Role of early radial optic neurotomy in central retinal vein occlusion.

PURPOSE: To determine safety, clinical and visual results, and potential complications of early radial optic neurotomy (RON) surgery in eyes with central retinal vein occlusion (CRVO), with relative afferent pupillary defect and visual acuity

MATERIALS AND METHODS: This prospective, interventional case-series included 24 patients of CRVO who underwent RON within 2 months of disease onset. The preoperative examination included slitlamp biomicroscopy, fundus photography and fluorescein angiography. Foveal thickness was measured using optical coherence tomography (OCT) in the last 6 eyes only. In each case, RON was performed after informed consent. Two radial incisions were placed in the nasal quadrant of the optic disc, using a micro-vitreoretinal blade. The postoperative change in vision, clinical picture, fundus photographs, angiograms and foveal thickness by OCT were the main outcome variables studied. The Wilcoxan signed test was used to assess the results.

RESULTS: Average symptom duration was 37.8 +/- 15.2 days (range 15-60 days, median: 34.5 days) and follow-up 7.7 +/- 2.1 months (range 1-12 months, median: 8 months). Visual outcome: 2 (8.33%) eyes each had fall and preservation of pre-RON visual acuity respectively. Twenty eyes (83.33%) showed increase in vision (of average 3 lines). Pre and postoperative vision ranged from 0.017-0.1 (average:0.061) and 0.017-0.667 (average: 0.17) respectively (P < 0.05). Clinical and angiographic outcome: decline in macular oedema, decreased or resolved intraretinal haemorrhages, resolution of venous dilatation and disc oedema could be appreciated in all cases. Foveal thickness: average pre and postoperative foveal thickness was 834.17 microm and 556.17 microm respectively (P < 0.05) in the 6 eyes where it was measured before and after RON. One eye developed retinal-detachment.

CONCLUSION: Radial optic neurotomy is better than the natural course in eyes with CRVO, with vision < 6/60.