中华眼视光学与视觉科学杂志
中華眼視光學與視覺科學雜誌
중화안시광학여시각과학잡지
CHINESE JOURNAL OF OPTOMETRY OPHTHALMOLOGY AND VISUAL SCIENCE
2013年
3期
131-136
,共6页
近视%远视%正视%Orbscan Ⅱ角膜地形图%正切曲率半径%Q值%曲线拟合计算
近視%遠視%正視%Orbscan Ⅱ角膜地形圖%正切麯率半徑%Q值%麯線擬閤計算
근시%원시%정시%Orbscan Ⅱ각막지형도%정절곡솔반경%Q치%곡선의합계산
Myopia%Hyperopia%Emmetropia%Orbscan Ⅱ Topography%Tangential radius of curvature%Q-value%Curve fitting calculation
目的 运用正切曲率半径推算儿童角膜前表面Q值并分析水平区间Q值规律及不同屈光状态与Q值的关系.通过拟合计算垂直方向Q值,得出360条半子午线范围的Q值,完成全角膜前表面数学模型的建立.方法 横断面研究.通过OrbscanⅡ角膜地形图仪得到84例儿童右眼(12例近视、45例正视、27例远视)360条半子午线Ft值,运用线性回归方程计算各半子午线Q值,分析角膜鼻、颞侧区间Q值分布规律(配对t检验)及屈光状态对Q值的影响(单因素方差分析).运用MatlabR2009b(矩阵实验室Matrix Laboratory)系统拟合计算其中62例儿童右眼数据(10例近视、25例正视、27例远视)得到360条半子午线Q值,并分析角膜360条半子午线Q值分布规律(配对t检验).结果 ①进行计算的所有半子午线所得到的决定系数R2均大于或等于0.5.84眼鼻侧、颞侧区间Q值均在-l与0之间,平均值分别为:-0.42±0.16,-0.23±0.08,二者差异有统计学意义(t=-9.527,P＜0.05).鼻侧、颞侧r0平均值分别为:7.85±0.24,7.83±0.24,二者差异有统计学意义(t=3.213,P＜0.05).鼻侧和颞侧半子午线Q值与r0不存在相关性(鼻侧r=-0.077,P=0.487;颞侧r=0.001,P=0.992).②近视组和正视组、近视组和远视组鼻侧Q平均值差异有统计学意义(F=3.907,P＜0.05),颞侧各组之间均无统计学意义(F=0.204,P＞0.05).③经过MATLAB系统进行拟合计算得到的曲线决定系数R2均大于0.9.④对48只眼进行垂直方向Q值拟合计算.拟合前后水平鼻侧方向半子午线Q值平均值分别为-0.45±0.16,-0.45±0.16,颞侧分别为-0.21±0.08,-0.20±0.10,拟合前后水平鼻、颞侧区间平均Q值t检验差异无统计学意义(鼻侧t=2.009,P＞0.05;颞侧t=2.009,P＞0.05).拟合后垂直方向上方、下方半子午线Q值平均值为-0.24±0.10、-0.17±0.08.结论 ①采用线性回归以正切曲率半径推算Q值的方法结果稳定可靠.研究对象角膜前表面趋向长椭圆形(prolate),鼻侧较颞侧区间显著,水平较垂直区间显著.屈光不正对Q值影响较小.②将360条半子午线Q值通过拟合曲线计算,Q值呈双峰状分布,峰顶分别为上方及下方垂直半子午线.③拟合计算后水平方向半子午线的非球面性均较垂直方向显著,垂直方向Q值向0靠拢.④采用MATLAB系统的曲线拟合计算全角膜Q值的方法证明是稳定可靠的.解决了垂直方向半子午线Q值的计算问题,使建立全角膜前表面数字模型成为现实.
目的 運用正切麯率半徑推算兒童角膜前錶麵Q值併分析水平區間Q值規律及不同屈光狀態與Q值的關繫.通過擬閤計算垂直方嚮Q值,得齣360條半子午線範圍的Q值,完成全角膜前錶麵數學模型的建立.方法 橫斷麵研究.通過OrbscanⅡ角膜地形圖儀得到84例兒童右眼(12例近視、45例正視、27例遠視)360條半子午線Ft值,運用線性迴歸方程計算各半子午線Q值,分析角膜鼻、顳側區間Q值分佈規律(配對t檢驗)及屈光狀態對Q值的影響(單因素方差分析).運用MatlabR2009b(矩陣實驗室Matrix Laboratory)繫統擬閤計算其中62例兒童右眼數據(10例近視、25例正視、27例遠視)得到360條半子午線Q值,併分析角膜360條半子午線Q值分佈規律(配對t檢驗).結果 ①進行計算的所有半子午線所得到的決定繫數R2均大于或等于0.5.84眼鼻側、顳側區間Q值均在-l與0之間,平均值分彆為:-0.42±0.16,-0.23±0.08,二者差異有統計學意義(t=-9.527,P＜0.05).鼻側、顳側r0平均值分彆為:7.85±0.24,7.83±0.24,二者差異有統計學意義(t=3.213,P＜0.05).鼻側和顳側半子午線Q值與r0不存在相關性(鼻側r=-0.077,P=0.487;顳側r=0.001,P=0.992).②近視組和正視組、近視組和遠視組鼻側Q平均值差異有統計學意義(F=3.907,P＜0.05),顳側各組之間均無統計學意義(F=0.204,P＞0.05).③經過MATLAB繫統進行擬閤計算得到的麯線決定繫數R2均大于0.9.④對48隻眼進行垂直方嚮Q值擬閤計算.擬閤前後水平鼻側方嚮半子午線Q值平均值分彆為-0.45±0.16,-0.45±0.16,顳側分彆為-0.21±0.08,-0.20±0.10,擬閤前後水平鼻、顳側區間平均Q值t檢驗差異無統計學意義(鼻側t=2.009,P＞0.05;顳側t=2.009,P＞0.05).擬閤後垂直方嚮上方、下方半子午線Q值平均值為-0.24±0.10、-0.17±0.08.結論 ①採用線性迴歸以正切麯率半徑推算Q值的方法結果穩定可靠.研究對象角膜前錶麵趨嚮長橢圓形(prolate),鼻側較顳側區間顯著,水平較垂直區間顯著.屈光不正對Q值影響較小.②將360條半子午線Q值通過擬閤麯線計算,Q值呈雙峰狀分佈,峰頂分彆為上方及下方垂直半子午線.③擬閤計算後水平方嚮半子午線的非毬麵性均較垂直方嚮顯著,垂直方嚮Q值嚮0靠攏.④採用MATLAB繫統的麯線擬閤計算全角膜Q值的方法證明是穩定可靠的.解決瞭垂直方嚮半子午線Q值的計算問題,使建立全角膜前錶麵數字模型成為現實.
목적 운용정절곡솔반경추산인동각막전표면Q치병분석수평구간Q치규률급불동굴광상태여Q치적관계.통과의합계산수직방향Q치,득출360조반자오선범위적Q치,완성전각막전표면수학모형적건립.방법 횡단면연구.통과OrbscanⅡ각막지형도의득도84례인동우안(12례근시、45례정시、27례원시)360조반자오선Ft치,운용선성회귀방정계산각반자오선Q치,분석각막비、섭측구간Q치분포규률(배대t검험)급굴광상태대Q치적영향(단인소방차분석).운용MatlabR2009b(구진실험실Matrix Laboratory)계통의합계산기중62례인동우안수거(10례근시、25례정시、27례원시)득도360조반자오선Q치,병분석각막360조반자오선Q치분포규률(배대t검험).결과 ①진행계산적소유반자오선소득도적결정계수R2균대우혹등우0.5.84안비측、섭측구간Q치균재-l여0지간,평균치분별위:-0.42±0.16,-0.23±0.08,이자차이유통계학의의(t=-9.527,P＜0.05).비측、섭측r0평균치분별위:7.85±0.24,7.83±0.24,이자차이유통계학의의(t=3.213,P＜0.05).비측화섭측반자오선Q치여r0불존재상관성(비측r=-0.077,P=0.487;섭측r=0.001,P=0.992).②근시조화정시조、근시조화원시조비측Q평균치차이유통계학의의(F=3.907,P＜0.05),섭측각조지간균무통계학의의(F=0.204,P＞0.05).③경과MATLAB계통진행의합계산득도적곡선결정계수R2균대우0.9.④대48지안진행수직방향Q치의합계산.의합전후수평비측방향반자오선Q치평균치분별위-0.45±0.16,-0.45±0.16,섭측분별위-0.21±0.08,-0.20±0.10,의합전후수평비、섭측구간평균Q치t검험차이무통계학의의(비측t=2.009,P＞0.05;섭측t=2.009,P＞0.05).의합후수직방향상방、하방반자오선Q치평균치위-0.24±0.10、-0.17±0.08.결론 ①채용선성회귀이정절곡솔반경추산Q치적방법결과은정가고.연구대상각막전표면추향장타원형(prolate),비측교섭측구간현저,수평교수직구간현저.굴광불정대Q치영향교소.②장360조반자오선Q치통과의합곡선계산,Q치정쌍봉상분포,봉정분별위상방급하방수직반자오선.③의합계산후수평방향반자오선적비구면성균교수직방향현저,수직방향Q치향0고롱.④채용MATLAB계통적곡선의합계산전각막Q치적방법증명시은정가고적.해결료수직방향반자오선Q치적계산문제,사건립전각막전표면수자모형성위현실.
Objective To calculate the Q-value of the anterior corneal surface of children by using the tangential radius of curvature; to analyze the distribution of horizontal Q-values and the relationship between Q-value and different refractions.The vertical Q-values were calculated by curve fitting,and the Q-values of the 360° semi-meridians were then obtained,to complete the mathematical model of the anterior corneal surface.Methods The Ft-values of the 360 semi-meridians from the 84 right eyes of the children (12 cases of myopia,45 cases of hyperopia,and 27 cases of emmetropia)were calculated by Orbscan Ⅱ topography using a linear regression equation to calculate the Q-values of the semi-meridians and analyze the nasal and temporal distribution of the Q-values and the effect of refractive state.MATLAB R2009b (Matrix Laboratory) was used for curve fitting calculations of the right eye data from 62 children (10 myopes,25 hyperopes and 27 emmetropes) to obtain Q-values of 360 semi-meridians and to analyze the distribution of the Q-values.Results ① All of the coefficients of determination (R2) were greater than or equal to 0.5.The Q-values of the nasal and temporal distributions were between 1 and 0.The mean Q-values of the nasal distribution of 84 right eyes was-0.42±0.16,and the temporal distribution was-0.23±0.08.The difference was statistically significant (t=-9.527,P＜0.05).The mean r0 of the nasal distribution of 84 right eyes was 7.85±0.24and the temporal distribution was 7.83±0.24.The difference was statistically significant (t=3.213,P＜0.05).No statistical correlation was found between Q-values and r0 in this study (nasal distribution r=-0.077,P=0.487,temporal distribution r=0.001,P=0.992).②The Q values of a one-way ANOVA analysis of emmetropes,myopes and hyperopes showed that the differences between the nasal corneas of myopes and emmetropes and of myopes and hyperopes were statistically significant (P＜O.05).No significant difference was found between the emmetropes and hyperopes (P＞0.05).The differences between the temporal distributions were not statistically significant (P＞0.05).③The coefficient of determination (R2) of the curve fitting by MATLAB was greater than 0.9.④Fitting the vertical Q-values of the 48 eyes:the mean Q-values of the nasal distribution of the semi-meridian before and after curve fitting were-0.45±0.16 and-0.45±0.16 and the temporal distributions were-0.21±0.08 and -0.20±0.10.There were no significant differences before and after curve fittings (nasal distribution,t =2.009,P＞0.05,temporal distribution,t =2.009,P＞O.05).The mean vertical Q-values of the superior and inferior distributions after curve fitting were-0.24±0.10 and-0.17±0.08.Conclusion ①The method of using linear regression to calculate the Q-value of the anterior corneal surface by the tangent radius of curvature proved to be stable and reliable.Corneal asphericity was represented by a prolate ellipse and a trend toward a more prolate Q-value was found in the nasal and horizontal distributions.The Q-value had a weak correlation to ametropia.②Fhe distribution of 360 semi-meridians of the Q-value calculated from the curve fits were in the form of a double hump and the two peaks were above and below the vertical semi-meridinans.③After curve fitting calculations,the horizontal semi-meridians had more asphericity than the vertical meridians,which were more round.④The method using the Curve Fitting Toolbox of the MATLAB System to fit the Q-values proved to be stable and reliable.It solves the problem of calculating Q-values,and enables the creation of a digital model of the corneal anterior surface to become a reality.
