Meta-analysis of medical intervention for normal tension glaucoma.

OBJECTIVE: To evaluate the intraocular pressure (IOP) reduction achieved by the most frequently prescribed antiglaucoma drugs in patients with normal tension glaucoma (NTG).

DESIGN: Systematic review and meta-analysis.

PARTICIPANTS: Fifteen randomized clinical trials reported 25 arms for peak IOP reduction, 16 arms for trough IOP reduction, and 13 arms for diurnal curve IOP reduction.

METHODS: Pertinent publications were identified through systematic searches of PubMed, EMBASE, and the Cochrane Controlled Trials Register. The patients had to be diagnosed as having NTG. Methodological quality was assessed by the Delphi list on a scale from 0 to 18. The pooled 1-month IOP-lowering effects were calculated using the 2-step DerSimonian and Laird estimate method of the random effects model.

MAIN OUTCOME MEASURES: Absolute and relative reductions in IOP from baseline for peak and trough moments.

RESULTS: Quality scores of included studies were generally high, with a mean quality score of 12.7 (range, 9-16). Relative IOP reductions were peak, 15% (12%-18%), and trough, 18% (8%-27%) for timolol; peak, 14% (8%-19%), and trough, 12% (-7% to 31%) for dorzolamide; peak, 24% (17%-31%), and trough, 11% (7%-14%) for brimonidine; peak, 20% (17%-24%), and trough, 20% (18%-23%) for latanoprost; peak, 21% (16%-25%), and trough, 18% (14%-22%) for bimatoprost. The differences in absolute IOP reductions between prostaglandin analogues and timolol varied from 0.9 to 1.0 mmHg at peak and -0.1 to 0.2 mmHg at trough.

CONCLUSIONS: Latanoprost, bimatoprost, and timolol are the most effective IOP-lowering agents in patients with NTG.