Optical coherence tomography characteristics of responses to intravitreal bevacizumab in idiopathic choroidal neovascularization

AIM

To investigate factors associated with responses to intravitreal bevacizumab (IVB) in naive idiopathic choroidal neovascularization (iCNV) by high domain optical coherence tomography (OCT).

METHODS

We retrospectively reviewed clinical data of 40 eyes of iCNV patients who received a single or multiple IVB on an as-needed basis (1.25 mg/0.05 mL). One month after the first injection, subretinal fluid (SRF) volume was evaluated and the eyes were divided into 3 groups based on responses to IVB. Good, moderate, and poor responses were defined as 61%-99%, 30%-60%, and <30% resolution of SRF on OCT after IVB in iCNV, respectively. OCT findings were analyzed to find factors associated with difference in response levels. Comparisons were made using Wilcoxon''s matched-pairs signed-rank test, the Mann-Whitney U test for means with continuous data and Fisher''s exact test for categorical data.

RESULTS

The mean number of IVB was 1.28±1.50 and mean follow up time was 3.60±1.20mo. At postoperative 1mo, there were 8 (20%) eyes in good response, 20 (50%) in moderate response and 12 (30%) eyes in poor response group and at last visit there were 28 good responders (70%), 8 (20%) moderate responders and 4 (10%) poor responders. Statistically significant difference was detected between good responders and non good responders in choroidal neovessels thickness (P=0.029), SRF height (P=0.049) and SRF volume (P=0.031) at post treatment 1mo.

CONCLUSION

OCT is a valuable diagnostic tool. Decrease in choroidal neovessels thickness, SRF height and volume predicts favorable response of iCNV to IVB therapy.