马方综合征患者角膜形态及厚度的特点

The morphology and thickness of cornea in patients with Marfan syndrome

目的 探讨马方综合征（MFS）患者角膜的形态与厚度变化特点.方法 病例对照研究.采用裂隙灯显微镜、自动屈光计和OrbscanⅡZ对2008年4月至2009年6月在厦门大学附属厦门眼科中心临床确诊的24例（48只眼）MFS患者与24例（48只眼）性别、年龄与其匹配的健康志愿者进行晶状体异位判断,眼轴测量,角膜形态检查[角膜前、后表面高度,中央角膜曲率,角膜中央3 mm区散光度数（Mean A）,模拟角膜散光度数（Sim A）,角膜中央3 mm区屈率（Mean K）和模拟角膜屈率（Sim K）,角膜中央3 mm区不规则性（3.0ZI）及角膜中央5 mm区不规则性（5.0ZI）,角膜厚度指数（CTI）]和角膜厚度检查（角膜最薄点厚度及9个区域平均厚度）.采用Crosstabs,单向方差分析,student-t检验及判别分析等方法对角膜各参数进行统计学分析.结果 MFS组与正常对照组在年龄（38±7）和（37±8）岁,男女比例8/16和9/15,以及眼轴长度（23.12±1.06）和（24.26±2.96）mm上差异无统计学意义（年龄x2=0.091,P=0.763;性别t=0.324,眼轴t=1.976,均P＞0.05）.在角膜前表面屈光力图形态上,MFS组患者相比对照组在椭圆形（25.0%与16.7%）、不规则蝴蝶结形（41.7%与37.5%）和不规则形地形（12.5%与8.3%）图的比例明显上升,同时扁平角膜比例明显升高（66.7%与12.5%）.MFS组与正常对照组的角膜最薄点厚度（489.8±42.9）μm与（544.8±25.7）μm、Mean K（40.60±1.30）D与（42.80±1.40）D、Sim K（40.50±1.30）D与（42.80±1.20）D、Sim A（1.08±0.86）D与（0.91±0.46）D、CTI 1.57±0.24与1.21±0.14、3.0ZI（1.76±0.96）D与（1.54±0.82）D及5.0ZI（1.91±1.26）D与（0.92±0.68）D等角膜地形图参数差异均有统计学意义（最薄点厚度t=6.996,Mean K t=2.554,Sim K t=3.326,Sim A t=2.324,CTI t=3.116,3.0ZIt=2.686,5.0ZI t=3.768,均P＜0.05）;角膜Mean A在MFS组（1.11±0.89）D与对照组（0.99±0.49）D之间差异无统计学意义（Mean A t=1.898,P=0.08）.与正常对照组相比,除颞下方除外,9个区域中的其他8个区域的平均角膜厚度明显下降.结论 MFS患者角膜的屈光力下降、厚度减少.

Objective To search for the characteristics of MFS in corneal morphology and thickness. Methods Twenty-four patients （48 eyes） with MFS and 24 healthy age- and gender-matched volunteers （48 eyes） were recruited in this clinical prospective, and comparative series study. Firstly,biomicroscopic examination and Type-A ultrasonometry was conducted to search for ectopia lentis and axis length. Secondly, the corneal morphologic parameter[including the height of anterior and posterior surface,the centre corneal curvature, the mean astigmatism in the 3.0-mm central zone （Mean A）, the mean simulated astigmatism （Sim A） , the mean keratometry in the 3.0-mm central zone （Mean K）, the mean simulated keratometry （Sim K）, the 3.0-mm zone irregularity （3.0ZI）, the 5.0-mm zone irregularity （5.0ZI） ,corneal thickness index （CTI）] and thickness （at the central location and at eight midperipheral locations） were obtained by the the autorefractometer and the Orbscan Ⅱ Z corneal topography. Last, the statistics method including Crosstabs, One-way ANOVA, student-t test and discriminant analysis were applied and the correlations were established. Results There is no statistically significance between MFS group and control group in ages （38 ±7） and （37 ±8） years, gender （8/16） and （9/15）, and axis length （23. 12 ±1.06） mm and （24. 26 ±2. 96） mm （age x2=0.091 ,P=0.763 ;gender t=0.324, axis length t=1.976,P 〉0.05）. Flat cornea ratio （66. 7% and 12. 5%） and topography of the oval （25.0% and 16. 7%）,irregular bow-shaped （41.7% and 37.5%） and irregular-shaped （12. 5% and 8. 3%） were increased significantly in patients with MFS. The corneal topography（MFS/control） showed that there are statistically significance in the thinnest thickness of cornea （489. 8 ± 42. 9） μm and （544. 8 ± 25.7） μm, Mean K （40.60±1.30） Dand （42.80± 1.40） D, Sim K （40.50±1.30） D and （42.80±1.20） D, Sim A（1.08 ± 0.86）D and （0.91 ±0.46） D, CTI 1.57±0.24 and 1.21 ±0.14, 3.0ZI （1.76±0.96） D and （1.54 ±0.82） D, and 5.0ZI （1.91 ± 1.26） D and （0.92 ±0.68） D（thinnest thickness t=6. 996, Mean K t=2. 554, Sim K t=3.326, Sim A t=2. 324, CTI t=3. 116,3. 0Z1 t=2. 686,5. 0ZI t=3.768, P 〈0.05）, while no statistically significance in the Mean A between the MFS （1.11 ± 0.89） D and control group （0.99 ±0.49） D（Mean A t=1.898 ,P=0.08） ;except for temple inferior, the significant decrease of pachymetry （including the center and the seven midperipheral locations） appeared in the MFS group compared with the control group. Conclusion The characteristic of MFS in corneal topography is that corneal axial refractive power descends and corneal thickness decreases.