Courtesy Dr. Tim Cleland
and Dr. Lina Marouf
These retinal photographs are a quick reminder of the ocular pathology caused by diabetes.
1. Normal Macula.
2. Exudate and small dot hemorrhages.
The exudate results from lipid molecules leaking out of damaged blood vessels and not being resorbed. If exudate accumulates in the center of the macula, vision can be permanently lost.
3. Exudate with scarring of macula.
The gray spots are from laser treatment given to reduce the exudate.
4. Neovascularization of the disc. Responding to the VEGF
stimulus caused by hypoxia, new vessels are growing from the disc.
There is exudate in the macula, and there is bleeding from retinal vessels as evidenced by the line of hemorrhage at the bottom of the image. The light spots at the lower left are from
laser treatment.
5. Post laser treatment.
The light spots around the edge of the macula are from laser treatment. The principal for such extensive treatment is that once the retinal tissue is destroyed it no longer produces VEGF and thus the stimulus for progressive retinopathy is removed. Surprisingly, a person can see rather well even after so much of the retina has been ablated.
New treatment for diabetic retinopathy includes intraocular injection of steroid and anti-VEGF drugs such as Avastin and Lucentis.
When to refer your diabetic patients to an ophthalmologist?
A diabetic who is not using insulin and who has no retinopathy can be seen by the ophthalmologist every two years. Once a patient goes on insulin or develops any retinopathy, then he should be seen every year. (The guidelines for referral vary slightly depending on their source).
Refer to a retina specialist?
It is appropriate for the general ophthalmologist to manage diabetic patients. He or she can accurately diagnose retinopathy and treat many patients with laser. The general ophthalmologist will refer the patient to the retina specialist if there is poor response to treatment or if there is major hemorrhage. As a rule, it is not necessary for the patient’s primary care doctor to refer directly to the retina specialist.
