Swept Source OCT-A Shows Structural Changes in Retinal Vasculitis

The novel use of swept-source optical coherence tomography angiography (SS-OCT-A) appears to help detect and monitor retinal vasculitis, but more study is needed to determine if it could offer “a semi-quantitative alternative” to fluorescein angiography (FA) when diagnosing and following the inflammation of retinal vessels, according to a study in Ophthalmology Retina.

“Swept-source OCT-A detects structural retinal thickening secondary to inflammatory retinal vascular leakage,” investigators report. “Further studies are required to confirm if OCT-A may serve as a semi-quantitative alternative to fluorescein angiography to diagnose and monitor the response to treatment in patients with retinal vasculitis.”

The study, a retrospective case series, looked at 21 patients with retinal vasculitis who were imaged on the same day with FA and 12 mm x 12 mm SS-OCT-A scans centered on the fovea. Investigators used a custom retina segmentation that superimposed a color retinal thickness map on a modified en face flow scan. Then, findings from the en face flow scans were correlated with localized perivascular retinal thickening on B-scans. They compared SS-OCT-A and FA results for the proportion of perivascular thickening to retinal vascular leakage or staining.

“Visible retinal vascular leakage/staining on FA corresponded to increased perivascular retinal thickness on SS-OCT-A in 17 patients,” they found. “Five patients had a second examination with same-day FA and SS-OCT-A after treatment of the vasculitis. Three of those 5 showed improved retinal vascular leakage/staining on post-treatment FA as well as decreased perivascular retinal thickness on SS-OCT-A scans.”

The study’s limitations included its retrospective design and lack of quantitative analysis, which might have created “limited cases with simultaneous OCT-A and FA scans pre and post-treatment.” They suggest a quantitative study is conducted to “grade the retinal vasculitis on FA and compare it with the perivascular retinal thickness on OCT-A in a blinded fashion.” This provides more quantitative data, such as sensitivity and specificity of OCT-A to detect and monitor the condition, compared with FA, researchers explain.

Disclosure: Several study authors declared affiliations with the biotech or pharmaceutical industries. Please see the original reference for a full list of authors’ disclosures.

Reference

Noori J, Shi Y, Yang J, et al. A Novel Method to Detect and Monitor Retinal Vasculitis Using Swept Source OCT Angiography. Ophthalmol Retina. Published online February 19, 2021. doi: 10.1016/j.oret.2021.02.007