The retina is the delicate membrane that coats the eye where the optic nerve enters, receiving the light that begins the process of vision. The retina sends nerve impulses to the brain to be interpreted into the images we see. Untreated retinal detachment can cause blindness. However, early symptoms can help patients seek out sight-saving surgical repair. Complications vary depending on the cause of detachment, which may include an injury, a disease or scarred tissue from a previous treatment.
Posterior Vitreous Detachment
The interior of the eye is filled with a gel called “vitreous." According to Drs. Gary H. Cassel, Michael D. Billig and Harry G. Randall, authors of “The Eye Book," the vitreous changes with normal aging as the gel slowly liquefies and the supportive fibers collapse and clump. The posterior vitreous membrane is the thicker part of the the supportive meshwork that holds the vitreous in place. This membrane can slide or pull away from the retina, causing a condition called posterior vitreous detachment, or PVD. Visual floaters or flashes are early indicators that this may be happening. The MayoClinic.com reports that as the retina tears, the vitreous liquid accumulates underneath it or leakage can occur through tiny holes where the retina has thinned. The collected liquid continues to cause the retina to peel away, losing blood supply and vision in those areas. Left untreated, PVD can cause complete loss of vision.
Tractional Retinal Detachment
Diabetics may develop many new fragile blood vessels on the surface of the retina. Drs. Donald S. Fong and Robin Demi Ross, authors of “The Diabetes Eye Care Sourcebook,” report that these new vessels can bleed, causing a “vitreous hemorrhage.” Over time the blood vessels contract and scar tissue develops, causing the retina to be lifted from its normal position and detached. At first vision may be distorted and then progressively deteriorate, causing blindness. Surgery is performed to release the retina from the scar tissue, resulting in improved vision.
Retinal Scarring
Retinal scarring may occur in people who have diabetic retinopathy or surgery to reattach the retina. Scarring also results from eye trauma, including trauma from cataract or LASIK surgery. According to Virginia E. Bishop, contributing author to “Foundations of Low Vision," whenever surgery is performed to reattach a retina, scar tissue is induced and there will be a scotoma, or blind spot. Although scarring results, the All About Vision website reports that sometimes vision lost from a detached retina will return after surgery and the sooner it is reattached the better the prognosis. Vision may be blurred during the weeks following surgery and take months to improve after a complicated repair. In addition, some patients do not recover any vision.
References
- “The Eye Book”; Gary H. Cassel, M.D., Michael D. Billig, O.D. and Harry G. Randall, M.D.; 1998
- MayoClinic.com: Retinal Detachment Causes
- “The Eye Book”; Gary H. Cassel, M.D., Michael D. Billig, O.D. and Harry G. Randall, M.D.; 1998
- “Foundations of Low Vision”; Anne L. Corn and Alan L. Koenig; 2004
- All About Vision: Detached Retina
