正切曲率半径对高度近视眼角膜表面Q值计算及特性分析  

Prospective analysis of the asphericity of the anterior corneal surface in high myopia with the Q-value calculated by tangential radius

作　　者：陈如利[1] 王若洁[1] 王波[2] 施明光[1] 

机构地区：[1]温州医学院附属第二医院眼科,浙江温州325027 [2]南京财经大学数学教研室,江苏南京210003

出　　处：《中华眼视光学与视觉科学杂志》2011年第1期34-38,共5页Chinese Journal Of Optometry Ophthalmology And Visual Science

基　　金：国家自然科学基金资助项目（30872816）

摘　　要：目的 研究高度近视患者角膜前表面水平方向的非球面特性.方法 回顾性研究.使用OrbscanⅡ角膜地形图仪采集38例高度近视患者右眼角膜地形图并导出角膜前表面正切图中的数据（θ,Ft,R）,利用线性回归拟合法及坐标旋转技术,以正切曲率半径计算得到角膜前表面360条半子午线截痕的Q值,对水平主子午线上下45°范围数据进行研究.取研究范围内间隔15°的半子午线Q值（鼻侧315°、330°、345°、0°、15°、30°、45°,颞侧135°、150°、165°、180°、195°、210°、225°,总共14条半子午线的Q值）.将研究范围划分为间隔15°的区间（鼻侧315°～329°、330°～344°、345°～359°、1°～15°、16°～30°、31°～45°,颞侧135°～149°、150°～164°、165°～179°、181°～195°、196°～210°、211°～225°,总共12个区间）,并分别计算出每个区间的Q均值.将研究对象按等效球镜度数分成高度近视组（-6.00～-9.00 D,26例）、超高度近视组（-9.00 D以上,12例）,采用独立样本t检验比较两组间的差异.结果 水平方向所取半子午线的Q值分别是：鼻侧315°为-0.17±0.05,330°为-0.22±0.06,345°为-0.30±0.09,0°为-0.36±0.08,15°为-0.37±0.10,30°为-0.32±0.09,45°为-0.26±0.10;颞侧135°为-0.26±0.11,150°为-0.34±0.12,165°为-0.36±0.12,180°为-0.38±0.12,195°为-0.41±0.12,210°为-0.40±0.10,225°为-0.36±0.11.水平方向所分区间的Q均值分别是：鼻侧315°～329°为-0.19±0.05,330°～344°为-0.26±0.08,345°～359°为-0.33±0.09,0°为-0.36±0.08,1°～15°为-0.37±0.08,16°～30°为-0.34±0.09,31°～45°为-0.30±0.10;颞侧135°～149°为-0.30±0.11,150°～164°为-0.35±0.11,165°～179°为-0.37±0.12,180°为-0.38±0.12,181°～195°为-0.40±0.11,196°～210°为-0.41±0.11,211°～225°为-0.38±0.11.Q值的区间（水平主子午线上下15°）均值,高度近视组：鼻侧为-0.34±0.09,颞侧为-0.35±0.12;超高度近视组：鼻侧为-0.31±0.08,颞侧为-0.34�Objective To study asphericity in the horizontal direction of the anterior corneal surface in high myopia. Methods This was a retrospective case series study. The corneal topographies of 38 cases （right eyes） with high myopia were collected from the Orbscan Ⅱ topography system and the data of the anterior corneal surface in the tangential map were filtered out. The Q-values of the 360 semi-meridians were calculated by linear regression using the tangential radius in corneal topography and the coordinate rotation technique. The data in the range of ±45° around the horizontal principal meridian were then studied. The Q-values of the semi-meridians in intervals of 15° from the principal meridian were selected （the semi-meridians of 315°, 330°, 345°, 0°, 15°,30° and 45° on the nasal side; 135°, 150°, 165°, 180°, 195°, 210°, 225° on the temporal side）.The average Q-values of the quadrants of all 15 semi-meridians were calculated （the quadrants of 315°-329°, 330°-344°, 345°-359°, 1°-15°, 16°-30°, 31°-45° on the nasal side; 135°-149°,150°-164°, 165°-179°, 181°-195°, 196°-210°, 211°-225° on the temporal side）. All the subjects were divided into two groups according to equivalent refractive power： high myopia group （-6.00-9.00 D,26 cases）; ultra-high myopia group （over -9.00 D, 12 cases）. Then an independent samples t test was used to compare the differences between the two groups. Results The Q-values of the selected semi-meridians in the horizontal direction： the nasal side, 315° was -0.17±0.05, 330° was -0.22±0.06, 345° was -0.30±0.09, 0° was -0.36±0.08, 15° was -0.37±0.10, 30° was -0.32±0.09, 45°was -0.26±0.10; the temporal side, 135° was -0.26±0.11, 150° was -0.34±0.12, 165° was -0.36±0.12, 180° was -0.38±0.12, 195° was -0.41±0.12, 210° was -0.40±0.10, 225° was -0.36±0.11.The average Q-values of the quadrants： the nasal side, 315°-329° was -0.19±0.05, 330°-344° was -0.26±0.08, 345°-359° was -0.33±0.09, 0° was -0

关 键 词：高度近视 角膜前表面 Q值 正切曲率半径 非球面 

分 类 号：R779.63[医药卫生—眼科]