Pathogenesis of blepharoconjunctivitis complicating 13-cis-retinoic acid (isotretinoin) therapy in a laboratory model.

Systemic treatment of adult male New Zealand albino rabbits with 13-cis-retinoic acid (isotretinoin) resulted in a reduction in the size of the meibomian gland. Clinical signs of toxicity included weight loss, alopecia, dry skin and mild conjunctival erythema with crusting on the eyelid margin. Histopathologic findings included thickening of duct and ductule epithelium, decrease in acinar tissue, accentuation of basaloid cells and evidence of periacinar fibrosis. The model presents the first experimental data to indicate that systemic 13-cis-retinoic acid effects meibomian gland structure in a laboratory model. Future functional studies of this model may yield important insights into the relationships between meibomian gland morphology, function, the ocular surface and the pathogenesis of blepharo-conjunctivitis.