Mohammadpour 2017.

Methods	Study design: randomized, controlled trial Study site(s): single‐center Number randomized (total and per group): 63 eyes of 48 participants; 32 eyes in the omega‐3 treatment group; 31 eyes in the control group Unit of randomization (individual or eye): individual Exclusions after randomization: none Losses to follow‐up: 2 eyes in the control group Unit of analysis (individual or eye): eye Reported power calculation? (Y/N): Y (80% power) Reported subgroup analysis? (Y/N): N
Participants	Baseline characteristics Country: Iran Age (mean ± SD, range): 59.75 ± 11.57 (range 37 to 82) years in the omega‐3 treatment group; 67.81 ± 9.62 (range 39 to 81) years in the control group Gender: 4 men and 21 women in the omega‐3 treatment group; 6 men and 13 women in the control group Inclusion criterion: 1. New‐onset dry eye symptoms (foreign body sensation, burning, itching, red eye, photophobia, or blurring of vision) with a history of recent cataract surgery via phacoemulsification Exclusion criteria: 1. History of ocular trauma, uveitis, other previous ocular surgeries 2. Contact lens wearing in the previous 2 years 3. Systemic diseases that are associated with dry eye syndrome including diabetes 4. Rheumatoid arthritis and Sjogren's syndrome 5. Existing dry eye symptoms before cataract surgery 6. Considerable change in lifestyle with an impact on ocular surface diseases (eg, computer use) during the postoperative period Equivalence of baseline characteristics? (Y/N): N (omega‐3 treatment group was significantly younger than the control group; P = 0.003)
Interventions	Intervention #1 (treatment group): standard therapy plus omega‐3 dietary supplement (1000 mg every 8 hours, Advanced Canada, each capsule containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid) every 8 hours (daily dose of 510 mg eicosapentaenoic acid and 360 mg docosahexaenoic acid) Intervention #2 (control group): standard therapy alone (artificial tears [every 4 hours] and betamethasone 0.1% eye drops [every 8 hours]) Length of follow‐up: 1 month Notes: standard therapy for dry eye (Artelac artificial tears every 4 hours, Dr. Gerhard Mann Company, Germany; and betamethasone 0.1% eye drops every 8 hours)
Outcomes	Primary and secondary outcome measures were not clearly distinguished Specified outcome(s): OSDI; TBUT; Schirmer test without anesthesia; tear osmolarity; each outcome was measured at study endpoint Adverse events reported? (Y/N): N Measurement time points (specify intervals at which outcomes were assessed): baseline, 1 month Other issues with outcome assessment (eg, quality control for outcomes, if any): unit of analysis error, whereby 63 eyes of 48 participants were included without taking into account the non‐independence of eyes
Notes	Study dates: recruitment occurred between September 2013 and May 2014 Funding source(s): "none of the authors has a financial or proprietary interest in any mentioned product, method, or material" Conflicts of interest: "none of the authors has a financial or proprietary interest in any mentioned product, method, or material" Publication language: English Registered on clinical trials registry? (Y/N): N
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Patients were randomly allocated into two groups using urn randomization"
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Masking of participants was not performed due to the nature of the interventions
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"All measurements were done by a single person (M.M), and the physician in charge of collecting outcome data was kept blinded to the allocation"
Incomplete outcome data (attrition bias) All outcomes	High risk	2/31 (6.5%) eyes in the control group were not included in the final analysis
Selective reporting (reporting bias)	Unclear risk	No access to study protocol or clinical trials registry
Other bias	High risk	63 eyes of 48 participants were included without taking into account the non‐independence of eyes (unit of analysis error); baselines were not equivalent for an important prognostic factor (age; P = 0.003)