Abstract
Abstract: :
Purpose: We report a patient whose radial optic neurotomy procedure for CRVO resulted in formation of chorioretinal venous anastomosis at the site of neurotomy. Methods: A 65-year-old white man suffered progressively ischemic CRVO, documented by history, clinical examination and fluorescein angiography (FA), in his left eye in March 2002. He presented to our office with visual acuity of 20/400 without correction. Pars plana vitrectomy, radial optic neurotomy and pan retinal photocoagulation were performed in May 2002. At the time of pars plana vitrectomy a radial optic neurotomy was made through the optic nerve head rim at the 10:30 meridian using specially designed blade. No intraoperative complications were noted. Results: In the immediate postoperative period (first 6 weeks), visual acuity had improved to 20/200 without correction. Fundus examination and FA showed improved caliber of the retinal vessels and better perfusion of the retinal vasculature. There was reduction in macular edema and intraretinal hemorrhage. The patient noted a second step of improvement three and one half months postoperatively with improvement of vision to 20/100. Coincident with this second improvement, a chorioretinal venous anastomosis was noted at the site of neurotomy. High-speed indocyanine green (HS ICG) angiography best demonstrated venous flow from the retinal vasculature into the choroidal vasculature. This anastomosis was not present on previous HS ICG's. At six-month follow up visit, visual acuity declined to 20/200, likely due to development of nuclear sclerosis. Conclusions: To our knowledge, this is the first written report of angiographic evidence demonstrating formation of chorioretinal venous anastomosis at the site of radial optic neurotomy. Reperfusion of the retina and visual improvement after radial optic neurotomy may be due to its ability to create venous anastomosis, in addition to the relief of neurovascular compression within the enclosed space of the optic nerve head. More studies are warranted in locating chorioretinal venous anastomosis in successful radial optic neurotomy procedures, and in refining surgical techniques to reliably create venous anastomosis.