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Vision screening for amblyopia in childhood
Christine Powell1, Sarah R Hatt
1Department of Ophthalmology, Royal Victoria Infirmary, Claremont Wing, Queen Victoria Road, Newcastle upon Tyne, UK, NE1 4LP.
Insights
Vision screening aims to detect amblyopia (lazy eye) early. However, a review found no robust trials proving its effectiveness in reducing prevalence, highlighting a need for further research.
Area of Science:
- Ophthalmology
- Public Health
Background:
- Amblyopia, or lazy eye, is a treatable vision deficit during childhood's sensitive developmental period.
- Vision screening programs aim to identify asymptomatic amblyopia for early intervention.
Purpose of the Study:
- To evaluate the effectiveness of vision screening in reducing the prevalence of amblyopia.
Main Methods:
- Searched major databases (Cochrane, MEDLINE, EMBASE) for randomized controlled trials (RCTs) and cluster-RCTs.
- Two authors independently reviewed abstracts and full texts; no meta-analysis was performed due to lack of data.
Main Results:
- No RCTs were found that compared amblyopia prevalence in screened versus unscreened populations.
- Despite extensive literature on vision screening, robust comparative data is absent.
Conclusions:
- The impact of vision screening on amblyopia prevalence cannot be determined due to a lack of RCTs.
- Further research requires normative data, a consensus on amblyopia definition, and quantification of untreated amblyopia's consequences.
Background:
Amblyopia is a reversible deficit of vision that has to be treated within the sensitive period for visual development. Screening programmes have been set up to detect this largely asymptomatic condition and refer children for treatment while an improvement in vision is still possible. The value of such programmes and the optimum protocol for administering them remain controversial.
Objectives:
The objective of this review was to evaluate the effectiveness of vision screening in reducing the prevalence of amblyopia.
Search Strategy:
We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2008), MEDLINE (January 1950 to August 2008) and EMBASE (January 1947 to August 2008). The electronic databases were last searched on 15 August 2008. No language restrictions were placed on these searches. No handsearching was done.
Selection Criteria:
We planned to analyse data from randomised controlled trials and cluster-randomised trials comparing the prevalence of amblyopia in screened versus unscreened populations.
Data Collection And Analysis:
Two authors independently assessed study abstracts identified by the electronic searches. Full text copies of appropriate studies were obtained and, where necessary, authors were contacted. No data were available for analysis and no meta-analysis was performed.
Main Results:
Despite the large amount of literature available regarding vision screening no trials designed to compare the prevalence of amblyopia in screened versus unscreened populations were found.
Authors' Conclusions:
The lack of data from randomised controlled trials makes it difficult to analyse the impact of existing screening programmes on the prevalence of amblyopia. The absence of such evidence cannot be taken to mean that vision screening is not beneficial; simply that this intervention has not yet been tested in robust trials. To facilitate such trials normative data on age-appropriate vision tests need to be available and a consensus reached regarding the definition of amblyopia. In addition, the consequences of living with untreated amblyopia have yet to be quantified and a cost-benefit analysis carried out.
