Correlation of Response between Both Eyes to First- and Second-Line Anti-VEGF Therapy in Diabetic Macular Edema

To evaluate the anatomical correlation between fellow eyes for bilateral second-line anti-VEGF treatment in eyes with bilateral diabetic macular edema (DME) with incomplete response to first-line bevacizumab therapy.

Seventy-four eyes (n = 37 patients) with bilateral-DME having incomplete response to first-line bevacizumab therapy that were switched for bilateral treatment with ranibizumab were retrospectively evaluated. Data collected included demographics, visual acuity and macular thickness. We evaluate the correlation for the response of both eyes in terms of macular thickness and visual acuity.

The mean±SD age was 76 ± 8 years. The mean±SD number of bevacizumab injections prior the switch was 11.03 ± 5.1 in the first eye (FE) and 10.9 ± 5.2 in the second eye (SE). The central subfield thickness (CST) reduced from 472 ± 171 microns at baseline to 418 ± 161 after the last bevacizumab injection and 365 ± 74 after 3 ranibizumab injections in the FE (p = .016, p = .004, respectively), and from 463 ± 145 microns to 446 ± 123, and 421 ± 103 in the SE (p = .112, p = .001, respectively). There was strong positive correlation between the eyes for the CST reduction under bevacizumab and ranibizumab treatments in each visit. BCVA± SD at baseline was 0.41 ± 0.30 LogMAR in the FE, and 0.42 ± 0.29 in the SE (p = .44). After 3 injections of bevacizumab, the BCVA was 0.37 ± 0.26 and 0.42 ± 0.23 in FE and SE respectively (p = .013, p = .132, respectively).

This study demonstrated a strong anatomical correlation responses between the eyes in patients with bilateral DME for both first-line bevacizumab therapy and second-line ranibizumab therapy. Response to second-line therapy was favorable and correlated among eyes regardless they were from the same or different individuals.