Biomedical subjects

M Sawa

Publications and source records attributed to M Sawa.

At least 145 records · Page 8Linked to original sources

PubMed1983

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

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.

Adult↗

PubMed1983

Topical flurbiprofen and diclofenac suppress blood-aqueous barrier breakdown in cataract surgery: a fluorophotometric study.

A total of 33 eyes which underwent intracapsular extraction of senile cataract were divided into three groups, 1) 13 eyes operated on with routine medication alone, 2) 10 eyes operated on with additional topical flurbiprofen and 3) 10 eyes operated on with additional topical diclofenac. In the latter two groups, in addition to routine medication, an ophthalmic solution of 0.1% flurbiprofen or diclofenac was instilled 3, 2, 1 and 0.5 hours prior to surgery and postoperatively 4 times a day for 6 days. On the 6th postoperative day, fluorophotometric examination with oral fluorescein administration was carried out in all eyes to determine the apparent transfer coefficient of the dye into the anterior chamber (k'in) and out of the anterior chamber (k'out). After oral administration of a 10% fluorescein solution at a dose of 5 mg per kg of body weight, the time-courses of the apparent fluorescein concentrations in the anterior chamber and in the whole plasma were determined for 7-8 hours. The apparent transfer coefficient was calculated from the time-courses by computer fitting of Davson's equation. The value of k'in represents the permeability of the blood-aqueous barrier and it averaged 0.039 +/- 0.021 hour-1 (Mean +/- SD) in the routine medication group, 0.014 +/- 0.007 hour-1 in the flurbiprofen group, and 0.017 +/- 0.008 hour-1 in the diclofenac group. The values in the latter two groups were significantly smaller than that in the routine medication group (Mann-Whitney U-test, P less than 0.005). It was concluded that topical flurbiprofen or diclofenac suppressed the disruption of the blood-aqueous barrier that had occurred during cataract surgery.

Administration, Topical↗

PubMed1982

Permeability of the corneal endothelium to fluorescein--a follow-up of keratoplasty cases.

The permeability of the corneal graft endothelium to fluorescein was determined, by the oral administration method, in 47 eyes with penetrating keratoplasty. The endothelial permeability was expressed as the transfer coefficient of the dye between the anterior chamber and the cornea. In the early postoperative period, an increase in the aqueous protein was noted and a correction was made for fluorescein binding to aqueous protein. The measurements of the graft thickness and morphometry of the endothelial cells by specular microscopy were also carried out concurrently. The transfer coefficient was high in the early postoperative period, and was reduced by time. Similarly the graft was thick in the early postoperative period but it thinned to a normal level over a period of several months. A significant correlation was found between the transfer coefficient and the corneal thickness. The mean cell size of the graft endothelium was significantly greater than that of the normal cornea. The mean cell size and the postoperative period were correlated using the present data and those reported by Sato previously. A significant positive correlation was found, indicating progressive enlargement of the graft endothelial cells over a long period of time. The mean cell size was not significantly correlated with the transfer coefficient nor with the graft thickness.

Administration, Oral↗

PubMed1982