Pre- and Postcycloplegic Refractions in Children and Adolescents

Abstract

PurposeTo determine the difference between cycloplegic and non-cycloplegic refractive error and its associated factors in Chinese children and adolescents with a high prevalence of myopia.MethodsA school-based study including 1565 students aged 6 to 21 years was conducted in 2013 in Ejina, Inner Mongolia, China. Comprehensive eye examinations were performed. Pre-and postcycloplegic refractive error were measured using an auto-refractor. For cycloplegic refraction, one drop of topical 1.0% cyclopentolate was administered to each eye twice with a 5-minute interval and a third drop was administered 15 minutes after the second drop if the pupil size was less than 6 mm or if the pupillary light reflex was still present.ResultsTwo drops of cyclopentolate were found to be sufficient in 59% of the study participants while the other 41% need an additional drop. The prevalence of myopia was 89.5% in participants aged over 12 years and 68.6% in those aged 12 years or younger (P<0.001). When myopia was defined as spherical equivalent (SE) of less than -0.5 diopter (D), the prevalence estimates were 76.7% (95% confidence interval [CI] 74.6–78.8) and 54.1% (95%CI 51.6–56.6) before and after cycloplegic refraction, respectively. When hyperopia was defined as SE of more than 0.5D, the prevalence was only 2.8% (95%CI 1.9–3.6) before cycloplegic refraction while it was 15.5% (95%CI 13.7–17.3) after cycloplegic refraction. Increased difference between cycloplegic and non-cycloplegic refractive error was associated with decreased intraocular pressures (P = 0.01).ConclusionsLack of cycloplegia in refractive error measurement was associated with significant misclassifications in both myopia and hyperopia among Chinese children and adolescents. Decreased intraocular pressure was related to a greater difference between cycloplegic and non-cycloplegic refractive error.

Comparison of retinoscopy results with and without 1% cyclopentolate in school‐aged children

“…Cycloplegic retinoscopy reveals significantly more hyperopia than is found under non-cycloplegic conditions, in line with previous studies using pre-and post-cycloplegic autorefraction, both in children and adults, 1,[13][14][15][16][17][18][19][20][21][22][23][24][25][26] with the mean difference reported by the present study (0.59 AE 0.51DS) similar to autorefraction values. 18,25 As found using autorefraction, the largest differences were demonstrated in the present study's youngest participants (6)(7) year-olds), with differences reducing significantly as age increased up to 12-13 years.…”

“…[9][10][11][12] Previous studies evaluating the difference between cycloplegic and non-cycloplegic measurement of refractive error have focused on the use of autorefraction measures in the context of epidemiological classification of refractive error or compared refractive measurement techniques and/or cycloplegic regimes. 1,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Outcomes from epidemiological studies using autorefraction for categorisation purposes are not relevant in the context of using retinoscopy to establish refractive error, either as a basis for undertaking a subjective refraction and/or for prescribing spectacles.…”

Effect of cycloplegia on the measurement of refractive error in Chinese children

“…In the present study, cycloplegia led to less myopia or greater hyperopia with auto‐refraction, with a mean difference of 0.52 D in M among children aged four to 16 years. Hu et al, Zhu et al and Zhao et al reported a mean difference of 0.78 D, 0.57 D and 1.23 D after and before cycloplegia among Chinese school‐aged children, respectively.…”

“…The principle of auto‐refraction has been demonstrated in detail in previous studies . Briefly, auto‐refraction was performed for each child by the same study optometrist without and with cycloplegia.…”

“…The common modalities for correcting myopia include spectacles, contact lenses, and surgical procedures. Cycloplegic refraction is considered the gold standard for measuring refractive errors, especially in children . Auto‐refractors are frequently used to obtain an objective refraction in clinical settings, followed by the refinement of vision with subjective refraction, which are also widely used in epidemiological surveys …”