Comparison of primary open-angle glaucoma and exfoliation glaucoma at diagnosis

Abstract

Purpose: To compare ocular findings in eyes with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EG) at the time of diagnosis when identical diagnostic criteria for glaucoma were applied.

Methods: We conducted a study on records of 519 consecutive, unselected patients with chronic glaucoma filing for cost-free medication from the Finnish National Social Insurance Institute (FSII). Fourteen cases were excluded for having other types of glaucoma. The documents were provided by eye hospitals or by licensed ophthalmologists. The criteria for glaucoma were set by the Parliament of Finland and applied by FSII. A total of 329 patients had POAG and 176 had EG. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), cup-to-disc ratio of the optic nerve head (C/D), and glaucomatous changes of the visual fields (VF).

Results: As regards sex, the 2 groups were comparable: 66% female with POAG and 68% with EG. The EG patients were older (mean ± SD 74 ± 8.6 years) vs POAG (68 ± 11.4 years). The EG eyes had slightly lower BCVA. The POAG eyes had mean intraocular pressure (IOP) 24 ± 5.4 mm Hg. A total of 12% in this group had highest IOP of less than 18 mm Hg (low-tension glaucoma [LTG]) but there were none of EG. All EG eyes had a mean IOP 28.3 ± 9.3 mm Hg. Among EG patients, 26% had unilateral disease, with a mean IOP of 33.7 ± 8.7 mm Hg, while the opposite eyes had a mean of 19 ± 3 mm Hg. There was not much difference in the C/D ratios of POAG and EG eyes and the VF profiles were similar.

Conclusions: At diagnosis, patients with EG were older than those with POAG and had higher mean IOP values. Among patients with POAG, there were 12% with LTG, but none among EG. A total of 26% among EG had unilateral disease with marked IOP asymmetry. The C/D and VF profiles were similar because the patients had been seen early in the disease course. Early recognition and lifelong most effective therapy of EG are strongly advocated.