Early Response after Initial Anti-VEGF Injection to Predict the Therapeutic Effect on Macular Edema Secondary to Branch Retinal Vein Occlusion

Abstract

Objective: To identify the relationship between the early changes in central macular thickness (CMT) 24 hours after initial anti-vascular endothelial growth factor (VEGF) injection and the long-term therapeutic effect; to determine the threshold of the long-term prognosis by measuring the receiver operating characteristic (ROC) curve in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Method: This was a retrospective series of consecutive cases conducted to recruit 276 BRVO patients from December 2014 to December 2016 in the ophthalmic outpatient department of the Second Affiliated Hospital of Harbin Medical University. CMT was measured by OCT before injection, 24 hours after injection, and every 4 weeks up to 48 weeks. The best corrected visual acuity (BCVA) was measured by the ETDRS visual acuity scale. The threshold of the treatment effect at 48 weeks was determined by an ROC curve. Pearson correlation analysis and logistic regression analysis were used to identify the factors that might affect the treatment outcome. Results: All 60 eligible BRVO patients (60 eyes) showed a significant decrease in CMT at each time point after injection and BCVA increased significantly. The decrease in CMT at 24 hours after the first injection was significantly correlated with both the decrease in CMT at 48 weeks (r=0.664, P<0.001), and the change in visual acuity at 48 weeks (r=0.642, P<0.001). ROC curve analysis showed that the 18% decrease in CMT at 24 hours was the most sensitive and specific. According to this threshold, the patients were divided into two groups: 24 cases in group A decreased less than 18% at 24 hours and 36 cases in group B decreased more than 18%. The logistic regression analysis group (<18%) was a positive predictor of cure (OR: 19.549, 95%CI: 4.324-88.378, P<0.01). The improvement in visual acuity was 13±11 and 19±14 letters, respectively, and the difference was statistically significant (t=-1.375, P<0.001). Conclusion: The long-term therapeutic effect of ME secondary to BRVO in patients is correlated with the decline in CMT 24 hours after the first anti-VEGF injection using OCT, the decrease more than 18% predicts a good the long-term therapeutic effect. Key words: branch retinal vein occlusion; macular edema; anti-VEGF; early response; receiver operating characteristic curve; predict