The case below is a case of a patient that I share with my good friend and colleague Jeffery Ing, MD of Stockton, CA. The patient had had LASIK performed elsewhere and subsequently developed ectasia. Below are Holladay reports by Visante omni and Pentacam.
In the above cases
- The K's
- 44.96 D and 42.63 D at 167 with Visante omni
- 44.6 D and 41.3 D at 157 with Pentacam
- The minimum pachymetry
- 450 microns with Visante omni
- 445 microns with Pentacam
- Anterior corneal surface protrusion
- approximately 30 microns with Visante omni
- highest point is 9 microns with Pentacam
- Posterior corneal surface protrusion
- 38.80 microns with Visante omni
- approximately 20 microns with Pentacam
Even though there is good correlation in the anterior surface topography and data, there is a large disconnect between the Visante omni system with the Pentacam. The clinical examination is certainly more consistent with the Visante omni. This is again a case of post LASIK ectasia where the peripheral Scheimpflug camera takes the image through the altered corneal tissue. Give the changes in the magnification and minification changes induced there is moderate miscalculation on part of the Scheimpflug system. In the above cases of native keratoconus there was excellent correlation, but post LASIK ectasia introduces new orders as does the case of post myopic LASIK.