- 作者：David Touboul ; MD ; toubould@gmail.com ; [Author Vitae] ; Elodie Trichet ; MD ; Perry S. Binder ; MD ; Delphine Praud ; MSc ; Camille Seguy ; MD ; Joseph Colin ; MD
- 刊名：Journal of Cataract and Refractive Surgery
- 出版年：2012
- 出版时间：June, 2012
- 年：2012
- 卷：38
- 期：6
- 页码：1043-1049
- 全文大小：745 K
Purpose
To define the contribution of the corneal epithelium in corneal topography in keratoconus and discuss the implications regarding combined topography-guided photorefractive keratectomy and corneal collagen crosslinking (CXL).Setting
French National Reference Center for Keratoconus, Bordeaux, France.
Design
Case series.
Methods
Specular topographies were performed before and immediately after epithelial removal during conventional CXL surgery in patients with keratoconus.
Results
The study included 1 eye with forme fruste keratoconus, 4 eyes in Krumeich stage I, and 3 eyes in stage II. The mean simulated maximum keratometry (K) increased by 2.87 diopters (D) after epithelial removal. The mean effective refractive power increased by a mean of 4.01 D and the astigmatic refractive power, by a mean of 2.17 D. The difference in mean axis deviation was not significant. The mean inferior-superior ratio irregularity index increased 1.51 units. All K and refractive readings except astigmatic refractive axis were significantly increased after epithelial removal. All regularity indices increased significantly without the epithelium. The amplitude of variations in K readings made it difficult to predict the refractive changes after custom laser photoablation based on epithelial-based topography.
Conclusions
The astigmatism refractive axis did not change significantly; therefore, this axis could be useful for astigmatic corrections, whereas the spherical component would not be useful. Topographic changes after epithelial removal can be important but not intuitive in keratoconus eyes. This should be considered in custom topography-guided photoablation strategies when attempting to correct refractive errors at the time of CXL.
Financial Disclosure
No author has a financial or proprietary interest in any material or method mentioned.