Johns G E
J Am Intraocul Implant Soc. 1979 Jul;5(3):213-6. doi: 10.1016/s0146-2776(79)80113-5.
One hundred and eight eyes of 106 patients were evaluated preoperatively with the DBR-300 A-scan ultrasonic instrument. Intraocular lens power was then calculated using the formula supplied with the instrument, and the accuracy of the instrument was evaluated. It was found that 61.1% of the eyes were within +/- 1.00 D of the calculated refractive error and 81.5% of the eyes were within +/- 1.50 D of the calculated refractive error when using a standard 3.5-mm anterior chamber depth. Various factors were then analyzed to determine which factors contributed to the inaccuracy of the instrument. No single factor could be found to account for the slight tendency toward myopia, although several were found to contribute. No single factor was found to contribute to large errors.
使用DBR - 300 A型超声仪对106例患者的108只眼睛进行了术前评估。然后使用该仪器附带的公式计算人工晶状体的度数，并评估该仪器的准确性。结果发现，当采用标准的3.5毫米前房深度时，61.1%的眼睛计算出的屈光不正误差在±1.00 D以内，81.5%的眼睛计算出的屈光不正误差在±1.50 D以内。随后分析了各种因素，以确定哪些因素导致了该仪器的不准确。虽然发现有几个因素起了作用，但没有发现单一因素能解释近视的轻微倾向。没有发现单一因素导致较大误差。
