Clinical efficacy of intravitreal conbercept injection and macular grid pattern photocoagulation in treating macular edema secondary to non-ischemic branch retinal vein oclussion

Abstract

Objective To study and compare the clinical efficacy between intravitreal conbercept injection and (or) macular grid pattern photocoagulation in treating macular edema secondary to non-ischemic branch retinal vein occlusion (BRVO). Methods Ninety eyes of 90 patients diagnosed as macular edema secondary to non-ischemic BRVO were enrolled in this study. Forty-eight patients (48 eyes) were male and 42 patients (42 eyes) were female. The average age was (51.25±12.24) years and the course was 5–17 days. All patients were given best corrected visual acuity (BCVA), intraocular pressure, slit lamp with preset lens, fluorescence fundus angiography (FFA) and optic coherent tomography (OCT) examination. The patients were divided into conbercept and laser group (group Ⅰ), laser group (group Ⅱ) and conbercept group (group Ⅲ), with 30 eyes in each group. The BCVA and central macular thickness (CMT) in the three groups at baseline were statistically no difference (F=0.072, 0.286;P=0.930, 0.752). Patients in group Ⅰ received intravitreal injection of 0.05 ml of 10.00 mg/ml conbercept solution (conbercept 0.5 mg), and macular grid pattern photocoagulation 3 days later. Group Ⅱ patients were given macular grid pattern photocoagulation. Times of injection between group Ⅰ and Ⅲ, laser energy between group Ⅰ and Ⅱ, changes of BCVA and CMT among 3 groups at 1 week, 1 month, 3 months and 6 months after treatment were compared. Results Patients in group Ⅰ and Ⅲ had received conbercept injections (1.20±0.41) and (2.23±1.04) times respectively, and 6 eyes (group Ⅰ) and 22 eyes (group Ⅲ) received 2-4 times re-injections. The difference of injection times between two groups was significant (P<0.001). Patients in group Ⅱ had received photocoagulation (1.43±0.63) times, 9 eyes had received twice photocoagulation and 2 eyes had received 3 times of photocoagulation. The average laser energy was (96.05±2.34) μV in group Ⅰ and (117.41±6.85) μV in group Ⅱ, the difference was statistical significant (P=0.003). BCVA improved in all three groups at last follow-up. However, the final visual acuity in group Ⅰ and group Ⅲ were better than in group Ⅱ (t=4.607, –4.603;P<0.001) and there is no statistical significant difference between group Ⅲ and group Ⅰ (t=–0.802,P=0.429). The mean CMT reduced in all three groups after treating for 1 week and 1 month, comparing that before treatment (t=–11.855, –10.620, –10.254;P<0.001). There was no statistical difference of CMT between group Ⅰand Ⅲ at each follow up (t=0.404, 1.723, –1.819, –1.755;P=0.689, 0.096, 0.079, 0.900). CMT reduction in group Ⅰ was more than that in group Ⅱ at 1 week and 1 month after treatments (t=–4.621, –3.230;P<0.001, 0.003). The CMT in group Ⅲ at 3 month after treatment had increased slightly comparing that at 1 month, but the difference was not statistically significant (t=1.995,P=0.056). All patients had no treatment-related complications, such as endophthalmitis, rubeosis iridis and retinal detachment. Conclusions Intravitreal conbercept injection combined with macular grid pattern photocoagulation is better than macular grid pattern photocoagulation alone in treating macular edema secondary to non-ischemic BRVO. Combined therapy also reduced injection times comparing to treatment using conbercept injection without laser photocoagulation. Key words: Retinal vein occlusion/therapy; Macular edema /therapy; Angiogenesis inhibitors/therapeutic use; Antibodies, monoclonal/therapeutic use; Laser coagulation