Normal Spherical Cornea


Here is a case of a perfectly normal cornea. The patient is 25 years old and is a perfect emmetrope.

 Normal Axial Curvature map of a perfectly spherical conrea on ATLAS topography

On the Visante OCT, the Global Pachymap can be seen. It takes 16 images of the cornea, each rising at 11.25 degrees, for the complete 180 coverage (since it is done on both sides of the semi-circle, it completes the 360 degrees).

 Global pachymetric map on the Visante omni 

In order to check for the quality of the images, I personally inspect all the 16 images. It can be done very rapidly (no more than 30 seconds). If adjustments need to be done, it is done fairly rapidly, by redrawing the border in the edit mode. Here is an example of an excellent quality match of the anterior and the posterior conreal surfaces as recognized by the Visante software.

 Surface matching on the Visante omni 


Once I have reviewed the topography, and the pachymap, I have them merged via Visante omni into the Holladay report. Here is a Holladay report for this case.

The perfect anterior axial curvature with a very uniform map, yields a very uniform anterior elevation map (all green, in the top right corner). The pachymetric map produces a very normal concentric increase in corneal thickness in the middle top. The posterior elevation map in the bottom right, as expected is also uniformely a regular green map.

 Holladay report of a normal spherical cornea as seen on the Visante omni 

It is harder than one thinks to find such a perfect example of truly normal spherical cornea.