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
2015年
1期
39-43
,共5页
角膜%非球面性%Scheimpflug照相技术
角膜%非毬麵性%Scheimpflug照相技術
각막%비구면성%Scheimpflug조상기술
Cornea%Asphericity%Scheimpflug Photography
目的 研究近视准分子激光人群术前角膜前后表面非球面参数(Q值)的分布特征,为临床诊疗提供理论基础.方法 前瞻性研究.应用基于Scheimpflug照相原理的Pentacam HR眼前节测量及分析系统对75例近视患者右眼进行测量,患者分为低度角膜散光组(前表面散光＜+1.00 D)和中高度角膜散光组(前表面散光≥+1.00 D),系统分析角膜前后表面平均Q值分布特征,角膜中央不同角度范围Q值分布特征,上方、下方、鼻侧及颞侧半子午线上Q值分布特征.2组间比较采用独立样本t检验,各组内Q值间比较采用单因素方差分析.结果 该75例角膜中央30°范围平均Q值前表面为-0.17±0.09,后表面为-0.02±0.16.角膜前表面2组不同角度范围平均Q值均小于0,且2组对应角度范围内Q值间差异无统计学意义,2组内不同角度范围平均Q值间差异有统计学意义(F=6.340、9.963,P＜0.01),2组Q20均大于Q30及Q25且差异具有统计学意义(P＜0.05),Q30及Q25之间差异无统计学意义.角膜后表面Q30趋近于0,Q25及Q20均大于0,Q30＜Q25＜Q20,且差异均具有统计学意义(F=54.614,P＜0.01).角膜前表面2组不同半子午线上平均Q值均为负且2组对应半子午线上平均Q值间差异无统计学意义,2组不同半子午线上平均Q值间差异有统计学意义(F=19.262、31.935,P＜0.01).低度角膜散光组QN30小于Q130、QS30及QI30,且差异均具有统计学意义(P＜0.05),QT30、QS30及QI30之间差异均无统计学意义(P＞0.05).中高度角膜散光组QS30及Q130之间差异无统计学意义(P＞0.05),QN30＜QT30且QN30及QT30小于QS30及Q130,差异均具有统计学意义(P＜0.05).角膜后表面QS30趋近于0,QI30为正,QN30及QT30为负,不同半子午线上平均Q值间差异有统计学意义(F=31.750,P＜0.01),其中QT30及QS30之间差异无统计学意义(P＞0.05),QN30＜QT30且QS30＜QI30,差异均具有统计学意义(P＜0.05).结论 近视人群角膜前表面形态由中央到周边逐渐变平坦,后表面由中央到周边逐渐变陡峭.随角度范围的变大,角膜前表面变平坦的速率加快,后表面变陡峭的速率减慢.前表面各半子午线方向均为长椭圆形,从中央到周边其表面均逐渐变平坦.角膜前表面散光的大小未影响角膜前表面的形态.后表面上下方半子午线方向为扁椭圆形,鼻颞侧半子午线方向为长椭圆形.
目的 研究近視準分子激光人群術前角膜前後錶麵非毬麵參數(Q值)的分佈特徵,為臨床診療提供理論基礎.方法 前瞻性研究.應用基于Scheimpflug照相原理的Pentacam HR眼前節測量及分析繫統對75例近視患者右眼進行測量,患者分為低度角膜散光組(前錶麵散光＜+1.00 D)和中高度角膜散光組(前錶麵散光≥+1.00 D),繫統分析角膜前後錶麵平均Q值分佈特徵,角膜中央不同角度範圍Q值分佈特徵,上方、下方、鼻側及顳側半子午線上Q值分佈特徵.2組間比較採用獨立樣本t檢驗,各組內Q值間比較採用單因素方差分析.結果 該75例角膜中央30°範圍平均Q值前錶麵為-0.17±0.09,後錶麵為-0.02±0.16.角膜前錶麵2組不同角度範圍平均Q值均小于0,且2組對應角度範圍內Q值間差異無統計學意義,2組內不同角度範圍平均Q值間差異有統計學意義(F=6.340、9.963,P＜0.01),2組Q20均大于Q30及Q25且差異具有統計學意義(P＜0.05),Q30及Q25之間差異無統計學意義.角膜後錶麵Q30趨近于0,Q25及Q20均大于0,Q30＜Q25＜Q20,且差異均具有統計學意義(F=54.614,P＜0.01).角膜前錶麵2組不同半子午線上平均Q值均為負且2組對應半子午線上平均Q值間差異無統計學意義,2組不同半子午線上平均Q值間差異有統計學意義(F=19.262、31.935,P＜0.01).低度角膜散光組QN30小于Q130、QS30及QI30,且差異均具有統計學意義(P＜0.05),QT30、QS30及QI30之間差異均無統計學意義(P＞0.05).中高度角膜散光組QS30及Q130之間差異無統計學意義(P＞0.05),QN30＜QT30且QN30及QT30小于QS30及Q130,差異均具有統計學意義(P＜0.05).角膜後錶麵QS30趨近于0,QI30為正,QN30及QT30為負,不同半子午線上平均Q值間差異有統計學意義(F=31.750,P＜0.01),其中QT30及QS30之間差異無統計學意義(P＞0.05),QN30＜QT30且QS30＜QI30,差異均具有統計學意義(P＜0.05).結論 近視人群角膜前錶麵形態由中央到週邊逐漸變平坦,後錶麵由中央到週邊逐漸變陡峭.隨角度範圍的變大,角膜前錶麵變平坦的速率加快,後錶麵變陡峭的速率減慢.前錶麵各半子午線方嚮均為長橢圓形,從中央到週邊其錶麵均逐漸變平坦.角膜前錶麵散光的大小未影響角膜前錶麵的形態.後錶麵上下方半子午線方嚮為扁橢圓形,鼻顳側半子午線方嚮為長橢圓形.
목적 연구근시준분자격광인군술전각막전후표면비구면삼수(Q치)적분포특정,위림상진료제공이론기출.방법 전첨성연구.응용기우Scheimpflug조상원리적Pentacam HR안전절측량급분석계통대75례근시환자우안진행측량,환자분위저도각막산광조(전표면산광＜+1.00 D)화중고도각막산광조(전표면산광≥+1.00 D),계통분석각막전후표면평균Q치분포특정,각막중앙불동각도범위Q치분포특정,상방、하방、비측급섭측반자오선상Q치분포특정.2조간비교채용독립양본t검험,각조내Q치간비교채용단인소방차분석.결과 해75례각막중앙30°범위평균Q치전표면위-0.17±0.09,후표면위-0.02±0.16.각막전표면2조불동각도범위평균Q치균소우0,차2조대응각도범위내Q치간차이무통계학의의,2조내불동각도범위평균Q치간차이유통계학의의(F=6.340、9.963,P＜0.01),2조Q20균대우Q30급Q25차차이구유통계학의의(P＜0.05),Q30급Q25지간차이무통계학의의.각막후표면Q30추근우0,Q25급Q20균대우0,Q30＜Q25＜Q20,차차이균구유통계학의의(F=54.614,P＜0.01).각막전표면2조불동반자오선상평균Q치균위부차2조대응반자오선상평균Q치간차이무통계학의의,2조불동반자오선상평균Q치간차이유통계학의의(F=19.262、31.935,P＜0.01).저도각막산광조QN30소우Q130、QS30급QI30,차차이균구유통계학의의(P＜0.05),QT30、QS30급QI30지간차이균무통계학의의(P＞0.05).중고도각막산광조QS30급Q130지간차이무통계학의의(P＞0.05),QN30＜QT30차QN30급QT30소우QS30급Q130,차이균구유통계학의의(P＜0.05).각막후표면QS30추근우0,QI30위정,QN30급QT30위부,불동반자오선상평균Q치간차이유통계학의의(F=31.750,P＜0.01),기중QT30급QS30지간차이무통계학의의(P＞0.05),QN30＜QT30차QS30＜QI30,차이균구유통계학의의(P＜0.05).결론 근시인군각막전표면형태유중앙도주변축점변평탄,후표면유중앙도주변축점변두초.수각도범위적변대,각막전표면변평탄적속솔가쾌,후표면변두초적속솔감만.전표면각반자오선방향균위장타원형,종중앙도주변기표면균축점변평탄.각막전표면산광적대소미영향각막전표면적형태.후표면상하방반자오선방향위편타원형,비섭측반자오선방향위장타원형.
Objective To evaluate the distribution characteristics of the asphericity (Q-value) of the corneal surfaces in a Chinese population who were candidates for excimer laser surgery; to provide some theoretical bases for clinical diagnosis and treatment.Methods This was a perspective study.Using the Pentacam HR measuring and analyzing system based on Scheimpflug photography,the right eyes of 75 Chinese myopes were evaluated for excimer laser surgery.Patients were divided into a low corneal astigmatism (＜+1.00 D) group and a medium-high corneal astigmatism (≥+1.00 D) group according to the anterior corneal surface astigmatism.The analysis was based on the distribution characteristics of the mean Q-values of both the anterior and posterior corneal surfaces and the distribution characteristics of the Q-value at different angles (20°,25° and 30°) and along different semi-meridians (superior,inferior,nasal and temporal).Single factor analysis of variance was used to determine if there was a difference among Q-values within a particular group.The differences between the two groups were analyzed by an independent samples t-test.Results The mean Q-values of the 30° angle in Chinese myopes evaluated for excimer laser surgery were-0.17±0.09 and-0.02±0.16 on the anterior and posterior corneal surfaces,respectively.The mean Q-values of the anterior corneal surface at different angles were negative and there was no statistically significant difference between the low corneal astigmatism group and medium-high corneal astigmatism group.There was a significant difference between the Q-values of the 2 groups at different angles (F=6.340,9.963,P＜0.01),and in both groups Q20 was significantly larger than Q30 and Q25 (P＜0.05) but there was no statistically significant difference between Q30 and Q25.The mean Q-values of the posterior corneal surface were positive at the 20° and 25° angles and approached zero at the 30° angle.Comparisons between the 3 angles showed statistically significant differences (F=54.614,P＜0.01).The comparisons showed that Q30＜Q25＜Q20.All mean Q-values along different semi-meridians of the anterior corneal surface were negative and there was no statistically significant difference between the 2 groups.There was a significant difference between Q-values along different semi-meridians in the 2 groups (F=19.262,31.935,P＜0.01).In the low corneal astigmatism group,QN30 was significantly smaller than QT300,QS30 and QI30 (P＜0.05) but there was no statistically significant difference between QT30,QS30 and Q130 (P＞0.05).In the medium-high corneal astigmatism group,QT30 was significantly bigger than QN30 (P＜0.05) but there was no statistically significant difference between QS30 and Q130 In addition,QN30 and QT30 were significantly smaller than QS30 and Q130 (P＜0.05).The Q-values of the posterior surface were positive along the inferior semi-meridian,negative along the nasal and temporal semi-meridians,and approached zero along the superior semi-meridian.There was also a significant difference between Q-values along different semi-meridians on the posterior surface (F=31.750,P＜0.01).There were statistically significant differences between QT30 and QN30 (P＜0.05) and Q130 and QS30 (P＜0.05).Comparisons showed that QT30＞QN30 and QS30＞QS30,but there was no statistically significant difference between QT30 and QS30.Conclusion The curvature along the anterior corneal surface becomes flatter from the center to the periphery,while it becomes steeper from the center to the periphery at the posterior corneal surface.The rate of the flattening of the anterior corneal surface increased as the range of the angle increased,while the rate decreased as the posterior corneal surface decreased.All the shapes on the anterior surface along different semi-meridians were long ovals.Corneal astigmatism does not affect corneal shape.The shapes of the posterior surface along the superior and inferior semi-meridians were short ovals,but were long ovals along the nasal and temporal semi-meridians.
