Quantifying pupillary dilation-induced alterations in intraocular pressure, angle, and anterior segment parameters in pseudoexfoliation syndrome using Scheimpflug imaging.

Abstract

Purpose: The aim of the study is to compare the effects of three mydriatic agents on anterior segment parameters and intraocular pressure (IOP) in pseudoexfoliation (PEX) patients and compare the results with healthy controls.

Patients and methods: This cross-sectional study involved 25 PEX and 16 control patients. Each received three dilating drops (phenylephrine, tropicamide, and cyclopentolate) with eye examinations before and after (over 3 weeks). The measured parameters included IOP, gonioscopy grading, and Scheimpflug imaging analysis of anterior chamber depth, anterior chamber volume, anterior chamber angle, pupillary diameter (PD), central corneal thickness (CCT), and corneal volume.

Results: The mean age was 66.12 years in the PEX group and 55 years in the control group. There were no significant differences between the groups in baseline parameters, except for CCT being significantly thicker in the control group (P = 0.049). After 2 h of using the dilating drops, the PEX group showed no change in CCT and gonioscopy measurement while all the other tested parameters showed a significant increase. Phenylephrine caused the greatest increase in pupil diameter. Correlation analysis of PD versus other parameters in both groups showed only a negative significant correlation between PD and IOP when using tropicamide on the PEX patients.

Conclusion: All three dilating drops are effective in dilating PEX patients. Phenylephrine is the most effective and ideal for both clinics and surgeries. Cyclopentolate is the least effective dilator in PEX patients compared to healthy controls. Tropicamide 1% provides a good balance between pupil dilation and minimal IOP elevation, making it safer for PEX patients.