Comparison of self-measured diurnal intraocular pressure profiles using rebound tonometry between primary angle closure glaucoma and primary open angle glaucoma patients.

Shaoying Tan,Shihui Wei,Linda Hansapinyo,Vishal Jhanji,Clement C Tham,Nafees Baig,Sanjoy Bhattacharya

doi:10.1371/journal.pone.0173905

Abstract

PurposeTo document the diurnal intraocular pressure (IOP) profile with rebound tonometry performed by primary glaucoma patients in non-clinic environment.Patients and methodsFifty-three medically-treated eyes of 31 primary angle closure glaucoma (PACG) and 22 primary open angle glaucoma (POAG) patients with no previous eye surgery were recruited. Diurnal IOP was measured 5 times per day at four-hourly intervals from 08:00 to 24:00 for 1 week in patients’ study eye using rebound tonometry in a non-clinic environment. The diurnal IOP profiles were compared between PACG and POAG eyes.ResultsFor both PACG and POAG eyes, mean patient-measured IOP was highest in the morning, gradually decreased over the course of a day, and was lowest by midnight (p < 0.001). The diurnal IOP fluctuation ± 1 standard deviation (SD), as documented by SD in daily IOP values, was lower in PACG group (1.6 ± 1.1 mmHg) than in POAG group (2.0 ± 1.2 mmHg; p = 0.049). The mean trough IOP ± 1 SD was higher in PACG group (12.9 ± 2.8 mmHg), compared to POAG group (11.5 ± 3.8 mmHg; p = 0.041). The mean IOP level at midnight ± 1 SD in PACG group (14.0 ± 3.2 mmHg) was higher than that in POAG group (12.1 ± 3.7 mmHg; p = 0.013).ConclusionsIOP in primary glaucoma patients was highest in the morning, and decreased over the course of a day in non-clinic environment. Treated diurnal IOP fluctuation seemed to be greater in POAG than PACG eyes.

Highlights

Glaucoma is the second leading cause of irreversible visual impairment and blindness worldwide.[1]
For both primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG) eyes, mean patient-measured intraocular pressure (IOP) was highest in the morning, gradually decreased over the course of a day, and was lowest by midnight (p < 0.001)
IOP in primary glaucoma patients was highest in the morning, and decreased over the course of a day in non-clinic environment

Summary

Introduction

Glaucoma is the second leading cause of irreversible visual impairment and blindness worldwide.[1] More than 60 million people in the world were affected by primary glaucoma in the year 2000.[1] According to angle status, primary glaucoma can be divided into primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) For both types of primary glaucoma, intraocular pressure (IOP) elevation is a major risk factor for the onset and progression of glaucomatous optic neuropathy.[2,3,4,5] IOP reduction is the only proven clinical therapy to slow down glaucoma progression.[4]. There has been no comparison of diurnal IOP fluctuation of PACG to POAG eyes

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