I have a patient, BG, with diabetes mellitus. BG has had diabetes for over 45 years. She is 60 years old. I saw her yesterday and will not see her for another 6 months. She has had a long course with proliferative diabetic retinopathy. Her vision is 20/25 in both eyes. BG has had multiple laser treatments and vitrectomy surgery. I want to share her success. I want to highlight that most patients with stage of disease actually do very well!
What you may know. Several years ago, BG developed the proliferative stage of diabetic retinopathy. You might remember that proliferative diabetic retinopathy (PDR) can lead to blindness. Signs of PDR include neovascularization (abnormal blood vessels growing on the surface of the retina and iris) as a result of severe retinal ischemia. The ischemia (lack of oxygen due to poor blood flow) can cause liberation of VEGF (vascular endothelial growth factor) which causes growth of the abnormal blood vessels. Treatment of choice is laser photocoagulation to the peripheral retina. If enough laser is performed, the VEGF is no longer produced, the abnormal blood vessels recede and the eye is stable.
Her Case History BG has Type I diabetes. She developed complications of proliferative diabetic retinopathy over the past several years for which she received panretinal photocoagulation (PRP). She temporarily lost vision several times over the years from recurrent vitreous hemorrhage (bleeding in the vitreous). She has always been under the care of a very attentive retina specialist, Dr. JT, who performed the panretinal photocoagulation.
Most recently BG developed a vitreous hemorrhage that did not absorb on its own. A vitrectomy was performed to clear the vitreous hemorrhage and to perform additional PRP. Unfortunately, she had significant post-operative bleeding which, again, did not clear. Re-operation occurred 3 weeks later and then again after the 5th week.
This time the she did not rebleed! She has had no hemorrhage over the past 2 months. As I noted above, I won’t see her for 6 months, her vision is excellent and stable!
What does this mean? BG’s story is not abnormal. There are many patients with proliferative diabetic retinopathy that require vitrectomy for non-clearing vitreous hemorrhage. There are many patients with proliferative diabetic retinopathy that could go blind, but don’t, thanks to modern vitrectomy and laser (especially the laser!).
Due to the diligence of her retinal specialist, BG was always treated in a timely fashion, thereby avoiding the development of diabetic retinal detachment. Recurrent vitreous hemorrhage really does not impact her visual prognosis, but severely interrupts her vision by physically blocking light. The key to treating BG was to remove the blood to allow the retina to be treated with laser. If blood remained in the eye, it would physically block the laser.
I don’t really know how long it takes for the panretinal photocoagulation to become effective. When enough laser is performed, VEGF production ceases and the neovascularization regresses. Laser works by interrupting a chemical pathway. Laser does not physically or directly destroy blood vessels. It is not a form of “cauterization,” but acts indirectly. It usually takes several weeks before PRP exerts its effects.
In the end, despite the severity of the disease, BG, like many others, is enjoying a normal visual outcome. She loves to garden and continues to paint. She continues her work as a graphic artist. Her course is atypical given her history, but I want to highlight another success story and to emphasize that treatments for patients with proliferative diabetic retinopathy are usually successful. Remember, the glass is half full!
Congratulations to BG!
Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist