ISSN: 2155-9570
Ahmad Mirshahi, Mahnaz Abdollahian, Alireza Lashay, Abed Namavari, Hooshang Faghihi and Mahdi Nili
Purpose: to evaluate the effect of Intravitreal tissue plasminogen activator (r-tPA) injection on improvement of visual acuity and decreasing the rate of complications in Branch Retinal Vein Occlusion (BRVO) and ischemic Complications in Retinal Vein Occlusion (CRVO).
Methods: 10 patients with BRVO and 19 patients with ischemic CRVO of recent onset (from 4 to 30 days duration) and visual acuity of <=20/50 were given 100 microgram of tPA intravitreally. Ischemia was defined as an area of nonperfusion >=10 DD for CRVO and >=5 DD for BRVO. Follow up schedule contained 6 visits : at the time of injection, and 1 week,1 month, 2months, 3months, and 6 months after. Fluorescein angiography was performed before injection and at the end of the study.
Results: In ischemic CRVO group: only one eye (5.6%) developed Iris neovascularization. The mean of baseline visual acuity increased from 1.8400 LogMAR to 1.5333 LogMAR at the end of the study (p=0.009). Pearson correlation coefficient was +0.874 for initial and final measured BCVAs. 8 patients (44.4%) had doubling of visual angle (0.3 LogMAR increase in BCVA).
In BRVO group: 3 patients (30%) were classified in the ischemic group and after a complete 6 month follow up none of the cases (0%) developed retinal neovascularization, vitreous hemorrhage, retinal detachment or endophthalmitis. The mean of baseline visual acuity increased from 1.0710 LogMAR to 0.6100 at the end of the study (p=0.001).
Discussion: Comparison between the results of our study and natural history of RVO indicates that after injection: There was doubling of visual angle in about 10% of cases. The rate of Iris neovascularization and neovascular glaucoma was decreased to 1/6 of what occurs without treatment.
Endophthalmitis, retinal detachment and vitreous hemorrhage which are known as major complications of this procedure did not occur in any of our 29 patients.