Methodological quality of the review: Low confidence

Author: Gilbert CE, Lepvrier-Chomette N.

Region: Africa, Asia, Latin America, Caribbean, UK, USA, the Republic of Korea, Australia, Italy, Denmark, Sweden.

Sector: Cataract surgery

Type of cataract: Paediatric cataract

Sub-sector: Bilateral cataract

Equity focus: None specified

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable 

Background:

Cataract is a common cause of avoidable blindness in children globally. Gender differences in service access among children are reported for several conditions, but not for surgery for bilateral cataract.

Research objectives:

The authors aimed to compare the proportion of children undergoing surgery for bilateral, non-traumatic cataract who were girls, using data from high-income, gender neutral countries as the reference.

Main findings:

Authors included a total of 38 studies in the review. a total of 6,854 children were included in these studies, of which 2,505 (36.5%) were girls. Ten studies were conducted in high-income countries: two each from the USA, the Republic of Korea, and the UK, and one each from Australia, Italy, Denmark, and Sweden. Across the 10 studies, 42.5% to 54.5% were girls, the overall figure being 47.5%.

Most of the other 28 studies were retrospective case series focusing on the outcome of surgery. A few were prospective studies or were undertaken to explore specific outcomes, such as nystagmus or corneal thickness after surgery, or were clinical trials. One study in India was a retrospective review of patients seeking treatment at the hospital regardless of whether they had undergone cataract surgery. Comparing data by region shows that the proportion of children undergoing surgery who were girls in the following regions were comparable to the proportion in high-income, gender-neutral countries: the Middle East, North Africa, and Central Asia region (48.6%) and in the Latin America and Caribbean region (43.7%), but were significantly lower in all other regions: sub-Saharan Africa (41.1%), East Asia and the Pacific (all from China; 36.0%), and South Asia (29.1%).

Based on review findings, authors conclude that access to surgery by girls with bilateral cataract is lower in some regions than boys. Authors also emphasize the need to identify the barriers to access specific girls particularly in Asia, to assess interventions to improve uptake.

Methodology:

This review was limited to children with bilateral cataract. Children with unilateral cataract were excluded. Studies published before 2000 were also excluded by the authors as surgical techniques and the provision of surgical services for children have improved over time. Authors did not restrict the inclusion of studies based on language and study design. Studies reporting epidemiologic data or data from registers, surgical techniques, clinical trials, the outcome or complication of surgery, or delay in presentation for surgery were included in the review. Articles were excluded if they reported fewer than 20 cases or if they reported cases with long-term follow-up only.

Authors conducted a search of the published literature in MEDLINE. Reference lists in published articles were also screened. Study selection was conducted by one reviewer only. Authors note attempting to contact authors reporting data on unilateral and bilateral cases together, to request data desegregated by gender for bilateral cases only. Data were extracted and entered into an Excel spreadsheet using predetermined headings. Data were prepared for countries classified as high income by the World Bank, and other countries classified under each of the six World Bank geographical regions. The proportion of children accessing cataract surgery who were girls was compared by region using the Z statistic; data from countries defined by the World Bank as high income were used as the reference.

Authors conducted a narrative synthesis of findings due to the heterogeneity nature of the study designs.

Applicability/external validity:

Authors do not discuss applicability/external validity of the results due to the heterogeneity across included studies.

Geographic focus:

Authors report findings specific to low/middle income countries and report that in gender-neutral countries, 47.5% of children (777/1636) were girls, being similar in the Middle East, North Africa, and Central Asia (48.6%; 87/179) and in Latin America and the Caribbean (43.7%; 188/430). Proportions were significantly lower in sub-Saharan Africa (41.1%; 225/547), East Asia and the Pacific (36.0%; 237/658), and South Asia (29.1%; 991/3404).

Quality assessment:

Overall, low confidence was attributed in the conclusions about the effects of this review. Authors did not conduct a thorough search of the literature to ensure that published and unpublished studies were included in the review. Authors did not use appropriate methods to select studies for inclusion in the review and to extract data of included studies. In addition, authors did not assess quality of included studies, therefore it is not clear which of included studies are subject to high or low risk of bias.