Correlation between Deep Capillary Plexus Perfusion and Long-Term Photoreceptor Recovery after Diabetic Macular Edema Treatment

Purpose To determine the association between baseline deep capillary plexus (DCP) integrity and long-term photoreceptor recovery as well as visual outcome after treatment in patients with diabetic macular edema (DME). Design Retrospective, interventional case series. Participants Sixty-seven eyes with DME that resolved successfully with initial treatment (baseline) and that remained edema free for 12 months after the initial DME resolution. Methods Best-corrected visual acuity (BCVA), spectral-domain (SD) OCT, and OCT angiography findings were collected at baseline and at 6 and 12 months after baseline. Correlations were analyzed between DCP integrity parameters (vascular flow density [VD] and area of the foveal avascular zone [FAZ]) and photoreceptor integrity parameters (ellipsoid zone [EZ] and external limiting membrane [ELM] integrity). Multivariate linear regression analysis was conducted to identify the baseline predictors for photoreceptor recovery and visual improvement. Main Outcome Measures The association between baseline DCP integrity and recovery of photoreceptor integrity over 12 months. Results At baseline, the mean central retinal thickness was 306.1±51.8 μm. The mean baseline DCP VD and FAZ were 14.4±5.2% and 0.71±0.36 mm 2 , and the mean baseline EZ and ELM integrity were 57.2±26.1% and 76.4±19.8%, respectively. Ellipsoid zone and ELM integrity recovered significantly at 12 months from baseline (both P P  = 0.004 and P  = 0.009, respectively) and DCP FAZ ( P  = 0.007 and P  = 0.009, respectively). Moreover, the mean change in BCVA from baseline to 12 months was significantly greater with higher baseline DCP VD ( P  = 0.003) and smaller DCP FAZ ( P  = 0.042). Compared with anti–vascular endothelial growth factor (VEGF) nonresponders, anti-VEGF responders had higher baseline DCP integrity and a significantly greater degree of photoreceptor recovery at 12 months. Conclusions The degree of DCP preservation at the time of initial DME resolution is correlated closely with long-term recovery of photoreceptor integrity and visual outcome in patients with resolved DME.