Symmetry in early response to intravitreal ranibizumab in bilateral diabetic macular oedema

Abstract

Purpose: To study the symmetry in response to bilateral diabetic macular oedema (DME) treated with bilateral intravitreal injections of ranibizumab (IVR). Methods: The charts of 36 eyes of 18 patients treated with a loading dose of three monthly IVR in both eyes were retrospectively reviewed. Favourable anatomical response was defined as a decrease by more than 10% in baseline central macular thickness (CMT), and favourable functional response was defined as an increase in visual acuity (VA) ≥5 letters. A symmetric response was defined as a similar anatomical and/or functional response in the first (FE) and second (SE) treated eyes. Results: The VA improved significantly after ranibizumab treatment in both eyes (p < 0.01). A statistically significant positive correlation was found for the functional response to ranibizumab between the FE and the SE (R 2 = 0.26, p = 0.03). The mean CMT decreased significantly in both eyes (p < 0.01). A strong positive correlation was observed between the anatomical response to ranibizumab in the FE and the SE (R 2 = 0.37, p = 0.01). Symmetric favourable anatomical and functional responses were observed in 13 patients (72%). In two additional patients, an asymmetric functional response was observed despite a decrease in retinal thickness in both eyes. Conclusion: Symmetric anatomical and functional responses were observed in 72% of patients with DME after three initial IVR in each eye. This finding could be of clinical interest in the decision to treat the fellow eye, in a disease where a bilateral involvement is frequent.