Posters

Contribution of the spectral domain OCT to the diagnosis of keratoconus progression

Poster Details

First Author: S.Ouanezar FRANCE

Co Author(s):    O. Sandali   C. Temstet   R. Atia   C. Georgeon   V. Borderie   N.      

Abstract Details

Purpose:

Determination of new anatomical criteria for diagnosing keratoconus progression by corneal optical coherence tomography (OCT).

Setting:

Quinze-Vingts National Ophthalmology Hospital, Paris, France.

Methods:

A total of 134 eyes from 134 patients with mild to moderate keratoconus, 98 with progressive ectasia and 36 with non-progressive ectasia. Corneal topography (Orbscan II©) and Fourier-domain corneal OCT (RTVue©) were performed at each examination, to follow keratoconus. Disease progression was defined as an increase of at least 1 D in the steepest keratometry measures over six months

Results:

Mean Kmax variation was 2.1 ± 1.2 D (p < 0.0001) in the progressive group and -0.03 ± 0.39D in the stable group (p = 0.31). Mean change in thinnest corneal thickness (TCT) was -7.98 ± 9.3 μm (p < 0.0001) in the progressive group and -0.52 ± 4.21 μm (p = 0.22) in the stable group. Change in Kmax was significantly correlated with changes in the thinnest corneal thickness (r = -0.61, p < 0.0001). A cutoff value of -5 μm for the change in TCT was identified as a threshold separating cases of progressive and stable keratoconus (AUC = 0.79, Se = 68%, Sp = 89%).

Conclusions:

Topographic data partly reflect the structural changes occurring during the progression of corneal ectasia. Based on the pachymetric parameters provided by OCT, we show that corneal and epithelial thinning are correlated with corneal deformation. The use of corneal OCT may therefore improve the diagnostic sensitivity for keratoconus progression.

Financial Disclosure:

None