Corneal lesions induced by antidepressants: a selective effect upon young Fischer 344 rats.

Within a few days of dosing with various structurally unrelated antidepressants, young Fischer 344 rats display punctate lesions on the posterior surface of the cornea. Similar lesions are not seen after treatment with stimulants, an anticholinergic, a serotonin uptake blocker or an alpha adrenergic antagonist. These lesions are peculiar to the Fischer strain; four other strains displayed no such effects. Within the Fischer strain, sensitivity to the lesion-inducing effects of antidepressants is progressively lost with increasing age and adults are insensitive. Examination of the corneal lesions with transmission and scanning electron microscopy revealed that the lesion involved focal eruptions of the endothelium containing fibroblasts, necrotic cells, collagen and mineralized deposits. The latter were confirmed by energy-dispersive X-ray analysis to contain calcium. Thus the reported corneal lesions are unusual in their morphology as well as in their strain, age and drug specificity.