Fritch C D, Burlew J A
Ophthalmic Surg. 1980 Sep;11(9):617-8.
The DBR-300 A-Scan ultrasonic unit was used to evaluate 100 patients preoperatively. Intraocular lens power was calculated using the formula supplied with the instrument and the accuracy of the instrument was then evaluated. It was determined that 54% of our patients were within +/- 1.00 diopter of the calculated refractive error and that 85% of the patients were within +/- 2.00 diopters and that 97% were within +/- 3.00 diopters. Only 3% of our patients had greater than a 3.00-diopter difference between predicted and actual postoperative refractive error. A standard 3.2-mm anterior chamber depth was utilized for Choyce lenses and 3.4 mm ACD was utilized for Medallion lenses. 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, though the 3% of patients with greater than three diopters variation from the predicted refractive error demonstrated high degrees of cylinder or corneal astigmatism postoperatively as compared to preoperatively. Though we are presently in the process of reviewing ACD postoperatively, one would not suggest any drastic changes in the values at this time due to the overall accuracy obtained. Certainly though small adjustments may be made in the Binkhorst formula in the future, this is yet to be proven clinically.
使用DBR - 300 A型超声仪对100例患者进行术前评估。使用该仪器附带的公式计算人工晶状体的度数，然后评估该仪器的准确性。结果显示，54%的患者术后屈光误差在计算值的±1.00屈光度范围内，85%的患者在±2.00屈光度范围内，97%的患者在±3.00屈光度范围内。只有3%的患者术后预测屈光误差与实际屈光误差的差值大于3.00屈光度。Choyce人工晶状体采用标准的3.2毫米前房深度，Medallion人工晶状体采用3.4毫米前房深度。虽然发现有几个因素与近视的轻微倾向有关，但找不到单一因素可以解释这一现象。没有发现单一因素会导致较大误差，不过，与术前相比，3%的患者术后屈光误差与预测值相差超过3屈光度，表现出高度的柱镜度数或角膜散光。虽然我们目前正在对术后前房深度进行评估，但鉴于总体准确性，目前暂不建议对这些数值进行任何大幅调整。当然，未来可能会对Binkhorst公式进行小的调整，但这还有待临床验证。
