Baseline Subfoveal Choroidal Thickness as a Predictor for Response to Short-Term Intravitreal Bevacizumab Injections in Diabetic Macular Edema

PURPOSE: This article aims to evaluate how the subfoveal choroidal thickness (SFCT) and best-corrected visual acuity (BCVA) respond to the intravitreal injection of bevacizumab and to assess the correlation between these changes. It will also assess the use of the baseline SFCT as a predictor for BCVA changes in eyes of treatment-naive, diabetic macular edema (DME) patients. METHODS: This retrospective, consecutive case series comprised 59 eyes of 39 treatment-naive DME patients. Complete slit-lamp assessment, swept-source optical coherence tomography (SS-OCT) scans to measure SFCT and BCVA values were performed at two stages: baseline and one month after the third monthly injection of intravitreal bevacizumab. RESULTS: Patients’ ages ranged from 46.3 to 76.4 years (mean: 62.6 ± 2.3). The mean SFCT was 318 ± 82 μm at baseline, which decreased after 3 months to 300 ± 66 μm (P-value = 0.021). There was an improvement in the mean of the logMAR best-corrected visual acuity (BCVA) from 0.7 (decimal equivalent: 0.2) to 0.5 (decimal equivalent: 0.3) (P-value = 0.019). There was no association between SFCT changes and BCVA changes (P-value = 0.180). Wilcoxon signed-rank test disclosed that a better BCVA improvement was related to a greater subfoveal choroidal thickness at baseline P-value <0.00. CONCLUSION: Eyes with a higher baseline subfoveal choroidal thickness (SFCT) attained greater BCVA improvement than eyes with a lower baseline SFCT. In addition to this, changes to SFCT do not appear to correlate with BCVA changes. These findings do not support using OCT SFCT changes as a prognostic factor for changes to BCVA after intravitreal bevacizumab treatment in evaluating treatment-naive DME eyes.