Purpose

To find an appropriate correlation between the base curve (BC) of rigid gas permeable (RGP) contact lenses and manual keratometry findings in Iranian patients with keratoconus (KCN) in order to simplify the fitting process, reduce the time, and lower the costs.

Method

This retrospective study was done in 121 eyes of 69 patients with KCN fitted with a specific trial set of RGP contact lenses over a 7-year period. The specifications of the final lens parameters included power, total diameter (1), and BC, the first two of which were fixed in all of the lenses in the trial set while BC was changed in 0.1-mm steps. Javal keratometer was used to measure keratometric values. The final fit assessment was performed based on the standard criterion of "three-point touch".

Result

Single and multiple linear correlations were done and the result was the following equation: BC = 2.455 (constant of the final multiple regression model) + 0.280 (steep keratometry) + 0.368 (flat keratometry) + 0.047 (corneal astigmatism)

Conclusion

The advantages of this study include simplifying the RGP fitting process, reducing the examination time, lowering the costs, enhancing the confidence of the examiners and patients, easier lens fitting in remote places where more advanced devices are not accessible.

中文翻译：

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根据圆锥角膜患者的 Javal 角膜曲率测量结果预测硬性隐形眼镜的初始基弧

目的

在伊朗圆锥角膜 (KCN) 患者中寻找刚性透气性 (RGP) 隐形眼镜的基曲线 (BC) 与手动角膜曲率测量结果之间的适当相关性，以简化配戴过程、减少时间并降低成本。

方法

这项回顾性研究是在 7 年期间对 69 名 KCN 患者的 121 只眼中进行的，这些患者装有一组特定的 RGP 隐形眼镜试验组。最终镜片参数的规格包括焦度、总直径 (1) 和 BC，其中前两个参数在试验组的所有镜片中都是固定的，而 BC 以 0.1 毫米的步长变化。Javal角膜曲率计用于测量角膜曲率值。最终合身评估基于“三点接触”的标准标准进行。

结果

进行了单一和多重线性相关，结果为以下方程：BC = 2.455（最终多元回归模型的常数）+ 0.280（陡峭角膜曲率）+ 0.368（平面角膜曲率）+ 0.047（角膜散光）

结论

这项研究的优势包括简化 RGP 验配过程、减少检查时间、降低成本、增强检查员和患者的信心、在无法使用更先进设备的偏远地区更容易配戴镜片。