Association of Diabetic Lesions and Retinal Nonperfusion Using Widefield Multimodal Imaging

Heiko Stino; Kim Lien Huber; Michael Niederleithner; Nikolaus Mahnert; Aleksandra Sedova; Thomas Schlegl; Irene Steiner; Stefan Sacu; Wolfgang Drexler; Tilman Schmoll; Rainer Leitgeb; Ursula Schmidt-Erfurth; Andreas Pollreisz

doi:10.1016/j.oret.2023.07.020

Association of Diabetic Lesions and Retinal Nonperfusion Using Widefield Multimodal Imaging

Ophthalmol Retina. 2023 Dec;7(12):1042-1050. doi: 10.1016/j.oret.2023.07.020. Epub 2023 Jul 28.

Affiliations

¹ Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
² Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
³ Center for Medical Data Science, Institute of Medical Statistics, Medical University of Vienna, Vienna, Austria.
⁴ Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria; Carl Zeiss Meditec, Inc., Dublin, California.
⁵ Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Electronic address: andreas.pollreisz@meduniwien.ac.at.

PMID: 37517798
DOI: 10.1016/j.oret.2023.07.020

Abstract

Purpose: To evaluate the association of microvascular lesions on ultrawidefield (UWF) color fundus (CF) images with retinal nonperfusion (RNP) up to the midperiphery on single-capture widefield (WF) OCT angiography (OCTA) in patients with diabetic retinopathy (DR).

Design: Cross-sectional study.

Subjects: Seventy-five eyes of 50 patients with mild to severe nonproliferative DR (NPDR) and proliferative DR (PDR) were included in this analysis.

Methods: ETDRS level and presence of predominantly peripheral lesions (PPLs) were assessed on UWF-CF images acquired with a Zeiss Clarus 700. Single-capture 65°-WF-OCTA was performed using a PlexElite prototype (Carl Zeiss Meditec, Inc.). A custom grid consisting of a central ETDRS grid extended by 2 rings reaching up to the midperiphery was overlaid to subdivide retinal areas visible on WF-OCTA en face images. Retinal nonperfusion was measured in each area and in total. Nonperfusion index (NPI) was calculated from total RNP. On UWF-CF images, the number of microaneurysms, hemorrhages, neovascularizations, and areas with intraretinal microvascular abnormalities (IRMAs) were evaluated using the same grid.

Main outcome measures: Association of diabetic lesions with RNP was calculated using Spearman correlations (r_s).

Results: Median RNP on WF-OCTA was 0 mm² (0-0.9), 4.9 mm² (1.9-5.4), 23.4 mm² (17.8-37), and 68.4 mm² (40.8-91.7) in mild, moderate, and severe NPDR and PDR, respectively. We found a statistically significant correlation (P < 0.01) of overall RNP (r_s = 0.96,) and NPI (r_s = 0.97) on WF-OCTA with ETDRS level. Number of grid-fields affected by IRMAs on CF images was highly associated with NPI (r_s = 0.86, P < 0.01). Intraretinal microvascular abnormalities and RNPs had similar topographic distributions with high correlations in affected areas. Eyes with PPLs (n = 43 eyes, 57%) on CF images had a significantly higher NPI (P = 0.014) than eyes without PPLs.

Conclusion: The combination of UWF-CF imaging and single-capture WF-OCTA allows precise and noninvasive analysis of the retinal vasculature up to the midperiphery in patients with DR. The presence and extent of IRMAs on CF images may serve as an indicator for underlying RNP, which is more pronounced in eyes with PPLs.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Color fundus imaging; Diabetic retinopathy; OCT angiography; Retina; Retinal nonperfusion.

MeSH terms

Cross-Sectional Studies
Diabetes Mellitus*
Diabetic Retinopathy* / complications
Diabetic Retinopathy* / diagnosis
Fluorescein Angiography / methods
Humans
Multimodal Imaging
Retina / pathology