Role of 24-Hour Intraocular Pressure Monitoring in Glaucoma Management.

Chun Hing Ho,Jasper K W Wong

doi:10.1155/2019/3632197

Abstract

Glaucoma is the leading cause of irreversible blindness worldwide and the prevalence is on the rising trend. Intraocular pressure (IOP) reduction is the mainstay of treatment. The current practice of IOP monitoring is based on spot measurements during clinic visits during office hours. However, there are up to 50% of glaucoma patients who had normal initial IOP, while some treated patients continued to have progressive glaucomatous optic nerve damage even with a low IOP. Recent studies have shown that the IOP of glaucoma patients fluctuated during the day with different patterns, and some of them had peak IOP outside office hours. These findings provided us with new insights on the role of 24-hour IOP monitoring in managing normal tension glaucoma and patients with progressive deterioration despite apparently well-controlled IOP. Nevertheless, results to date are rather inconsistent, and there is no consensus yet. In this review, we briefly highlighted the current modalities of 24-hour IOP monitoring and summarized the characteristic 24-hour IOP pattern and the clinical relevance of IOP parameters in predicting glaucomatous progression in different glaucoma subtypes. We also discussed the therapeutic efficacy of current glaucoma treatment modalities with respect to the mentioned 24-hour IOP profiles, so as to strengthen the role of 24-hour IOP monitoring in identifying and stratifying the risks of progression in glaucoma patients, as well as optimizing treatments according to their IOP profiles.

Highlights

Glaucoma is defined as a group of progressive optic neuropathies characterized by the degeneration of retinal ganglion cells which results in optic nerve head changes and subsequent visual field loss [1, 2]
Sood and Ramanathan performed a study involving 18 patients with treated normal tension glaucoma (NTG) using rebound tonometry (RTONE) for 1 year [21]. e Intraocular pressure IOPf (IOP) measurements obtained with RTONE were shown to be strongly correlated with Goldmann applanation tonometer used in clinic visits, and for patients with NTG with a progression that was disproportionate to their office IOP measurements, the use of RTONE can reveal higher IOP spikes which was unidentified during office hours. erefore, self-tonometry is definitely a valuable adjunct to spot office measurements as it provides a more complete data on the diurnal change of IOP which may assist in glaucoma management [22]
We hypothesized that such controversy may be explained by the difference in study designs and the variety in glaucoma subtypes. erefore, we reviewed the literature and characterized the important findings of the studies regarding the 24-hour IOP patterns of primary and secondary open-angle glaucoma, normal tension glaucoma (NTG), primary angle closure glaucoma (PACG), and ocular hypertension (OHT)

Summary

Introduction

Glaucoma is defined as a group of progressive optic neuropathies characterized by the degeneration of retinal ganglion cells which results in optic nerve head changes and subsequent visual field loss [1, 2]. It is the leading cause of irreversible blindness worldwide [3]. High intraocular pressure causes mechanical stress and strain on the posterior structures of eyes, the lamina cribrosa, where the sclera is perforated and the retinal ganglion cell axons leave the eye [7]. Different mechanisms have been postulated to explain such phenomenon, including variations in optic nerve head (ONH) microcirculation [13,14,15,16] and pitfalls in IOP measurements

Methods

Findings

Discussion

Conclusion