Contribution of the spectral domain OCT to the diagnosis of keratoconus progression
Session Details
Session Title: Corneal Biomechanics
Session Date/Time: Monday 09/10/2017 | 08:00-10:30
Paper Time: 09:39
Venue: Room 2.1
First Author: : S.Ouanezar FRANCE
Co Author(s): : O. Sandali N. Bouheraoua C. Temstet O. Levy V. Borderie L. Laroche
Abstract Details
Purpose:
Determination of new anatomical criteria to the diagnosis of keratoconus progression based on corneal OCT in a large population patients.
Setting:
Reference center for keratoconus, Quinze-Vingts National Ophtalmology Hospital, Paris, France.
Methods:
We performed an analysis of prospectively collected datas of consecutive evolutive mild to moderate keratoconus cases followed from January 2014 to January 2016. The progression of keratoconus was defined as an increase at least 0.5D in the steepest keratometry over 6 months or 1D over 12 months. All patients underwent corneal topography OrbscanIIz® and Fourier Domain OCT RTvue® A Student t-test was performed to compare initial parameters in each group, to compare the variation of each parameter in and between both groups. Linear regression with evaluation of the Spearman coefficient analysed associations between continuous variables.
Results:
Datas from 98 evolutives and 36 stables keratoconus. Mean follow-up was 7.1 months. Mean Kmax variation was 1.55±1.15D in the evolutive and 0.00+/-1.23D in the stable group. Mean change of Thinnest Corneal Thickness in the evolutive group was -6.93±8.84µm (p<0,0001) and -0,67±8.43µm (p=0,16) in the stable group. Variation of Kmax was significantly correlated with the changes of Central and Thinnnest Corneal Thickness (r=-0,39, p<0.0001), and Thinnest Epithelial Thickness (r=-0.26,p=0,043). ROC curves shows a cut-off value set at -4µm thinning of TCT to identify stable and evolutive keratoconus (AUC= 0,797, Se=65.3%, Sp=88.9%).
Conclusions:
Topographic datas don't reflect structural changes which occure during corneal ectasia evolution. Following pachymetric parameters given by the RTVue® OCT we showed that corneal and epithelial thinning are correlated with corneal deformation.Use of corneal OCT can improve the sensitivity to the diagnosis of corneal ectasia.
Financial Disclosure:
NONE
