Clinicians who don’t perform cycloplegic refraction testing in young adults may wind up making significant misestimations of refractive status.¹ These are the findings of a new study that looked at 7,971 Chinese undergraduate students in their early twenties who underwent cycloplegic or non-cycloplegic refractions. Researchers performed the cycloplegic refractions with two drops of 1% cyclopentolate and one drop of Mydrin P (tropicamide 0.5%/phenylephrine HCl 0.5%, Santen) with a five-minute interval. The investigators used an autorefractor for both non-cycloplegic and cycloplegic readings.

Researchers found there was a significant difference between non-cycloplegic and cycloplegic spherical equivalent (SE) of 0.83±0.81D: 1.80±1.11D, 1.26±0.93D and 0.69±0.69D for those with cycloplegic hyperopia, emmetropia and myopia, respectively. Those with a hyperopic shift less than 0.25D accounted for 11.1%, and those with hyperopic shift less than 0.5D was 34.1%. Without cycloplegia, hyperopia would be underestimated by 6.2% and emmetropia by 5.7%. Additionally, researchers found the prevalence of myopia would be overestimated by 12.1% and high myopia by 6.1% without the cycloplegic refraction.

“Lack of cycloplegia will lead to significant misclassification of myopia, emmetropia and hyperopia in Chinese young adults. Cycloplegia is therefore essential for this age-group in epidemiological studies,” the researchers concluded.