagulation (laser treatment of the ischemic peripheral retina) as soon as possible following diagnosis of the condition. This treatment is also known as pan-retinal laser photocoagulation. By causing regression of the neovascular tissues, the risk of severe vision loss is substantially reduced. Scatter laser photocoagulation (also known as PRP, or pan-retinal photocoagulation) is an in-office or out-patient procedure done with or without an anesthetic injection adjacent to the eye. Many patients will experience mild discomfort with the laser treatment, although this can be resolved with an anesthetic block. The laser treatment usually takes less than 30 to 45 minutes per session. A complete laser treatment, however, may require up to 3 or 4 different sessions, with a total of one to two thousand laser applications ("spots").

In some patients with PDR, the vitreous hemorrhage prevents the ophthalmologist from performing the laser treatment. Simply put, the blood is in the way of the laser beam. If the vitreous hemorrhage fails to clear within a few weeks or months, a vitrectomy surgery may be performed to mechanically clear the hemorrhage and laser photocoagulation is then applied, either at the time of the vitrectomy or shortly thereafter. Patients who have tractional retinal detachment are usually scheduled for vitrectomy surgery promptly.