Colocalization of Ellipsoid Zone Disruption With Capillary Nonperfusion in Different Retinal Vascular Layers and
Reza Mirshahi1, Amir Rahdar2, Mohamad Javad Ahmadi2
1Eye Research Center, The Five Senses Health Institute, Moheb Kowsar Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Purpose:
To assess the colocalization of ellipsoid zone (EZ) disruption with nonperfusion in choriocapillaris (CC), retinal superficial capillary plexus (SCP), and deep capillary plexus (DCP) in diabetic patients using en face optical coherence tomography (OCT) and OCT angiography (OCTA).
Methods:
Macular OCT and OCTA scans (3 × 3 mm) of 41 patients with diabetic retinopathy were obtained using an RTVue XR Avanti instrument. After correcting the shadow artifacts, EZ integrity was assessed in the en face OCT slab using the Gaussian mixture model clustering method compared with the corresponding EZ en face OCT of 11 age-matched normal patients. A similar technique was used for detecting capillary nonperfusion using CC en face OCTA. Geometric perfusion density (GPD) maps were also generated for the SCP and DCP. Maps of capillary nonperfusion in the CC, SCP, and DCP were compared pixel by pixel with the map generated from EZ disruption.
Results:
Twenty-one patients with diabetic macular edema (DME) and 20 patients with diabetic retinopathy without macular edema were included in this study. In both groups, the overlap of EZ disruption was significantly greater with choriocapillaris nonperfusion than with nonperfusion in the SCP and DCP (dry macular group: 33.15% with CC vs. 0.46% with SCP vs. 1.70% with DCP, p < 0.001; DME group: 29.81% with CC vs. 1.22% with SCP vs. 6.25% with DCP, p < 0.001). In multivariate analysis, after adjusting for stage of diabetic retinopathy and DME, EZ disruption was only associated with nonperfusion in CC (p value = 0.03). According to the linear regression model, there was a statistically significant correlation between logMAR visual acuity and EZ disruption in the dry macular group (p = 0.041).
Conclusion:
In patients with diabetic retinopathy, choriocapillaris nonperfusion may play a more significant role in photoreceptor loss than retinal nonperfusion.
