Ophthalmic Examinations in Preclinical Safety Studies

Abstract

Evaluation of potential ophthalmic toxicity of chemicals and medicines is an integral part of safety assessment studies before clinical trials in humans. Each ophthalmic examination can be considered a screening test or a specific diagnostic test. Screening examinations include physical examinations (for facial symmetry, evaluation of tear film, movements of the nictitans and pupillary light response), indirect ophthalmoscopy, slit lamp biomicroscopy and light microscopy. Diagnostic ophthalmic examinations may include Schirmer tear test, fluorescein staining, specific neuro-ophthalmic examinations, pachymetry, tonometry, electrophysiological examinations and electron microscopy. The choice of examination method will be determined by the species used, the type of study being performed and the ”expected” effects of the test compound. Familiarity with characteristics of numerous ophthalmic lesions enables a significant increase of the quality of ophthalmic examinations in preclinical safety assessment studies.