September 27, 2008
Question from Wytheville, Virginia, USA:
Just today, my 20-year-old nephew found out he is blind in one eye. He had laser surgery on the other today due to bleeding behind his eyes. His vision is even more blurry now after the surgery in his good eye. The doctor told him he needs to wait three weeks before having surgery on his blind eye to wait and see if the bleeding will stop. This surgery will not be laser, but another kind, maybe a vitrectomy from reading on the web. Should he wait three weeks? Will the bleeding stop or only get worse? This does not make any sense to me. Will the surgery help or will he be blind forever?
It sounds as if your nephew had developed proliferative diabetic retinopathy (PDR), a condition wherein abnormally fragile blood vessels grow (proliferate) on the surface of the eye’s light sensitive retina and easily bleed into the normally clear gelatin (called the vitreous) filling the majority of the internal eye (vitreous hemorrhage), resulting in severe vision loss. Laser treatment itself often causes the abnormal blood vessels to bleed more for a short time, which can decrease vision (what I suspect has happened in the “good” eye). Laser therapy reduces the risk of permanent, severe vision loss by 50 to 75%. The blood in the vitreous may clear on its own, but sometimes needs to be removed surgically with the rest of the gelatin (vitrectomy surgery). The new vessels also cause development of fibrous tissue that can pull on the retina, leading to what is called “tractional retinal detachment” and vision loss.
If the cause of vision loss were purely vitreous hemorrhage, the vision would improve either with time or with a vitrectomy. If there were a retinal detachment, the prognosis would be much poorer. The difficulty for the doctor is seeing the retina because blood in the vitreous blocks the doctor’s view. Sometimes, an ultrasound is done to get a sense of whether or not the retina has become detached. Sometimes, waiting a few weeks for the blood to clear on its own helps both the doctor and patient to make better treatment decisions. Laser treatment to the “bad” eye may be applied at the time of vitrectomy (what is called “endolaser”). Another possibility, one worth asking about, is the injection of a drug called Avastin, which has been shown to stop the growth of new blood vessels due to PDR. There are even a few reports that Avastin dramatically improves vitreous hemorrhage in young patients with type 1 diabetes.
To learn more about diabetic retinopathy, I would recommend that you check out the columns I have written for the DLife web site.