Diurnal intraocular pressure variation in pseudoexfoliation syndrome.

PURPOSE To describe and compare the diurnal intraocular pressure (IOP) variation in patients with pseudoexfoliation syndrome (PXS) and normal subjects. METHODS The authors prospectively investigated 19 PXS patients (10 bilateral and 9 unilateral) and 25 age- and sex-matched normal subjects. One eye of each control subject and bilateral PXS patient was selected randomly, and pseudoexfoliative eyes of unilateral cases were enrolled in this study. All patients were admitted to the authors' ophthalmology department and underwent diurnal IOP testing (six measurements over 24 hours). RESULTS The mean IOP of PXS patients at all time intervals was significantly higher than the control group (p<0.05). Likewise, a significant difference in the maximum IOP, range of IOP, and minimum IOP, as well as the standard deviation of the pressure at each time point, existed between groups (p<0.05). Normal individuals did not show diurnal variation greater than 5 mmHg. Of patients with PXS, 55.6% showed diurnal variation greater than 5 mm Hg. In addition, in 10% of patients with PXS, the diurnal variations were equal to or higher than 10 mmHg. CONCLUSIONS Variations in IOP during the daily 24-hour cycle in patients with PXS were higher than control groups. Significant fluctuations in the diurnal curve of IOP in PXS may be an important factor in predicting eyes that may develop pseudoexfoliative glaucoma. IOP fluctuation could influence the diagnostic and prognostic evaluation of PXS.