Effectiveness of screening preschool children for amblyopia: a systematic review

<p>Abstract</p> <p>Background</p> <p>Amblyopia and amblyogenic factors like strabismus and refractive errors are the most common vision disorders in children. Although different studies suggest that preschool vision screening is associated with a reduced prevalence rate of amblyopia, the value of these programmes is the subject of a continuing scientific and health policy discussion. Therefore, this systematic review focuses on the question of whether screening for amblyopia in children up to the age of six years leads to better vision outcomes.</p> <p>Methods</p> <p>Ten bibliographic databases were searched for randomised controlled trials, non-randomised controlled trials and cohort studies with no limitations to a specific year of publication and language. The searches were supplemented by handsearching the bibliographies of included studies and reviews to identify articles not captured through our main search strategy.</p> <p>Results</p> <p>Five studies met the inclusion criteria. Of these, three studies suggested that screening is associated with an absolute reduction in the prevalence of amblyopia between 0.9% and 1.6% (relative reduction: between 45% and 62%). However, the studies showed weaknesses, limiting the validity and reliability of their findings. The main limitation was that studies with significant results considered only a proportion of the originally recruited children in their analysis. On the other hand, retrospective sample size calculation indicated that the power based on the cohort size was not sufficient to detect small changes between the groups. Outcome parameters such as quality of life or adverse effects of screening have not been adequately investigated in the literature currently available.</p> <p>Conclusion</p> <p>Population based preschool vision screening programmes cannot be sufficiently assessed by the literature currently available. However, it is most likely that the present systematic review contains the most detailed description of the main limitations in current available literature evaluating these programmes. Therefore, future research work should be guided by the findings of this publication.</p

Corrective lens wear among adolescents: Findings from the national health and nutrition examination survey

Purpose: To evaluate demographic variations in the use of corrective lenses among adolescents. Methods: Cross-sectional analysis of 3,916 adolescents between ages 12 and 18 years who participated in the 1999-2002 National Health and Nutrition Examination Survey (NHANES) vision examination component, which included questions regarding use of corrective lenses, distance visual acuity (VA; with corrective lenses if available), and non-cycloplegic autorefraction. Results reflect population-level estimates. Results: Overall, 32.2% (95% confidence interval [CI], 29.5%-35.0%) reported wearing corrective lenses. The adjusted odds of reporting corrective lens wear were greater for female and privately insured participants. In contrast, the adjusted odds of having corrective lenses available at the time of NHANES participation were greater for participants between ages 15 and 18 years compared with those between 12 and 14 years, and participants who were white compared with those who were black or Hispanic. Although 12.6% (95% CI, 8.8%-16.3%) of participants without their corrective lenses available for the NHANES had 20/25 or better distance VA in both eyes, 26.9% (95% CI, 21.6%-32.1%) of those with their corrective lenses had distance VA of 20/40 or worse in at least 1 eye. Near VA was not measured and participants with their corrective lenses available had only their corrected distance VA measured. No data regarding the accuracy of the NHANES assessment of distance VA are available. Autorefraction was performed without cycloplegia. Conclusions: Many adolescents report wearing corrective lenses. Variations across demographic characteristics are possibly due to a combination of undertreatment, overtreatment, and compliance with previously recommended corrective lenses