Goyal 2017.
| Methods |
Study design: randomized, controlled trial Study site(s): single center Number randomized (total and per group): 60 participants in total; 30 participants in each of the 2 intervention arms Unit of randomization (individual or eye): individual Exclusions after randomization: not reported Losses to follow‐up: not reported Unit of analysis (individual or eye): eye Reported power calculation? (Y/N): N Reported subgroup analysis? (Y/N): N |
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| Participants |
Baseline characteristics Country: India Age (mean ± SE, range): 23.6 ± 2.4 (range 20 to 32) years in the treatment group; 23.6 ± 3.4 (range 20 to 34) years in the control group Gender: 27 men and 33 women in total Inclusion criteria: 1. Participants attending the Cornea and Refractive Services of the Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India, undergoing LASIK 2. Aged 20 years or greater 3. Stable refractive error for the last 1 year 4. Maximum manifest refraction spherical equivalent of 26.00 diopters (D) Exclusion criteria: 1. Presence of any inflammatory pathology of the lid margin/tarsal conjunctiva, which could be expected to adversely affect the tear film, that is, significant allergic conjunctivitis (symptoms of itching in the presence of papillae ≥ 0.3 mm over the upper tarsal conjunctiva), anterior blepharitis (hyperemia of lid margins, crusting around the base of lashes), or MGD (meibum quality total score ≥ 4, meibum expressibility score > 1, presence of lid margin signs, ie, meibomian gland dropout or displacement) 2. Lacrimal drainage abnormalities, for example, punctal stenosis or nasolacrimal duct obstruction 3. History of lacrimal gland pathology, such as dacryoadenitis or lacrimal gland surgery 4. Presence of structural or functional lid anomalies including lid laxity; lid laxity was assessed on a scale of 0 to 4 (0 = normal laxity, 4 = severe laxity), using the “snap back test” by pulling the lower lid away and down from the globe for several seconds and waiting to see the time taken before it returned to the original position without the patient blinking. Any patients having greater than grade 0 laxity (ie, normal lid springing back to its original position immediately) were excluded 5. Presence of pre‐existing dry eye due to any cause, defined for the purpose of the study as Schirmer test I readings without anesthesia < 10 mm/5 min and an ocular surface disease index (OSDI) questionnaire score ≥ 13 6. Current use of systemic corticosteroid or immunosuppressive therapy 7. Patients taking antidepressants, antihistamines, or anticoagulants 8. Presence of autoimmune diseases, collagen vascular diseases, diabetes mellitus 9. Pregnant, nursing, or lactating women 10. Patients having malabsorption syndromes 11. Allergy to fish oils Equivalence of baseline characteristics? (Y/N): Y |
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| Interventions |
Intervention #1 (treatment group): oral capsule containing 180 mg EPA and 120 mg DHA, 2 capsules/time, twice daily (daily dose of 720 mg EPA and 480 mg DHA) Intervention #2 (control group): soft gel capsules of vitamin E (daily dose of 400 mg/d) Length of follow‐up: 13 weeks (1 week before LASIK, and 12 weeks post LASIK) Notes: contact lens use, if any, was stopped at least 2 weeks before the patient was recruited for the study |
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| Outcomes |
Primary outcome(s): mean change from baseline in both of Schirmer test without anesthesia and TBUT Secondary outcome(s): corneal fluorescein staining and conjunctival lissamine green staining at study endpoint (measured as percentage of participants with abnormal ocular surface staining, defined as a score > 3 (of a total of 15 for corneal staining and of a total of 18 for conjunctival staining); change from baseline in symptoms of dry eye (OSDI score) Adverse events reported? (Y/N): N Measurement time points (specify intervals at which outcomes were assessed): baseline (presurgery); 1 week, 1 month, and 3 months post surgery Other issues with outcome assessment (eg, quality control for outcomes if any): this study has a unit of analysis issue, whereby both eyes from participants were included in the analyses without apparent statistical adjustment for within‐person (between‐eye) correlation |
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| Notes |
Study dates: recruitment occurred between July 2014 and September 2015 Funding source(s): "the authors have no funding or conflicts of interest to disclose" Conflicts of interest: "the authors have no funding or conflicts of interest to disclose" Publication language: English Registered on clinical trials registry? (Y/N): N |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Sixty consecutive patients who were considered fit for the procedure were allocated either to a treatment group or a control group using a random number table, after obtaining written signed consent" |
| Allocation concealment (selection bias) | Unclear risk | Allocation concealment was not reported |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | This was an "open‐label" study |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | "All examinations were performed by a single observer who was not masked to the intervention received by the patients" |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Missing data are not reported |
| Selective reporting (reporting bias) | Unclear risk | No access to study protocol or clinical trials registry |
| Other bias | High risk | Unit of analysis error: both eyes of a single participant were included in the analysis separately, without statistical adjustment |