Complete retinal fluid resorption with low visual acuity in patients with diabetic macular edema (DME) over the course of ranibizumab treatment: OCT analysis

Abstract

AbstractPurpose Intravitreal ranibizumab injections in DME often leads to resorption of edema. Nevertheless, complete resorption of DME is weakly correlated with good visual acuity (VA). The purpose of our study was to investigate the anatomical OCT features of patients treated with ranibizumab for DME with low VA despite of complete dry retina.Methods We included in a retrospective fashion all patients over the course of ranibizumab treatment for DME at Avicenne Hospital (Bobigny, France) with a dry retina after treatment (central foveal thickness (CFT) ≤ 250 μm and presence of foveal pit). We analyzed the characteristics of outer retinal layers in spectral‐domain OCT (Optos OCT SLO) in case of low final VA (best‐corrected VA (BCVA) with dry retina < 5/10 after at least 3 injections).Results We included 40 patients. Complete retinal fluid resorption was achieved for 24 patients (60%). Among these patients, half of them (12 patients ie 30 % of our cohort) had low VA (group 1) and 12 patients had good VA ( group 2). Mean CFT was 713 μm in group 1 (G1) and 666μm (p = 0.64) in group 2 (G2). After treatment, mean CFT in G1 was 165 μm against 174 μm (p = 0.6) in G2. For all patients in G1, anatomical changes were noted on OCT pictures after treatment: loss or thinning of ellipsoid band (n = 6), atrophic cyst (n = 6), exudates (n = 3), epiretinal membrane (n = 2).Conclusion Insufficient improvement of BCVA after complete retinal fluid resorption happened in about 30% of patients over the course of ranibizumab treatment for DME, and was often associated in our study with alterations of outer retinal layers in SD‐OCT imaging.