Radial optic neurotorny for ischemic central retinal vein occlusion

Introduction: Occlusion of the central retinal vein (CRVO) is the second most frequent cause for blindness in the course of pathological changes of the vascular system. Vitreous haemorrhages and neovascular glaucoma are known as serious complications. Clinically accepted guidelines for treating CRVO do not exist up to now. In this report our results after radial optic neurotomy (RON) of patients suffering from CRVO associated with visual deterioration are summarised. Patients and Method: 78 patients (mean age 68 year, gender: 41 male, 37 female) with visual acuity of 0.2 or worse were treated with RON. Mean follow-up was 13 months. 35 patients underwent previously haemodilution treatment without success. Visual acuity tests, fluorescein angiographic appearance, OCT and postoperative complications were analysed, in 47% additionally VEP, ERG and the visual field were evaluated. RON was carried out by conventional pars plana vitrectomy. Neurotomy was performed at the nasal side of the optic disc in all cases. Neither ILM peeling nor gas tamponade was used. Follow-up examinations were carried out after 2 and 4 weeks, after 3 and 6 months and after 3 years. Results: Improvement of morpholocial parameters could be registered in 95% of our patients by means of fluorescein angiography or OCT. Visual acuity improved in 81% and worsened in 10%. After 6 months patients with non-ischamic CRVO had a significantly better visual acuity compared to patients with ischaemic CRVO. A retino-chorllliodal anastomosis could be observed in 38 (48%) eyes, all these patients experienced visual improvement. The results of VEP and ERG showed partial recovery in all cases. A temporal visual field defect occurred postoperatively in 95 % of our patients. Conclusion: Visual acuitiy of patients suffering from non-ischaemic CRVO with low preoperative visual acuity and short history may improve after RON. Frequent complications were temporal field defects and vitreous haemorhage. Further randomised studies are necessary to compare these results after RON with other alternative therapeutic procedures, for example, intravitreal injection of VEGF inhibitors.