I am 27 year old, have had diabetes or 14 years, and I have a non-proliferative retinopathy. I had a cataract that began two years ago, and a month ago, I had an ultrasound cataract operation on both eyes. After that, the doctor said to me that this operation causes progressing retinopathy in people with diabetes, and that he would recommend full laser photocoagulation in five sessions. I have read many different opinions about laser. What do you think of it? What are the risks of that operation?

I am not aware of any studies that suggest that having cataract surgery predisposes one to subsequent development of proliferative retinopathy. Certainly, if you have severe retinopathy at the time of cataract surgery, this can worsen immediately after surgery. For this reason, one would not normally operate until the retinopathy has improved or, in some cases, treating the eye with laser first. In the past, we did treat eyes with severe retinopathy (classified as pre-proliferative retinopathy) with laser. This is rarely done now.

Despite its obvious and proven benefits in the presence of sight-threatening retinopathy (i.e., proliferative retinopathy or clinically significant maculopathy), laser treatment causes damage to the retina. Pan-retinal photocoagulation always reduces night vision, and in many cases reduces the sensitivity of the peripheral retina to the extent that the area of sight (visual field) is reduced. In some cases, this can be so severe that the patient cannot hold a driving license. The damage from the laser is less than the effect of the disease itself, hence it is “worth the price”.

If the retinopathy is severe, but not yet sight-threatening, then it is often possible to improve or slow the progression of the retinopathy with good control of the diabetes, blood pressure, cholesterol, etc. Furthermore, it has been shown that the success of laser, after sight-threatening retinopathy has developed, is as good as if performed before. Since not everybody who has severe retinopathy progresses to sight-threatening retinopathy, unnecessary treatments can be avoided by waiting for proliferative retinopathy to be present before treatment is done. So, unless you have developed sight-threatening retinopathy, I would not recommend that you have pan-retinal laser photocoagulation.

DAdA

[Editor’s comment: See Diabetic Retinopathy: Your Questions Answered.

SS]