A fluorophotometric study of the barrier functions in the anterior segment of the eye after intracapsular cataract extraction

Abstract

The transfer coefficient of fluorescein across the corneal endothelium, kc.ac, was determined by a method of oral dye administration in 54 normal eyes. The kc.ac averaged 0.46 +/- 0.13 (SD) hour-1, and the fluorescein distribution ratio between the anterior chamber and the cornea, rac, was 0.57 +/- 0.20. There were no significant differences in these values between young subjects and those older than 50 years. A total of 56 eyes which underwent intracapsular cataract extraction were divided into three groups, 1) those operated on with routine medications, 2) with topical indomethacin and 3) with alpha-chymotrypsin of 7,500 times dilution. The value of rac was fixed at 0.57 and kc.ac was calculated taking the fraction, X, of unbound fluorescein in the aqueous into account. In addition, the apparent transfer coefficients of the dye between the blood and anterior chamber, k'in and k'out, were also calculated from the apparent fluorescein concentrations in the whole plasma and aqueous. The kc.ac was significantly greater in patients than in normal eyes, showing damage of the corneal endothelium by the surgery. The value of X was less than unity, indicating an increase in aqueous protein in the patients, but it was closer to unity in the indomethacin group than in other groups. The value of k'in was significantly less in the indomethacin group than in other groups. Between the groups with routine medication and with chymotrypsin, no significant difference was found in X or in k'in. It was concluded that topical indomethacin suppressed disruption of the blood-aqueous barrier and also that chymotrypsin at the present dilution did not cause serious disruption of the barrier.