Comparison of cycloplegia at 20- and 30-minutes following proxymetacaine and cyclopentolate instillation in white 12-13-year-olds

Reducing the time between drop instillation and refraction reduces the time paediatric patients and young adults spend in practice, facilitating more eye examinations daily. The current procedure for paediatric cycloplegic refraction is to wait for at least 30-minutes post-instillation of a cycloplegic before measuring spherical equivalent refraction. This study compared cycloplegia at 20- and 30-minutes following 0.5% proxymetacaine and 1.0% cyclopentolate in 12-13-year-olds. Participants were 99 white 12-13-year-olds. One drop of proxymetacaine hydrochloride (Minims, 0.5% w/v, Bausch & Lomb, UK) followed by one drop of cyclopentolate hydrochloride (Minims, 1.0% w/v, Bausch & Lomb, UK) was instilled into both eyes. Spherical equivalent refraction was measured by autorefraction (Dong Yang Rekto ORK-11 Auto Ref-Keratometer) at 20- and 30-minutes post-instillation. Data were analysed through paired t-testing, correlations, and linear regression analysis. There was no significant difference in level of cycloplegia achieved at 20- (Mean spherical equivalent refraction (standard deviation) 0.438 (1.404) D) and 30-minutes (0.487 (1.420) D) post-eyedrop instillation (t (98) = 1.667, p = 0.099). The mean spherical equivalent refraction difference between time points was small (0.049 (0.294) D, 95% confidence interval =-0.108 ̶ 0.009D). Agreement indices: Accuracy = 0.999, Precision = 0.973, Concordance = 0.972. Spherical equivalent refraction at 20- and 30-minutes differed by ≤0.50D in 92% of eyes, and by There was no clinically significant difference in spherical equivalent refraction or level of cycloplegia at 20- and 30-minutes post-eyedrop instillation. The latent time between drop instillation and measurement of refractive error may be reduced to 20 minutes in White 12-13-year-olds and young adults. Further studies must determine if these results persist in younger children and non-White populations.

缩短滴药至屈光检查的间隔时长，可减少儿科患者与年轻成人在诊疗中的耗时，从而助力每日开展更多眼科检查。当前儿童睫状肌麻痹验光（paediatric cycloplegic refraction）的标准流程为：在滴用睫状肌麻痹剂后至少等待30分钟，再测量球等效屈光度数（spherical equivalent refraction）。本研究针对12至13岁青少年，对比了0.5%丙美卡因与1.0%环喷托酯滴药后20分钟与30分钟的睫状肌麻痹效果。共计99名白人12-13岁青少年参与本研究。为双眼滴用1滴盐酸丙美卡因（Minims, 0.5% w/v, Bausch & Lomb, UK），随后再滴用1滴盐酸环喷托酯（Minims, 1.0% w/v, Bausch & Lomb, UK）。分别于滴药后20分钟与30分钟，通过自动验光仪（autorefraction, Dong Yang Rekto ORK-11自动验光角膜曲率计）测量球等效屈光度数。采用配对t检验、相关性分析与线性回归分析对数据进行处理。结果显示，滴药后20分钟的球等效屈光度数均值（标准差）为0.438（1.404）屈光度（D），30分钟时为0.487（1.420）D，二者无显著统计学差异（t (98) = 1.667, p = 0.099）。两个时间点的球等效屈光度数均值差极小，为0.049（0.294）D，95%置信区间（confidence interval）为-0.108至0.009D。一致性指数分别为：准确度=0.999，精密度=0.973，一致性系数=0.972。92%的患眼在两个时间点的球等效屈光度数差值≤0.50D，且滴药后20分钟与30分钟的球等效屈光度数及睫状肌麻痹程度均无临床意义上的显著差异。针对白人12-13岁青少年与年轻成人，滴药至屈光误差测量的等待时长可缩短至20分钟。未来仍需开展进一步研究，以验证该结果在低龄儿童与非白人人群中是否同样成立。