Long-Term Effect of Dalteparin in the Prevention of Neovascularization of Iris in Recent-Onset Central Retinal Vein Occlusion

Background: To compare the long-term effect of dalteparin in the prevention of neovascularization of iris in recent-onset central retinal vein occlusion with that of aspirin. Methods: A randomized controlled clinical trial was conducted on patients with central retinal vein occlusion of less than 30 days duration. Patients in the dalteparin group received subcutaneous dalteparin 100 IU/kg twice a day for 10 days, and then 100 IU/kg once a day for another ten days. In the aspirin group the patients received 100 mg aspirin daily throughout the study. Results: Forty seven patients were enrolled, 24 in the dalteparin group and 23 in the aspirin group, and were followed up for one year. One (4.1%) of the 24 patients in dalteparin group, and 9 (39.1%) of 23 patients in aspirin group developed iris neovascularization. the difference was significant (P=0.0001). The visual outcomes of the two groups were compared, and a significant difference was found (P=0.016). Conclusion: Patients treated with dalteparin within 30 days of the onset of central retinal vein occlusion were less likely to develop neovascularization of iris. There was also a significant difference in the visual acuity between two groups.