Anterior segment optical coherence tomography angiography in the assessment of ocular surface lesions

Purpose: Describe the utility of anterior segment optical coherence tomography angiography (AS-OCTA) to assess ocular surface lesions. Methods: Retrospective, case-control study of 10 eyes of 9 patients with malignant lesions and 23 eyes of 22 patients with benign lesions. Lesions included 13 epithelial, 10 pigmented and 10 lymphoid lesions. Graders performed an average of 3 depth and diameter measurements of peri-lesional vessels entering each lesion on ASOCTA. Statistical models to assess differences between groups accounted for bilateral eye inclusion and lesion thickness (on AS-OCT). Receiver operating characteristic (ROC) curve and area under the curve (AUC) were performed for each parameter. Results: In the benign and malignant groups, age was 49.5 +/- 22.4 and 64.3 +/- 10.6 years (p = 0.145) with 45% males and 55% males (p = 0.458), in their respective groups. AS-OCTA showed greater peri-lesional vessel depth and diameter in malignant lesions (315.2 +/- 73.0 mu m, p < 0.001 and 76.4 +/- 18.2 mu m, p < 0.001; respectively) compared to benign lesions (199.4 +/- 34.1 mu m and 44.0 +/- 9.4 mu m, respectively). Malignant lesions showed deep and dilated peri-lesional vessels, which may represent feeder vessels. Vessel depth showed AUC = 0.980, 90.9% sensitivity and 100.0% specificity with a 236.5 mu m cutoff. Vessel diameter showed AUC = 0.960, 100.0% sensitivity and 88.9% specificity with a 53.9 mu m cutoff. Conclusion: AS-OCTA shows greater peri-lesional vessel depth and diameter of malignant lesions compared to benign lesions. This imaging modality provides novel and non-invasive functional vascular parameters that can potentially aid the assessment of ocular surface lesions.