Objective Because intraocular lens ( IOL ) tilt and decentration have an effect on postoperative defocus, astigmatism and other refractive states as well as wavefront aberration, the results of IOL tilt and decentration measured by many methods have certain deviations. This paper provides a more accurate method for calculating the IOL tilt and decentration. Methods Based on anterior segment images of three cases with subluxation lens after operation,we collected the IOL surface data with three different methods. The IOL tilt and decentration values were obtained through image registration and the spherical surface fitting of the anterior and posterior surfaces of IOL,respectively. Results Based on the formula of IOL tilt and decentration, we obtained the IOL tilt angles,decentration values,the horizontal and vertical tilt angles collected by the three methods. The first method based on the spherical surface fitting was better than the other two methods. Conclusions To calculate the IOL tilt and decentration by spherical surface fitting of the IOL surface,we should choose the clearest image among images of each scanning rotated angle for collecting IOL surface data. This method can accurately analyze the IOL' s location.%目的 术后人工晶状体(intraocular lens,IOL)的倾斜和偏心对患者的离焦和散光等屈光状态及波前相差产生影响,而目前测量人工晶状体的倾斜和偏心的方法得到的结果存在一定偏差.本文提供一种人工晶状体的倾斜度和偏心量的精确估算方法.方法 基于3例先天性晶状体半脱位的术后人工晶状体眼前段图像,经过图像配准,用3种方法采集IOL表面数据并分别用球面方程拟合,从而用数学方法计算人工晶状体的倾斜度和偏心量.结果 在给出计算IOL的倾斜度和偏心量的公式的基础上,以3种采集方法得到IOL的倾斜度、偏心量、水平方向倾斜度和垂直方向倾斜度,结果显示基于球面拟合的第一种方法优于其它两种.结论 基于球面拟合人工晶状体表面计算倾斜度和偏心量,应从每个扫描角度中选择一幅最清晰的图像采集数据,此方法可较准确地分析人工晶状体的位置.
展开▼
