PURPOSE.To determine the pharmacokinetics of perorally administered caffeine, a widely consumed and potent dietary antioxidant, in the anterior lens capsule and lens epithelial cells, a crucial cell monolayer for cataract development.METHODS. Bilateral cataract patients were scheduled for cataract surgery with a caffeine abstinence of 1 week before surgery of each eye. At the day of surgery of the second eye patients were administered no drink (0-mg group) or coffee with 60-, 120-, or 180-mg caffeine. After capsulorhexis the lens capsule including lens epithelial cells was transferred to a test tube for analysis of caffeine concentration by gas chromatography-mass spectrometry (GC-MS/MS).
RESULTS.Coffee consumption significantly (P < 0.05) increased caffeine levels of the lens capsule/epithelium in the 60-, 120-, and 180-mg group. Caffeine concentrations (caffeine ng/ lens capsule/epithelium) measured as difference between 1st and 2nd eye were À0.52 6 1.16 (0-mg group, n ¼ 7), 1.88 6 2.02 (60-mg group, n ¼ 8), 2.09 6 0.67 (120-mg group, n ¼ 9), and 3.68 6 1.86 (180-mg group, n ¼ 9). The increase constant of caffeine in a linear regression model was estimated as a 95% CI 0.02 6 0.0046 (degrees of freedom; 25; r ¼ 0.85).CONCLUSIONS. Peroral intake of coffee significantly increased caffeine concentrations in the lens capsule and lens epithelial cells in a dose-dependent manner. This information is important for further investigations on preventing cataract.