In diabetic macular edema (DME) patients, optical coherence tomography angiography (OCT-A) may detect fewer microaneurysms than fundus fluorescein angiography (FA), likely due to leakage and retinal thickening, new research reports.

Investigators examined OCT-A and FA images of 31 eyes of 24 participants and graded them for microaneurysms. They found just 58% of microaneurysms detected on FA were also visible on OCT-A. Additionally, microaneurysms with focal leakage in a thickened retinal area were detected more frequently on OCT-A than non-leaking microaneurysms in non-thickened retinal areas. Most microaneurysms on OCT-A were seen in the intermediate (23%) and deep capillary plexus (22%). Of all microaneurysms visualized on OCT-A, saccular microaneurysms were detected most often (31%), as opposed to pedunculated microaneurysms (9%).

“Retinal microaneurysms in DME could be classified topographically and morphologically by OCT-A,” researchers said. “OCT-A detected less microaneurysms than FA, and this appeared to be dependent on leakage activity and retinal thickening. Morphological appearance of microaneurysms (irregular, fusiform and mixed saccular/fusiform) was associated with increased leakage activity and retinal thickening.”

Schreur V, Domanian A, Liefers B, et al. Morphological and topographical appearance of microaneurysms on optical coherence tomography angiography. Br J Ophthalmol. June 20, 2018. [Epub ahead of print].