Purchase this article with an account.
Natalia Ximena Minguez, Pablo Raul Ruisenor Vazquez, Jonatan David Galletti, Marianella Delrivo, Fernando Fuentes Bonthoux, Tomas Pförtner, Jeremias Gaston Galletti; Corneal changes in time in normal and keratoconic patients assessed by Pentacam Scheimpflug tomography. Invest. Ophthalmol. Vis. Sci. 2014;55(13):2463.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To evaluate corneal changes in time in control and keratoconic subjects with the Pentacam Scheimpflug tomograph in order to better characterize ectasia progression.
Observational case series of 20 eyes from 10 healthy subjects (group 1) and 44 eyes from 22 keratoconic patients (group 2), evaluated with Scheimpflug tomography (Pentacam HR, Oculus Optikgeräte GmbH, Germany) on two visits at least 6 months apart. Main outcome measurements were mean keratometry (KmAnt), flat and steep keratometry (K1Ant and K2Ant), thinnest pachymetry (ThinPac) and anterior (AntElev) and posterior (PostElev) elevation at the thinnest corneal point. Statistical significance was set at p<0.05.
In group 1 vs group 2, age (27.4±7.3 vs 36.6±17.1 yrs, p<0.05) and median follow up (21 vs 11 months, p < 0.05), but not gender distribution (50% vs 68% male), differed significantly. Between groups there were no significant differences at first visit in KmAnt (44.3±1.8 vs 45.8±3.4) and K1Ant (43.4±1.6 vs 44.0±3.5), but K2Ant (45.1±2.2 vs 47.4±4.2, p=0.04), ThinPac (526±40 vs 491±6, p=0.01), AntElev (2±3 vs 17±19, p<0.01) and PostElev (3±3 vs 39±37, p<0.01) did differ. In group 1, there was no significant change between visits in the studied variables. Mean (min-max) change was: KmAnt 0 (-0.3 - 0.2) D, K1Ant 0 (-0.3 - 0.2) D, K2Ant -0.1 (-0.4 - 0.3) D, ThinPac -4 (-26 - 13) µm, AntElev 0 (-4 - 8) µm and PostElev 0 (-2 - 5) µm. In group 2, only ThinPac changed significantly between visits: -6 (-67 - 21) µm (p=0.04). Mean (min-max) change was: KmAnt 0.1 (-4.9 - 4.7) D, K1Ant 0.4 (-4.0 - 8.1) D, K2Ant -0.3 (-5.8 - 2.8) D, AntElev -2 (-59 - 20) µm and Post Elev -1 (-32 - 25) µm. In group 2, 10 (23%) eyes showed a >1.5D change in KmAnt and 7 (16%) eyes had a >20 µm decrease in ThinPac. There was no significant correlation between the changes in any of the studied variables in either group or within the group 2 eyes that had a >1.5D change in KmAnt.
Keratoconic eyes exhibited greater fluctuations in measurements that cannot necessarily be ascribed to ectatic progression. Lack of correlation between changes in different corneal descriptors probably reflects the variable nature of keratoconus evolution. In contrast to keratometric readings, thinnest pachymetry varied considerably even in control eyes, suggesting that it might not be as reliable as the former for monitoring keratoconic patients.
This PDF is available to Subscribers Only