Suryakumar R, Bobier W R
School of Optometry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Optom Vis Sci. 2003 Aug;80(8):578-86. doi: 10.1097/00006324-200308000-00012.
To investigate the factors that govern the manifestation of hyperopic refractive errors of pre-school children when tested with and without the application of cycloplegics.
Forty-three pre-school children (mean age, 3.68 +/- 0.59 years) were tested before and during cycloplegia in the following order: retinoscopy with optical fogging; Retinomax K plus; Welch Allyn SureSight (DAV SureSight), and PowerRefractor. In the case of the PowerRefractor, the children viewed a difference of Gaussian target (0.20 cpd) at 3.5 m in addition to viewing the instrument LED sources.
Instruments with close working distances (Retinomax) showed the greatest underestimation of hyperopia and the largest variation, followed by the instruments having a greater working distance (PowerRefractor LED view and retinoscopy). The addition of a far target (PowerRefractor difference of Gaussian view) showed the least underestimation, whereas DAV SureSight showed a mean overestimation of the refractive state.
When autorefractors are applied to vision screening of pre-school children without the use of cycloplegics, autorefractor designs must be developed that both stabilize and relax the child's accommodation. Our results suggest that designs should include large working distances and distant fixation targets.
研究在使用和不使用睫状肌麻痹剂的情况下，学龄前儿童远视屈光不正表现的影响因素。
43名学龄前儿童（平均年龄3.68±0.59岁）按以下顺序在睫状肌麻痹前和麻痹期间进行检查：雾视验光；Retinomax K plus；Welch Allyn SureSight（DAV SureSight），以及PowerRefractor。对于PowerRefractor，儿童除了观看仪器LED光源外，还需在3.5米处观看高斯目标差异（0.20 cpd）。
工作距离近的仪器（Retinomax）对远视的低估程度最大且变化最大，其次是工作距离较远的仪器（PowerRefractor LED视图和验光）。添加远目标（PowerRefractor高斯视图差异）时低估程度最小，而DAV SureSight对屈光状态平均存在高估。
在不对学龄前儿童使用睫状肌麻痹剂进行自动验光筛查时，必须开发既能稳定又能放松儿童调节的自动验光仪设计。我们的结果表明，设计应包括较大的工作距离和远处注视目标。
