Ventura Bruna V, Moraes Haroldo V, Kara-Junior Newton, Santhiago Marcony R
Ophthalmology Department, Altino Ventura Foundation, Recife, PE, Brazil ; The Cole Eye Institute, The Cleveland Clinic Foundation, Cleveland, OH 44114, USA.
J Ophthalmol. 2012;2012:676740. doi: 10.1155/2012/676740. Epub 2012 Sep 5.
This paper focuses on reviewing the roles of optical coherence tomography (OCT) on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructure in vivo. There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laser in situ keratomileusis (LASIK) and in excimer laser phototherapeutic keratectomy (PTK), OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.
本文着重综述光学相干断层扫描（OCT）在角膜表面激光消融手术中的作用。OCT是一种光学成像方式，它利用低相干干涉测量法在体内提供组织微观结构的无创横断面成像。有两种类型的OCT，每种的横向和轴向空间分辨率均为几微米：时域OCT和傅里叶域OCT。两者都越来越多地被屈光手术医生所使用，且各有其特定优势。当前哪种成像仪器是更好的选择取决于具体应用。在准分子原位角膜磨镶术（LASIK）和准分子激光角膜切削术（PTK）中，OCT可用于评估角膜特征并指导治疗决策。OCT能精确测量中央角膜厚度，评估LASIK瓣的规整性，并量化瓣和剩余基质床的厚度。通过术前测量减去术后测量来评估消融深度准确性时，OCT测厚法与激光消融设置密切相关。此外，OCT可用于提供有关角膜病理异常（如角膜变性、营养不良和混浊）的形态和深度的精确信息，与组织病理学发现相关。
