Abstract
Purpose :
To identify retinal, cones and rods nonperfusion on ultrawide field (UWF) fluorescein angiography (UWF-FA) and determine its correlation to diabetic retinopathy (DR) severity and center-involving diabetic macular edema (ciDME) in diabetic eyes.
Methods :
Sixty-nine eyes from 43 patients with diabetes underwent imaging. DR severity was assessed on UWF color photos (UWF-CP) and the presence of ciDME was evaluated using optical coherence tomography (OCT) by 2 independent graders at a centralized reading center. UWF-FA images were segmented into posterior pole (within 10 mm from the foveal center), mid-periphery (10-15 mm) and far periphery (beyond 15 mm), and into macula, within ETDRS and each of the extended peripheral fields (P3-P7) using customizable software measurement tools from the imaging device supplier. Ischemic areas were identified on UWF-FA using Image J software and the nonperfusion index (NPI), cones NPI (CPI) and rods NPI (RPI) within each segmented area of the retina were calculated. Pearson correlation (r) was measured.
Results :
DR severity was correlated with NPI in the entire fundus (r=0.55944, p<0.0001) and within all segmented areas of the fundus (r 0.34536 – 0.57411). This remained significant even after distinguishing between cones [CPI: entire fundus (r=0.55617, p<0.0001); all segmented areas (r 0.42368 – 0.59082)] and rods [RPI: entire fundus (r=0.55285, p<0.0001); all segmented areas (r 0.39798 – 0.59311)]. Similarly, the presence of ciDME on OCT is correlated with increasing NPI: entire fundus (r=0.39718, p=0.0014), some segmented areas (r 0.42262 – 0.53961); CPI: entire fundus (r=0.46521, p=0.0001), all segmented areas (r 0.32012 – 0.55029); and RPI: entire fundus (r=0.45586, p=0.0002), all segmented areas (r 0.33034 – 0.53882). The values of the correlation of DR severity and presence of ciDME with NPI, CPI and RPI within each segmented area of the fundus are summarized in Table 1.
Conclusions :
Retinal nonperfusion is associated with increasing DR severity and the presence of ciDME. Thus, UWF-FA may potentially be used in identifying eyes at high-risk for developing ciDME and in surveilling DME among patients with diabetes. Detecting the level of retinal ischemia at which point it is likely to threaten vision requires further study.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.