健康人眼角膜光密度分析及与眼内散射光的相关性研究

Distribution of corneal densitometry and its correlation with ocular straylight in healthy eyes

目的探讨健康人眼的角膜光密度分布及其与眼内散射光的相关性。方法前瞻性研究。采用随机数字表法选择进行常规眼科检查的健康人116例（232只眼），其中男55例（110只眼），女61例（122只眼），年龄为20～49岁，划分三个年龄段：20～29岁，30～39岁，40～49岁。利用Pentaeam三维眼前节分析诊断系统进行检查，以角膜顶点为中心，分别取≤2mm、〉2ram且≤6mm、〉6ram且≤10mm直径范围的角膜光密度平均值，以及2、6、10mm直径虚拟圆的角膜厚度平均值，并使用C—quant散射光计量仪对人眼内的散射光进行定量测量。不同性别以及左右眼之间的角膜光密度比较采用独立样本t检验，不同年龄段的角膜光密度之间以及不同直径范围的角膜光密度之间比较采用单因素方差分析，不同直径范围的角膜光密度之间以及与年龄，角膜厚度，眼内散射光定量值之间的相关性研究采用Pearson相关分析。结果≤2mm、〉2mm且≤6mm、〉6nlm且≤10mm直径范围角膜光密度为10．1±1．5，9．3±1．3，9．6±1．7，范围8．2～16．7，7．9～14．2，7．3～16．2。〉6mm且≤10mm直径范围的角膜光密度在20～29岁、30-39岁、40-49岁年龄段分别为8．9-4-1．1，9．3±1．2，10．7±2．1，差异有统计学意义（F=28．939，P=0．000），〉6mm且≤10mm直径范围的角膜光密度与年龄之间存在明显的正相关关系（r=0．417，P=0．000），≤2mm、〉2mm且≤6mm直径范围的角膜光密度在不同年龄段的统计值间均无统计学差异（F=1．575，1．436；P〉0．05），与年龄之间亦未发现相关性存在（r=0．002，0．048；P〉0．05）。男性与女性相同直径范围的角膜光密度值之间不存在统计学差异（t=1．744，1．647，-1．181；P〉0．05）。左右眼的角膜光密度值之间存在明显的相关性（r=0．977，0．992，0．933；P〈0．01），差异无统计学意义（t=0．124，0．199，-0．020；P〉0．05）。〉6mm且≤10mm直径范围的角膜光密度值与≤2mm及〉2mm且≤6mm直径范围的角膜光密度值之间呈正相关（r=0．710，P=0．000；r=0．748，P=0．000），≤2mm直径范围与〉2mm且≤6mm直径范围的角膜光密度值呈正相关（r=0．973，P=0．000），相邻直径范围的角膜光密度存在更明显的相关关系，不同直径范围的角膜光密度之间存在显著性差异（F=17．057，P=0．000）。眼内散射光定量值平均为0．95±0．19≤2mm、〉2mm且≤6mm、〉6mm且≤10mm直径范围的角膜光密度值与眼内散射光计量值均能呈正相关（r=0．134，0．146，0．159；P=0．042，0．026，0．016）。结论年龄对角膜光密度具有一定程度的影响，对周边角膜光密度的影响更大些。角膜光密度与角膜厚度之间无相关性。健康人眼的角膜光密度对眼内散射光存在一定的影响。

Objective To evaluate and investigate the distribution of corneal density and its Correlation with stray-light value in adult and healthy eyes. Methods A prospective study. Human corneal specimens ranging in age between 20 and 49 years, 116 patients （232 eyes） in total, divided into three groups ： 20 - 29, 30 - 39, 40 - 49. Pentacam was used to evaluate total corneal average density and corneal thickness at different diameter around the corneal apex, for corneal density were ~〈 2 mm, 〉 2 mm and ~〈6 mm, 〉6 mm and 410 mm, for corneal thickness were 2 mm,6 mm and 10 ram, C-quant was used for the stray-light value. Software SPSS 17.0 was used for statistical analysis. Independent samples t testing mothed was applied to compare the corneal densitometry in different gender and between left eyes and right ones, One-way ANOVA was applied to analyze the differences of corneal density in different age groups and diameters. Pearson correlation analysis was applied to assess the correlation in corneal densitometry values of different diameters, between corneal density of different diameters and age, corneal density of different diameters and corneal thickness of different diameters, corneal density of different diameters and stray-light values. Results Corneal density for ~〈2 ram, 〉2 mm and ~〈6 mm, 〉6 mm and 410 mm diameter are 10.1-＋1.5（8.2-16.7）, 9.3 -＋1.3（7.9 -14.2）, 9.6 ＋1.7（7.3 -16.2）. Corneal density of 〉6 mm and ~〈10 mm diameter in different age groups were 8.9 -＋ 1.1, 9.3 -＋ 1.2, 10.7 -＋2.1, there was a statistical difference in these values （ F = 28. 939, P = 0. 000 ） , and there was a positive correlation between corneal density of 〉 6 mm and ~〈 10 mm diameter and age （ r = 0. 417, P = 0. 000） , There were no statistical differences in corneal density values of ~〈 2 mm and 〉 2 mm and ~〈 6 mm in different age groups （ F = 1. 575,1. 436 ; P 〉 0.05 ） , and they had no correlation with age （ r = 0. 002,0. 048 ;P 〉 0. 05 ）. There was no statistical difference in corneal density in different gender （t = 1. 744,1. 647, -1. 181 ;P 〉0. 05）. Corneal density values of left eyes and right ones had positive relationships at the same diameter （ r = 0. 977, P = 0. 000 ; r = 0. 992,P = 0. 000 ; r = 0. 933, P = 0. 000 ）, and there were no statistical differences （ t ： 0. 124, 0. 199,-0. 020;P 〉 0. 05）. Between corneal density values of different diameter, there are also some positive relationships, 〉6 mm and ~〈10 mm and ~〈2 mm （r =0. 710,P =0. 000）, 〉6 mm and 〈~10 mm and 〉2 remand ~〈6 mm （r=0.748,P =0.000）, ~〈2 mm and 〉2 mm and ~〈6 mm （r =0.973,P= 0. 000）, relationship between ~〈2 mm and 〉2 mm and ~〈6 ram, 〉2 mm and ~〈6 mm and 〉6 mm and ~〈 10 mm was obvious, and there was statistical difference in them （ F = 17. 057, P = 0. 000）. The ocular straylight value was 0. 95 -＋0. 19（0. 48 -1.38）, Corneal density values of ~〈2 mm, 〉2 mm and ~〈6 mm and 〉 6 mm and ~〈 10 mm diameter had positive relationships with the straylight value （r = 0. 134,0. 146, 0. 159, P =0. 042,0. 026,0. 016）. Conclusions Corneal density can be influenced by age, the influence from age infected the corneal density of peripheral more. There was no correlation between corneal density and corneal thickness. There were some influences of corneal density of healthy eyes to the ocular straylight.