Anterior segment-optical coherence tomography angiography (AS OCT-A) can visualize and measure the vessels in a variety of conjunctival lesions with high repeatability, according to a study published in The Ocular Surface.

Typically, morphological lesion characteristics, such as anatomical location, basal diameter, pigmentation, or the presence of cysts or feeder vessels on slit-lamp examinations, are used to distinguish benign from malignant tumors. However, further diagnostic imaging can provide more data to assess these lesions, according to the study.

AS OCT-A has been used to assess lesion thickness and epithelial thickness in ocular surface squamous neoplasia. However, that modality has some limitations. AS OCT-A, however, can compensate for some of those limitations by detecting blood vessel flow from the red blood cell movement within the vessels through sequential en face scans at the same location. The application of AS OCT-A has shown promising results in corneal neovascularization and other ocular surface diseases, according to investigators.


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This retrospective, case-control study included 10 eyes of 9 patients with malignant lesions and 23 eyes of 22 patients with benign lesions. In the benign and malignant groups, mean ages were 49.5±22.4 and 64.3±10.6 years (P =.145). The lesions examined included 13 epithelial, 10 pigmented, and 10 lymphoid.

Graders performed an average of 3 depth and diameter measurements of perilesional vessels entering each lesion on AS OCT-A. The technology showed greater perilesional vessel depth and diameter in malignant lesions (315.2±73.0 μm, P <.001 and 76.4±18.2 μm, P <.001; respectively) compared with benign lesions (199.4±34.1 μm and 44.0±9.4 μm, respectively). Malignant lesions showed deep and dilated perilesional vessels, which researchers believe may represent feeder vessels. Vessel depth showed AUC =0.980, 90.9% sensitivity and 100.0% specificity with a 236.5 μm cutoff. Vessel diameter showed AUC=0.960, 100.0% sensitivity and 88.9% specificity with a 53.9 μm cutoff.

The malignant lesions showed significantly greater perilesional vessel depth and diameter than benign lesions in this study, and might be an important diagnostic marker in ocular surface lesions, specifically in epithelial and pigmented lesions. 

The main limitations of this study include its retrospective nature and small sample size in each group. Other limitations include the penetration of the spectral domain wavelength in dense tissues and that imaging thick and extensive lesions can be challenging due to the limitations of commercially available devices.

Disclosure: Several of the study’s authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Binotti WW, Mills H, Nosé RM, et al. Anterior segment optical coherence tomography angiography in the assessment of ocular surface lesions. Ocul Surf. 2021;22:86-93. doi:10.1016/j.jtos.2021.07.009