J Refract Surg. 2021 Aug;37(8):562-569. doi: 10.3928/1081597X-20210609-01. Epub 2021 Aug 1.
To compare 1-year visual and tomographic outcomes of topography-guided photorefractive keratectomy (TGPRK) and topography-assisted phototherapeutic keratectomy (TPTK) with corneal cross-linking (CXL).
TGPRK and TPTK were performed in 72 eyes (68 patients) and 74 eyes (71 patients), respectively. Based on the TGPRK ablation plan, the eyes underwent TPTK where the theoretical minimum corneal thickness (MCT) after surgery was less than 400 µm. In the TGPRK group, the theoretical maximum ablation depth was 50 µm after epithelium removal. In TPTK, a decentered single-step PTK was performed only in the steepest anterior curvature zone and the stromal ablation depth was limited to 25 µm. After ablation, accelerated CXL was performed in the central 8-mm zone (9 mW/cm for 10 minutes in "epithelium-off" mode) in both TGPRK and TPTK. The visual acuity and tomography were assessed.
Improvement in uncorrected ( = .73) and corrected ( = .66) distance visual acuity was similar between the two groups. However, TGPRK eyes had a greater decrease in keratometry, anterior defocus, and spherical aberration ( < .001) at the cost of greater ablation of tissue ( < .001). The median MCT decreased by 27 and 52.5 µm in the TPTK and TGPRK eyes, respectively. Both groups had similar decreases in anterior root mean square of lower ( = .10) and higher ( = .12) order aberrations.
Both TGPRK and TPTK improved visual acuity in the keratoconic eyes at 1 year of follow-up. However, TPTK removed less volume of tissue. Further, it could be an alternative to TGPRK if the theoretical stromal ablation exceeds 50 µm in thin keratoconic corneas. .
比较角膜地形图引导的光性角膜切削术（TGPRK）和角膜地形图辅助光性角膜切削术（TPTK）联合角膜交联术（CXL）在 1 年时的视力和断层成像结果。
72 只眼（68 例患者）接受 TGPRK 治疗，74 只眼（71 例患者）接受 TPTK 治疗。根据 TGPRK 消融计划，对理论术后最小角膜厚度（MCT）小于 400 µm 的眼行 TPTK 治疗。在 TGPRK 组中，上皮去除后最大理论消融深度为 50 µm。在 TPTK 中，仅在前曲率最陡区行偏心性单步 PTK，基质消融深度限制在 25 µm。消融后，在 TGPRK 和 TPTK 中均在中央 8-mm 区域（“上皮去除”模式下 9 mW/cm，10 分钟）进行加速 CXL。评估视力和断层成像结果。
两组间未矫正（ =.73）和矫正（ =.66）远视力的改善相似。然而，TGPRK 眼的角膜曲率、前离焦和球差降低更多（ <.001），代价是组织消融更多（ <.001）。TPTK 和 TGPRK 眼的 MCT 中位数分别降低了 27 和 52.5 µm。两组前根方均数较低（ =.10）和较高（ =.12）阶像差的降低也相似。
在随访 1 年时，TGPRK 和 TPTK 均可改善圆锥角膜眼的视力。然而，TPTK 切除的组织体积更少。在薄的圆锥角膜中，如果理论基质消融超过 50 µm，TPTK 可能是 TGPRK 的替代方法。
