Automated hyperemia analysis software: reliability and reproducibility in healthy subjects
Tsuyoshi Yoneda1, Tamaki Sumi, Ayako Takahashi
1Department of Ophthalmology and Visual Science, Kochi Medical School, Kohasu, Oko-cho, Nankoku 783-8505, Japan.
Purpose:
To evaluate the reliability and reproducibility of automated software to analyze human bulbar hyperemia.
Methods:
We enrolled 89 healthy volunteers in this study. A slit lamp was used to take pictures of the conjunctiva on the temporal side of each subject's right eye. Photographic conditions were standardized by using a single photographer. Images were transferred to software for automatic pixel value calculation in the green channel of the region of interest (ROI). We investigated optimal ROI size, mean ROI pixel frequency, percentage ROI blood vessel coverage, and data reproducibility. We also used this software to evaluate bimatoprost-induced hyperemia and hyperemia in allergic conjunctival diseases.
Results:
The optimal ROI was found to be 400 vertical pixels by 300 horizontal pixels. Mean ROI pixel frequency was 5305 and % coverage was 4.4%. We confirmed the reproducibility of the analysis by comparing two images (r (2) = 0.7, P < 0.0001). Percentage blood vessel coverage increased in images of bimatoprost-induced hyperemia and hyperemia in allergic conjunctival diseases compared to the data from healthy volunteers.
Conclusions:
The software was simple to use and provided reproducible data. We established standard settings for the operation of the software. The use of our software will improve hyperemia evaluation, which is presently done using nonquantitative methods.
