Assistant Lecturer of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Assistant Professor of Ophthalmology and Ophthalmic Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Arch Soc Esp Oftalmol (Engl Ed). 2022 Aug;97(8):424-431. doi: 10.1016/j.oftale.2022.05.005. Epub 2022 Jun 22.
To analyze the changes in the anterior and posterior corneal surfaces measured with a Scheimpflug imaging device in keratoconus patients implanted with intracorneal ring segments (ICRS) and to correlate those changes with the visual outcomes.
This prospective interventional case series study included 92 eyes of 60 patients with keratoconus who underwent Kerarings (Mediphacos, Belo Horizonte, Brazil) ICRS implantation. Keratometric (K) readings, corneal asphericity (Q value) and elevations of both anterior and posterior corneal surfaces were evaluated using a Scheimpflug imaging device preoperatively and at 1, 3, 6 and 12 months after surgery.
The mean best corrected visual acuity (BCVA) improved from 0.61 to 0.19 logMAR at 12 months after surgery. Both anterior and posterior corneal surfaces showed significant flattening with statistically significant reduction of the mean anterior K reading by 3.39 D and the mean posterior K reading by 0.39 D (p<0.001) at 12 months. Statistically significant change of the anterior Q to a less negative value (from -1.05 to -0.36) was observed (p<0.001) with no significant change of the posterior Q value. Improvement of the anterior Q was significantly correlated to better postoperative BCVA (p=0.03). Better postoperative BCVA significantly correlated to better preoperative BCVA, flatter preoperative anterior and posterior K, less prolate anterior Q value and lower anterior elevations.
ICRS implantation has a significant flattening effect on both anterior and posterior corneal surfaces. Improvement of corneal asphericity is correlated to better visual outcome. Certain preoperative parameters were predictive factors of the postoperative visual improvement.
分析植入角膜内环段（ICRS）的圆锥角膜患者的眼前节和后节角膜表面在 Scheimpflug 成像设备测量下的变化，并将这些变化与视觉结果相关联。
本前瞻性干预性病例系列研究纳入了 60 名圆锥角膜患者的 92 只眼，这些患者接受了 Kerarings（Mediphacos，贝洛奥里藏特，巴西）ICRS 植入。在术前和术后 1、3、6 和 12 个月，使用 Scheimpflug 成像设备评估角膜曲率（K）读数、角膜非球面性（Q 值）和前后角膜表面的隆起。
术后 12 个月，平均最佳矫正视力（BCVA）从 0.61 提高到 0.19 logMAR。术后 12 个月，前、后角膜表面均明显变平，平均前 K 读数降低 3.39 D，平均后 K 读数降低 0.39 D（均 p<0.001）。前 Q 值显著向更负方向变化（从-1.05 变为-0.36）（p<0.001），而后 Q 值无显著变化。前 Q 值的改善与术后 BCVA 的提高显著相关（p=0.03）。术后 BCVA 的提高与术前 BCVA 的提高、术前前、后 K 的变平、前 Q 值的变扁和前角膜隆起的降低显著相关。
ICRS 植入对前、后角膜表面均有显著的变平作用。角膜非球面性的改善与更好的视觉结果相关。某些术前参数是术后视力改善的预测因素。
