McKendrick A M, Brennan N A
Department of Optometry, University of Melbourne, Carlton, Australia.
J Am Optom Assoc. 1995 Dec;66(12):758-65.
The accuracy of two commercially available auto kerato-refractometers (Shin-Nippon Automatic Ref-Keratometer model RC380 and Topcon Auto Kerato-Refractometer model KR-3100) and one autokeratometer (Alcon Systems Auto-Keratometer) was compared to that of subjective refraction and conventional keratometry.
Refractive error and corneal curvature were measured on 20 subjects. Measurements were converted from the standard clinical format of sphere, cylinder and axis to a vector format to assess the contribution of spherical and cylindrical errors simultaneously.
For measurements of refractive error taken in immediate succession, the Shin-Nippon instrument was found to be more repeatable than the Topcon instrument. This trend reversed when subjects were realigned between measurements. The 95 percent confidence limit for precision for subjective refraction was considerably greater: 93 percent of subjective refractions resulted in visual acuities better than or equal to 6/6, compared with 85 percent for the Topcon instrument and 45 percent for the Shin-Nippon instrument. Each of the methods for measuring corneal curvature showed minimal bias and comparable precision.
Although subjective methods of determining refractive error generally achieved the same or better visual acuity as the automated methods, they displayed considerably poorer precision. Each of the methods of measurement of corneal curvature produced similar results.
将两款市售自动角膜验光仪（日本新日本自动验光角膜曲率计RC380型和拓普康自动验光角膜曲率计KR - 3100型）以及一款自动角膜曲率计（爱尔康系统自动角膜曲率计）的准确性与主观验光和传统角膜曲率测量的准确性进行比较。
对20名受试者测量屈光不正和角膜曲率。测量结果从球镜、柱镜和轴位的标准临床格式转换为向量格式，以同时评估球镜和柱镜误差的影响。
对于连续立即进行的屈光不正测量，发现日本新日本仪器比拓普康仪器更具可重复性。当在测量之间重新调整受试者位置时，这种趋势发生逆转。主观验光精度的95%置信限要大得多：93%的主观验光结果导致视力优于或等于6/6，相比之下，拓普康仪器为85%，日本新日本仪器为45%。每种测量角膜曲率的方法显示出最小的偏差和相当的精度。
虽然确定屈光不正的主观方法通常能达到与自动方法相同或更好的视力，但它们的精度明显较差。每种测量角膜曲率的方法都产生了相似的结果。
