Reinstein Dan Z, Archer Timothy J, Vida Ryan S
London Vision Clinic, London, United Kingdom.
Department of Ophthalmology, Columbia University Medical Center, New York, USA.
Saudi J Ophthalmol. 2022 Jul 11;36(1):25-35. doi: 10.4103/sjopt.sjopt_227_21. eCollection 2022 Jan-Mar.
In this review, we discuss the applications of epithelial thickness mapping in corneal refractive surgery. The review describes that the epithelial thickness profile is nonuniform in the normal eye, being thinner superiorly than inferiorly and thinner temporally than nasally. It is postulated that this is due to the eyelid forces and blinking action on the superior cornea. Changes in the epithelial thickness profile have been found to be highly predictable, responding to compensate for changes in the stromal curvature gradient, using the eyelid as an outer template. This leads to characteristic changes in the epithelial thickness profile that can be used for early screening in keratoconus, postoperative monitoring for early signs of corneal ectasia, and for determining whether further steepening can be performed without the risk of apical syndrome following primary hyperopic treatment. Compensatory epithelial thickness changes are also a critical part of diagnosis in irregular astigmatism as these partially mask the stromal surface irregularities. The epithelial thickness map can then be used to plan a trans-epithelial photorefractive keratectomy treatment for cases of irregularly irregular astigmatism.
在本综述中，我们讨论上皮厚度测绘在角膜屈光手术中的应用。该综述描述了在正常眼中上皮厚度分布并不均匀，上方比下方薄，颞侧比鼻侧薄。据推测，这是由于上睑对角膜上方的作用力和眨眼动作所致。已发现上皮厚度分布的变化具有高度可预测性，它会以眼睑为外部模板进行响应，以补偿基质曲率梯度的变化。这会导致上皮厚度分布出现特征性变化，可用于圆锥角膜的早期筛查、角膜扩张早期体征的术后监测，以及确定在原发性远视治疗后进一步增加角膜陡峭度而无发生顶点综合征风险的情况。代偿性上皮厚度变化也是不规则散光诊断的关键部分，因为这些变化会部分掩盖基质表面的不规则性。然后，上皮厚度图可用于为不规则性不规则散光病例规划经上皮光性屈光性角膜切削术治疗方案。
