Novel Parameters to Assess the Severity of Corneal Neovascularization Using Anterior Segment Optical Coherence Tomography Angiography

PURPOSE: Assessment of anterior segment-optical coherence tomography angiography (AS-OCTA) to determine severity of corneal neovascularization (CoNV). DESIGN: Retrospective, cross-sectional, single-center study. METHODS: Patients of various CoNV etiologies were selected and classified into mild, moderate, and severe. Their AS-OCTA images were measured for CoNV anterior limit, CoNV posterior limit, CoNV thickness, CoNV depth%, CoNV vessel density, CoNV area, and CoNV volume. Further, AS-OCTA parameters were correlated to clinical parameters, such as classification, a numerical severity scale, vascular clock hours, and best-corrected visual acuity (BCVA). RESULTS: A total of 19 mild, 10 moderate, and 6 severe CoNV eyes were included with no significant age-gender differences. CoNV depth% and volume increased from mild to moderate (9.3 +/- 1.1% to 17.7 +/- 3.3%, P = .030, and 0.2 +/- 0.1 mm(3) to 1.0 +/- 0.3 mm(3), P = .025, respectively) and from moderate to severe CoNV (44.6 +/- 5.3%, P < .001, and 2.0 +/- 0.3 mm(3), P = .014, respectively). CoNV area and posterior limit increased from mild to moderate (1.7 +/- 0.3 mm(2) to 4.6 +/- 0.7 mm(2) , P = .001, and 217.7 +/- 16.8 mu m to 349.1 +/- 54.9 mu m, P = .048, respectively), not from moderate to severe (P = .999 and P = .403, respectively). CoNV thickness increased from moderate to severe (218.2 +/- 46.6 mu m to 340.2 +/- 8.7 mu m, P = .020), but not from mild to moderate. CoNV area and volume showed good correlations to CoNV staging (r = 0.703 and r = 0.771, respectively; P < .001) and severity scale (r = 0.794 and r = 0.712, respectively; P < .001). CoNV area showed good corre- lation to clock hours (r = 0.749, P < .001). CoNV depth and volume showed good correlation to BCVA (r = 0.744 and r = 0.722, respectively; P < .001). CoNV anterior limit and vessel density showed no significant correlations (P >=.05). CONCLUSIONS: Severe CoNV shows greater CoNV posterior limit, thickness, depth%, area, and volume on AS-OCTA compared to mild. CoNV volume and depth strongly correlate to BCVA. AS-OCTA provides novel, quantitative, and noninvasive parameters for assessing CoNV severity. (C) 2020 Elsevier Inc. All rights reserved.