Evaluation of Intraocular Pressure Fluctuations in Primary Open-Angle Glaucoma

Abstract

Background: Intraocular pressure (IOP) fluctuation is a known risk factor for glaucoma progression. This study aimed to evaluate diurnal IOP fluctuations and their association with treatment regimens in patients with primary open-angle glaucoma (POAG). Methods: This cross-sectional study was conducted in the Department of Ophthalmology, Dr. Sirajul Islam Medical College & Hospital Ltd, Dhaka and Bangladesh Eye Hospital, Malibagh, Dhaka, Bangladesh, from July 2022 to June 2023. A total of 120 patients with diagnosed POAG were enrolled. Baseline demographic and clinical characteristics were recorded, including visual acuity, visual field parameters, and ocular biometric measurements. IOP was measured at four fixed time points (08:00 AM, 12:00 PM, 04:00 PM, and 08:00 PM) in a single day to assess diurnal variation. Results: The mean age of participants was 58.4 ± 9.3 years, with a slight male predominance (53.33%). The average IOP was highest at 08:00 AM (20.76 ± 3.08 mmHg) and lowest at 04:00 PM (18.87 ± 2.86 mmHg). The overall mean daily IOP fluctuation was 3.41 ± 1.64 mmHg. Most patients (43.33%) had moderate fluctuations between 3–4 mmHg. IOP fluctuation was significantly associated with the type of medical therapy. Patients on monotherapy had the highest mean fluctuation (4.1 ± 1.2 mmHg), while those on triple therapy had the lowest (3.2 ± 1.3 mmHg) (p = 0.045). Conclusion: Diurnal IOP fluctuation is common among POAG patients and varies with the intensity of medical therapy. More aggressive treatment regimens may be beneficial in minimizing IOP variability, potentially reducing the risk of disease progression.