Researchers found that it was more beneficial to use OCT-A over other imaging methods when identifying and diagnosing patients with macular neovascularization. Photo: Steven Ferrucci, OD, and Jay M. Haynie, OD. Click image to enlarge.

Practitioners with access to OCT-A have come to rely on it for the evaluation of retinal disorders with a vascular component, but protocols are still being developed for these newer applications. To better understand the relative merits of cross-sectional and en face OCT-A, researchers recently conducted a prospective cohort study comparing both and found that cross-sectional OCT-A not only yields high sensitivity and specificity in the detection of this condition but also improves diagnostic accuracy vs. en face OCT-A imaging alone.

The study included 102 eyes of 63 consecutive patients with various chorioretinal diseases who had subretinal hyperreflective material and/or pigment epithelial detachment on OCT, possibly corresponding to macular neovascularization in at least one eye. Enrolled patients underwent fluorescein angiography (FA), OCT and swept-source OCT-A.

The researchers evaluated FA images, the outer retina to choriocapillaris OCT-A en face slab, a manually modified en face slab and cross-sectional OCT-A for the presence of macular neovascularization. A combination of cross-section and en face OCT-A was also analyzed.

A sensitivity for the detection of macular neovascularization of 46.3% and a specificity of 93.4% was observed when using the automatically provided outer retina to choriocapillaris OCT-A en face slab. The manually modified slab showed a sensitivity of 78.1% and a specificity of 88.5%, the study authors reported. Comparatively, cross-sectional OCT-A resulted in a sensitivity of 85.4% and a specificity of 82%. When evaluating en face in combination with cross-sectional OCT-A, macular neovascularization was identified with a sensitivity of 82.9% and a specificity of 85.3%.

These findings demonstrate the high level of sensitivity and specificity provided by cross-sectional OCT-A, according to the study authors, who also noted that the decreased sensitivity for disease detection on automatically generated OCT-A en face images is a result of segmentation errors.

“Cross-sectional OCT-A is independent of the position of segmentation lines and may improve accuracy of image evaluation compared with en face images alone by identifying the macular neovascularization-suspicious area and without time-consuming manual correction of segmentation errors in daily routine,” the researchers concluded.