To evaluate the utility of different optical coherence tomography angiography scan protocols in evaluating retinal changes in non–proliferative diabetic retinopathy.
Patients were imaged with the RTVue XR Avanti OCT 3 mm × 3 mm and 6 mm × 6 mm “Angio Retina” scan protocols. Ability to clearly delineate the foveal avascular zone (FAZ), FAZ remodeling, microaneurysms, capillary nonperfusion, motion, and doubling artifacts were evaluated.
Forty-six eyes from 27 patients were enrolled. Eighty-nine percent of 3 mm × 3 mm versus 59% of 6 mm × 6 mm scans clearly delineated the FAZ (P = 0.001). Eighty percent of 3 mm × 3 mm versus 43% of 6 mm × 6 mm scans demonstrated FAZ remodeling (P = 0.0002). Microaneurysms were detected by 57% of 6 mm × 6 mm and 35% of 3 mm × 3 mm scans (P = 0.003). Capillary nonperfusion was detected in 87% of 3 mm × 3 mm scans versus 89% of 6 mm × 6 mm scans (P = 0.99). No significant differences were noted in the incidence of artifacts between the scan sizes (motion artifact P = 0.29 and doubling artifact P = 0.29).
3 mm × 3 mm scan delineated FAZ and remodeling better than 6 mm × 6 mm scan, likely because of its higher scan density. 6 mm × 6 mm scans detected microaneurysms more readily than 3 mm × 3 mm, likely because of its larger scan area. There were utility for both 3 mm × 3 mm and 6 mm × 6 mm scans when evaluating these patients.
Two different optical coherence tomography angiography scan protocols were compared to evaluate their utilities in imaging various non–proliferative diabetic retinopathy pathologies. Although smaller field of view scans more clearly delineated the anatomy of the foveal avascular zone, the larger scan protocol better demonstrated microaneurysms and capillary nonperfusion.
*Shiley Eye Institute, University of California, San Diego, Department of Ophthalmology, La Jolla, California; and
†Tongren Eye Hospital, Beijing, China.
Reprint requests: William R. Freeman, MD, Department of Ophthalmology, University of California, San Diego, 9415 Campus Point Drive, La Jolla, CA 92093; e-mail: firstname.lastname@example.org
Supported in part by a core grant from the National Eye Institute P30 EY022589 and an unrestricted grant from Research to Prevent Blindness, NY (W.R.F.). The funding organizations had no role in the design or conduct of this research.
The data in this study were previously presented at the American Society of Retina Specialists Meeting August 2016, San Francisco, CA.
None of the authors has any conflicting interests to disclose.