Effect of mydriatic and cycloplegic drugs in glaucomatous and nonglaucomatous eyes using ultrasound biomicroscopy

Abstract

Purpose: To study the anatomical relationships of the anterior segment of the eye, using ultrasound biomicroscopy in patients with chronic simple glaucoma and nonglaucomatous eyes, after mydriatic and cycloplegic instillation. Patients and Methods: Thirty eyes with chronic simple glaucoma and 30 nonglaucomatous eyes were studied. Anterior chamber depth, iris-lens contact and iris-zonule distance were measured, in both groups, using ultrasound biomicroscopy, in the three following conditions: without mydriatic and cycloplegic instillation, with 1% tropicamide alone and with 1% tropicamide plus 10% phenylephrine chlorhydrate. Results: Ultrasound biomicroscopy examinations of glaucomatous and nonglaucomatous eyes, without mydriatic and cycloplegic instillation, showed no statistically significant difference in the central anterior chamber depth, iris-lens contact and iris-zonule distance. The difference between examinations without mydriatic and cycloplegic instillation, with 1% tropicamide and with 1% tropicamide plus 10% phenylephrine chlorhydrate was statistically significant regarding the variables measured in both groups. Conclusions: No anatomical difference was observed between the anterior segment of glaucomatous and nonglaucomatous eyes after mydriatic and cycloplegic instillation. The results of this clinical investigation, using ultrasound biomicroscopy were innovative, allowing a dynamic and quantitative evaluation of the anatomical relationships between intraocular structures when submitted to mydriasis and cycloplegy, which up to now were only qualitative.