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.

The tigroid fundus is one of the unique characters of Japanese macaques distributed from the north of the Japanese main island, Honshu, to Yaku-shima Island in the East China Sea, south of Kyushu Island.

The ocular fundi of over 360 monkeys living at ten points around the country were photographed and compared.

In the Mann-Whitney U-test, the Yaku macaque, a subspecies of the Japanese monkey, showed a typical, heavy tigroid fundus. The incidence of this character in the Yaku monkey showed significant difference from that of other groups in main islands (p<0.01). The other monkey groups did not have such a strong incidence of tigroid fundi. However, the incidences of the Hakusan group on the Japan Sea side and that of the Hagachi monkeys on the Pacific Ocean side were different significantly (p<0.05) from each other.