Wilson M Edward, Trivedi Rupal H
Miles Center for Pediatric Ophthalmology, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA.
Saudi J Ophthalmol. 2012 Jan;26(1):13-7. doi: 10.1016/j.sjopt.2011.11.002.
Globe axial length (AL) in children is commonly measured using either contact or immersion technique. Office measurement of AL can be difficult in young children and infants and must often be done under anesthesia in an eye that is unable to cooperate with precise fixation and centration. Contact A-scan measurements yield shorter AL, on average, than immersion A-scan measurements in pediatric eyes. This difference is mainly the result of the anterior chamber depth rather than the lens thickness value. During intraocular lens power calculation, if globe axial length is measured by the contact technique, it will result in the use of an average 1-D stronger IOL power than is actually required. This can lead to induced myopia in the postoperative refraction. In our studied patients, there was a significant difference in prediction error between contact A-scan biometry and immersion A-scan biometry. The immersion A-scan technique is recommended for pediatric IOL power calculation. We also provide a review of biometry in pediatric eyes. The overall mean AL of pediatric cataractous eyes is significantly different than the mean AL of non cataractous eyes. More importantly, the standard deviation is higher in eyes with cataract than in those without. Three phases of eye growth in children have been documented: A rapid, postnatal phase from birth to 6 months of age, followed by a slower, infantile phase from 6 to 18 months of age, and finally a slow, juvenile phase from 18 months forward. In our study, girls had shorter ALs than boys and African-American subjects had longer ALs than Caucasians. Eyes with unilateral cataract had shorter ALs than eyes with bilateral cataract during the earlier years, but had longer ALs during later childhood.
儿童的眼球轴长（AL）通常采用接触式或浸没式技术进行测量。对于幼儿和婴儿，在门诊测量眼球轴长可能会很困难，通常必须在麻醉下对无法配合精确注视和定中心的眼睛进行测量。与浸没式A超测量相比，接触式A超测量得出的儿童眼球平均轴长较短。这种差异主要是前房深度造成的，而非晶状体厚度值。在人工晶状体屈光度计算过程中，如果采用接触式技术测量眼球轴长，将导致所使用的人工晶状体屈光度比实际所需平均强1D。这可能会导致术后验光出现诱导性近视。在我们研究的患者中，接触式A超生物测量法和浸没式A超生物测量法在预测误差方面存在显著差异。对于儿童人工晶状体屈光度计算，推荐使用浸没式A超技术。我们还对儿童眼部生物测量进行了综述。患有白内障的儿童眼睛的总体平均轴长与未患白内障的眼睛的平均轴长显著不同。更重要的是，白内障患者眼睛的标准差高于非白内障患者。已记录到儿童眼睛生长的三个阶段：从出生到6个月龄的快速出生后阶段，接着是6至18个月龄的较慢婴儿期阶段，最后是18个月龄以后的缓慢青少年期阶段。在我们的研究中，女孩的眼球轴长比男孩短，非裔美国受试者的眼球轴长比白种人长。在早年，单侧白内障患者的眼睛轴长比双侧白内障患者的眼睛短，但在儿童后期则较长。
