Table 4.

Studies included in meta-analysis on open angle glaucoma (both primary open angle glaucoma and normal tension glaucoma (reported data only)

Study	Study design	Outcome	Comment
Heijl et al 200211,12 (early manifest glaucoma trial)	Randomised controlled trial, laser trabeculoplasty, betaxolol (5 mg/ml, twice daily) and latanoprost (50 μg/ml, once daily) when intraocular pressure >25 mm Hg in treated v observation in primary open angle glaucoma or normal tension glaucoma Randomised: 255 patients Duration: 6 years End point: deterioration of visual field or optic disc	Intention to treat analysis: 58 of 129 treated v 78 of 126 control patients reached end point (P=0.007, log rank test)	Significant protective treatment effect of reduction of intraocular pressure. Dropout rate about 11%
Collaborative Normal Tension Glaucoma Study Group 199813	Randomised controlled trial, medication or surgery (to lower intraocular pressure 30%) v observation in normal tension glaucoma. Randomised: 145 patients Duration: 5 years End point: deterioration of visual. field or optic disc	Intention to treat analysis: 22 of 66 treated v 31 of 79 control patients reached end point (P=0.21, log rank test). When censored for cataracts, 10 treated v 29 control patients reached end point (P=0.0018, log rank test).	Significant only when analysis censored for newly developed cataracts. Dropout rate not clear