Long-term progression at individual mean intraocular pressure levels in primary open-angle and exfoliative glaucoma

PURPOSE: To describe progression and non-progression rates at individual mean intraocular pressure (IOP) levels for patients with primary open-angle and exfoliative glaucoma. METHODS: A meta-analysis of five previously published retrospective studies describing progression and non-progression rates at individual intraocular pressure levels over 5 or more years of follow-up. All patients had primary open-angle (four studies) or exfoliative glaucoma (one study). RESULTS: This meta-analysis included 822 patients of whom 655 (80%) had primary openangle glaucoma and 167 (20%) had exfoliative glaucoma. In total, 220 patients progressed (27%), while 602 (73%) remained stable over 5 years. The mean IOP was 20.0 for progressed and 17.1 mmHg for stable patients (p=0.0004). The peak IOP was 29.1 for progressed and 23.6 mmHg for stable patients (p=0.0014). At an IOP level >18 mmHg, 49% of patients remained stable; at 18 mmHg, 78%; between 13 and 17 mmHg, 82%; and <13 mmHg, 96%.Additional factors associated with progression were older age (p=0.0004) and exfoliative glaucoma (p=0.0001). However, multivariant regression analysis identified only mean IOP as a risk factor for progression (p=0.039). CONCLUSIONS: This study suggests that maintaining an IOP well within the normal range over 5 years in patients with primary open-angle or exfoliative glaucoma helps to prevent glaucomatousprogression.