Evaluation of Keratometric, Pachymetric, and Elevation Parameters of Keratoconic Corneas With Pentacam

Abstract

Posterior and anterior elevation, pachymetric, and keratometric parameters measured by the Pentacam camera can effectively discriminate keratoconus from normal corneas serving as a useful diagnostic tool for disease staging.

Keratoconus Diagnosis Using Anterior Segment Polarization-Sensitive Optical Coherence Tomography

“…Since PS-OCT is able to detect corneal shape as with conventional OCT, PS-OCT can acquire information on internal tissue properties and corneal outer shape simultaneously. Recently, many indices or parameters have been investigated for diagnosing keratoconus [4][5][6][7][8] ; however, these parameters describe the same tendency, that is, for the corneal outer shape to become ectatic and asymmetric. Thus, even if a new outer shape profile index was added to the conventional ones (such as corneal curvature, irregularity, and elevation), the improvement in diagnostic capability would be limited.…”

“…Detection of initial and subclinical keratoconus is especially important for preoperative screening for laser refractive surgeries to avoid unpredictable outcomes. 2,3 Recently, parameters such as anterior and posterior corneal curvature, 4 elevation, 5,6 topography mapping, 7 corneal regular and irregular astigmatism, 8 and pachymetry mapping 9 were found to be useful for evaluation of keratoconic cornea morphology. However, these parameters describe the morphological profile of the cornea and consequently are not useful for evaluating the strength of corneal tissue microstructure, such as collagen fibers.…”

Corneal structure in tilted disc syndrome

“…Prior studies only evaluated refractive and pachymetric measurements of the cornea. The Scheimpflug imaging system uses the elevation-based tomography principle and therefore provides accurate and reliable data on the actual shape of the cornea, independent of position, orientation and axis (18) . It therefore enables a much more detailed evaluation of the cornea than do refractive or ultrasonographic pachymetry measurements.…”

Prevalence of keratoconus among refractive surgery candidates Abstract: Background: Reasons for refraining from refractive surgery were numerous, with a change of mind after the pre examination being the most common. Patients who changed their minds were very similar to those who had surgery. World Wide Keratoconus is a comparatively common diseases frequency ranging from 50 to 230 per 100,000. Keratoconus is increasing rapidly in Asir Province, Saudi Arabia and more fastly occurred / create complications

“…According to Mihaltz et al 23 As he performed ROC curve analysis which shown that posterior elevation was the most important criterion in the diagnosis of KCN. A threshold value of 15.5 µm had sensitivity of 95.1% and specificity of 94.3% for differentiating normal eyes from KCN Pinero et al 24 investigated corneal volume, pachymetry and the correlation between anterior and posterior corneal shape in normal and KCN eyes.…”