Prognostic factors for visual outcomes 2-years after intravitreal bevacizumab for myopic choroidal neovascularization

Abstract

To determine the pre-treatment ocular factors significantly associated with the visual outcome 24 months after intravitreal bevacizumab (IVB) for myopic choroidal neovascularization (mCNV). A total of 23 eyes of 23 patients with mCNV were treated with IVB followed by as needed therapy. The efficacy of IVB was evaluated by the best-corrected visual acuity (BCVA) at 24 months after the initial treatment. Forward stepwise multiple linear regression analyses were performed to evaluate the influence of pre-treatment factors on the BCVA and the improvement of the BCVA at 24 months. The mean pre-IVB BCVA was 0.74 ± 0.30 logarithm of the minimum angle of resolution (logMAR) units, and it improved to 0.43 ± 0.31 logMAR units after 1 month (P < 0.001, paired t-test). The improvement was maintained at 24 months (0.46 ± 0.40, P < 0.005). The mean number of IVB performed during the 24 months was 1.35 ± 0.71. Forward stepwise regression analysis showed that the pre-IVB CNV size (standardized β = 0.52, P < 0.01) and BCVA (standardized β = -0.44, P < 0.05) significantly affected the visual acuity change after 24 months. The CNV size was the only factor that significantly affected the BCVA after 24 months (standardized β=0.56, P < 0.01). IVB with as needed therapy for mCNV led to a rapid and sustained visual improvement. Smaller CNV size was a significant prognostic factor that predicts better visual acuity. Patients with lower pre-treatment BCVA had better visual recovery than those with better pre-treatment BCVA, however, this may be due to a ceiling/floor effect.