Assessment of Parafoveal Diabetic Macular Ischemia on Optical Coherence Tomography Angiography Images to Predict Diabetic Retinal Disease Progression and Visual Acuity Deterioration

Abstract

Importance: The presence of diabetic macular ischemia (DMI) on optical coherence tomography angiography (OCTA) images predicts diabetic retinal disease progression and visual acuity (VA) deterioration, suggesting an OCTA-based DMI evaluation can further enhance diabetic retinopathy (DR) management.

Objective: To investigate whether an automated binary DMI algorithm using OCTA images provides prognostic value on DR progression, diabetic macular edema (DME) development, and VA deterioration in a cohort of patients with diabetes.

Design, setting, and participants: In this cohort study, DMI assessment of superficial capillary plexus and deep capillary plexus OCTA images was performed by a previously developed deep learning algorithm. The presence of DMI was defined as images exhibiting disruption of fovea avascular zone with or without additional areas of capillary loss, while absence of DMI was defined as images presented with intact fovea avascular zone outline and normal distribution of vasculature. Patients with diabetes were recruited starting in July 2015 and were followed up for at least 4 years. Cox proportional hazards models were used to evaluate the association of the presence of DMI with DR progression, DME development, and VA deterioration. Analysis took place between June and December 2022.

Main outcomes and measures: DR progression, DME development, and VA deterioration.

Results: A total of 321 eyes from 178 patients were included for analysis (85 [47.75%] female; mean [SD] age, 63.39 [11.04] years). Over a median (IQR) follow-up of 50.41 (48.16-56.48) months, 105 eyes (32.71%) had DR progression, 33 eyes (10.28%) developed DME, and 68 eyes (21.18%) had VA deterioration. Presence of superficial capillary plexus-DMI (hazard ratio [HR], 2.69; 95% CI, 1.64-4.43; P < .001) and deep capillary plexus-DMI (HR, 3.21; 95% CI, 1.94-5.30; P < .001) at baseline were significantly associated with DR progression, whereas presence of deep capillary plexus-DMI was also associated with DME development (HR, 4.60; 95% CI, 1.15-8.20; P = .003) and VA deterioration (HR, 2.12; 95% CI, 1.01-5.22; P = .04) after adjusting for age, duration of diabetes, fasting glucose, glycated hemoglobin, mean arterial blood pressure, DR severity, ganglion cell-inner plexiform layer thickness, axial length, and smoking at baseline.

Conclusions and relevance: In this study, the presence of DMI on OCTA images demonstrates prognostic value for DR progression, DME development, and VA deterioration.

Figure 1.. Case Example of the Presence of Diabetic Macular Ischemia (DMI) on Optical Coherence Tomography Angiography Images Resulting in the Diabetic Retinopathy Progression Over a 4-Year Follow-Up

This case had a baseline Early Treatment of Diabetic Retinopathy Study level of 35 (A) and 71 (B) after 24.48 months of follow-up. The optical coherence tomography angiography images were analyzed by our deep learning algorithm with an output of presence of DMI on superficial capillary plexus. The heat map was overlaid on the superficial capillary plexus–optical coherence tomography angiography image.

Figure 2.. Case Example of the Presence of Diabetic Macular Ischemia on Optical Coherence Tomography Angiography Images Resulting in Diabetic Macular Edema (DME) Development Over a 4-Year Follow-Up

This case was without DME at baseline (A) with retinal thickness equals to 286 μm measured by Spectralis optical coherence tomography and developed DME after 31.82 months of follow-up (B) with retinal thickness equals to 342 μm. The optical coherence tomography angiography images were analyzed by our deep learning algorithm with an output of presence of DMI on deep capillary plexus. The heat map was overlaid on the deep capillary plexus–optical coherence tomography angiography image.