A randomized clinical trial of early panretinal photocoagulation for ischemic central vein occlusion. The Central Vein Occlusion Study Group N report

Ophthalmology. 1995 Oct;102(10):1434-44.


Purpose: To answer whether prophylactic panretinal photocoagulation (PRP) in ischemic central vein occlusion (CVO) prevents development of 2 clock hours of iris neovascularization or any angle neovascularization (TC-INV/ANV) or whether it is more appropriate to apply PRP only when TC-INV/ANV occurs.

Methods: Multicenter randomized controlled clinical trial in eyes with ischemic CVO. Eyes were assigned to immediate prophylactic PRP (90 eyes) or to frequent close observation (91 eyes). If TC-INV/ANV developed, untreated eyes received PRP and previously treated eyes received supplemental PRP.

Results: In both groups, TC-INV/ANV developed less often in prophylactically treated than untreated eyes, but the difference was not statistically significant when adjusted for baseline imbalance. Treatment of TC-INV/ANV was followed by prompt regression (within 1 month) in 18 (56%) of 32 previously untreated eyes and in 4 (22%) of 18 eyes that had had prophylactic treatment. All eyes except eight eventually stabilized without neovascularization. TC-INV/ANV was correlated with the amount of nonperfused retina (P = 0.0001) and extent of retinal hemorrhage (P = 0.03). Males were at higher risk than females for TC-INV/ANV (P = 0.01), as were patients with occlusions of less than one month duration (P = 0.01).

Conclusions: Prophylactic PRP does not totally prevent TC-INV/ANV, and prompt regression of TC-INV/ANV in response to PRP is more likely to occur in eyes that have not been treated previously. The authors recommend careful observation with frequent follow-up examinations in the early months (including undilated slit-lamp examination of the iris and gonioscopy) and prompt PRP of eyes in which TC-INV/ANV develops.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Fundus Oculi
  • Humans
  • Iris / blood supply
  • Ischemia / physiopathology
  • Ischemia / surgery*
  • Laser Coagulation*
  • Male
  • Middle Aged
  • Neovascularization, Pathologic / prevention & control
  • Postoperative Complications
  • Retinal Vein / physiopathology
  • Retinal Vein / surgery*
  • Retinal Vein Occlusion / physiopathology
  • Retinal Vein Occlusion / prevention & control
  • Retinal Vein Occlusion / surgery*
  • Risk Factors
  • Treatment Outcome
  • Visual Acuity / physiology