Long-term perimetric stabilization with a management algorithm of set target intraocular pressure in different severities of primary angle-closure glaucoma

Abstract

Purpose: To evaluate long-term perimetric stabilization at set Target (IOPs) in primary angle-closure glaucoma with visual field defects. Methods: Two hundred forty-eight eyes, of 124 primary angle-closure glaucoma (PACG) patients on medical treatment, and 124 eyes, of 95 patients after trabeculectomy performed at least 5 years prior were evaluated. One hundred eighty-five eyes had a follow-up of ≥10 years. Target IOPs for mild, moderate, and severe glaucomatous optic neuropathy were set at ≤18, ≤15, and ≤12 mmHg, respectively. Progression was evaluated by event-based changes on guided progression analysis. Primary outcome measure was therapy required to achieve individualized Target IOP. Secondary outcome measure was assessment of perimetric change over time. Results: Mean baseline IOP was 23.34 ± 6.16 mmHg in medically treated and 36.08 ± 9.73 mmHg in surgically treated eyes (P = 0.0001). All eyes with a baseline IOP of <25 mmHg were on medications alone, 65.33%, of those with a baseline IOP of 25-30 mmHg were on medications, while 34.67% required trabeculectomy. In total, 91.4% of eyes with a baseline IOP of >30 mmHg underwent a trabeculectomy for achieving Target IOP. Perimetric stabilization was achieved in 98.17% of PACG eyes. 'Target' IOP was achieved for mild, moderate, and severe glaucomatous optic neuropathy, medically in 90.2, 73.9, and 29.7%, and surgery was required in 9.8, 26.1, and 70.3%, respectively. Overall analysis found that percentage reduction in IOP was significantly more after trabeculectomy than medical treatment, 64.16 ± 14.91 and 43.61 ± 13.73%, P = 0.0001. Decrease in IOP was significantly greater 5-9 years after trabeculectomy, in comparison to ≥10 years, P = 0.001. Conclusion: Medications controlled IOP to 'Target' in PACG eyes with mild and moderate glaucoma for over ≥10 years, when the baseline IOP off treatment was <30 mmHg. Trabeculectomy was necessary in PACG eyes having severe glaucomatous optic neuropathy, or with a baseline IOP of >30 mmHg to achieve Target IOP. These appropriate initial therapeutic interventions and Target IOPs are therefore suggested as a clinically validated algorithm of care for different severities of PACG.