Spontaneous Ocular Findings in the Common Marmoset (Callithrix jacchus)

Since the use of common marmosets (Callithrix jacchus) to replace or complement the cynomolgus and rhesus macaques as experimental models in toxicity studies is likely to increase, a better knowledge of their anatomical, physiological, and histopathological characteristics is needed.In this study, the normal ocular pattern of the marmoset is described, in order to differentiate between spontaneous and induced ophthalmological abnormalities that may occur in subsequent toxicity studies. Consequently, the same examinations were performed in our colony of marmosets as those required for toxicity studies in nonrodent species.External gross examinations of the eye and its adnexae, ocular reflexes, anterior ocular segment biomicroscopic examinations, and indirect fundic examinations performed with an indirect ophthalmoscope were carried out. Ophthalmological findings often consisted of embryonic remnants. The most important findings were either considered to be congenital in origin or of nondeterminate etiology.The visual capabilities of the marmosets did not seem to be affected by these findings.