Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China.
Invest Ophthalmol Vis Sci. 2010 Jan;51(1):156-9. doi: 10.1167/iovs.08-3265. Epub 2009 Aug 26.
To report a novel method for pachymetry mapping of human precorneal tear film using Pentacam.
Precorneal tear film is routinely undetected by Pentacam but could be well visualized with the aid of fluorescein. Twenty patients with dry eye and 20 age-matched control subjects with normal eyes were enrolled in this prospective study. The right eye of each subject was scanned once with Pentacam and rescanned after instillation of 1 microL 0.1% fluorescein, and the differential map of corneal thickness between the two measurements was identified as the pachymetry map of tear film. Then the central tear film thickness was evaluated, and the pattern of each pachymetry map was determined.
Mean central tear film thickness in dry eyes (22.2 +/- 4.5 microm) was less than in normal eyes (24.7 +/- 3.9 microm) (Student's t-test, P = 0.0614). Additionally, the tear film pachymetry map could be classified into three patterns: pattern 1, thickening upward; pattern 2, uniform distribution; pattern 3, thickening downward. Tear film pachymetry maps of normal eyes consisted of pattern 1 (40%), pattern 2 (40%), and pattern 3 (20%), whereas those of dry eyes consisted of pattern 1 (70%), pattern 2 (20%), and pattern 3 (10%). Dry eyes tended to have a higher proportion of pattern 1 pachymetry maps than normal eyes, though still no significant difference was found between two groups (Cochran-Mantel-Haenszel chi(2) test, P = 0.0852).
This novel method feasibly could be used to map tear film thickness, and it provides a valuable means to investigate the spatial distribution of tear film.
报告一种使用 Pentacam 对人眼前部泪膜进行厚度测绘的新方法。
Pentacam 常规情况下无法检测到眼前部泪膜，但在荧光素的辅助下可以很好地显示。本前瞻性研究纳入 20 例干眼症患者和 20 例年龄匹配的正常眼对照者。每位受试者的右眼均用 Pentacam 扫描一次，然后滴入 1 微升 0.1%荧光素后再次扫描，两次测量之间的角膜厚度差异图被识别为泪膜厚度图。然后评估中央泪膜厚度，并确定每个厚度图的模式。
干眼症患者的中央泪膜厚度平均值（22.2 ± 4.5 µm）小于正常眼（24.7 ± 3.9 µm）（Student's t 检验，P = 0.0614）。此外，泪膜厚度图可分为三种模式：模式 1，向上增厚；模式 2，均匀分布；模式 3，向下增厚。正常眼的泪膜厚度图包括模式 1（40%）、模式 2（40%）和模式 3（20%），而干眼症的泪膜厚度图包括模式 1（70%）、模式 2（20%）和模式 3（10%）。干眼症患者的模式 1 厚度图比例高于正常眼，但两组间差异仍无统计学意义（Cochran-Mantel-Haenszel χ² 检验，P = 0.0852）。
该新方法可行地用于测绘泪膜厚度，为研究泪膜的空间分布提供了有价值的手段。
