Automated hyperemia analysis software: reliability and reproducibility in healthy subjects

Abstract

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.

Objectifying the Conjunctival Provocation Test: Photography-Based Rating and Digital Analysis

“…Thus, the ROI may have differed from patient to patient and from visit to visit, but not between photos of a patient's visit and of a CPT session, respectively. All photos were taken so as to capture the whole visible bulbar conjunctival space, so that the segmented ROI could be very large and cover as much as possible of the conjunctiva, unlike other methods using small ROIs of constant size and form [28]. Second, all images were modified by a four-filter system, which was integrated in the software and used to enhance color contrast, depict vessel edges and rims, and reduce background noise.…”

“…The current literature describes several achievements in digital image analysis of conjunctival vessels, which are reported to be more sensitive than subjective ratings [19,20,27,28,29,30,31,32,33,34,35,36]. Combinations of different techniques are described, such as threshold-setting, edge-detection, color extraction, smoothing, fractal analysis or densitometry [28,33].…”

“…Combinations of different techniques are described, such as threshold-setting, edge-detection, color extraction, smoothing, fractal analysis or densitometry [28,33]. …”

“…The authors used ImageJ software to select vessel pixels in a predefined region of interest (ROI) after image processing with threshold setting and binarization. In a consecutive work, Yoneda et al [28] investigated the reproducibility and reliability of automated software in analyzing conjunctival hyperemia in humans. They figured that current subjective evaluation methods using various grading scales needed to be replaced by more objective procedures.…”

“…Although no CPTs were conducted here, the patient collective included a few subjects with allergic conjunctivitis. The methods described [28] seem to possess the applicability in hyperemia measurement of the CPT. …”