[QUANTIFICATION OF CONJUNCTIVAL HYPEREMIA IN RABBITS USING ANALYSIS SOFTWARE].

BACKGROUND/PURPOSE: In a method evaluating conjunctival hyperemia using rabbits, it is common to visually grade the degree of vasodilation. However, this method is limited in evaluating consecutive value and in reproducibility. We quantified the degree of conjunctival hyperemia in rabbits as the area ratio of blood vessels by image analysis, and compared the vascular area percentage calculated by image analysis with the hyperemia score.

METHODS

The conjunctiva was photographed before and after the instillation of 0.1% arachidonic acid using a digital medical scope VersaCam® (Nidek Co., Ltd.). Next, the area of the conjunctival blood vessels occupying the area of interest was calculated using hyperemia analysis software. The hyperemia score was visually graded for the degree of conjunctiva vasodilation. Furthermore, the hyperemia score and the vascular area ratio were compared.

RESULTS

Fifteen minutes after the instillation of arachidonic acid, the area ratio of the blood vessels in the conjunctiva increased significantly and gradually decreased over time. This trend correlated with the hyperemia score.

CONCLUSION

We found that the degree of conjunctival hyperemia in rabbits can be evaluated numerically and quantitatively. This method is considered to be useful for evaluating conjunctival hyperemia in allergic conjunctival diseases.