Chan Kahei, Hersh Peter S
CLEI Center for Keratoconus, Cornea and Laser Eye Institute-Hersh Vision Group, Teaneck, and the Department of Ophthalmology, Rutgers New Jersey Medical School, Newark, NJ.
Cornea. 2017 Feb;36(2):244-248. doi: 10.1097/ICO.0000000000001075.
To evaluate the efficacy of removal and relocation of intracorneal ring segments for improving outcomes in treatment of keratoconus and corneal ectasia.
This is a retrospective case series conducted at a cornea and refractive surgery subspecialty practice setting. Patients with previous insertion of 2 intracorneal ring segments underwent surgical removal and repositioning of segments because of unsatisfactory visual and topographic outcomes. The principal outcomes included uncorrected and corrected visual acuities, manifest refraction, topography-derived maximum keratometry (Kmax), inferior-superior topography power difference (I - S), and higher-order aberration profile derived from wavefront analysis.
Three patients are presented in this case series. Uncorrected visual acuity improved in all eyes by an average of 2.75 lines. Corrected visual acuity improved in 2 eyes and remained unchanged in 1 eye. Refractive astigmatism decreased in all patients by an average of 2.50 D. Kmax decreased by an average of 1.43 D. All patients had improvement in the I - S value with a mean decrease of 5.13 D.
Topography-guided repositioning and/or replacement of corneal ring segments can result in improved topographic, optical, and visual outcomes in patients in whom the initial result is suboptimal. In these cases, a single segment repositioned beneath the cone resulted in an improved outcome. Analysis of corneal topography can guide the surgeon in treatment planning and can suggest patients in whom such an effort will be rewarded with better results.
评估取出并重新定位角膜内环片对改善圆锥角膜和角膜扩张症治疗效果的有效性。
这是一项在角膜和屈光手术专科诊所开展的回顾性病例系列研究。曾植入2个角膜内环片的患者因视觉和地形图结果不理想而接受了手术取出和重新定位内环片。主要结果包括裸眼视力和矫正视力、显验光、地形图衍生的最大角膜曲率(Kmax)、上下地形图屈光力差值(I - S)以及波前分析得出的高阶像差曲线。
本病例系列展示了3例患者。所有术眼的裸眼视力平均提高了2.75行。2只术眼的矫正视力提高,1只术眼保持不变。所有患者的屈光性散光平均降低了2.50 D。Kmax平均降低了1.43 D。所有患者的I - S值均有改善,平均降低了5.13 D。
地形图引导下的角膜环片重新定位和/或更换可使初始结果欠佳的患者在地形图、光学和视觉方面的结果得到改善。在这些病例中,将单个环片重新定位到圆锥下方可改善结果。角膜地形图分析可指导外科医生进行治疗规划,并可提示哪些患者进行这种操作会获得更好的效果。