Conjunctival
hyperemia is observed in a variety of ocular inflammatory conditions. The evaluation of
hyperemia is indispensable for the treatment of patients with ocular
inflammation. However, the major methods currently available for evaluation are based on nonquantitative and subjective methods. Therefore, we developed novel software to evaluate bulbar
hyperemia quantitatively and objectively. First, we investigated whether the
histamine-induced
hyperemia of guinea pigs could be quantified by image analysis. Bulbar conjunctival images were taken by means of a digital camera, followed by the binarization of the images and the selection of regions of interest (ROIs) for evaluation. The ROIs were evaluated by counting the number of absolute pixel values. Pixel values peaked significantly 1 minute after
histamine challenge was performed and were still increased after 5 minutes. Second, we applied the same method to
antigen (
ovalbumin)-induced
hyperemia of sensitized guinea pigs, acquiring similar results except for the substantial upregulation in the first 5 minutes after challenge. Finally, we analyzed human bulbar
hyperemia using the new software we developed especially for human usage. The new software allows the automatic calculation of pixel values once the ROIs have been selected. In our clinical trials, the percentage of blood vessel coverage of ROIs was significantly higher in the images of
hyperemia caused by allergic
conjunctival diseases and
hyperemia induced by
Bimatoprost, compared with those of healthy volunteers. We propose that this newly developed automated
hyperemia analysis software will be an objective clinical tool for the evaluation of ocular
hyperemia.