The Impact of Pupillary Dilation on Intraocular Pressure and Anterior Segment Morphology in Subjects with and without Pseudoexfoliation.

Purpose: To investigate the change in pre- and post-dilation anterior segment parameters and intraocular pressure (IOP) of patients with and without pseudoexfoliation, after topical application of phenylephrine HCl 10% and tropicamide 1%.
Materials and Methods: Totally 129 eyes of 129 patients were included in the study. Of the 129 eyes; 31 had pseudoexfoliation syndrome (PXS), 37 had pseudoexfoliation glaucoma (PXG), 31 eyes were the fellow eyes of subjects with unilateral pseudoexfoliation syndrome (subclinical PXS) and 30 eyes were the eyes of subjects without PXS (controls). Patients underwent Pentacam analysis and IOP measurement before and after dilation. The changes in IOP, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), central corneal thickness (CCT) and pupillary diameter (PD) were investigated 30 min after the application of mydriatic agents.
Results: The mean change of IOP in eyes with PXS, in eyes with PXG, in eyes with subclinical PXS and eyes of control subjects were 1.45 ± 2.03 mmhg, 0.27 ± 2.25 mmhg, -0.35 ± 1.58 mmHg and -1.06 ± 1.59mmHg, respectively. Post-dilation IOP values were lower (p = 0.001) in eyes of controls but higher (p < 0.001) in eyes of PXS than the pre-dilation levels. All patients exhibited statistically significant increase in ACD, ACV and PD after the dilation procedure (p < 0.001). Additionally, post dilation CCT values were significantly lower than pre-dilation values in all groups; the difference was statistically significant only for eyes with PXG, eyes with subclinical PXS and eyes of controls.
Conclusion: Eyes with PXS had a higher tendency of IOP elevation after pupillary dilation. Eyes with subclinical PXS, however, exhibited a minor increase in IOP, reflecting the asymmetrical character of the disease. Anti-glaucoma medications may have blunted any IOP elevation induced by pupillary dilation in eyes with PXG.