Female gender remains a significant barrier to access cataract surgery in South Asia: a systematic review and meta-analysis

Author: Ye Q, Chen Y, Yan W, Wang W, Zhong J, Tang C, Müller A, Qiu B.

Geographical coverage: South Asia

Sector: Prevalence

Sub-sector: Epidemiology

Equity focus: Gender

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Globally, cataract remains the leading cause of blindness. It disproportionately affecting women who represent about 60% of the blind population. Despite socioeconomic progress, South Asia continues to bear a high burden of blindness, with women experiencing higher blindness rates than men. Cataract surgery is a cost-effective intervention which greatly improves quality of life and economic well-being. To monitor accessibility, the WHO recommends cataract surgical coverage (CSC) as an indicator. Gender disparities in eye care have long been recognised, prompting initiatives like VISION 2020. Earlier meta-analyses suggested that women had lower access to cataract surgery, but comprehensive regional assessments are still limited. Therefore, this study revisits the issue using updated and extensive population-based data to assess gender barriers in South Asia.

Objectives: To determine whether the female gender is a barrier for the access to cataract surgery services in South Asia in the last two decades.

Main findings: The review included 16 studies with a total of 135972 participants. Of these, one study was national, while the others were regional. The studies were conducted in Bangladesh (n=2), Bhutan (n=1), India (n=4), Nepal (n=5), and Pakistan (n=4). All 16 studies were categorised as having a low bias.

The meta-analysis showed that males had significantly higher cataract surgical coverage (CSC) than females. Specifically, the pooled odds ratio (OR) for CSC by person at visual acuity <3/60 was 1.46 (95% CI: 1.23 to 1.75), indicating males were 46% more likely than females to receive cataract surgery at this level of visual impairment. A similar but weaker association was found at visual acuity <6/18, with a pooled OR of 1.14 (95% CI: 1.05 to 1.24). On a per-eye basis at <3/60, the pooled OR was 1.40 (95% CI: 1.16 to 1.70), while no significant association was observed at <6/18 due to high heterogeneity (pooled OR: 1.07, 95% CI: 0.94 to 1.22).

Subgroup analyses by study design and location type yielded similar results to the primary analyses. Sensitivity analyses confirmed the robustness of the findings, and publication bias was not detected Begg’s tests P=0.488, Egger’s tests P=0.173). The population attributable risk percentage (ARP) suggested that cataract blindness could be reduced by 6.28% per person and 7.48% per eye if gender disparities in access to cataract surgery were eliminated.

Methodology: The searches were conducted in PubMed, Embase, and Web of Science to identify population-based studies conducted in general adult population and reporting the number of cataract surgeries performed (person/eyes) and the number requiring cataract surgery (person/eyes) at visual acuities of <3/60 (20/400) or 6/18 (20/60), or provided the data needed to calculate them. No language limits were applied. Additional searches of all relevant trials and review articles were conducted to find further eligible studies. The review did not apply any language restrictions in the search of trials. Additional searches were conducted in the Google Scholar, Rapid Assessment of Avoidable Blindness (RAAB) repository, and WHO website to identify further eligible studies. Furthermore, reference lists of the included studies and relevant review articles were scanned to identify additional relevant publications.

Two reviewers independently screened the articles and extracted the relevant data. Discrepancies were resolved through discussion or by contacting a third reviewer. The methodological quality of the included studies was assessed using a risk and bias tool in prevalence studies. The findings were synthesised by calculating the odds ratio, pooling relative risk and performing a meta-analysis using raw data. Subgroup analyses were performed by study design and location type. Sensitivity analysis was performed using single-study influence analysis. Heterogeneity was assessed using I² and Chi-squared tests, and publication bias was assessed using Begg’s tests and Egger’s test.

Applicability/external validity: The review found that most studies were conducted in selected subnational regions, often rural areas, and may not represent national populations, particularly in large countries like India. Studies from five South Asian countries were included, excluding Sri Lanka and Maldives due to insufficient data, which limits generalization to all of South Asia. Additionally, many studies were not designed to assess gender inequity in cataract surgery access. CSC rates were calculated based on all operated eyes, regardless of preoperative visual status, potentially overestimating need-based surgery rates and affecting gender disparity interpretation.

Geographic focus: The review was limited to South Asia, with two studies from Bangladesh, one from Bhutan, four from India, five from Nepal, and four from Pakistan.

Summary of quality assessment: Overall, there is high confidence in the review’s conclusions as authors used appropriate and rigorous methods to conduct the review.