Importance of early ocular examination to detect transitory irritation

Abstract The usefulness of early ocular examination in the design of rabbit eye irritation protocols is supported by the incidence of transitory hyperemia of the iris associated with topical corneal and conjunctival exposure to 10 different substances. The iridial effects, as well as signs of conjunctival irritation and transitory corneal opacity, were detected by inclusion of a 1 hr ocular examination. Five of the 10 substances produced moderate eye irritation and the others produced inconsequential eye irritation when a descriptive scale1.2 of ocular responses based on severity, persistence, and reversibility was applied. If the Federal Hazardous Substances Act (FHSA) Regulations Test for Eye Irritants3 is used to evaluate ocular toxicity, each substance would be classified as a nonirritant.