Time for effective cycloplegia in patients with brown iris

摘要

We aimed to evaluate the time needed for effective cycloplegia after instillation of cyclopentolate 1% in patients with brown irides. A prospective analytical study involving 161 patients (322 eyes) with a mean (SD) age of 9.0 (3.1) years (range: 3-16 years), who attended outpatient eye clinic. All had brown irides, cyclopentolate 1% was instilled two times, 10 minutes apart, spherical equivalent (SE) was calculated using readings taken by Nidek AR-1000 autorefractometer before the first drop and at 15, 30, 45 and 60 minutes after the first drop. The time for effective cycloplegia was determined from the time point at which the 95% confidence interval of the differences between the average spherical equivalent (SE) at each point and its final value at 60 minutes was reached and remained within +/- 0.25 D. We found that maximum cycloplegia was reached 30 minutes after the instillation of first drop of cyclopentolate 1% in all refractive error categories (emmetropia, hyperopia and myopia) with the exception of high hyperopia subgroup (SE >= +6.0D) where at least 45 minutes were needed to achieve cycloplegia. Additionally no clinically significant difference in the minimum time required to achieve maximum cycloplegia was noticed in subjects under 10 years old and those aged 10 years or older with both groups needed at least 30 minutes to achieve maximum cycloplegia after the instillation of first drop of cyclopentolate 1%. In this group of patients with brown irides, most children reached maximum cycloplegia after 30 minutes of instillation of cyclopentolate 1% eye drops.