The role of 24-hour intraocular pressure fluctuation on glaucoma progression in primary open angle claucoma

Introduction: The accurate assessment of patient’s intraocular pressure profile is critical in the management of primary open angle glaucoma. Although it is a multifactorial disease, IOP remain the only treatable risk factor for the condition. Currently, wide diurnal IOP fluctuation has been identified as an independent risk factor of glaucoma progression. Therefore a single IOP reading taken in our clinic will failed to detect diurnal IOP fluctuation in glaucoma patients. The recognition of diurnal IOP may also explain the progression of visual field in patients who appear to be controlled. Objectives: To study the pattern of 24-hour intraocular pressure fluctuation in primary open angle glaucoma patients and compare the 24 hours mean intraocular pressure, peak trough and IOP fluctuation between POAG patients with and without visual field progression. Patients and Methods: A comparative cross sectional study was conducted involving POAG patients. They divided into non-progressed and progressed group based on AGIS score. Patients were admitted in the ward and IOP measured by GAT at 4-hourly interval for 24-hour. Mean intraocular pressure, peak trough and IOP fluctuation IOP were compared between non-progressed and progressed groups. Analysis was conducted using repeated measure ANOVA and independent t-test A total of 68 patients (36 non-progressed and 32 progressed) were recruited. Mean age for all recruited patients were 68.3±8.6 years old. There was significant more Male among patient with progressed group than in non-progressed group (P=0.022). Mean follow-up was 6.7±3.8 years in progressed group and 5.0±2.6 years in non-progressed group. Patient in progressed group has significantly more moderate to severe glaucoma (P=0.001) and 71.9% of them were on more than two topical pressure lowering agents (P=0.001). There was significantly higher 24-hour mean peak IOP (P=0.001) and wider 24-hour mean IOP fluctuation (P=0.003) in progressed group compared to non-progressed group. There was significant higher mean IOP at 1200 hour in progressed group (P=0.003). Both group showed afternoon peak pattern. Conclusion: 24-hour IOP profile showed that there was significant higher 24-hour mean peak IOP and wider 24-hour mean IOP fluctuation found in progressed group. Both group showed pattern of afternoon peak