Retinal blood flow and macular edema after radial optic neurotomy for central retinal vein occlusion.

Abstract

To determine the effect of radial optic neurotomy (RON) on retinal blood flow (RBF) and macular edema in eyes with a central retinal vein occlusion. Prospective interventional study. Seven eyes of seven patients with central retinal vein occlusion underwent RON and vitrectomy and were followed for at least 6 months. The RBF was calculated from dye dilution curves of video fluorescein angiograms. The foveal thickness was determined by optical coherence tomography. At 1 week after surgery, the RBF was significantly reduced from 28.5 +/- 5.4 to 21.1 +/- 6.6 pixel(2)/s (P < .01). At 6 months after surgery, the RBF (26.0 +/- 7.7 pixel(2)/s) was not significantly different from the preoperative RBF, although chorioretinal anastomoses were found in all seven eyes. The foveal thickness was significantly decreased from 711 +/- 271 to 488 +/- 182 mum (P = .03). The postoperative visual acuity was better than the preoperative visual acuity by two or more lines in three out of seven eyes, and was worse in two eyes. Neither RON nor chorioretinal anastomoses improved the RBF but macular edema was improved. These findings suggest that removal of the vitreous could reduce macular edema as in diabetic macular edema. However, we cannot exclude the possibility that the changes represent the natural course of this disease.