Conjunctival Impression Cytology Changes Induced by Oral Isotretinoin

Purpose: To evaluate the bulbar conjunctiva using impression cytology in patients submitted to oral isotretinoin treatment. Methods: A prospective, cohort study was carried out in a referral ophthalmology practice at the Federal University of Paraiba and in the External Eye Disease Laboratory of the Federal University of Sao Paulo. Twenty-eight patients with acne vulgaris were selected. Impression cytology specimens collected from the temporal bulbar conjunctiva and the superior bulbar conjunctiva of both eyes before and after 3 months of oral isotretinoin treatment were assessed. The doses of isotretinoin varied from 0.35 to 0.88 mg . kg(-1) . d(-1). Results: The percentage of patients in whom impression cytology results were normal was significantly lower during oral isotretinoin treatment compared to the pretreatment phase, decreasing from 75% to 43% in the temporal bulbar conjunctiva and from 100% to 82% in the superior bulbar conjunctiva. In both regions, the parameters most affected were cell-to-cell contact, nucleus-to-cytoplasm ratio, and goblet cell density. Conclusion: Oral isotretinoin for the treatment of acne induces alterations in the conjunctival epithelium of a significant percentage of patients treated with the drug. These alterations are seen both in the exposed conjunctiva (temporal bulbar region) and in the unexposed conjunctiva (superior bulbar region).