| Methods |
Design: three group, three period cross‐over trial
Purpose: study the effect of oral antioxidant therapy on marginal dry eye |
| Participants |
Patients: out‐patients with marginal dry eyes |
| Interventions |
Placebo: capsules without antioxidants
Untreated: no capsules
Experimental: capsules with antioxidants
(Co‐intervention: NS ) |
| Outcomes |
Glasgow Caledonian University threads phenol read thread test (G‐CUT)
Tear thinning time
McMonnies dry eye questionnaire
Squamous cell metaplasia
Goblet cell density |
| Notes |
The outcome data from this cross‐over trial was not available from the first period only, and was calculated as deriving from a parallel group trial. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
'Latin squares' |
| Allocation concealment? |
Unclear risk |
No stated |
| Blinding?
Treatment provider |
Low risk |
'This trial was double‐masked...' |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
High risk |
Drop‐out > 15% or NS |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Unclear risk |
The outcome data from this cross‐over trial was not available from the first period only, and was calculated as deriving from a parallel group trial. |
| No signs of variance inequality or skewness? |
Unclear risk |
Not relevant (not naturally positive continuous outcomes e.g. change) |
| Trial size > 49? |
Low risk |
N = 80 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Drop‐out > 15% or NS |
