PURPOSE To assess corneal stability and corrected distance visual acuity (CDVA) 3, 6, and 12 months following corneal cross-linking (CXL) using the ABCD keratoconus staging system. METHODS This prospective longitudinal study included 31 eyes with keratoconus receiving CXL based on the standard Dresden protocol. CDVA, refraction, and Scheimpflug tomography with the Pentacam HR (Oculus Optikgeräte GmbH) were evaluated before and after surgery. Geometric and functional changes were assessed using the actual values and staging of each element of the ABCD keratoconus staging system. A, B, C, and D refer to the anterior and posterior radii of curvature in a 3-mm zone centered on the cor-neal thinnest point, minimum corneal thickness, and CDVA, respectively. RESULTS There were no significant changes in the actual values of anterior radius of curvature (P = .497) and CDVA (P = .082), whereas posterior radius of curvature (P = .007) and corneal thinnest point (P < .001) showed significant changes statistically. Pairwise comparison showed only a statistically significant steepening in posterior radius of curvature at 3 months after CXL compared to the preoperative radius (P = .002) and a significant decrease in corneal thinnest point at 3 (P < .001) and 6 (P = .028) months after CXL compared to baseline assessment. Staging of each element of the ABCD keratoconus staging system indicated no change between baseline and 3, 6, and 12 months after CXL. CONCLUSIONS The geometric and functional parameters included in the ABCD keratoconus staging system showed stability of corneal status and CDVA 1 year after CXL. [J Refract Surg. 2021;37(10):700-706.].

中文翻译：

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使用 ABCD 圆锥角膜分期系统评估角膜交联后 1 年的角膜稳定性和视力。

目的 使用 ABCD 圆锥角膜分期系统评估角膜交联 (CXL) 后 3、6 和 12 个月的角膜稳定性和矫正远视力 (CDVA)。方法 这项前瞻性纵向研究包括 31 只圆锥角膜，根据标准德累斯顿协议接受 CXL。在手术前后评估 CDVA、屈光度和使用 Pentacam HR (Oculus Optikgeräte GmbH) 的 Scheimpflug 断层扫描。使用 ABCD 圆锥角膜分期系统的每个元素的实际值和分期来评估几何和功能变化。A、B、C 和 D 分别是指以角膜最薄点、最小角膜厚度和 CDVA 为中心的 3 毫米区域内的前后曲率半径。结果前曲率半径 (P = .497) 和 CDVA (P = .082) 的实际值没有显着变化，而后曲率半径 (P = .007) 和角膜最薄点 (P < .001 ) 显示出统计学上的显着变化。成对比较显示，与术前半径 (P = .002) 相比，CXL 后 3 个月后曲率半径仅在统计学上显着变陡，并且角膜最薄点在 3 (P < .001) 和 6 (P = .028) 个月后 CXL 与基线评估相比。ABCD 圆锥角膜分期系统的每个要素的分期表明在基线和 CXL 后 3、6 和 12 个月之间没有变化。结论 ABCD 圆锥角膜分期系统中包含的几何和功能参数显示 CXL 后 1 年角膜状态和 CDVA 的稳定性。[J 屈光手术。2021;37(10):700-706.]。