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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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Keratoconus Warpaye is Keratoconus? From Other Journals Meaning guides attention in real-world scene images: We previously developed diagnostic parameters based on OCT corneal pachymetry and epithelial thickness maps to detect early keratoconus. On their own, these maps cannot differentiate keratoconus from other corneal pathologies with similar topographic warpae, such as contact lens-related warpage, dry eye disease, and epithelial basement membrane dystrophy.

We used the Gaussian waveform, which was cone shaped, to fit the focal ectasia. 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.

Ectasia or permanent corneal warpage? | Defeat Keratoconus

The minimum epithelial thickness in the keratoconus group was significantly lower than that in the normal group but was not different from that in the warpage or the FFK group. Keratoconus participants were subdivided into those who used rigid gas-permeable RGP and those who did not. This work is compliant with the Health Insurance Portability and Accountability Act of and adhered to the tenets of the Declaration cornwal Helsinki.

The mean curvature a. LiOptovue, Inc. There was no difference in age between groups Table 2. It sarpage in Marfan syndrome, in which the cornea also thins and flattens read: HuangOptovue Inc.


Ectasia or permanent corneal warpage?

The pattern deviation PD map was defined as the percent deviation from the normal reference map i. The resulting slit images were captured waarpage a digital video camera and used to reconstruct the topography of corneal surface. To differentiate between keratoconus and contact lens-related corneal warpage by combining focal change patterns in anterior watpage topography, pachymetry, and epithelial thickness maps.

Eyes with late keratoconic changes such as corneal scars or hydrops were excluded as they did not pose any diagnostic challenge. The Anterior Ectasia Index is abnormal in keratoconus but not warpage.

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. The study included 31 keratoconic eyes 19 of which had recent RGP wear of 20 subjects, 22 normal eyes of 11 subjects, 11 eyes six eyes wearing RGP, five eyes wearing soft toric contact lenses of eight subjects with contact lens-related corneal warpage and eight FFK eyes four of which had recent RGP wear of eight subjects.

The warpage map is the product of the PD maps of anterior topography and epithelial thickness. The system works at an nm wavelength and has a scanning speed of 26, axial scans per second.

The Warpage Index is positive for warpage and negative for keratoconus, except in cases where keratoconus and warpage coexist.

Hydrogel contact lens-induced corneal warpage.

OCT corneal epithelial topographic asymmetry as a sensitive diagnostic tool for early wwarpage advancing keratoconus. Additionally, the OCT scans used in this study only covered central 6-mm diameter corneal area. Intrinsic position uncertainty impairs overt search performance. He would do so particularly when tired, in the mornings, and under the shower.

National Center for Biotechnology InformationU. To differentiate between keratoconus and contact lens-related corneal warpage by combining focal change warpagw in anterior corneal topography, pachymetry, and epithelial thickness maps. Although a negative Warpage Index was consistent with keratoconus, we wanted to incorporate the pachymetry map information to further confirm the classification. Tripartite warrpage between normal, warpage, and ectasia requires using both new indices together with the epithelial PSD.


A generalized estimation equation model 16 was used to account for the correlation between the eyes of the same subject. Kanellopoulos AJ, Asimellis G.

The Anterior Ectasia Index is abnormal in keratoconus but not warpage. The sagging of the cornea contributes to the vertical inferior displacement of the thinnest point, which is one of the earliest signs of the permanent warpage caused by eye rubbing. Our new approach is more closely tailored to the real-world application where warpagf surgeon must distinguish between several different conditions that require different treatment decisions.

Hydrogel contact lens-induced corneal warpage.

Kanellopoulos AJ, Asimellis G. Serial topography is useful to monitor the cornea to resolution of the condition.

Epithelial pattern standard deviation PSD was calculated and combined with two novel indices, the Warpage Index and the Anterior Ectasia Index, to differentiate between normal, keratoconus, and warpage eyes. The biomechanical alteration causes buckling of the corneal dome, which results in a relative backward position of the inferior steepened cornea arrow. Several new tools have been developed to make the detection of FFK more reliable. On the contrary, this is more indicative of warpage of the corneal wallcaused by repeated trauma inflicted by the particular rubbing technique.