Koop N, Brinkmann R, Lankenau E, Flache S, Engelhardt R, Birngruber R
Medizinisches Laserzentrum Lübeck GmbH.
Ophthalmologe. 1997 Jul;94(7):481-6. doi: 10.1007/s003470050143.
The method of optical coherence tomography (OCT) was investigated regarding its suitability and limits for measuring the cornea and the anterior segment of the eye. Furthermore, the stromal expansion of thermally induced lesions in the cornea directly after irradiation was determined within the scope of the laser thermokeratoplasty (LTK).
With the experimental scanning OCT system, x-z sections of the anterior eye segment were made with an optical resolution of about 20 microns axially and 25 microns laterally. Freshly enucleated, tonicized porcine eyes were used as model eyes. Thermal lesions were applied with a continuously emitting laser diode (lambda = 1.86 microns) and various radiation parameters. Before and after coagulation, the cornea was viewed from limbus to limbus in a central OCT scan and the individual coagulation source was measured.
Global and local changes of the thickness of the cornea as well as the distance between cornea and lens were measured with high precision. Thermal lesions in their expansion can be dearly presented and matching well with the histologically stained sections, but are not as exactly defined at the edges due to the limited optical resolution, as known from histological preparations.
With the OCT method quantitative measuring of the anterior eye segment can be performed in vitro and with reduced resolutions also in vivo. Due to the qualitatively good correspondence regarding the dimensions of thermal damage of the cornea with histologically obtained morphometric results, this method can be used for supervision of coagulation directly after LTK as well as for examination of the individual healing process.
研究光学相干断层扫描（OCT）方法在测量角膜和眼前节方面的适用性及局限性。此外，在激光热角膜成形术（LTK）范围内，确定照射后角膜热诱导损伤的基质扩张情况。
使用实验性扫描OCT系统，以轴向约20微米、横向约25微米的光学分辨率获取眼前节的x-z截面图像。使用刚摘除的、经张力处理的猪眼作为模型眼。用连续发射的激光二极管（波长=1.86微米）及不同辐射参数施加热损伤。在凝固前后，通过中央OCT扫描从角膜缘到角膜缘观察角膜，并测量各个凝固源。
能高精度测量角膜厚度的整体及局部变化以及角膜与晶状体之间的距离。热损伤的扩张情况能清晰呈现，且与组织学染色切片匹配良好，但由于光学分辨率有限，其边缘不像组织学标本那样界定精确。
利用OCT方法可在体外对眼前节进行定量测量，分辨率降低时也可在体内进行测量。由于角膜热损伤尺寸与组织学获得的形态测量结果在质量上具有良好的对应关系，该方法可用于LTK术后直接监测凝固情况以及检查个体愈合过程。
