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±0.13,两组间鼻侧(t=--1.058,P=0.297)、颢侧(t=-0.162,P=0.873)差异均无统计学意义.结论 角膜前表面水平方向为长椭球面,即从中央到周边逐渐趋于平坦.且自水平主子午线向斜向子午线方向延伸时,这种趋于平坦的趋势逐渐减弱.屈光度对非球面特性的影响较小.
目的 研究高度近視患者角膜前錶麵水平方嚮的非毬麵特性.方法 迴顧性研究.使用OrbscanⅡ角膜地形圖儀採集38例高度近視患者右眼角膜地形圖併導齣角膜前錶麵正切圖中的數據(θ,Ft,R),利用線性迴歸擬閤法及坐標鏇轉技術,以正切麯率半徑計算得到角膜前錶麵360條半子午線截痕的Q值,對水平主子午線上下45°範圍數據進行研究.取研究範圍內間隔15°的半子午線Q值(鼻側315°、330°、345°、0°、15°、30°、45°,顳側135°、150°、165°、180°、195°、210°、225°,總共14條半子午線的Q值).將研究範圍劃分為間隔15°的區間(鼻側315°～329°、330°～344°、345°～359°、1°～15°、16°～30°、31°～45°,顳側135°～149°、150°～164°、165°～179°、181°～195°、196°～210°、211°～225°,總共12箇區間),併分彆計算齣每箇區間的Q均值.將研究對象按等效毬鏡度數分成高度近視組(-6.00～-9.00 D,26例)、超高度近視組(-9.00 D以上,12例),採用獨立樣本t檢驗比較兩組間的差異.結果 水平方嚮所取半子午線的Q值分彆是:鼻側315°為-0.17±0.05,330°為-0.22±0.06,345°為-0.30±0.09,0°為-0.36±0.08,15°為-0.37±0.10,30°為-0.32±0.09,45°為-0.26±0.10;顳側135°為-0.26±0.11,150°為-0.34±0.12,165°為-0.36±0.12,180°為-0.38±0.12,195°為-0.41±0.12,210°為-0.40±0.10,225°為-0.36±0.11.水平方嚮所分區間的Q均值分彆是:鼻側315°～329°為-0.19±0.05,330°～344°為-0.26±0.08,345°～359°為-0.33±0.09,0°為-0.36±0.08,1°～15°為-0.37±0.08,16°～30°為-0.34±0.09,31°～45°為-0.30±0.10;顳側135°～149°為-0.30±0.11,150°～164°為-0.35±0.11,165°～179°為-0.37±0.12,180°為-0.38±0.12,181°～195°為-0.40±0.11,196°～210°為-0.41±0.11,211°～225°為-0.38±0.11.Q值的區間(水平主子午線上下15°)均值,高度近視組:鼻側為-0.34±0.09,顳側為-0.35±0.12;超高度近視組:鼻側為-0.31±0.08,顳側為-0.34±0.13,兩組間鼻側(t=--1.058,P=0.297)、顥側(t=-0.162,P=0.873)差異均無統計學意義.結論 角膜前錶麵水平方嚮為長橢毬麵,即從中央到週邊逐漸趨于平坦.且自水平主子午線嚮斜嚮子午線方嚮延伸時,這種趨于平坦的趨勢逐漸減弱.屈光度對非毬麵特性的影響較小.
목적 연구고도근시환자각막전표면수평방향적비구면특성.방법 회고성연구.사용OrbscanⅡ각막지형도의채집38례고도근시환자우안각막지형도병도출각막전표면정절도중적수거(θ,Ft,R),이용선성회귀의합법급좌표선전기술,이정절곡솔반경계산득도각막전표면360조반자오선절흔적Q치,대수평주자오선상하45°범위수거진행연구.취연구범위내간격15°적반자오선Q치(비측315°、330°、345°、0°、15°、30°、45°,섭측135°、150°、165°、180°、195°、210°、225°,총공14조반자오선적Q치).장연구범위화분위간격15°적구간(비측315°～329°、330°～344°、345°～359°、1°～15°、16°～30°、31°～45°,섭측135°～149°、150°～164°、165°～179°、181°～195°、196°～210°、211°～225°,총공12개구간),병분별계산출매개구간적Q균치.장연구대상안등효구경도수분성고도근시조(-6.00～-9.00 D,26례)、초고도근시조(-9.00 D이상,12례),채용독립양본t검험비교량조간적차이.결과 수평방향소취반자오선적Q치분별시:비측315°위-0.17±0.05,330°위-0.22±0.06,345°위-0.30±0.09,0°위-0.36±0.08,15°위-0.37±0.10,30°위-0.32±0.09,45°위-0.26±0.10;섭측135°위-0.26±0.11,150°위-0.34±0.12,165°위-0.36±0.12,180°위-0.38±0.12,195°위-0.41±0.12,210°위-0.40±0.10,225°위-0.36±0.11.수평방향소분구간적Q균치분별시:비측315°～329°위-0.19±0.05,330°～344°위-0.26±0.08,345°～359°위-0.33±0.09,0°위-0.36±0.08,1°～15°위-0.37±0.08,16°～30°위-0.34±0.09,31°～45°위-0.30±0.10;섭측135°～149°위-0.30±0.11,150°～164°위-0.35±0.11,165°～179°위-0.37±0.12,180°위-0.38±0.12,181°～195°위-0.40±0.11,196°～210°위-0.41±0.11,211°～225°위-0.38±0.11.Q치적구간(수평주자오선상하15°)균치,고도근시조:비측위-0.34±0.09,섭측위-0.35±0.12;초고도근시조:비측위-0.31±0.08,섭측위-0.34±0.13,량조간비측(t=--1.058,P=0.297)、호측(t=-0.162,P=0.873)차이균무통계학의의.결론 각막전표면수평방향위장타구면,즉종중앙도주변축점추우평탄.차자수평주자오선향사향자오선방향연신시,저충추우평탄적추세축점감약.굴광도대비구면특성적영향교소.
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 -0.36±0.08, 1°-15° was -0.37±0.08, 16°-30° was -0.34±0.09, and 31°-45° was -0.30±0.10;the temporal side, 135°-149° was -0.30±0.11, 150°-164°was -0.35±0.11, 165°-179° was -0.37±0.12, 180° was -0.38±0.12, 181°-195° was -0.40±0.11,196°-210° was -0.41±0.11, and 211°-225° was -0.38±0.11. The average Q-values of the quadrants (15° on eac side around the horizontal meridian) for the high myopia group: the nasal side was -0.34±0.09 and the temporal side was -0.35±0.12; for the ultra-high myopia group: the nasal side was -0.31±0.08 and the temporal side was -0.34±0.13. The differences between the two groups (the nasal side: t=-1.058, P=0.297; the temporal side: t=-0.162, P=0.873) were not statistically significant.Conclusion The horizontal direction of the anterior corneal surface is a prolate ellipsoid. This means it becomes gradually flatter from the central to perimeter zone, and the trend declines gradually from the horizontal to oblique meridian. The influence of refractive power on asphericity is quite weak.
