• 1 January 1989
    • journal article
    • research article
    • Vol. 33  (3) , 271-278
Abstract
The influence of a commonly used short-acting mydriatic agent, tropicamide-phenylephrine, on aqueous flare intensity and cell number was studied both in postsurgical cases and normal subjects. Measurements with a laser flare-cell meter were carried out in 40 patients who had undergone planned extracapsular cataract extraction with posterior chamber intraocular lens implantation. On the second postoperative day, 20 patients received one drop of a combined solution of 0.5% tropicamide and 0.5% phenylephrine, and the remaining patients received no mydriatic agents. Flare-cell meter measurements in the non-mydriasis group were rather difficult, and measurements in 12 out of 20 (60%) cases were discontinued. In the mydriasis group, flare intensity became significantly lower 2 hours after the application (P < 0.01) and continued to decrease throughout the rest of the measurement period. The cell counts tended to decrease throughout the period after mydriasis and showed significantly lower values compared to the initial value (P < 0.01). It was considered that measurements with this instrument in postoperative cases are best performed between 30 minutes to 1 hour after the application of the short-acting mydriatic agents. In normal human eyes, the effects of 0.5% phenylephrine-0.5% tropicamide, 0.4% tropicamide, and 5% phenylephrine on aqueous flare and cells were tested separately. Aqueous flare intensity was significantly decreased by tropicamide-phenylephrine at 1, 1.5 and 2 hours (P < 0.05), by tropicamide at 1 and 1.5 hours (P < 0.01), and by phenylephrine at 3 hours (P < 0.01) after the application, respectively. Values returned to normal following these transient decreases. It was considered that changes in the flare intensity in normal subjects could be attributed to the pharmacological effects of the agents, while decreases in the postoperative flare intensity and cell count were mainly due to the mechanical effects of pupillary dilatation, which led to changes in anterior and posterior chamber dynamics.