Choroidal thickness as a possible predictor of non-response to intravitreal bevacizumab for macular edema after retinal vein occlusion

Abstract

To evaluate outcomes of intravitreal bevacizumab treating macular edema (ME) after retinal vein occlusion (RVO) following PRN (pro re nata) regimen and investigate potential predictors of non-response. Retrospective analysis of 126 treatment-naive eyes with ME after RVO. Eyes were treated initially with bevacizumab intravitreal injections (IVIs) of 1.25 mg/ml. Therapy was switched in case of non-response. Outcome measures included best-corrected visual acuity (BCVA) and central macular thickness (CMT), which were recorded over 4 years of treatment. BCVA improved significantly during first 2 years. CMT decreased significantly during the 4-year follow-up period. Switching was required in 42 eyes (33%). 34 eyes (26.9%) were switched to intravitreal steroids, while 8 eyes (6.3%) were switched to other anti-VEFG due to diagnosed glaucoma. Switching occurred after 12.4±8.3 months after an average of 8±4.1 bevacizumab IVIs. Compared with the treatment-responsive group, the treatment-unresponsive group had significantly worse BCVA, higher CMT and subfoveal choroidal thickness (SFCT) at baseline. Treatment with intravitreal bevacizumab following PRN regimen showed significant functional and anatomic improvement in patients with ME after RVO. A therapy switching was required in more than one third of eyes. Higher SFCT at baseline could be considered as predictor for non-response to such therapy.