Impact of 85 kHz versus 125 kHz SHIFT OCTA scan speeds on image quality in retinal diseases and diagnostic reliability of choroidal neovascular membranes

The purpose of the study was to compare Optical Coherence Tomography Angiography (OCTA) scan speeds of 85 kHz and 125 kHz with respect to image quality, diagnostic reliability, and scan time in patients with retinal diseases. In this prospective cohort study, OCTA images were obtained at both scan speeds in 70 eyes from 40 patients with retinal diseases. Masked expert graders evaluated qualitative parameters including clinical utility, artifacts, and overall image quality. Quantitative parameters including scan time, Heidelberg Q-score, and OCTA-Q score were recorded. In 46 eyes with visible choroidal neovascular membrane in the avascular layer of OCTA, AngioTool (Image J) was used to assess vessel percentage area, vessel junction density, average vessel length, and E-Lacunarity. Acquisition speed of 125 kHz OCTA was significantly faster than that of 85 kHz. There were no statistically significant differences in AngioTool parameters between the two protocols. 125 kHz was significantly better than 85 kHz for image quality with fewer noise artefacts and vessel projection artefacts. In conclusion, 125 kHz SHIFT OCTA offers comparable to better image quality to the 85 kHz OCTA with significantly faster acquisition, potentially improving clinical workflow without compromising diagnostic reliability.