Predictive factors for changes in macular edema in intravitreal bevacizumab therapy of retinal vein occlusion

Abstract

To evaluate prognostic factors of response to intravitreal bevacizumab therapy of macular edema (ME) due to central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). Patients with ME due to CRVO (32 patients) or BRVO (38 patients) received intravitreal bevacizumab (2.5 mg/0.1 ml) at baseline, and every 6 to 8 weeks if OCT showed persistent or recurrent ME. Visual acuity (EDTRS), ophthalmic examination and OCT were performed at baseline and at all follow-up visits. Six to 8 weeks after first injection, baseline factors (visual acuity, central retinal thickness, age and gender) were analyzed retrospectively between patients with resolved ME (group 1) and persisting ME (group 2). At last visit, baseline factors of patients with resolved ME since first injection (group A), with recurrent ME since baseline (group B) and with persistent ME since baseline (group C) were compared. In CRVO patients, central retinal thickness (CRT) and patients' age are prognostic predictors in bevacizumab therapy. Age of CRVO patients differed significantly between groups 1 and 2 after first injection, while CRT only showed a strong trend to thinner CRT. At last visit, age and CRT differed statistically significantly between groups A, B and C. In BRVO patients, none of the investigated factors revealed any prognostic value. In CRVO and BRVO patients, final CRT is correlated with the CRT after first injection. CRT and age of patients have prognostic value in bevacizumab therapy of ME due to CRVO. CRVO patients who benefit from therapy are significantly younger and have a lower CRT at baseline than patients with persisting ME. In BRVO patients, no predictive factors for effectiveness of bevacizumab therapy could be observed.