Schulzer 1991.

Methods	RCT. Open label.
Participants	137 people with OHT. Racial constitution is not reported. Inclusion criteria: IOP above or equal to 22 mmHg, normal visual fields (Goldmann perimeter). Exclusion criteria: Obvious sign of glaucomatous disc changes, ocular infections, trauma or surgery within 6 months before the study, resting pulse of 50 beats or less, systemic beta‐blockers.
Interventions	Timolol 0.5% twice daily. No treatment.
Outcomes	Incidence of reproducible visual field defect. Incidence of disc haemorrhages. Incidence of stereophotographically documented optic nerve changes.
Notes	6 years follow up. 22 drop‐outs: 12 timolol (2 adverse drug reaction) and 10 untreated. The reasons for drop‐out are not specified.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear