Early histologic and functional study of radial optic neurotomy outcomes in normal rat eyes

• Published in: Retina (Philadelphia, Pa.) Vol. 31; no. 10; p. 2115
• Main Authors: Belforte, Nicolás A, Sande, Pablo H, Dorfman, Damián, Croxatto, J Oscar, Rosenstein, Ruth E
• Format: Journal Article
• Language: English
• Published: United States 01.11.2011
• Subjects: Animals; Decompression, Surgical; Electroretinography; Evoked Potentials, Visual - physiology; Intraocular Pressure - physiology; Male; Ophthalmologic Surgical Procedures; Optic Disk - blood supply; Optic Disk - surgery; Optic Nerve - blood supply; Optic Nerve - surgery; Photic Stimulation; Rats; Rats, Wistar; Reflex, Pupillary - physiology; Retina - physiology; Visual Pathways - physiology
• ISSN: 1539-2864
• DOI: 10.1097/IAE.0b013e31820f4bcb

Radial optic neurotomy (RON) has been proposed as a treatment for central retinal vein occlusion. However, it is still under debate whether RON would be an adequate treatment or a dangerous procedure, and persuasive animal studies are lacking. The aim of this study was to analyze the early histologic and functional outcomes of RON in normal rat eyes. Radial optic neurotomy was performed by cutting into the optic nerve edge at the nasal hemisphere, while the contralateral eye underwent a sham procedure. The retinal function was assessed by scotopic electroretinography, and the visual pathway was assessed by flash visual evoked potentials. Intraocular pressure was assessed with a tonometer, the pupillary light reflex was measured after exposing eyes to a 30-second light flash, whereas the optic nerve head structure was examined by histologic analysis. In normal rat eyes, RON provoked minor histologic alterations at the optic nerve head level and a transient decrease in the electroretinography. No changes in visual evoked potentials, intraocular pressure, and pupillary light reflex were observed in rat eyes submitted to RON. To our knowledge, this is the first study describing the early histopathologic and functional consequences of RON in normal rat eyes.