Rong 2017.

Methods	Study design: randomised controlled trial Study grouping: intra‐person (between eye) comparative trial Exclusions after randomisation? (If Yes, provide relevant details from the paper): 2 exclusions, but the paper did not state the time point that this occurred. Percentage of participant follow‐up (include details from all intervention groups): 95.7%; quote: "Two patients quit the study due to reasons not related to the study, and were not included in the analysis." Study duration (of intervention): not reported Was a sample size calculation reported? (Yes/No): no
Participants	Baseline characteristics IPL group Number of participants (number of eyes): 44 (44) Sex (number of females/males): 32/12 Age (mean): 46 (SD 17) years Sham (control) group Number of participants (number of eyes): 44 (44) Sex (number of females/males): 32/12 Age (mean): 46 (SD 17) years Overall Number of participants (number of eyes): 44 (88) Sex (number of females/males): 32/12 Age (mean): 46 (SD 17) years Inclusion criteria: aged ≥ 18 years; SPEED test > 6; MGYSS ≤ 12; Fitzpatrick skin type 1. Exclusion criteria: eye infections, allergies, surgery within 6 months; pupil abnormalities; skin tumours; numb nerves; Fitzpatrick 5, 6 or sunburnt within 4 weeks; pregnant or breastfeeding. Significant pretreatment baseline differences? None Severity of dry eye: not reported
Interventions	IPL group Description: IPL therapy (M22 strong pulsed system) of energy 14–16 J/cm². Duration: not reported. Co‐interventions: MGX (Arita tarsal gland massager to upper and lower eyelids); see 'Notes' below. Sham (control) group Description: sham IPL therapy (M22 strong pulsed system) of energy 0 J/cm². Duration: not reported. Co‐interventions: MGX (Arita tarsal gland massager to upper and lower eyelids); see 'Notes' below.
Outcomes	Primary outcome: MGYSS evaluated using the MGE‐1000 to assess tarsal excretion function. Each tarsal gland scored using the standard schema: the secreted liquid fat is: clear = 3 points, sticky white or light yellow fat = 2 points, concentrated toothpaste‐like fat = 1 point, no excretion = 0 points. Each squeeze with the MGE device can assess 5 connecting tarsal gland openings. In total, 15 glands were assessed and the MGYSS of upper and lower eyelids gives a combined score of 0–45. Secondary outcomes: tear film BUT, SPEED dry eye symptoms questionnaire (score 0–28), corneal fluorescein dye (scored using a 12‐point system), meibomian gland score (meibography‐based), safety evaluation (checking for eyelid burns, blisters, missing eyelashes or brow and skin pigmentation, Snellen vision chart BCVA, non‐contact intraocular pressure, slit lamp examination and OCT).
Identification	Funding sources: none reported Declarations of interest: none reported Country: China Setting: eye hospital Comments: Publication status: published study Journal of publication: various Language: Chinese Trial registration number: ChiCRT‐INR‐16010256 Contacting study investigators: 1 review author (LED) contacted the corresponding author in August 2019 to clarify whether the study population in this study was the same as the Rong 2018 study, which was confirmed to be the case. LED contacted the corresponding author in November 2019 to obtain further information about the random sequence generation and allocation concealment methods, to inform the risk of bias assessment, but received no response. Date study conducted: not reported Corresponding author's name: Xiaoming Yan Institution: Peking University First Hospital Email: yanxiaoming7908@163.com Address: 8 Xishiku Street, Xicheng District, Beijing, China
Notes	Additional treatments (in both intervention arms) Polyethylene glycol eyedrops 3 times per day Icepacks for 5 minutes after treatment, if heat or redness noted on the skin 5% compound lidocaine cream applied to eyelid, washed after 30 minutes 0.4% hydrochlorobupivacaine eye drops were dropped into the conjunctiva, 1 drop per 5 minute for total of 2 drops A metallic cover with 0.5% erythromycin was placed on the conjunctiva and fully covered the cornea and sclera. Adverse events: 5 participants had mild pain and burning, and 1 participant experienced an event that led to them partially missing their eyelashes "following mistakes from the doctors during treatment." These authors indicated that 0 participants experienced inflammation, retinal damage, ocular surface injury or injury to the posterior eye. Comments on statistical analysis: this study was an intra‐person (between eye) comparative trial. However, the results presented in the paper appeared not to be from a paired analysis. This represents a statistical analysis error, which limits our confidence in the reported inter‐eye differences.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: not reported how list was generated. Trial was described as "randomised" but with no further details.
Allocation concealment (selection bias)	Unclear risk	Judgement comment: allocation administration not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Judgement comment: stated as "double‐blind" but no indication of who was masked.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Judgement comment: stated as "double‐blind" but no indication of who was masked.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: missing data < 20% (i.e. > 80% participant follow‐up) and equal follow‐up in both groups and no obvious reason why loss to follow‐up should be related to outcome.
Selective reporting (reporting bias)	High risk	Judgement comment: retrospective registration of trial.
Other bias	Low risk	Judgement comment: no other apparent sources of bias.

BCVA: best‐corrected visual acuity; BUT: break‐up time; CFS: corneal fluorescein staining; IPL: intense pulsed light; LLT: lipid layer thickness; MGD: meibomian gland dysfunction; MGX: meibomian gland expression; MGYSS: Meibomian Glands Yielding Secretion Score; NIBUT: non‐invasive break‐up time; OCT: optical coherence tomography; SD: standard deviation; SPEED: Standard Patient Evaluation of Eye Dryness; TER: tear evaporation rate; TMH: tear meniscus height; VAS: visual analogue scale.