Time of maximum cycloplegia after instillation of cyclopentolate 1% in children with brown irises

PURPOSE We aimed to 1) determine the time of maximum cycloplegia after instillation of cyclopentolate 1% in children with brown irises, 2) evaluate the correlation between the pupillary reaction and time of maximum cycloplegia, and 3) identify any side effects of the medication. PATIENTS AND METHODS This was a prospective analytical study involving children aged 5 to 14 years who were attending refraction clinic. Cyclopentolate 1% was instilled three times at 10-minute intervals. The spherical equivalent, pupillary reaction, and pupillary diameter were recorded before the first drop and nine times after the last drop at 10-minute intervals. Side effects were assessed. Time of maximum cycloplegia was determined from the time point at which the 95% confidence interval of the differences between the mean spherical equivalent at each point and its final value at 110 minutes was reached and remained within the equivalence limit (±0.25 D). RESULTS Sixty children were enrolled in this study. Their mean age was 9.8 years (range: 5-4 years). Time of maximum cycloplegia was reached at 30 minutes after the first instillation of cyclopentolate. A poor correlation was observed between the pupillary reaction and the time of maximum cycloplegia (r=-0.07). The mean pupillary diameter at 30 minutes was 3.7±1.3 mm, and further dilation occurred thereafter. No side effects were observed. CONCLUSION In most children, maximum cycloplegia was reached 30 minutes after the first instillation of cyclopentolate. The absence of a pupillary reaction should not be used as an indicator of maximum cycloplegia.