Prevalence of Primary Open-Angle Glaucoma and Pseudoexfoliative Glaucoma (PEXG) by IOP Level in a Population-Based Study. Thessaloniki Eye Study

Abstract

Purpose:: To evaluate the association of primary open angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG) and screening intraocular pressures (IOPs) in the Thessaloniki Eye Study (TES).

Methods:: TES is a cross-sectional, population-based of 2554 individuals in Thessaloniki, Greece. Subjects were diagnosed with POAG if they had glaucomatous optic nerve damage and open, normal-appearing anterior chamber angles in absence of secondary causes in either eye. Subjects were diagnosed with PEXG if they had glaucomatous optic nerve damage and pseudoexfoliative material in either eye.

Results:: Among the clinic-visit participants (n=2261), 94 subjects had POAG (4.2%) and 41 had PEXG (1.8%). 270 (12%) subjects had pseudoexfoliation. The prevalence of PEXG among subjects with pseudoexfoliation was 15.2% and the prevalence of POAG among subjects without pseudoexfoliation was 4.7%. Mean IOPs were 19.2 mmHg and 21.3 mmHg for the POAG and PEXG, respectively. 39 POAG and 26 PEXG subjects were receiving treatment (medications or prior surgery) and had mean IOPs of 18.6 mmHg and 19.3, respectively. In subjects without treatment the mean IOP was 19.6 mmHg and 24.6 for POAG and PEXG, respectively. PEXG presented with greater prevalence among subjects with pseudoexfoliation compared to POAG prevalence among subjects without pseudoexfoliation for the same IOP level throughout the whole IOP range. The risk of being diagnosed with glaucoma increased exponentially for IOPs greater than 21 mmHg for both POAG and PEXG.

Conclusions:: Greater prevalence of PEXG compared to POAG for the same IOP level was observed in TES. This may be due to higher IOP fluctuations in eyes with pseudoexfoliation or to more susceptible optic nerves in eyes with pseudoexfoliation.

Keywords: clinical (human) or epidemiologic studies: prevalence/incidence