Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran.
Department of Optometry, School of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran.
Cont Lens Anterior Eye. 2021 Jun;44(3):101340. doi: 10.1016/j.clae.2020.05.009. Epub 2020 Jun 1.
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.
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".
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.
在伊朗圆锥角膜（KCN）患者中，寻找硬性透气性（RGP）隐形眼镜基弧（BC）与手动角膜曲率计测量结果之间的合适相关性，以简化配镜过程、缩短检查时间、降低成本。
这是一项回顾性研究，共纳入 69 例 KCN 患者的 121 只眼，这些患者在 7 年内使用特定的 RGP 试戴片进行配镜。最终镜片参数包括屈光度、总直径（1）和 BC，其中前两个参数在试戴片中的所有镜片中均固定，而 BC 则以 0.1mm 的步长改变。使用 Javal 角膜曲率计测量角膜曲率值。最终的适配评估基于“三点接触”的标准标准进行。
进行了单因素和多因素线性相关性分析，结果得到以下方程：BC=2.455（最终多元回归模型的常数）+0.280（陡峭角膜曲率值）+0.368（平坦角膜曲率值）+0.047（角膜散光）。
本研究的优势包括简化 RGP 配镜过程、缩短检查时间、降低成本、增强检查者和患者的信心、便于在较偏远地区进行镜片适配，而这些地区可能无法使用更先进的设备。
