Abstract
Purpose :
To evaluate the detection of microaneurysms (MAs) in healthy and diseased eyes by two different OCTA devices, using fluorescein angiography (FA) as the gold standard.
Methods :
Eyes with pathologies, including but not limited to diabetic retinopathy (DR), branch retinal vein occlusion and exudative age-related macular degeneration, were prospectively enrolled in the study. All eyes underwent OCTA imaging including macula 3mm x 3mm scan, macula 6mm x 6mm scan, and disc 4.5mm x 4.5mm scan, using the Cirrus (Zeiss, Dublin, CA), and the Maestro2 (Topcon Healthcare, Tokyo, Japan) devices, as well as FA. OCTA scans and FA images were graded by three graders from the Boston Image Reading Center. Presence and absence of MAs was graded on OCTA scans and on FA images within regions demarcating the OCTA scanning area. The final scores for each eye for each device was determined based on 2-out-of-3 agreement. The positive percent agreement (PPA, proportion of eyes with the OCTA showing MAs given the corresponding FA showed MAs), and negative percent agreement (NPA, proportion of eyes with the OCTA showing no MAs given the corresponding FA showed no MAs) were calculated. Since FA was the gold standard, eyes with indistinguishable MAs on FA were excluded from the analysis.
Results :
In total, 38 healthy eyes and 86 pathologic eyes were enrolled. For healthy eyes, FA detected MAs in a few eyes, while OCTA observed none, meaning PPAs for the two devices and the 3 scan types were zero. The NPA were all 100%, except one macula 6mm × 6mm scan on the Cirrus revealed a false positive detection in one eye reducing the corresponding NPA to 96.9%. For the eyes with pathology, the PPAs for MAs were all above 95% for the macular scan types on both OCTA devices and 73.9% and 70.0% for the disc scan for the Maestro and Cirrus, respectively. For both OCTA devices and all 3 scan types, the NPA ranged from 92.7% to 100% in eyes with pathologies.
Conclusions :
There was no significant difference between the Maestro and Cirrus OCTA in identifying MAs. When comparing to the clinical gold standard FA, both had excellent performance in identifying MAs on or around the macula. The disc scan on both devices showed comparatively lower detection of MAs, suggesting that known limitations of OCTA technology, such as projection artifacts from the presence of bigger vessels, are more likely to obscure the identification of MAs in the circumpapillary area.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.