Effect of Cataract Surgery on Frequency of Falls among Older Persons: A Systematic Review and Meta-analysis

Author: Gutiérrez-Robledo LM, Villasís-Keever MA, Avila-Avila A, Medina-Campos RH, Castrejón-Pérez RC, García-Peña C.

Geographical coverage: United Kingdom, Australia, the United States and Vietnam

Sector: Cataract surgery

Sub-sector: Risk of falling

Equity focus: Not reported

Study population: Patients with cataract undergoing surgery, assessed for falls

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background:

Falls are a major public-health concern worldwide, causing almost 646 000 deaths each year, most in people aged ≥ 60 years, and a further 37.3 million non-fatal falls. Key risk factors include advanced age, previous falls, visual impairment and neurological or mobility disorders. Cataract is the leading cause of visual impairment in older adults, particularly in low- and middle-income countries. Cataract surgery removes the opacified lens and implants an intra-ocular lens to restore vision. Since the 1950s visual impairment has been linked with a higher risk of falling, prompting investigation into whether cataract surgery mitigates this risk. Earlier studies produced inconsistent findings; recent trials warrant an updated synthesis.

Objective:

To determine whether cataract surgery reduces the frequency of falls in older people.

Main findings: The review included 8 studies (2 randomised controlled trials [RCTs] and 6 quasi-experimental design studies), published between 2003 and 2018. Of the included studies, 4 were conducted in the United Kingdom, 2 in Australia, one in the United States, and one in Vietnam. Five studies included patients 65 years of age or older, two included patients 55 years or older, and one included patients 50 years or older. Two studies were performed exclusively in women, while the rest included patients of both sexes. Regarding the risk of bias, both RCTs were rated as having a low risk of bias. As for the quasi-experimental studies, no bias was detected in the intervention itself; however, four studies lacked sufficient details on patient selection.

The meta-analysis revealed that first cataract surgery significantly reduces the frequency of falls in older adults. Specifically, a pooled analysis of six quasi-experimental studies showed a 32% reduction in the relative risk of falling after surgery (RR = 0.68, 95% confidence interval [CI] 0.48 to 0.96), despite notable heterogeneity (I² = 74%). Similarly, one of the two RCTs reported a 34% reduction in the risk of frequent falls (risk ratio, RR = 0.66, 95% CI 0.45–0.96), although the other RCT did not find statistically significant results.

In contrast, the meta-analysis of three studies evaluating the impact of second-eye cataract surgery did not demonstrate a statistically significant reduction in fall frequency (RR = 0.66, 95% CI 0.37 to 1.20), with considerable heterogeneity (I² = 66%). The findings suggest that while the first cataract surgery offers clear benefits in fall prevention, the additional benefit from the second surgery is less certain.

Methodology:

MEDLINE, Embase and the Cochrane Library were searched to March 2019 for English- or Spanish-language RCTs or quasi-experimental studies evaluating unilateral or bilateral cataract surgery in adults aged ≥ 60 years. Two reviewers independently screened the articles, extracted the relevant data and critically appraised the quality of the included studies using Cochrane’s risk of bias tools for the relevant study design. Disagreements between the reviewers were resolved through discussion. The findings were synthesised using a random-effects model meta-analysis.

Applicability / external validity:

Marked heterogeneity, potential recall bias in fall reporting and varying selection criteria limit generalisability. Studies spanned both high-income (UK, Australia, USA) and lower-income (Vietnam) settings, but the review did not explore how health-care systems, surgical access or population characteristics might modify effects. Further high-quality trials across diverse contexts are needed.

Geographic focus:

Included were conducted in the United Kingdom, Australia, United States and Vietnam; no geographical restrictions were applied by the reviewers.

Summary of quality assessment:

There is medium confidence in the review’s conclusion. Searches were adequate; inclusion criteria were clear; dual-reviewer processes were used for screening, extraction and quality appraisal; and meta-analysis methods were appropriate. Limitations include language restriction, absence of an excluded-studies list and reliance on studies at high risk of bias.