Department of Surgery, University of Murcia, Murcia, Spain.
J Refract Surg. 2012 Nov;28(11):781-6. doi: 10.3928/1081597X-20121011-06.
To evaluate the changes in corneal transparency and thickness measured objectively using Pentacam Scheimpflug (Oculus Optikgeräte GmbH) corneal tomography (densitometry) after corneal cross-linking (CXL).
Twenty-two eyes from 15 patients with keratoconus underwent CXL. Corneal thickness and curvature as well as lens and corneal densitometry were measured at baseline and 1, 3, 6, and 12 months after CXL with Pentacam.
Immediately after CXL, central corneal thickness significantly decreased (-40 μm) and corneal densitometry increased significantly. At 6-month follow-up, densitometry values were reduced and seemed to stabilize at a higher value than baseline. No statistically significant differences were noted (mean difference at 12 months: +30%). Changes in corneal densitometry were detected with the Pentacam even when clinical haze did not increase beyond grade 1 during follow-up.
Corneal CXL is associated with a transient reduction in central corneal thickness, which recovered to baseline after 12 months. During the same time period, corneal densitometry experienced a transient increase that recovered to baseline values after 3 months. Changes in compactness of the corneal tissue after CXL may have an impact in corneal power not due to curvature changes, but to refractive index changes as a result of hydration changes. Pentacam is a useful objective method to monitor corneal transparency after CXL.
使用 Pentacam 眼前节断层扫描仪（Oculus Optikgeräte GmbH）角膜断层（密度测量）客观评估角膜交联（CXL）后角膜透明度和厚度的变化。
15 例圆锥角膜患者的 22 只眼接受了 CXL。使用 Pentacam 在基线和 CXL 后 1、3、6 和 12 个月时测量角膜厚度和曲率以及晶状体和角膜密度。
CXL 后即刻，中央角膜厚度显著降低（-40μm），角膜密度显著增加。在 6 个月的随访中，密度值降低，并似乎稳定在高于基线的较高值。未发现统计学差异（12 个月时的平均差异：+30%）。即使在随访期间临床混浊度未超过 1 级，Pentacam 也能检测到角膜密度的变化。
角膜 CXL 与中央角膜厚度的短暂降低相关，在 12 个月后恢复到基线。在同一时期，角膜密度经历了短暂的增加，在 3 个月后恢复到基线值。CXL 后角膜组织致密性的变化可能会对角膜功率产生影响，这不是由于曲率变化，而是由于水合变化导致折射率变化。Pentacam 是监测 CXL 后角膜透明度的一种有用的客观方法。
