Radius and asphericity of the posterior corneal surface determined by corrected Scheimpflug photography
Radius and asphericity of the posterior corneal surface determined by corrected Scheimpflug photography
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DOI：
10.1034/j.1600-0420.2002.800406.x
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发表时间：
2002-08-01
期刊：
影响因子：
--
通讯作者：
Völker-Dieben, HJ
中科院分区：
文献类型：
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作者：
Dubbelman, M;Weeber, HA;Völker-Dieben, HJ
目的：为了获得健康人群角膜后表面的形状，使用Scheimpflg摄影，校正由于Scheimpflg成像系统的几何形状和角膜前表面屈光引起的变形。方法：使用修正的Scheimpflg摄影测量83例16~62岁的受试者的后角膜。结果：角膜前表面平均半径为7.87±0.27 mm(SD)，后表面平均半径为6.40±0.28 mm(SD)。前后屈曲半径之比为0.81+/-0.02。角膜前表面和后表面的非球面度分别为0.82±0.18和0.62±0.27。随着年龄的增长，角膜后表面的非球面度明显降低。后/前非球面比也与年龄有关，16岁时为0.98+/-0.17，62岁时为0.53+/-0.30。结论：矫正Scheimpflg摄影是测量角膜后表面半径和非球面度的合适方法。角膜后表面的非球面度随年龄的变化而变化。
Purpose: To obtain the shape of the posterior corneal surface in a healthy population, using Scheimpflug photography corrected for distortion due to the geometry of the Scheimpflug imaging system and the refraction of the anterior corneal surface.Methods: The posterior corneas of 83 subjects, ranging in age from 16 to 62 years, were measured in the vertical meridian using corrected Scheimpflug photography. The aspherical shape of the anterior Corneal surface was also determined in conjunction with the correction of Scheimpflug images.Results: The average radius of the anterior corneal surface was 7.87 +/- 0.27 mm (SD), while the average radius of the posterior corneal surface was 6.40 +/- 0.28 mm (SD). The ratio between the posterior and the anterior radius of curvature was 0.81 +/- 0.02. The asphericity of the anterior and the posterior corneal surfaces was 0.82 +/- 0.18 and 0.62 +/- 0.27, respectively. The asphericity of the posterior corneal surface decreased significantly with age. The posterior/anterior asphericity ratio is also dependent on age and was 0.98 +/- 0.17 at 16 years of age and 0.53 +/- 0.30 at 62 years of age.Conclusion: Corrected Scheimpflug photography is an appropriate technique for measuring the radius and asphericity of the posterior corneal surface. The asphericity of the posterior corneal surface changes with age.