title: Retinal choroidal collateral circulation after radial optic neurotomy correlated with the lessening of macular edema.
abstract: OBJECTIVE
  To evaluate patients who had undergone radial optic neurotomy for central retinal vein occlusion for the presence of retinal choroidal collateral circulation and to correlate these collaterals with changes in macular thickness during follow-up. Radial optic neurotomy is designed to release proposed pressure within the scleral canal.
  
  
  METHODS
  Retrospective review of patients undergoing radial optic neurotomy. The patients had a baseline examination including ophthalmoscopy, fluorescein angiography, and optical coherence tomography. At an interval follow-up at approximately 3 months the patients were reevaluated with ophthalmoscopy, optical coherence tomography, and indocyanine green angiography.
  
  
  RESULTS
  There were 6 patients, and the mean age was 68.3 years. The mean time from onset of the central retinal vein occlusion to the radial optic neurotomy was 2.3 months. One patient had no collateral vessels, three patients had significant collaterals, and two patients had moderate-caliber collaterals. The mean central macular thickness preoperatively was 1,021 microm and the mean central macular thickness postoperatively was 733 microm. The change in macular thickness was highly correlated with the degree of development of collaterals from the retinal to the choroidal circulation (P = 0.008, Spearman's rho = 0.93).
  
  
  CONCLUSIONS
  Although all patients had a radial optic neurotomy a significant determinant in reduction of macular edema was the presence of retinal-choroidal collateral circulation. This suggests that there may be additional mechanisms, other than simple release of alleged pressure in the scleral canal, for any observed effects from radial optic neurotomy.
authors.affiliation: Vitreous-Retina-Macula Consultants of New York and the Manhattan Eye Ear and Throat Hospital, New York, New York 10021, USA. vrmny@aol.com
authors.forename: Richard F
authors.initials: RF
authors.lastname: Spaide
authors.forename: James M
authors.initials: JM
authors.lastname: Klancnik
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Gross
mesh_terms: D000368:Aged; D002829:Choroid / Q000098:blood supply*; D003097:Collateral Circulation / Q000502:physiology*; D004396:Coloring Agents; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D007208:Indocyanine Green; D008269:Macular Edema / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D009887:Ophthalmoscopy; D009900:Optic Nerve / Q000601:surgery*; D012170:Retinal Vein Occlusion / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D012171:Retinal Vessels; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green