Objiective To observe the changes of angioarchitecture of the optic disc in cats eyes after radial optic neurotomy (RON). Methods Ten healthy adult cats underwent unilateral RON randomly in 10 eyes as an operative group in this trial, and the fellow eyes (10 eyes) were as the control group. The colophony samples of vascular angioarchitecture of 20 eyes were made 90 days after RON and scanning electron microscope was used for the observation. Results In the control group, the blood supply of optic disc mainly came from the short posterior ciliary artery, pial artery, and retinal ciliary artery; the choroidal capillary vessels around the optic disc didnprime;t take part in the blood supply in the anterior area; retinal central vascular system and complete arterial circle around the optic nerves were not seen. In the operative group, a V-shaped defect of the optic disc, retinal blood vessels and choroidal capillary vessels was found at the surgical incision; no injury of retinal blood vessels and choroidal large vascular layer was seen, and neovascularization at the incision were not found. Conclusions RON may cause the vascular defect of the optic disc and the peripheral local tissues. The depth of the incision doesnprime;t reach the Zinn-Hallers circle. (Chin J Ocul Fundus Dis, 2007, 23: 170-172)
ObjectiveTo explore the histopathological changes of the pigs′ eyes in vivo after radial optic neurotomy (RON), and provide the experimental foundation for the safety of RON.MethodsA total of 12 healthy miniature pigs were used in the experiment, in whom 8 were executed at the 1st, 3rd , 7th , and 48th day respectively after underwent RON in both eyes, and 4 were executed at the 120th day after underwent RON unilaterally (the other eye was as the control in 2 and underwent single vitrectomy in 2). All the enucleated eyes were cut in sections routinely and embeded in paraffin. The sections were stained by HE, Masson trichrome staining or Luxol fast blue staining and the different sections of optic nerve were observed by light microscope.ResultsNo damages of the major vessel wall were found and the cerebral pia mater of orbital optic nerves kept integrated. At the 1st day after the operation, the incisions came into being and local hemorrhages infiltrated into the circumambience and backside. The vacuole-like change induced by the demyelination of optic nerve fiber located at the incisions. At the 3rdday, the vacuolelike changes widened. At the 7thday, the fibroblasts aggregated at the incision, with hyperplastic neuroglia cells and dispersed pigmented granules. Lymphocytes and monocytes were the major infiltrated inflammatory cells. At the 48th day, collagen filled in the incisions and aggregated neuroglia cells of the rear optic nerves behind the incision were found, which showed weak staining with obvious boundary which was somewhat beyond the midline of optic nerves. At the 120th day, localized atrophy of optic nerve occurred under the incision. No abnormal pathological findings were found in the normal eyes and the eyes underogo vitrectomy.ConclusionsLocalized atrophy of optic nerves comes into being after the normal pig eyes in vivo underwent RON. The surgery is safe to some extent.(Chin J Ocul Fundus Dis, 2005,21:13-15)
ObjectiveTo observe the clinical therapeutic effects of radial optic neurotomy (RON) for central retinal vein occlusion (CRVO).MethodsThe clinical data of 12 patients (12 eyes) with CRVO who had undergone RON were retrospectively analyzed. The patients were examined by visual acuity and fundus examination, photography, fundus fluorescein angiography, and optical coherence tomography (OCT). The visual acuities of all of the 12 eyes with severe hemorrhage and retinal edema were less than 0.1. A microvitreoretinal blade or CRVO knife was penetrate into the nasal side of the optic disk, and the incision reached the cribriform plate and even the back, and then dissected at the nasal side of the cribriform plate. The postoperative follow-up period lasted 2 to 15 months with the mean of 6.5 months, and the visual acuity, the condition of visual field and ocular fundus of the eyes undergone the surgery were observed.ResultsIn 12 eyes undergone RON successfully, the visual acuity after the surgery improved more or less in 9 (75%), and more than or up to 0.1 in 6. The results of the examinations showed that the retinal edema and hemorrhage disappeared gradually, varicosity mitigated, retinal serous detachment mitigated or disappeared, and macular cystoid edema faded; macular fovea recovered in 3 eyes, optic nerve had a hemorrhage during the operation in 3 eyes, and the dissected part of optic nerve became atrophic afterward in 4.ConclusionsRON performed at the edge of the nasal side of the optic disc is safe and effective, which may improve the visual acuity of the eyes with CRVO and mitigate retinal hemorrhage and edema.(Chin J Ocul Fundus Dis, 2005,21:10-12)