Two types of retinal detachments. One group, called rhegmatogenous retinal detachment, can occur in any one and involves the formation of a tear or hole in the retina. The second group, called traction retinal detachments, involves tissue forming on the surface of the retina and “pulling” the retina to form a detachment. This is the case with diabetic related retinal detachments.
Maintain Your Perspective While Reading! Remember fewer than 0.3% of patients with diabetes now (as of 2007) suffer severe vision loss. Retinal detachment in diabetics is the most common way a diabetic can lose significant vision, including blindness.
There are several stages of diabetic retinopathy. The proliferative phase, by definition, involves the formation of neovascularization (new, abnormal blood vessels) on the surface of the retina. As ivy may creep along the forest floor, these abnormal vessels may creep along the surface of the retina.
At some point the neovascular vessels, reaching from “Point A” to “Point B,” begin to contract, pull up on the retina and cause a retinal detachment. The neovascular vessels cause “traction” on the retinal surface thereby pulling the retina apart.
Retinal Detachments Can Blind. Left untreated, the retinal detachment may spread and eventually detach the macula (the functional center of the retina). The prognosis for restoration of vision is poor when a diabetic retinal detachment involves the macula. This is the basic mechanism by which diabetes may lead to blindness.
Vitrectomy surgery is indicated to literally cut away the offending neovascular complex. Intraocular surgery, also known as a vitrectomy, is required to gently separate the abnormal surface tissue from the underlying retina. If successful, the retina may be reattached and the vision, and retina, becomes stable.
Too often, patients are unaware that a retinal detachment has formed. The macula may be still attached and, though misleading, the vision is still quite useful. Many other times, patients may have lost significant vision in one eye and retain good vision in the other. Believe it or not, many patients are unaware of significant vision loss when only one eye is affected.
Recommendations for diabetic eye exams include routine visits to look for disease while the vision is still good. This stuff is usually preventable and avoidable!
Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist