Radial Optic Neurotomy Associated With Intravitreous Triamcinolone Injection: An Alternative Approach for Central Retinal Vein Occlusion

Abstract

Abstract: : Purpose: To report a series of six eyes with central retinal vein occlusion (CRVO) that underwent vitrectomy, radial optic neurotomy (RON) and intravitreous triamcinolone acetonide injection. Methods: Six eyes of six patients with macular edema due to CRVO who had best–corrected visual acuity (BCVA) of 20/400 or worse and no history of improvement of BCVA since the occlusion for at least two months underwent pars plana vitrectomy, posterior hyaloid detachment, RON, endophotocoagulation (if neovessels were present) and 4 mg of intravitreous triamcinolone acetonide injection. Follow–up was performed 1 day, 7 days, 4 weeks, 3 months and 6 months after the surgical procedure. BCVA was measured by ETDRS charts. Slit–lamp examination, intraocular pressure (IOP) measurements, fluorescein angiography, indocyanine green angiography and optical coherence tomography were also performed.Two patients had perfused CRVO, two patients had nonperfused CRVO and two patients had indeterminate type of CRVO. Results: Six eyes were followed and all eyes except one had at least two lines of BCVA improvement. In 50% of eyes, the final BCVA was better than 20/80. Retina/iris neovascularization was observed in 2 eyes treated by endophotocoagulation that resulted in neovessels regression. One eye had subretinal hemorrhage at the nasal site of the RON and BCVA improved from hand motions to 20/60. High level of IOP was observed in two eyes at the 4^th week and returned to normal after 3 weeks following eyedrops treatment. One eye had recurrence of macular edema at the 3^rd month evaluation which was treated by intravitreous re–injection of 4mg of triamcinolone acetonide that resulted in BCVA improvement to 20/60 at the 6^th month. Chorioretinal anastomosis formation was observed in two eyes after the surgical procedure and there were no vision–threatening intraoperative complications in this series. Conclusions: Although only 6 patients were evaluated and no controls were analysed, this combined surgical technique was an effective procedure which improved the BCVA in 83% of cases. The BCVA improvement may be related to posterior hyaloid detachment, RON itself, chorioretinal anastomosis formation, intravitreal triamcinole injection or even a combination of these factors which resulted in macular edema improvement. Further studies are warranted to evaluate the long term results of this procedure, the mechanisms of macular edema improvement as well as comparison of this combined surgical procedure with the natural history of the disease.

Keywords: retina • optic disc • vascular occlusion/vascular occlusive disease