Verin 2001.

Methods	Parallel‐group RCT
Participants	222 participants with seasonal allergic conjunctivitis
Interventions	Two treatment arms: levocabastine; emedastine. Duration of treatment 6 weeks
Outcomes	Participants' assessment of itching and redness using diaries and visual analogue scale (0 = none; 9 = severe) Physician assessment of itching, redness Time points: day 0‐14 and day 30‐42 of treatment
Country	Europe, South Africa, and Australia
Number randomised, gender (male:female)	222 participants randomised, 202 participants analysed. Gender not stated
Age mean (SD), median, range	Mean (range) 30 years (4‐76)
Notes	Not reported when study was conducted. Source of funding Alcon Research Ltd. Declaration of interest by the authors was not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The method used to generate the allocation sequence was not described
Allocation concealment (selection bias)	Unclear risk	The method used to conceal the allocation sequence was not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not intention‐to‐treat analysis
Selective reporting (reporting bias)	Low risk	Evidence was available of proper outcome reporting
Other bias	Low risk	No apparent evidence of other risk of bias
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Identical containers (p.692 ‐ methods): "Study medications were provided in identical containers so that both patients and investigators remained masked."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Identical containers (p.692 ‐ methods): "Study medications were provided in identical containers so that both patients and investigators remained masked."