Abstract：
OBJECTIVE: To explore the corneal biomechanical properties (CBPs) of patients with vernal keratoconjunctivitis (VKC) and the discrepancies among three subtypes of VKC including palpebral, limbal, and mixed forms.
METHODS: Forty eyes of 20 VKC patients and twenty eyes of ten non-VKC patients were included in this case-control study. Patients with VKC were further divided into three subtypes (six patients in Palpebral form, five patients in limbal form, and nine patients in mixed form). The CBPs of all patients were obtained from the Corneal Visualization Scheimpflug Technology (Corvis ST).
RESULTS: First applanation (A1) length, Ambrosio relational thickness in horizontal (ARTh), and stiffness parameter at first applanation (SP-A1) were significantly lower in the VKC group while A1 velocity was significantly higher in the VKC group (p < 0.05), compared to the non-VKC group. Furthermore, A1 velocity presented a positive correlation with disease course (p < 0.05). In addition, VKC patients of limbal form had lower central corneal thickness (CCT), SP-A1, and higher deformation amplitude ratio (DA ratio), compared to the other two subtypes (p < 0.05). Besides, patients in limbal form had higher A1 velocity, integrated radius, and corneal biomechanical index (CBI) compared with mixed form, and lower A1 length than palpebral form (p < 0.05).
CONCLUSIONS: The corneas of VKC patients were softer and more protruded compared with the control group, and the property of steepness was closely related to disease course. VKC patients in limbal form were more inclined to be keratoconus than the other two subtypes due to their CBPs` discrepancies.
METHODS: Forty eyes of 20 VKC patients and twenty eyes of ten non-VKC patients were included in this case-control study. Patients with VKC were further divided into three subtypes (six patients in Palpebral form, five patients in limbal form, and nine patients in mixed form). The CBPs of all patients were obtained from the Corneal Visualization Scheimpflug Technology (Corvis ST).
RESULTS: First applanation (A1) length, Ambrosio relational thickness in horizontal (ARTh), and stiffness parameter at first applanation (SP-A1) were significantly lower in the VKC group while A1 velocity was significantly higher in the VKC group (p < 0.05), compared to the non-VKC group. Furthermore, A1 velocity presented a positive correlation with disease course (p < 0.05). In addition, VKC patients of limbal form had lower central corneal thickness (CCT), SP-A1, and higher deformation amplitude ratio (DA ratio), compared to the other two subtypes (p < 0.05). Besides, patients in limbal form had higher A1 velocity, integrated radius, and corneal biomechanical index (CBI) compared with mixed form, and lower A1 length than palpebral form (p < 0.05).
CONCLUSIONS: The corneas of VKC patients were softer and more protruded compared with the control group, and the property of steepness was closely related to disease course. VKC patients in limbal form were more inclined to be keratoconus than the other two subtypes due to their CBPs` discrepancies.
摘要：
目的：探讨春季角膜结膜炎（VKC）患者的角膜生物力学特性（CBPs）以及包括眼睑在内的三种VKC亚型之间的差异。角膜缘,混合形式。
方法：本病例对照研究包括20例VKC患者的40只眼和10例非VKC患者的20只眼。VKC患者进一步分为3种亚型（6例患者为眼睑形式，五名角膜缘形式的患者，和9名混合形式的患者)。所有患者的CBP均来自角膜可视化Scheimpflug技术（CorvisST）。
结果：第一个扁平(A1)长度，Ambrosio水平关系厚度(ARTh)，VKC组首次压平时的刚度参数（SP-A1）显着降低，而VKC组的A1速度显着升高（p<0.05），与非VKC组相比。此外，A1速度与病程呈正相关(p<0.05)。此外,角膜缘形式的VKC患者中央角膜厚度（CCT）较低，SP-A1，和更高的变形幅度比（DA比），与其他两种亚型相比（p<0.05）。此外,角膜缘形式的患者有更高的A1速度，综合半径,和角膜生物力学指数（CBI）与混合形式相比，A1长度低于眼睑形式（p<0.05）。
结论：与对照组相比，VKC患者的角膜更柔软，更突出，陡度的性质与病程密切相关。由于CBPs的差异，角膜缘形式的VKC患者比其他两种亚型更倾向于圆锥角膜。
方法：本病例对照研究包括20例VKC患者的40只眼和10例非VKC患者的20只眼。VKC患者进一步分为3种亚型（6例患者为眼睑形式，五名角膜缘形式的患者，和9名混合形式的患者)。所有患者的CBP均来自角膜可视化Scheimpflug技术（CorvisST）。
结果：第一个扁平(A1)长度，Ambrosio水平关系厚度(ARTh)，VKC组首次压平时的刚度参数（SP-A1）显着降低，而VKC组的A1速度显着升高（p<0.05），与非VKC组相比。此外，A1速度与病程呈正相关(p<0.05)。此外,角膜缘形式的VKC患者中央角膜厚度（CCT）较低，SP-A1，和更高的变形幅度比（DA比），与其他两种亚型相比（p<0.05）。此外,角膜缘形式的患者有更高的A1速度，综合半径,和角膜生物力学指数（CBI）与混合形式相比，A1长度低于眼睑形式（p<0.05）。
结论：与对照组相比，VKC患者的角膜更柔软，更突出，陡度的性质与病程密切相关。由于CBPs的差异，角膜缘形式的VKC患者比其他两种亚型更倾向于圆锥角膜。
