Giasson Claude J, Gosselin Lucie, Masella Aviva, Forcier Pierre
School of Optometry and Research Unit in Vision Health, Université de Montréal, Montreal, Quebec, Canada.
Cornea. 2008 Jul;27(6):640-3. doi: 10.1097/QAI.0b013e31815e4062.
In children, but not in the elderly, an association exists between corneal diameter and endothelial cell density (ECD). We tested whether such an association also held true in young adults.
The eyes of 35 healthy subjects (mean age, 23.1 +/- 3.1 years) were photographed by using a video camera and a noncontact endothelial microscope. Both sets of images were analyzed with image software and the contour method to measure corneal diameter, ECD, and endothelial coefficients. Axial lengths, refractive errors, and corneal curvatures were measured by using an A-scan ultrasonic biometer and kerato-refractometer. Measurements, averaged for the right and left eyes, were analyzed depending on (1) use of contact lenses, (2) ametropia, and on whether (3) axial length or (4) corneal diameter was above or below group means. Differences were tested for statistical significance with independent t tests and association with the Pearson correlation coefficient.
ECD, corneal diameter, and spherical equivalent refraction were 3022 +/- 262 cells/mm2, 12.0 +/- 0.5 mm, and -3.1 +/- 2.5 D, respectively. The only significant differences between wearers and nonwearers of contact lenses were the spherical refractive equivalent and axial length. There was no correlation between ECD and corneal diameter or axial length.
As opposed to previously reported results in children, but as found in the elderly, there is no correlation between ECD and corneal diameter in young adults. Therefore, corneal size cannot be considered a determinant of ECD in young adults.
在儿童中,角膜直径与内皮细胞密度(ECD)之间存在关联,但在老年人中不存在这种关联。我们测试了这种关联在年轻成年人中是否也成立。
使用摄像机和非接触式内皮显微镜对35名健康受试者(平均年龄23.1±3.1岁)的眼睛进行拍照。两组图像均使用图像软件和轮廓法进行分析,以测量角膜直径、ECD和内皮系数。使用A超超声生物测量仪和角膜屈光仪测量眼轴长度、屈光不正和角膜曲率。将右眼和左眼的测量值平均后,根据以下因素进行分析:(1)是否佩戴隐形眼镜;(2)屈光不正情况;以及(3)眼轴长度或(4)角膜直径是否高于或低于组均值。使用独立t检验检验差异的统计学意义,并使用Pearson相关系数检验相关性。
ECD、角膜直径和等效球镜度分别为3022±262个细胞/mm²、12.0±0.5mm和-3.1±2.5D。佩戴和未佩戴隐形眼镜者之间唯一显著的差异是等效球镜度和眼轴长度。ECD与角膜直径或眼轴长度之间无相关性。
与先前报道的儿童结果相反,但与老年人的情况一样,年轻成年人的ECD与角膜直径之间无相关性。因此,在年轻成年人中,角膜大小不能被视为ECD的决定因素。