[Variations of Intraocular Pressure with the Variations of Measurement Environment in Patients with Primary Open Angle Glaucoma].

Abstract

Objectives: To examine the variations in intraocular pressure (IOP) occuring upon changes in clinical premises' relocation in patients with primary open angle glaucoma (POAG).

Subjects and methods: Two hundred and twenty-four eyes of 224 patients with POAG were examined. We compared the IOP values measured with an identical noncontact tonometer (NCT) (CT-90A) obtained on May 2014 (IOP514) before the clinical premises' relocation, and those obtained on June (IOP614), July or August (IOP7814) 2014 after relocation. To examine the systematic errors of the NCT, Bland-Altman plot analysis was applied.

Results: IOP614 (12.2 ± 2.7 mmHg) and IOP7814 (12.1 ± 2.7mmHg) were significantly lower than IOP514 (13.1 ± 2.9 mmHg) (p < 0.001). IOP614 was also lower than IOP514, both in the β-blocker and prostaglandin analogue groups. When these values were adjusted using those obtained one year before the clinical relocation to take seasonal variations into consideration, IOP after relocation was lower than IOP before relocation (p < 0.001). Proportional bias was not detected (r = 0.082; p = 0.999).

Conclusion: There was a variation in IOP determined by the identical noncontact tonometer between before and after the clinical premises' relocation in patients with POAG.