Rajabi Mohammad Taher, Mohajernezhad-Fard Zahra, Naseri Seyede Khojaste, Jafari Fahimeh, Doostdar Askar, Zarrinbakhsh Parviz, Rajabi Mohammad Bagher, Kohansal Sedigheh
Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Int J Ophthalmol. 2011;4(5):525-8. doi: 10.3980/j.issn.2222-3959.2011.05.13. Epub 2011 Oct 18.
To find a simple mathematical correlation between the lens base curve (BC) and keratometry findings (krf).
This retrospective study included 400 keratoconic eyes (350 patients) previously fit with rigid contact lenses at an academic eye center over a five year period. The patients were classified into five groups based on the keratometry findings (krf<7, krf:7-8, krf>8, krf-krs (difference between two keratometry; flat and steep)= 0.3-0.6, krf-krs >0.6mm as groups 1 to 5, respectively. Multivariate linear regression and Munro's correlation coefficient were employed to defer the formulas.
A linear correlation could be found in all groups except for patients in group 3. For group 1, BC=0.211×krf+ 5.904. For group 2, BC=0.456×krf+4.160. For group 4, BC= 0.321×krf+5.219. For group 5, BC=0.337×krf+ 5.090.
The development of new formulas for RGP fitting enables ophthalmologists to work with confidence and prevents unnecessary and frequent lens trials. The customary lens fitting methods are needed to be replaced by new formulas, which help to save time and costs.
寻找晶状体基弧（BC）与角膜曲率测量结果（krf）之间简单的数学关联。
这项回顾性研究纳入了400只圆锥角膜眼（350例患者），这些患者在一所学术性眼科中心于五年期间曾佩戴过硬性接触镜。根据角膜曲率测量结果将患者分为五组（krf<7、krf:7 - 8、krf>8、krf - krs（两个角膜曲率测量值之差；平曲率和陡曲率）= 0.3 - 0.6、krf - krs>0.6mm，分别为第1至5组）。采用多元线性回归和门罗相关系数来推导公式。
除第3组患者外，所有组均发现存在线性相关性。对于第1组，BC = 0.211×krf + 5.904。对于第2组，BC = 0.456×krf + 4.160。对于第4组，BC = 0.321×krf + 5.219。对于第5组，BC = 0.337×krf + 5.090。
用于RGP（硬性透氧性接触镜）验配的新公式的开发使眼科医生能够自信地开展工作，并避免不必要且频繁的镜片试戴。传统的镜片验配方法需要被新公式所取代，这有助于节省时间和成本。
