Dalteparin Versus Aspirin in Recent-Onset Branch Retinal Vein Occlusion: A Randomized Clinical Trial

Retinal vein occlusion is the second most common vascular disease of retina after diabetic retinopathy, affecting 1.6% of the population above the age of 40. The aim of this study was to compare the effect of dalteparin and aspirin in patients with recent-onset branch retinal vein occlusion. A randomized clinical trial was conducted on patients with branch retinal vein occlusion of less than 30 days'' duration. Ophthalmic, systemic, and hematologic evaluations were made. Visual acuity was measured with Early Treatment Diabetic Retinopathy Study chart. Patients in the dalteparin group received subcutaneous dalteparin 100 IU/kg twice daily for 10 days, then 100 IU/kg once daily for another 10 days while the patients in the aspirin group were given aspirin 100 mg daily throughout the study. Seventy-eight patients were enrolled, 37 in the dalteparin and 41 in the aspirin group. The patients were followed for six months. The visual outcomes of the two groups were compared. Although dalteparin improved mean visual acuity slightly more than aspirin, no statistically significant differences were found between the groups at one (P=0.37), two (P=0.16), three (P=0.11), or six (P=0.13) months. Resolution of macular edema and development of new vessels made no statistically significant difference between the groups [(P=0.08) and (P=0.49), respectively]. In recent-onset branch retinal vein occlusion, no significant difference was found in the final visual acuity between the patients treated by dalteparin or aspirin. A further study with larger sample size is recommended.