Min Ji Sang, Min Byung Moo
Kim's Eye Hospital, Division of Cornea, Cataract, and Refractive Surgery, Konyang University School of Medicine, Seoul, South Korea.
Woori Eye Clinic, Department of Ophthalmology, Yonsei University School of Medicine, Daejon, South Korea.
Clin Ophthalmol. 2021 Apr 23;15:1751-1758. doi: 10.2147/OPTH.S306636. eCollection 2021.
We aimed to introduce a new technique to reduce regional asymmetry of corneal thickness by assessing its effectiveness in four patients with myopic regression after laser refractive surgery (LRS).
Four patients (four eyes) with myopic regression after LRS were included in this study. A new technique of enhancement with laser epithelial keratomileusis-linked laser asymmetric keratectomy using semi-cylindrical ablation pattern (E-LAK-SCAP) with full integration of the Vision-Up software for analyzing the corneal thickness deviation can be used to create central symmetry by blocking laser ablation on the thin cornea. It reduces the regional asymmetry of the corneal thickness, thus improving corneal symmetry and correcting the refractive power and myopic shift due to E-LAK-SCAP. We measured refraction, visual acuity, intraocular pressure (IOP), central corneal thickness (CCT), corneal irregularities in the 3.0mm, and 5.0 zones on Orbscan maps, the sum of corneal thickness deviations in four directions (SUM), distance between the maximum posterior elevation (best-fit-sphere [BFS]) and the visual axis (DISTANCE), and angle kappa before and after LRS and E-LAK-SCAP. Blurring scores were measured before and after E-LAK-SCAP.
The uncorrected far visual acuity (LogMAR) increased after LRS and E-LAK-SCAP. SUM (µm) increased after LRS in three cases, but decreased in all four cases after E-LAK-SCAP. DISTANCE increased after LRS, but decreased after E-LAK-SCAP. The spherical equivalent, CCT, decreased after LRS and E-LAK-SCAP. Blurring scores decreased after E-LAK-SCAP, and angle kappa was similar before and after LRS, but decreased after E-LAK-SCAP. IOP was similar before and after both LRS and E-LAK-SCAP.
E-LAK-SCAP improved corneal symmetry by reducing the SUM and DISTANCE, showing good postoperative visual acuity, and blurring was reduced postoperatively. There was no myopic regression in the one-year postoperative period.
我们旨在引入一种新技术，通过评估其对4例激光屈光手术（LRS）后近视回退患者的有效性，来减少角膜厚度的区域不对称性。
本研究纳入4例（4只眼）LRS后近视回退的患者。一种采用半圆柱形消融模式的激光上皮下角膜磨镶术联合激光非对称角膜切除术（E-LAK-SCAP）并完全集成Vision-Up软件以分析角膜厚度偏差的新技术，可通过在薄角膜上阻断激光消融来创建中心对称性。它减少了角膜厚度的区域不对称性，从而改善角膜对称性，并矫正因E-LAK-SCAP导致的屈光力和近视偏移。我们测量了LRS和E-LAK-SCAP前后的验光、视力、眼压（IOP）、中央角膜厚度（CCT）、Orbscan地图上3.0mm和5.0区域的角膜不规则度、四个方向上角膜厚度偏差的总和（SUM）、最大后表面隆起（最佳拟合球[BFS]）与视轴之间的距离（DISTANCE）以及kappa角。在E-LAK-SCAP前后测量了模糊评分。
LRS和E-LAK-SCAP后未矫正远视力（LogMAR）提高。3例患者LRS后SUM（μm）增加，但4例患者E-LAK-SCAP后均降低。DISTANCE在LRS后增加，但在E-LAK-SCAP后降低。等效球镜度、CCT在LRS和E-LAK-SCAP后降低。E-LAK-SCAP后模糊评分降低，LRS前后kappa角相似，但E-LAK-SCAP后降低。LRS和E-LAK-SCAP前后IOP相似。
E-LAK-SCAP通过降低SUM和DISTANCE改善了角膜对称性，术后视力良好，术后模糊度降低。术后1年期无近视回退。
