Pentacam眼前节测量分析系统对青壮年近视患者角膜前、后表面Q值的测量和分析

目的探讨青壮年近视患者角膜前、后表面不同范围非球面性参数Q值的分布及它与其他参数间的关系。方法使用Pentacam眼前节测量与分析系统检测203例（406眼）等效球镜（spherical equivalent，SE）为-1．00～11.38D的18—36岁青壮年近视患者，获取角膜前、后表面Q值、角膜像差、角膜表面散光△K值。结果角膜前表面Q20、Q25、Q30、Q35、Q40分别为-0．14±0．15、-0．20±O．11、-0．24±0．09、-0．30±0．23、-031±0．23。角膜后表面Q20、Q25、Q30、Q35、Q40分别为0．48±0．32、0．27±0．25、0．09±0．20、-0．05±0．18、-0．20±0．17。角膜前表面Q30与球镜、柱镜、SE之间呈正相关（r值分别为0．11、0．19、0．15），与角膜前表面散光△K、z40、RMSh呈正相关（r值分别为0-31、O．64、0．56）；角膜后表面Q30与角膜后表面z40、RMSh、RMSg呈正相关（r值分别为0．82、0．59、0．24）。性别、年龄、配戴角膜接触镜对Q值无显著影响。双眼Q值呈-致性。结论大多数青壮年近视患者角膜前表面为长椭圆形（prolate），前、后表面的Q值均随着测定范围的扩大变得越来越小。角膜Q值受许多因素的影响。

Investigation of the Q-values of the ante-rior and posterior corneal surfaces of young myopic patients using a Pentacam measurement system and an evaluation system for the anterior segment of the eye

Objective To evaluate the distribution of asphericity of the anterior and posterior corneal surfaces of young myopic pa- tients, and to study the relationship between the Q-value and other factors. Methods Two hundred and three patients （406 eyes） with a spherical equivalence （SE） from -1.00 D to -11.38 D and age from 18 to 36 years were examined with a Pentacam measurement system and an evaluation system for the anterior segment of the eye. Q-values, corneal aberrations, and corneal astigmatisms were assessed. Results The Q23, Q25, Q30, Q35, and Q40 of the anterior corneal surface were -0.14±0.15, -0.20±0.11, -0.24±0.09, -0.30± 0.23, and -0.31±0.23, respectively. The Q20, Q25, Q30, Q35, and Q40 of the posterior corneal surface were 0.48±0.32, 0.27±0.25, 0.09±0.20, -0.05±0.18, and-0.20±0.17, respectively. Positive re- lationships were found between the anterior corneal surface Q30 and the sphere （r=0.11）, cylinder （r=0.19）, spherical equivalent （r= 0.15）, corneal astigmatism （r=0.31）, and the values of Z4^0 （r=0.64） and RMSh （r=0.56） of the anterior corneal surface. Positive relation- ships were also found between the posterior corneal surface Q30 and the values of Z4^0 （r=0.82）, RMSh （r=0.59）, and RMSg （r=0.24） of the posterior corneal surface. Variables such as gender, age, and the history of corneal contact lens wear had no significant effect on the Q30. The difference in the Q-value between the right and left eyes showed no statistical significance. Conclusion The anterior corneal surface of most young myopic patients is prolate, the Q-value of the anterior and posterior corneal surface becomes smaller as the measurement area is extended. Many factors affect the Q-value.