Espíndola 2012a.

Methods	Study design: RCT Study grouping: parallel group, with two study groups (non‐blue‐light filtering IOL vs different non‐blue‐light filtering IOL, n = 25 eyes each per comparison; non‐blue‐light filtering IOL vs blue‐light filtering IOL, n = 27 eyes each per comparison) Exclusions after randomisation: participants with incomplete follow‐up were excluded from the analyses Losses to follow‐up: participants with incomplete follow‐up were excluded from the analyses How missing data were handled: not reported Reported power size calculation? yes
Participants	Baseline characteristics Blue‐light filtering IOLs Number of participants: number of people (number of eyes): 27 (27) Sex (number of women/number of men): 7/20 Age (mean ± unit of error): 68.5 ± 3.84 years (unit of error not specified) Non‐blue‐light filtering IOL Number of participants: number of people (number of eyes): 52 (77) Sex (number of women/number of men): 20/32 Age (mean ± unit of error): not reported Inclusion criteria: people with visually significant bilateral cataract; people with no history of glaucoma Exclusion criteria: people with any ocular disease, such as corneal opacities or irregularity, dry eye, amblyopia, anisometropia, retinal abnormalities, surgical complications, IOL tilt, previous or current use of medications known to cause colour‐vision deficiencies, or incomplete follow‐up Comparison of study groups at baseline: paired eye study; no group differences reported and "no eye had intraoperative complications"
Interventions	Intervention characteristics Blue‐light filtering IOL Type of IOL: AcrySof Natural SN60AT (Alcon) Non‐blue‐light filtering IOLs Type of IOL: Akreos Fit (Bausch & Lomb) or Akreos AO (Bausch & Lomb) or AcrySof SA60AT (Alcon ‐ but also described as MA60AC in the paper)
Outcomes	The primary outcome measures were contrast sensitivity (photopic and mesopic) and blue‐on‐yellow perimetry values (mean deviation and pattern standard deviation), at two years postoperatively Safety outcomes were the rate of intraoperative complications and the proportion of participants requiring capsulotomy at two years postoperatively
Identification	Sponsorship source: Funding sources: no specific financial support Declaration of interest: no potential conflicts of interest for any authors Country: Brazil Setting: Study conducted in Ophthalmology Department of the University of São Paulo, São Paulo, Brazil Comments: Date study conducted: not reported Trial registration number: not reported Contacting study investigators: study authors not contacted; no additional information used for review Corresponding author's name: Rodrigo F. Espíndola Institution: Ophthalmology Department of the University of São Paulo, São Paulo, Brazil Email: rodrigo166@uol.com.br Address: Rodrigo F. EspíndolaPraça das Hortências, 70 ‐ Itu (SP) ‐ 13301‐689 ‐ Brazil
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: not reported how list was generated. Study is described as “randomised” but with no further details
Allocation concealment (selection bias)	Low risk	Quote: "Sequenced and sealed envelopes containing the first type of IOL (Akreos AO or Akreos Fit; SN60AT or MA60AC) were prepared before surgery. An unscrubbed observer in the operating room opened the envelopes and assigned each patient." Judgement comment: clearly states how the intervention allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "All patients and observers were masked about the IOL type implanted." Judgement comment: clearly states that all participants and observers were masked to the intervention
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The observers who conducted the postoperative visual evaluations did not have access to the randomization code or information about the surgical procedures." Judgement comment: clearly states that outcome assessors were masked
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "All patients completed 24 months of follow‐up." Judgement comment: although the paper states "All patients completed 24 months of follow‐up", an exclusion criterion was that "Patients with surgical complications or incomplete follow‐up were excluded". Although "there were no eyes with intraoperative complications," it is unclear whether follow‐up was 100‐percent for all participants as this was an exclusion criterion.
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no access to protocol or trials registry entry
Other bias	Low risk	Judgement comment: no other apparent sources of bias