Kaur Manpreet, Shaikh Farin, Falera Ruchita, Titiyal Jeewan S
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
Indian J Ophthalmol. 2017 Dec;65(12):1301-1313. doi: 10.4103/ijo.IJO_810_17.
Toric intraocular lenses (IOLs) are the procedure of choice to correct corneal astigmatism of 1 D or more in cases undergoing cataract surgery. Comprehensive literature search was performed in MEDLINE using "toric intraocular lenses," "astigmatism," and "cataract surgery" as keywords. The outcomes after toric IOL implantation are influenced by numerous factors, right from the preoperative case selection and investigations to accurate intraoperative alignment and postoperative care. Enhanced accuracy of keratometry estimation may be achieved by taking multiple measurements and employing at least two separate devices based on different principles. The importance of posterior corneal curvature is increasingly being recognized in various studies, and newer investigative modalities that account for both the anterior and posterior corneal power are becoming the standard of care. An ideal IOL power calculation formula should take into account the surgically induced astigmatism, the posterior corneal curvature as well as the effective lens position. Conventional manual marking has given way to image-guided systems and intraoperative aberrometry, which provide a mark-less IOL alignment and also aid in planning the incisions, capsulorhexis size, and optimal IOL centration. Postoperative toric IOL misalignment is the major factor responsible for suboptimal visual outcomes after toric IOL implantation. Realignment of the toric IOL is needed in 0.65%-3.3% cases, with more than 10° of rotation from the target axis. Newer toric IOLs have enhanced rotational stability and provide precise visual outcomes with minimal higher order aberrations.
对于白内障手术患者,矫正1 D或更高角膜散光时,环曲面人工晶状体(IOL)是首选的手术方式。在MEDLINE中使用“环曲面人工晶状体”“散光”和“白内障手术”作为关键词进行了全面的文献检索。环曲面IOL植入后的结果受众多因素影响,从术前病例选择和检查到术中准确的对准以及术后护理。通过多次测量并使用至少两种基于不同原理的独立设备,可以提高角膜曲率测量估计的准确性。在各种研究中,后角膜曲率的重要性越来越受到认可,同时考虑前后角膜屈光力的更新的检查方法正成为标准的治疗手段。理想的IOL屈光力计算公式应考虑手术引起的散光、后角膜曲率以及有效晶状体位置。传统的手动标记已被图像引导系统和术中像差测量法所取代,这些方法提供无标记的IOL对准,并且有助于规划切口、撕囊大小和最佳IOL中心定位。术后环曲面IOL错位是环曲面IOL植入后视觉效果欠佳的主要因素。在0.65%-3.3%的病例中,当环曲面IOL相对于目标轴旋转超过10°时,需要重新对准。新型环曲面IOL具有更高的旋转稳定性,并能以最小的高阶像差提供精确的视觉效果。