Delayed intraocular pressure elevation after pupillary dilation in exfoliation syndrome

To determine the effect of pupillary dilation on intraocular pressure (IOP) in normotensive patients with exfoliation syndrome (XFS).

Patients with XFS were enrolled in this prospective trial. All eyes were untreated, had no previous laser or operative surgery and were normotensive with full visual fields and open angles. IOP was measured before dilation and hourly for four consecutive hours after dilation with tropicamide 1% and phenylephrine 2.5% eyedrops.

Twenty-five eyes of 19 White patients (nine male, 10 female) with XFS were enrolled. Twelve eyes (48%) had a rise in IOP of ≥ 4 mmHg above the pre-dilation baseline IOP and four (16%) had a rise of ≥ 9 mmHg (9-28 mmHg). Post-dilation gonioscopy confirmed the presence of an open anterior chamber angle in all eyes. The maximum IOP was reached 3 hr post-dilation in three eyes and after 2 hr in the remaining eyes. The four eyes with marked IOP rise exhibited an elevation of between 1 and 7 mmHg at 1 hr. Extensive pigment release was noticed in all eyes that had a rise in IOP.

Patients with XFS are at risk of developing delayed post-dilation IOP rises. Awareness of this phenomenon is particularly important in patients with advanced cupping and/or severe visual field loss who may not be able to tolerate a marked elevation of IOP. An early, mild rise in IOP at 1 hr may serve as a warning sign for a more severe, delayed response. Eyes with XFS should be monitored carefully after dilation, especially those with marked pigment release.