Prevalence of Undiagnosed Primary Open Angle Glaucoma and Pseudoexfoliative Glaucoma in Greece: Thessaloniki Eye Study

Abstract

Purpose: : ^{To compare the prevalence of undiagnosed glaucoma in primary open angle glaucoma (POAG) and pseudoexfoliative glaucoma (PXEG) in an elderly Greek population.}

Methods: : ^{: Randomly sampled people aged 60 years and older from the municipality registries of the city of Thessaloniki were invited to participate in the Thessaloniki Eye Study (TES) in which an extensive ophthalmic examination was performed by trained ophthalmologists. The examination included a dilated slit lamp examination, evaluation of the optic nerve head, imaging of the optic nerve head, and automated perimetry. Glaucoma was defined as the presence of both glaucomatous optic disc and confirmed glaucomatous visual field (VF) damage in either eye irrespective of the intraocular pressure (IOP) (definition 1) or the presence of either glaucomatous visual field defect or glaucomatous optic nerve damage in either eye with additional clinical evidence strongly in favor of glaucoma (definition 2). POAG was diagnosed when the angles were open and there was no evidence of a secondary cause of glaucoma. PXEG was diagnosed when the angle was open and pseudoexfoliative material was noted on the anterior lens capsule and/or the iris. Undiagnosed glaucoma was defined as a negative response on all of the following questions which were administered to participants: history of prior diagnosis of glaucoma, history of prior diagnosis of ocular hypertension (OHT), history of medical treatment for glaucoma and history of prior glaucoma surgery. Answers to these questions by POAG and PXEG patients were compared with Fisher’s exact tests. P–values were considered statistically significant when less than 0.05.}

Results: : ^{In TES 2554 subjects were enrolled (participation rate 71%). POAG was diagnosed in 2.7% of the population with definition 1 and in 3.8% with definition 2. PXEG was diagnosed in 1.1% and 1.7%, respectively. Compared to PXEG patients, POAG patients reported more undiagnosed glaucoma (54.1% vs 32.6%, p=0.027).}

Conclusions: : ^{In TES, patients with POAG were less likely to have been diagnosed with glaucoma than patients with PXEG. More patients with PXEG may be diagnosed with glaucoma than POAG patients. This may be linked to the lens changes seen in PXEG and an increased awareness of eye doctors in Greece regarding the association between PXE and glaucoma}

Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: health care delivery/economics/manpower