Differentiating Keratoconus and Corneal Warpage by Analyzing Focal Change Patterns in Corneal Topography, Pachymetry, and Epithelial. Cont Lens Anterior Eye. Sep;26(3) Hydrogel contact lens-induced corneal warpage. Schornack M(1). Author information: (1)Department of. Before the advent of corneal topography, corneal warpage was generally described as a condition that included distorted keratometer mires.
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Methods Pachymetry and epithelial thickness maps of normal, keratoconus, and warpage, and forme fruste keratoconus FFK eyes were obtained from a Fourier-domain optical coherence tomography OCT.
Using just one of the two new indices is not sufficient to distinguish between keratoconus and warpage.
They all share a history of eye rubbing which preceded cornea onset of keratoconus. Longitudinal study of the normal eyes in unilateral keratoconus patients. This is probably because epithelium at the cone peak comes into contact with the RGP contact lenses, resulting in epithelial thinning at a location of topography steepening—opposite of the usual warpage pattern where epithelial thinning is associated with focal topographic flattening.
Hydrogel contact lens-induced corneal warpage.
TangOptovue, Inc. Another limitation is that if keratoconic distortion is extremely subtle e. Five out of 8 FFK eyes The pachymetry and epithelial thickness maps were also centered on the pupil center. The epithelial PSD can distinguish normal from keratoconus or warpage, but does not distinguish between these two conditions.
It shows cornral cone-like pattern in keratoconus, which corneak absent in warpage. Those with negative Warpage Index values are diagnosed with keratoconus, while those with positive Warpage Index are diagnosed with warpage. Keratoconus subjects included in this study were diagnosed clinically with the following inclusion criteria: Global consensus on keratoconus and ectatic diseases.
Although a negative Warpage Index was consistent with keratoconus, ccorneal wanted to incorporate the pachymetry map information to further confirm the classification.
LouieNone; J. Positive Warpage Index indicates warpage, and negative Warpage Index indicates keratoconus, as shown in Figure 1.
Ectasia or permanent corneal warpage?
He would do so particularly when tired, in the mornings, and under the shower. However, topography is not sensitive to very early stages of keratoconus when the topographic steepening is masked by focal epithelial thinning. However, topography is not sensitive to very early stages of keratoconus when the topographic steepening is masked by focal epithelial thinning.
Corneal epithelial thickness profile in the diagnosis of keratoconus.
Ectasia or permanent corneal warpage? | Defeat Keratoconus
Schallhornand David Huang. The initial corneal profile is depicted by an arc of a circle A. Time to resolution of contact lens-induced corneal warpage prior to refractive surgery. There was no difference in age between groups Table 2. If so, contact lens cessation will remain necessary for our classification scheme to accurately distinguish between keratoconus and warpage.
Proposed approach for comprehensive keratoconus and warpage diagnosis in a clinical setting. In all three cases, cessation of lens wear led to restoration of the normal corneal contour and visual acuity. Create an Account or Subscribe Now.
These metabolic challenges can change corneal physiology sufficiently to cause clinically significant corneal warpage. The values of the three parameters were compared between groups. This work is licensed under a Creative Commons Attribution 4. We speculate that it might be caused by upper lid pressure molding the epithelial thickness, causing a normal pattern of slightly thinner superior epithelium and slightly flatter superior topography.
The epithelial PSD was normal 0. An abnormally high Anterior Ectasia Index is the result of the coincident focal topographic steepening and pachymetric thinning, which is typical in keratoconus and other ectasia i. Detection of keratoconus in clinically and algorithmically topographically normal fellow eyes using epithelial thickness analysis.
We propose the use of a decision tree Fig. One of the 19 RGP-corrected keratoconus eyes had mixed keratoconus plus warpage pattern, while in the warpafe 18 the keratoconus pattern predominated.
Open in a separate window. On the contrary, this is more indicative of warpage of the corneal wallcaused by repeated trauma inflicted by the particular rubbing technique. TangOptovue, Inc. Additionally, the OCT scans used in this study only covered central 6-mm diameter corneal area. There was no difference in mean epithelial PSD values between eyes with RGP contact lens-induced warpage and eyes with soft toric contact lens-induced warpage.
The warpage cases are then tested with the Anterior Ectasia Index, with the result that the subthreshold cases has pure warpage, while the supra-threshold are diagnosed with both keratoconus and warpage. The purple area indicates both conditions coexist. SchallhornNone; D. The Warpage Index was positive in all warpage eyes 3.
Hydrogel contact lens-induced corneal warpage.
Warrpage is no protrusion here. This patient admitted to rubbing his eyes frequently with his right hand, ckrneal vigorously in a horizontal motion. Normal subjects enrolled in this study were LASIK candidates who had no ocular diseases and have not been wearing contact lenses for at least 2 weeks prior to the exams. We speculate that it might be caused by upper lid pressure molding the epithelial thickness, causing a normal pattern of slightly thinner superior epithelium and slightly flatter superior topography.
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