CAJ | 학술논문

背景角膜Q值是描述角膜前表面非球面形态特性的重要参数,而角膜作为光学曲面,是由一系列通过光轴正切面的截痕集合而成.所以只有正切面对于曲面所截的截痕才能代表其真实的光学形态,也就是说用正切曲率半径推算的Q值能真正代表角膜前表面的非球面特性. 目的运用角膜地形图正切曲率半径推算角膜前表面子午线截痕Q值,分析青年近视受试者角膜前表面水平方向非球面特性. 方法 16～30岁的近视受试者90例90眼行OrbscanⅡ角膜地形图检查,均取右眼,受试者平均等效屈光度为(-5.45±2.75)D,按近视度数不同分为低度近视组30眼、中度近视组30眼、高度近视组30眼.采集并导出角膜前表面间隔0.1 mm的360条半子午线正切曲率Ft值.将所需计算半子午线截痕上的所有Ft值代入正切曲率半径公式,应用线性回归方法并通过计算机编程的模型处理系统计算碍到各半子午线Q值,并进行区间整合,同时对每位研究对象进行检影验光、眼压测量、裂隙灯检查、角膜曲率计检查及眼底检查. 结果所有受检眼角膜的半子午线确定系数(R2)均＞0.5.90眼水平方向鼻侧区间和颞侧区间Q值均数分别为-0.32±0.11和-0.30±0.12,差异有统计学意义(t=2.009,P＜0.05)；角膜顶点曲率半径(r0)值均数分别为(7.78±0.27) mm、(7.72±0.25)mm,差异无统计学意义(t=-1.016,P＞0.05)；不同近视度组鼻侧、颞侧区间平均Q值差异均无统计学意义(鼻侧:F=0.192,P=0.825;颞侧:F=0.912,P=0.406).水平鼻侧和颞侧半子午线平均Q值分别为-0.33±0.14和-0.30±0.13,r0平均值分别为7.76±0.30和7.74±0.24,r0与水平鼻侧半子午线平均Q值呈弱正相关(r=0.320,P＜0.05),与水平颞侧半子午线平均Q值无明显相关(r=0.104,P＞0.05).水平鼻侧半子午线与鼻侧区间及水平颞侧半子午线与颞侧区间Q值比较,差异均无统计学意义(t=0.349、-0.373,P＞0.05). 结论用线性回归方法以角膜地形图正切曲率半径可以推算出角膜前表面非球面系数Q值和区间Q值整合的结果.本组近视受试者角膜前表面水平方向形态趋向于长椭圆. 揹景角膜Q值是描述角膜前錶麵非毬麵形態特性的重要參數,而角膜作為光學麯麵,是由一繫列通過光軸正切麵的截痕集閤而成.所以隻有正切麵對于麯麵所截的截痕纔能代錶其真實的光學形態,也就是說用正切麯率半徑推算的Q值能真正代錶角膜前錶麵的非毬麵特性. 目的運用角膜地形圖正切麯率半徑推算角膜前錶麵子午線截痕Q值,分析青年近視受試者角膜前錶麵水平方嚮非毬麵特性. 方法 16～30歲的近視受試者90例90眼行OrbscanⅡ角膜地形圖檢查,均取右眼,受試者平均等效屈光度為(-5.45±2.75)D,按近視度數不同分為低度近視組30眼、中度近視組30眼、高度近視組30眼.採集併導齣角膜前錶麵間隔0.1 mm的360條半子午線正切麯率Ft值.將所需計算半子午線截痕上的所有Ft值代入正切麯率半徑公式,應用線性迴歸方法併通過計算機編程的模型處理繫統計算礙到各半子午線Q值,併進行區間整閤,同時對每位研究對象進行檢影驗光、眼壓測量、裂隙燈檢查、角膜麯率計檢查及眼底檢查. 結果所有受檢眼角膜的半子午線確定繫數(R2)均＞0.5.90眼水平方嚮鼻側區間和顳側區間Q值均數分彆為-0.32±0.11和-0.30±0.12,差異有統計學意義(t=2.009,P＜0.05)；角膜頂點麯率半徑(r0)值均數分彆為(7.78±0.27) mm、(7.72±0.25)mm,差異無統計學意義(t=-1.016,P＞0.05)；不同近視度組鼻側、顳側區間平均Q值差異均無統計學意義(鼻側:F=0.192,P=0.825;顳側:F=0.912,P=0.406).水平鼻側和顳側半子午線平均Q值分彆為-0.33±0.14和-0.30±0.13,r0平均值分彆為7.76±0.30和7.74±0.24,r0與水平鼻側半子午線平均Q值呈弱正相關(r=0.320,P＜0.05),與水平顳側半子午線平均Q值無明顯相關(r=0.104,P＞0.05).水平鼻側半子午線與鼻側區間及水平顳側半子午線與顳側區間Q值比較,差異均無統計學意義(t=0.349、-0.373,P＞0.05). 結論用線性迴歸方法以角膜地形圖正切麯率半徑可以推算齣角膜前錶麵非毬麵繫數Q值和區間Q值整閤的結果.本組近視受試者角膜前錶麵水平方嚮形態趨嚮于長橢圓.
배경 각막Q치시묘술각막전표면비구면형태특성적중요삼수,이각막작위광학곡면,시유일계렬통과광축정절면적절흔집합이성.소이지유정절면대우곡면소절적절흔재능대표기진실적광학형태,야취시설용정절곡솔반경추산적Q치능진정대표각막전표면적비구면특성. 목적 운용각막지형도정절곡솔반경추산각막전표면자오선절흔Q치,분석청년근시수시자각막전표면수평방향비구면특성. 방법 16～30세적근시수시자90례90안행OrbscanⅡ각막지형도검사,균취우안,수시자평균등효굴광도위(-5.45±2.75)D,안근시도수불동분위저도근시조30안、중도근시조30안、고도근시조30안.채집병도출각막전표면간격0.1 mm적360조반자오선정절곡솔Ft치.장소수계산반자오선절흔상적소유Ft치대입정절곡솔반경공식,응용선성회귀방법병통과계산궤편정적모형처리계통계산애도각반자오선Q치,병진행구간정합,동시대매위연구대상진행검영험광、안압측량、렬극등검사、각막곡솔계검사급안저검사. 결과 소유수검안각막적반자오선학정계수(R2)균＞0.5.90안수평방향비측구간화섭측구간Q치균수분별위-0.32±0.11화-0.30±0.12,차이유통계학의의(t=2.009,P＜0.05)；각막정점곡솔반경(r0)치균수분별위(7.78±0.27) mm、(7.72±0.25)mm,차이무통계학의의(t=-1.016,P＞0.05)；불동근시도조비측、섭측구간평균Q치차이균무통계학의의(비측:F=0.192,P=0.825;섭측:F=0.912,P=0.406).수평비측화섭측반자오선평균Q치분별위-0.33±0.14화-0.30±0.13,r0평균치분별위7.76±0.30화7.74±0.24,r0여수평비측반자오선평균Q치정약정상관(r=0.320,P＜0.05),여수평섭측반자오선평균Q치무명현상관(r=0.104,P＞0.05).수평비측반자오선여비측구간급수평섭측반자오선여섭측구간Q치비교,차이균무통계학의의(t=0.349、-0.373,P＞0.05). 결론 용선성회귀방법이각막지형도정절곡솔반경가이추산출각막전표면비구면계수Q치화구간Q치정합적결과.본조근시수시자각막전표면수평방향형태추향우장타원.
Background Q-value is used to express the asphricity of the anterior corneal surface.As a optical surface,the optial morphology of cornea is composed of a series of tangential sections that cut-off through the optical axial.Therefore,tangential section could represent the true optical morphology of the corneal surface,and Q-value calculation by tangential radius can better represent the asphericity.Objective This study was to calculate Q-value of meridian section of the anterior corneal surface by tangential radius of the tangential topography and analyze the corneal asphericity in horizontal interval.Methods Ninety right eyes of 90 myopia subjects aged 16-30years and with mean spherical equivalent of (-5.45 ± 2.75) D received corneal topography examination using Orbscan Ⅱ system.The subjects were assigned to low myopia group,moderate myopia group and high myopia group based on their diopter and 30 eyes for each group.The tangential curvatures on meridian section at a 0.1 mm interval from apex to periphery of the anterior surface were accepted and the Q value of the semimeridian section was calculated by linear regression mathematical formulas of the tangential radius.Mydriatic optometry,intraocular pressure,keratometer and fundus examinations were performed on the subjects.Written informed consent was obtained from each subject before any medical examination.Results The coefficients of determination in all the semimeridians were over 0.5.The average calculated Q-values in the nasal and temporal horizontal interval were -0.32±0.11 and-0.30±0.12,with a significant difference between them (t =2.009,P＜0.05).The vertex radius of curvature was (7.78±0.27)mm and (7.72±0.25)mm respectively in the nasal and temporal horizontal interval,showing a significant difference(t=-1.016,P＞0.05).No significant difference was seen in Q values of both nasal and temporal areas among three myopic groups (nasal:F =0.192,P =0.825 ; temporal:F =0.912,P =0.406).The average Q value of the nasal and temporal principal meridian was-0.33±0.14 and-0.30±0.13 respectively,and the r0 was 7.76±0.30 and 7.74±0.24 respectively.A weak positive correlation was found between r0 and mean Q value of nasal meridian (r=0.320,P＜0.05),but no significant correlation was found between r0 and mean Q-value of temporal meridian (r=0.104,P＞0.05).No significant differenees were seen in the Q values between nasal meridian and nasal zone (t=0.349,P＞0.05) as well as between temporal meridian and temporal zone(t=-0.373,P＞0.05).Conclusions The study analyzes the calculated Q-value of the semimeridian section in borizontal area with myopia by linear regression mathematical formulas of tangential radius on tangential topography.The anterior surface of the cornea is proved to be prolate ellipse in shape in the subjects with myopia.