Donshik P C, Reisner D S, Luistro A E
Division of Ophthalmology, University of Connecticut Health Center, Farmington, USA.
Trans Am Ophthalmol Soc. 1996;94:135-43; discussion 143-5. doi: 10.1016/s0002-9394(14)70162-x.
To assess the efficacy of computerized corneal topography in (1) fitting cosmetic rigid gas permeable contact lenses on normal corneas and (2) patients who have keratoconus.
In study 1, 26 patients were fitted with cosmetic contact lenses. In 13 patients, the first rigid gas permeable lens was chosen on the basis of corneal topography using the EyeSys videokeratoscope and contact lens software version 2.11w. Thirteen control patients were fitted with rigid gas permeable contact lenses by means of diagnostic contact lenses. The number of parameter changes required in each group to reach the best fit were compared. In study 2, the records of 28 patients (41 eyes) with keratoconus who had been successfully fit with rigid gas permeable lenses were reviewed. Topographic analysis using the EyeSys videokeratoscope was conducted. The following 8 data points were analyzed: maximum dioptric curvature with respect to the central visual axis, the power at the visual axis (VK), the average keratometry readings within the 3-mm zone, the average flat K at 3-mm central and 5-mm paracentral regions, and the K reading at 1.5, 2.0, and 2.5 mm superior to the visual axis.
Study 1: In 10 eyes (38%) fitted with cosmetic contact lenses utilizing corneal topography and the EyeSys contact lens program, the first lens chosen by the computer program was correct with no additional changes in lens parameters required. In the other 16 eyes, 21 parameter changes were required. In the control group, 14 eyes (53%) required no additional change in parameters from the original contact lens that was fitted using diagnostic lenses. In the other 12 eyes, 12 parameter changes were required. Study 2: In the keratoconus group, of the 9 measurements analyzed, the final base curve of patients' rigid gas permeable lenses was correlated most closely with the average flat corneal curvature at the 3-mm central zone.
Study 1: In fitting cosmetic rigid gas permeable contact lenses, the videokeratoscope with the EyeSys software 2.11w contact lens program proved to be inferior to diagnostic lenses in selecting the final correct contact lens parameters. However, it may be useful in selecting an initial diagnostic lens with which to begin rigid gas permeable fitting. Study 2: In patients with irregular corneas such as keratoconus, corneal topography is helpful in determining the initial base curve of the contact lens. In patients with keratoconus, it appears to be the average flat corneal curvature at the 3.0-mm zone.
评估电脑角膜地形图在以下两方面的效果：（1）为正常角膜佩戴美容性硬性透气性隐形眼镜；（2）为圆锥角膜患者佩戴美容性硬性透气性隐形眼镜。
在研究1中，26例患者佩戴美容性隐形眼镜。其中13例患者，基于使用EyeSys角膜地形图仪和2.11w版隐形眼镜软件获得的角膜地形图来选择首副硬性透气性隐形眼镜。另外13例对照患者通过诊断性隐形眼镜来佩戴硬性透气性隐形眼镜。比较两组为达到最佳适配所需的参数改变次数。在研究2中，回顾了28例（41只眼）成功佩戴硬性透气性隐形眼镜的圆锥角膜患者的记录。使用EyeSys角膜地形图仪进行地形分析。分析了以下8个数据点：相对于中心视轴的最大屈光曲率、视轴处的屈光度（VK）、3毫米区域内的平均角膜曲率读数、3毫米中心区域和5毫米旁中心区域的平均平坦K值，以及视轴上方1.5、2.0和2.5毫米处的K值读数。
研究1：在10只眼（38%）中，利用角膜地形图和EyeSys隐形眼镜程序佩戴美容性隐形眼镜时，计算机程序选择的首副隐形眼镜是合适的，无需对镜片参数进行额外更改。在另外16只眼中，需要进行21次参数更改。在对照组中，14只眼（53%）在使用诊断性镜片佩戴的初始隐形眼镜基础上无需进行参数更改。在另外12只眼中，需要进行12次参数更改。研究2：在圆锥角膜组中，在所分析 的9项测量中，患者硬性透气性隐形眼镜的最终基弧与3毫米中心区域的平均平坦角膜曲率相关性最强。
研究1：在佩戴美容性硬性透气性隐形眼镜时，配备EyeSys软件2.11w隐形眼镜程序的角膜地形图仪在选择最终正确的隐形眼镜参数方面被证明不如诊断性镜片。然而，它在选择用于开始硬性透气性配镜的初始诊断性镜片时可能有用。研究2：在圆锥角膜等不规则角膜患者中，角膜地形图有助于确定隐形眼镜的初始基弧。对于圆锥角膜患者，似乎是3.0毫米区域的平均平坦角膜曲率。
