Ball 2010.

Study characteristics
Methods	Study design: parallel RCT Unit of randomization: individual (1 eye included) Study start date: 10 January 2005 Study end date: 9 January 2006 Participant follow‐up time: 1 week Treatment time: 1 week Time from abrasion to randomization (hours): 24 Power calculation: “We determined that 16 participants in each group would be needed to have an 80% chance of detecting a pain reduction of 2 cm on the visual analog scale between the 2 groups, assuming an α of 0.05, and a standard deviation of 2 cm. We chose 2 cm to represent a clinically meaningful difference based on an informal survey of attending emergency physicians at our hospital.”
Participants	Country/countries: Canada Setting: 2 tertiary care emergency departments Inclusion criteria: adult patients with acute (within 24 hours) traumatic corneal injuries Exclusion criteria: immunocompromised, known allergy to local anesthetic, unable to consent/follow instructions for dosing/go to follow‐up appointments, previous ocular pathology Reported a subgroup analyses (Y/N): no Total randomized (n): 43, not reported by group Exclusions and loss to follow‐up (n; reasons): 11, not reported by group; noncompliance with treatment Analyzed (n): 33 Proparacaine 0.05% group: 15 Placebo group: 18 Age (mean ± SD, range): no total Proparacaine 0.05% group: 38.0 (28.0 ± 47.0) Placebo group: 39.3 (27.0 ± 46.0) Gender (number, % female): 5 (15%) Proparacaine 0.05% group: 2 (13%) Placebo group: 3 (17%) Race/ethnicity (study definition, n, %): not reported Etiology of corneal abrasion (study definition, n, %): not reported Baseline pain (study scale): not reported
Interventions	Interventions proparacaine 0.05% (diluted from proparacaine 0.5%), 2 to 4 drops as needed for 7 days, 40 mL total dispensed Comparison: "colour‐ and smell‐matched placebo", 2 to 4 drops as needed for 7 days, 40 mL total dispensed Co‐interventions: Topical gatifloxacin, 1 drop every 2 hours for 7 days Oral acetaminophen 325 mg with 30 mg of codeine, 1 to 2 tablets every 4 hours if needed, for 7 days
Outcomes	Primary study outcome(s): Pain reduction from baseline as measured on a 10 cm VAS (0 to 10; 0 = “no pain”, 10 = “the worst imaginable pain”). Mean difference in pain scores before and 5 minutes after drug administration as recorded by each study participant Secondary study outcome(s): Patient satisfaction with the study drug at 5 days post injury on a 10 cm VAS (0 to 10; 0 = "completely unsatisfied", 10 = "completely satisfied") Median number of drops of the study drug that patients self‐administered each time the study drug was used Median time interval between administration of the first and last drop of study drug for each time the study drug was used Median number of tablets of acetaminophen (300 mg) with codeine (30 mg) used after administration of the study drug Signs of delayed wound healing at days 3, 5, and 7 post‐injury Corneal toxicity on follow‐up Adverse event(s): ophthalmologist to assess for increased corneal thickness, corneal opacification, new corneal epithelial defects, or any other ocular pathology that could be related to either the initial injury or the use of study medication Measurement time points: all patients attended for follow‐up at an outpatient clinic on days 1, 3, 5, and 7
Notes	Sponsorship source: not reported Conflicts of interest: "none" declared Informed consent obtained?: yes Ethics approval obtained?: yes Investigator's name: Ian Michael Ball Affiliated institution: Divisions of Emergency Medicine and Critical Care Medicine, Department of Medicine, London Health Sciences Centre Trial registration ID: NCT00620997