The Association between Choroidal Thickness Variations and Response to Intravitreal Bevacizumab in Central Serous Chorioretinopathy

PURPOSE To analyze differences in the subfoveal choroidal thickness (SFChT) between bevacizumab responders (BevRs) and nonresponders (BevNRs) in patients with idiopathic central serous chorioretinopathy (CSC). METHODS The medical records of 30 unilateral chronic CSC patients who were treated with intravitreal bevacizumab (IVB) as a first line treatment were reviewed. Patients were categorized as BevNRs when CSC did not completely resolve after a minimum of 3 IVB treatments. Enhanced depth imaging-optical coherence tomography was used and SFChT was measured before and after treatment. Choroidal hyperpermeability was also evaluated using indocyanine angiography. RESULTS Twenty and 10 eyes were classified as BevRs or BevNRs, respectively. The mean number of IVB treatments was 2.22 ± 0.89 in BevRs, and 4.80 ± 1.03 in BevNRs. Compared with BevNRs, BevRs demonstrated significantly greater pretreatment SFChT (441.25 ± 88.09 vs. 364.10 ± 61.97 µm); SFChT reduction following IVB was significantly greater in BevRs than BevNRs. SFChT in the unaffected eyes was also greater in BevRs than BevNRs. Choroidal hyperpermeability was detected less frequently in BevNRs (hypofluorescence on late-phase, 0.0% and 33.3% in BevNRs and BevRs, respectively; p= 0.049). CONCLUSIONS Compared with CSC eyes that did not respond well to IVB, BevRs demonstrated significantly thicker SFChT at baseline, greater reduction in SFChT after IVB treatment, and hyperfluorescence on late-phase indocyanine green angiography. We recommend IVB injection as the first-line therapy for CSC eyes with relatively high SFChT and hyperfluorescence on late-phase indocyanine green angiography.