Information on background changes in the ocular tissues of rabbits ( Oryctolagus cuniculus), a common species employed in ophthalmic toxicology studies, is sparse. This complicates interpretation of changes in light of small sample sizes on any single study. The purpose of this publication is to document the interstudy incidence of spontaneous or iatrogenic changes occurring in eyes of control rabbits. Photomicrographs of select lesions are provided. The data set was derived from a total of 54 studies conducted over an eleven-year period at Alcon Research Ltd., a Novartis Division, which featured topical ocular and contact lens routes of administration. It includes a total of 1,222 pigmented and albino New Zealand rabbits and a total of 2,084 eyes which were either untreated or treated with innocuous control articles. There were no noteworthy differences across routes of administration. Changes in anterior segment ocular and adnexal tissues were more common than in posterior segment ocular tissues. Overall, mononuclear cell infiltration was the most common finding. The retina was the posterior tissue most commonly observed with spontaneous changes, with folds and rosettes being the most common retinal finding. Retinal changes were more common in albino as compared to pigmented rabbits. Understanding the incidence and characteristics of spontaneous ocular lesions facilitates accurate and consistent diagnosis and data interpretation.
Keywords: control; eye; histopathology; historical; lesion; pathology; rabbit; spontaneous; toxicology.