Iris neovascularization in Diabetic Retinopathy

This patient had proliferative diabetic retinopathy and iris neovascularization. Note that the iris new vessels begin at the pupillary margin (blue arrow) and that the mid iris stroma is uninvolved. This pupil has been partially dilated, which makes it more difficult to see iris neovascularization (compare the vessels at the green arrow). Under conditions in which iris neovascularization is suspected, the ophthalmologist should examine the eye before dilation. In diabetic retinopathy, if any iris neovascularization is seen, the angle should be examined with gonioscopy. In central retinal vein occlusion, gonioscopy should be performed even if no pupillary margin neovascularization is seen, as it is known to begin in the angle in approxiamtely 10% of cases in which anterior segment neovascularization develops. The treatment for iris neovascularization is laser panretinal photocoagulation. Time is important. If prompt treatment cannot be arranged, consideration should be given to giving an intravitreal injection of bevacizumab, which temporarily causes iris neovascularization to regress.