1：Experimental Design and Method Selection:

This prospective cross-sectional study involved imaging healthy volunteers using two SS-OCTA devices (PLEXElite and Triton) with a 3x3-mm volume scan pattern centered on the fovea. Six binarization methods (two global and four local adaptive thresholding) were applied using ImageJ software to calculate vessel density. Reproducibility was assessed through intraobserver coefficients of correlation (ICC) and coefficients of variation (CV).

2：Sample Selection and Data Sources:

Healthy subjects aged 20 years or older were recruited from an ophthalmology outpatient clinic. Exclusion criteria included various ocular diseases, poor image quality, and specific refractive errors. A total of 60 eyes from 30 subjects were initially included, with 38 eyes from 23 subjects ultimately analyzed after exclusions.

3：List of Experimental Equipment and Materials:

SS-OCTA devices: PLEXElite (PLEX Elite 9000, Carl Zeiss Meditec) and Triton (Topcon DRI OCT Triton); ImageJ software (National Institutes of Health); other ophthalmic equipment for comprehensive exams (e.g., slit-lamp biomicroscopy, noncontact tonometry, fundus photography).

4：Experimental Procedures and Operational Workflow:

Subjects underwent imaging with both SS-OCTA devices twice a day. Images were binarized using the six methods in ImageJ without noise removal. Two blinded reviewers assessed image quality, excluding poor-quality scans. Vessel density was calculated as the proportion of angiography signal in the 3x3-mm macula area.

5：Data Analysis Methods:

Statistical analyses included calculation of ICC and CV for reproducibility, paired t-tests to compare vessel densities between instruments, and use of JMP, Stata, and SPSS software for analysis. A P-value less than 0.05 was considered significant.