Influence of topically applied cyclosporine A in olive oil on corneal epithelium permeability.

The effect that topically administered cyclosporine A (CsA) dissolved in olive oil has on corneal epithelial permeability was determined by fluorophotometry. Twenty-six healthy volunteers, who had no ocular or general disease and were not receiving any topical or systemic treatments, were studied. A Fluorotron Master fluorophotometer was used. Measurements were taken before and 45 min after the instillation of 40 microliters of a 2% aqueous solution of sodium fluorescein without preservatives. Basal corneal epithelial permeability, as well as the permeability 24 h after the instillation of 2% CsA-olive oil and of the solvent alone, were calculated. Under sterile conditions, the Sandimmun oral solution (Sandoz, Basel, Switzerland) was used to prepare the topical 2% CsA. Immediately after the 2% CsA-olive oil or the solvent alone were instilled, the volunteers complained of itching for approximately 1 h and developed punctate keratopathy, which improved the next day. Epithelial permeability 24 h after instillation of 2% CsA-olive oil increased 7.03 times (p < 0.001), and that of the solvent alone increased 6.68 times (p < 0.001). No differences in corneal permeability were found between CsA-olive oil and the vehicle (p = 0.651). We concluded that the olive oil used to dissolve CsA is responsible for the increased corneal epithelial permeability.