Routine preoperative medical testing for cataract surgery: A Cochrane systematic review

Author: Keay L, Lindsley K, Tielsch J, Katz J, Schein O.

Geographical coverage: Canada, the United States, Brazil and Italy

Sector: Cataract treatment, economic evaluation

Sub-sector: Preoperative treatment, costs

Equity focus: Not reported

Study population: Patients undergoing cataract surgery

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background

Cataract surgery is one of the most commonly performed operations worldwide, particularly in older adults with multiple co-morbidities. Routine pre-operative medical tests are intended to uncover occult risk factors, yet their value in enhancing surgical safety is disputed. Many tests detect conditions that seldom influence peri-operative management and may inflate healthcare costs without demonstrable clinical benefit. A clear assessment of their necessity and cost-effectiveness is therefore essential.

Objective

To determine whether routine pre-operative medical testing reduces adverse events associated with cataract surgery and to estimate its cost implications.

Main findings

Three randomised controlled trials (21,531 surgeries) compared routine testing with selective or no testing. Review findings include:

• Medical adverse events: 707 events occurred (353 with testing, 354 without); odds ratio (OR) = 1.00, 95 % CI 0.86 – 1.16 (high-certainty evidence). Cardiovascular events during surgery predominated.
• Intra-operative ocular events: OR = 0.99, 95 % CI 0.71 – 1.38.
• Post-operative ocular events: OR = 1.11, 95 % CI 0.74 – 1.67.
• Surgical cancellations: no difference between groups (OR = 0.97, 95 % CI 0.78 – 1.21).
• Costs: one study found total costs 2.55 times higher when routine tests were performed.

Overall, routine testing neither reduced adverse events nor improved surgical logistics, but it substantially increased costs.

Methodology

Searches of CENTRAL, MEDLINE, Embase, PubMed, LILACS, mRCT, ClinicalTrials.gov and WHO ICTRP up to 29 June 2018 identified RCTs comparing routine with selective or no testing before cataract surgery. Two reviewers independently screened studies, extracted data and assessed risk of bias; disagreements were adjudicated by a third reviewer. Fixed-effect meta-analysis was applied; heterogeneity (I²) and publication bias (funnel plot, Egger’s test) were evaluated. Certainty of evidence was graded using GRADE.

Applicability / external validity

Participants reflected typical cataract-surgery populations, including common co-morbidities, and most procedures used local anaesthesia, enhancing applicability to routine practice. Results may be less transferable to low-resource settings, where routine tests sometimes substitute for limited access to primary care.

Geographic focus

Included trials were undertaken in Canada, the United States, Brazil and Italy; no geographical restrictions were imposed.

Summary of quality assessment

Confidence in the review’s conclusions is high. Searches were comprehensive and unrestricted by language; inclusion criteria were explicit; dual processes for screening, data extraction and quality appraisal were employed; study characteristics were fully described; appropriate meta-analyses were conducted; and heterogeneity was explored. A list of included and excluded studies was supplied.