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目的应用角膜地形图仪研究老年人角膜前表面光学特征。方法对50例老年人79只眼和29例青年人54只眼行角膜地形图检查及检影验光,对所得的角膜地形图参数:模拟角膜曲率(SimK)、角膜不规则指数和形状系数进行分析。结果老年组逆规性散光33例(41．78％)．近水平子午线曲率SimK1为(43．77±1．36)D,角膜不规则指数为(0．95±0．33)D,均高于青年组[(42．72±1．57)和(0．68±0．16)D],两组比较差异有统计学意义(P<0．01);近垂直子午线曲率SimK2为(43．85±1．33)D,形状系数为(0．24±0．12)D,青年组分别为(43．59±1．5)和(0．28±0．12) D,二者比较差异无统计学意义(P>0．05)。结论老年人眼角膜表面水平子午线曲率变陡,散光属性向着逆规发展;老年人眼角膜的光滑性降低;角膜由中央区到周边各子午线曲率的变化趋势保持稳定。
Objective To study the optical characteristics of corneal anterior surface in the elderly with corneal topographer. Methods Corneal topography and retinoscopy were performed in 79 eyes of 50 elderly and 54 of 29 young adults. The parameters of corneal topography: simulated corneal curvature (SimK), corneal irregularity index and shape coefficient analysis. Results The elderly group of astigmatism in 33 cases (41.78%). SimK1 was (43.77 ± 1.36) D and corneal irregularity index was (0.95 ± 0.33) D in the near horizontal meridian, which were higher than those in the young group [(42.72 ± 1.57) and 0.68 ± 0.16) D]. The difference between the two groups was statistically significant (P <0.01). The SimK2 of near vertical meridional curvature was (43.85 ± 1.33) D, and the shape coefficient was (0. 24 ± 0.12) D, the young group was (43.59 ± 1.5) and (0.28 ± 0.12) D, respectively. There was no significant difference between the two groups (P> 0.05). Conclusions The meridional curvature of corneal surface at the level of the cornea becomes steeper and the astigmatism property develops toward the inverse regulation. The smoothness of the cornea of the elderly is decreased. The curvature of the meridian from the central region to the periphery is stable.