Cycloplegic refraction and non-cycloplegic refraction using contralateral fogging: a comparative study

Abstract

The purpose of this study is to compare the retinoscopy values obtained from cycloplegic refraction and non-cycloplegic refraction done with contralateral fogging procedure on children. Performing retinoscopy on children is a challenge because of two significant problems encountered during the procedure, which include maintaining fixation and control of accommodation. Although cycloplegic refraction is a gold standard in order to relax the accommodation completely, it has its own limitations. Whereas when assessing refractive error using static retinoscopy, it is conventional to fog the contralateral eye with a high amount of plus lens, to prevent a blur-driven accommodative response from stimulating consensual accommodation in the examined eye. The study was performed on 31 healthy, non-strabismic subjects of 7 to 16 years of age. Initially the refractive status of the eye was assessed objectively by non-cycloplegic refraction, done by fogging the contralateral eye with +6.00 D, in a dimly illuminated room. Then 2 drops of cyclopentolate 1% were instilled separated by 5 min, in the tested eye. Retinoscopy was performed 25 to 30 min after the first drop was instilled. A statistically significant mean difference exists between the findings obtained (p < 0.05) in the spherical equivalent retinoscopy values (mean of 0.2944 D higher) with cycloplegic refraction when compared to non-cycloplegic refraction done with contralateral fogging. Non-cycloplegic refraction done with contralateral fogging technique as effective as the gold standard cycloplegic refraction technique for the measurement of refractive error in healthy, non-strabismic children.