The role of primary intraocular lens implantation in the risk of secondary glaucoma following congenital cataract surgery: A systematic review and meta-analysis.

Author: Zhang S, Wang J, Li Y, Liu Y, He L, Xia X.

Geographical coverage: Not reported

Sector: Glaucoma

Sub–sector: Risk

Equity focus:  Not reported

Study population: Children (under 2 years) with congenital cataract

Review type: Epidemiology (risk association) review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background 

Congenital cataract is a major cause of childhood visual impairment, affecting 20 000–40 000 newborns globally each year. Primary intra‑ocular lens (IOL) implantation – removal of the cataract and lens implantation in a single procedure – is considered safe for children over 2 years, but its use in younger patients is controversial because of post‑operative complications such as secondary glaucoma.

Objectives 

To evaluate the incidence of secondary glaucoma after primary IOL implantation compared with aphakia or secondary IOL implantation in children under 2 years.

Main findings

Primary IOL implantation during bilateral congenital cataract surgery in children under 2 years is associated with a lower incidence of secondary glaucoma.

Eight studies (892 eyes) met the inclusion criteria. Overall, the long‑term incidence of secondary glaucoma was lower in eyes with primary IOL than in eyes without primary IOL (9.5 % versus 15.1 %; pooled risk ratio [RR] 0.63). In bilateral cases, incidence was 6.7 % with primary IOL and 16.7 % without (RR 0.44). In unilateral cases incidence was similar (12.4 % versus 12.0 %; RR 0.87).

Methodology 

PubMed, EMBASE and Web of Science were searched in 2018 for prospective or retrospective studies of children under 2 years undergoing congenital cataract extraction with or without primary IOL implantation and at least one year’s follow‑up. Two reviewers screened and extracted data; study authors were contacted for missing information. Random‑effects meta‑analysis generated pooled RRs; heterogeneity was assessed with I² and χ², and publication bias with Egger tests and funnel plots.

Applicability / external validity

Variation in age, surgical technique and follow‑up limits generalisability; personalised treatment remains essential.

Geographic focus

The location of included studies was not reported by the review authors.

Summary of quality assessment

Low confidence in the conclusions: excluded studies were not listed, risk of bias was not assessed and results were not stratified by bias status.