Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
Shandong Lunan Eye Hospital, Linyi, Shandong, China.
Int Ophthalmol. 2023 Sep;43(9):3165-3173. doi: 10.1007/s10792-023-02716-z. Epub 2023 Apr 28.
To investigate the distribution of 50 layers of corneal densitometry and related factors.
Clinical data, including age, sex, central corneal thickness, corneal keratometry, and diopters, were collected from 102 healthy participants (102 eyes) in this retrospective study. The cornea was divided into 50 layers, and densitometry of each layer at 19 points was measured by the Pentacam. The value versus the depth curve was plotted. Paired-sample t test and one-way analysis of variance were used to compare densitometry in different regions or depth. Statistical significance was defined as P < .05.
The densitometry values of the Bowman membrane (10-14% depth), anterior stroma (14-30% depth), epithelium (0-10% depth), and Descemet membrane (94-98% depth) decreased sequentially, and the densitometry values of the middle and posterior stroma (30-94% depth) and endothelium (98-100% depth) were the lowest. The higher the degree of astigmatism, the higher the second densitometry peak (R = 0.277, P < .001). The densitometry values of the vertex and superior parts of the cornea were higher than those in the periphery and inferior parts, respectively (all P < .001). In the Bowman membrane, the densitometry is lowest in the inferior nasal part, while in the Descemet membrane, it is lowest in the inferior temporal part.
Two densitometry peaks appeared near the Bowman membrane and Descemet membrane. For different depths, the distribution of densitometry within a layer is different. We provide a methodological reference and data basis for corneal research based on local changes in densitometry, and help understand the details of corneal structure from an optical perspective through detailed layering and zoning analysis of densitometry.
研究 50 层角膜密度分布及其相关因素。
本回顾性研究纳入了 102 名（102 只眼）健康受试者的临床资料，包括年龄、性别、中央角膜厚度、角膜曲率和屈光度。使用 Pentacam 对角膜进行 50 层划分，并在 19 个点测量各层的密度值。绘制值与深度曲线。采用配对样本 t 检验和单因素方差分析比较不同区域或深度的密度值。P<0.05 为差异有统计学意义。
Bowman 膜（10%-14%深度）、前基质（14%-30%深度）、上皮（0%-10%深度）和 Descemet 膜（94%-98%深度）的密度值依次降低，而中后基质（30%-94%深度）和内皮（98%-100%深度）的密度值最低。散光程度越高，第二个密度峰值越高（R=0.277，P<0.001）。角膜顶点和上方的密度值高于周边和下方（均 P<0.001）。在 Bowman 膜中，密度值最低的部位在下鼻侧，而在 Descemet 膜中，密度值最低的部位在下颞侧。
Bowman 膜和 Descemet 膜附近出现两个密度峰值。对于不同深度，同一层内的密度分布不同。我们基于密度的局部变化为角膜研究提供了一种方法学参考和数据基础，并通过对密度进行详细分层和分区分析，从光学角度帮助了解角膜结构的细节。
