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Comparison of cycloplegic and noncycloplegic retinoscopy in Chinese pre-school children
Insights
This study found a formula to predict cycloplegic refractive error in Hong Kong Chinese children. The formula uses manifest refractive error measurements to estimate the refractive state after cycloplegia.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Refractive Error Research
Background:
- Accurate refractive error assessment is crucial for early detection of visual impairments in children.
- Understanding refractive error development in diverse pediatric populations is essential for targeted interventions.
Purpose of the Study:
- To establish a predictive relationship between manifest and cycloplegic refractive error in Hong Kong Chinese preschool children.
- To develop a formula for approximating cycloplegic refractive error from non-cycloplegic measurements.
Main Methods:
- Recruited 27 Hong Kong Chinese children aged 3 to 5.5 years.
- Measured retinoscopic refractive error before and after cycloplegia using cyclopentolate 1%.
- Analyzed the correlation between manifest and cycloplegic spherical and astigmatic errors.
Main Results:
- Developed a formula: Cycloplegic spherical error ≈ (1.45 * manifest spherical error) + 0.39 D.
- Astigmatic power and axis remained unchanged in the prediction.
- Cyclopentolate 1% efficacy was independent of iris pigmentation but dependent on initial refractive error.
Conclusions:
- The derived formula provides a reliable approximation for cycloplegic refractive error in this pediatric cohort.
- This predictive method can aid in efficient refractive error screening and management in young children.
- Further research can validate this formula across different ethnicities and age groups.
Abstract:
Twenty-seven Hong Kong Chinese children, aged 3 to 5 1/2 years, were recruited in this study to evaluate the relation between refractive error as measured retinoscopically before and after cycloplegia using cyclopentolate 1%. The noncycloplegic spherical refractive error of these children ranged from -0.75 to +2.50 D and approximately 98% of the Hong Kong pre-school children have a manifest spherical error within this range. The cycloplegic refractive error can be approximated by multiplying the spherical component of the manifest error by 1.45 and adding +0.39 D to the product, while keeping the astigmatic power and axis unchanged. Cyclopentolate 1% requires more time to produce mydriasis and cycloplegia in eyes with heavily pigmented irides; however, its final effect on refractive error is apparently independent of iris pigmentation and depends on the amount of spherical refractive error present.