Biomechanical Assessment of Radial Optic Neurotomy

Purpose A biomechanical model was constructed to simulate the potential therapeutic effect that the surgical procedure radial optic neurotomy (RON) would have on an eye with a central retinal vein occlusion. Design Experimental study. Controls Model eyes undergoing RON were compared to control eyes under the same baseline conditions. Intervention Radial optic neurotomy. We modeled the optic nerve, lamina cribrosa, and the sclera separately and then reassembled the components. Material properties of the sclera and lamina cribrosa were extracted from the literature and both stiff and more elastic values were used for the optic nerve. Intraocular and arterial pressures were varied across a wide range in the analysis. Main Outcome Measure Change in central retinal vein lumen size. Results Over a clinically relevant range of boundary conditions, the increase in the lumen area of the central retinal vein lumen after RON remained trivial, ranging from 1% to a maximum of 5%. Conclusions The biomechanical effect of RON is negligible, and is unlikely to be a procedure that could mechanically ameliorate the clinical sequelae of a central vein occlusion.