Comparison of cycloplegic retinoscopy using cyclopentolate or tropicamide eye drops in an epidemiologic study of pediatric refraction among 1907 school-aged children

Compound tropicamide eye drop (0.5% tropicamide + sodium hyaluronate) and 1% cyclopentolate eye drop were compared in an epidemiologic study of pediatric refraction in school-aged children. A total of 1907 school-aged children were divided into three age groups: 6 to 8, 9 to 12, and 13 to 15 years old. Compound tropicamide eye drop and 1% cyclopentolate eye drop were used in the same individual before conducting retinoscopy, sequentially. The administration protocols were as follows. Three drops of compound tropicamide eye drop were administrated (one drop every 10 min), followed by retinoscopy 30 to 45 min later. Three drops of 1% cyclopentolate eye drop were administrated (one drop every 10 min), followed by retinoscopy 45 to 75 min later. There was a 7-day interval between the two times of retinoscopy. Average diopter was significantly higher using cyclopentolate than tropicamide in all age groups (p<0.001). The diopter (spherical equivalent value) < 0.50 D was considered as the coincidence rate between retinoscopies using the two different cycloplegic agents. Classified by the age group, the coincidence rate was 57.14% in 6 to 8 years old group (n=595), 67.79% in 9 to 12 years old group (n=798) and 81.70% in 13 to 15 years old group (n=514). Classified by refractive status, the coincidence rate was 94.97% (n=199) in myopia population, 79.53% in emmetropia population (n=337) and 61.56% in hyperopia population (n=1371). The cycloplegic effect of cyclopentolate was stronger than that of tropicamide. The variation was even more significant with the reduction of age and increase of diopter.   Key words: Child, refractive error, tropicamide, cyclopentolate, retinoscopy.