Abstract
Purpose :
Tracking of eye motion has a major impact on optical coherence tomography angiography (OCTA) image quality by, among other effects, reducing eye motion artifacts. We evaluated the performance of a newly implemented tracking approach, by comparing its resulting images and acquisition times with those of the commercially available tracking algorithm, for the Spectralis device.
Methods :
We included 30 eyes (30 healthy subjects; 15 female; mean age 28±3) with clear media, no ocular diseases or surgery, and healthy systemic status. We collected the following OCTA acquisitions, by using Spectralis TruTrack (TT) and next-gen TruTrack (ngTT): macular high-resolution (HR) 85 kHz, high-speed (HS) 85 kHz, HR 125 kHz and HS 125 kHz (all ART 7; 15°x15°; Q-value >25) (Spectralis, Heidelberg Engineering, Germany). One blinded expert grader assessed intraretinal OCTA vascular slabs of co-registered OCTA volumes. The presence of artifacts was evaluated on a 3-point scale; 0 (no artifacts) to 1/ 2/ 3 (artifacts involving 1, 2, or ≥3 quadrants), as well as foveal avascular zone (FAZ) area, overall vessel density (VD) and sectorial VD analysis using a standardized 9-sector ETDRS grid. Agreements between continuous variables were analyzed by two-tailed T-tests. Tau-Kendall correlation analysis was also performed for the above variables and automatically logged OCTA acquisition times. P-values <0.05 were considered statistically significant.
Results :
Compared to TT, ngTT OCTA acquisitions showed shortened acquisition times (p<0.05). FAZ area and overall VD values were comparable (p>0.05); however, by 9-sector ETDRS grid analysis we detected VD differences (p<0.05). TT showed higher prevalence of artifacts; these strongly correlated with the acquisition time (p<0.05). ngTT OCTA provided more consistent VD data than TT; on visual inspection the 85 kHz HR OCTA with ngTT provided the most detailed vascular reconstructions.
Conclusions :
Probably due to improved patient compliance and reduced tear film degradation, ngTT outperformed TT in terms of artifact prevalence and microvascular visibility. Given that ngTT was specifically designed to address poor eye fixation combined with the encouraging data of the present study, ngTT would appear to substantially improve OCTA acquisition in patients with retinal disease: further study in that population is warranted.
This abstract was presented at the 2023 ARVO Imaging in the Eye Conference, held in New Orleans, LA, April 21-22, 2023.