Patterns of ellipsoid zone change associated with visual outcome for diabetic macular oedema.

Clinical relevance : Optical coherence tomography biomarkers are dynamic and possibly change over time. The dynamic biomarkers may better predict improvement of final vision than those at baseline for diabetic macular oedema after treatment. Background : To investigate predictors for ellipsoid zone (EZ) dynamics and the association with visual acuity after treatment for diabetic macular oedema Methods : A total of 135 eyes from 135 patients with anti-vascular endothelial growth factor treatment for diabetic macular oedema were retrospectively enrolled in this study. EZ status was evaluated by optical coherence tomography at baseline, 1, 3, 6, and 12 months post-operatively. Macular perfusion status was analysed by fluorescein angiography. Duration of EZ disruption was quantified by giving scores from 0 to 5 based on the sum of visits with evidence of EZ disruption. Linear regression models were used to predict factors for scores of EZ disruption. Binary logistic regression was used to predict various EZ biomarkers for final visual acuity improvement. Results : Thirty of 87 eyes (34.4%) with intact EZ at baseline developed subsequent EZ disruption. For those with EZ disruption at baseline, 17 of 48 (35.4%) patients had restoration of disrupted EZ over time. Non-perfused macula was associated with both earlier development of EZ disruption and poor restoration (p < 0.001 and p = 0.011, respectively). Non-perfused macula, absence of epiretinal membrane, and EZ disruption at baseline predicted higher EZ scores (p < 0.001, p = 0.022 and p < 0.001, respectively). Higher EZ scores (p = 0.016), but not baseline EZ disruption (p = 0.56), were less likely to have improvement of final vision 5 letters or more. Conclusion : Macular perfusion status played an independent role in EZ dynamics. Duration of EZ disruption could be more predictive than baseline status for improvement of vision over 12 months.