Vision Care

One of the best ways to evaluate the cornea is through the use of Corneal Topography. There are various signs in the mapping that show the doctors signs of keratoconus and other progressive eye conditions. The topography can show irregular and steepening of the shape of the cornea. The normal cornea also has a 90 degree axes perpendicular in the cornea. In the normal cornea during corneal topographies there is a smooth and flat surface.

If the topography shows irregularities or steepening this is a sign that there are problems. Any irregularities in the cornea such as steepening and/or irregular shaping of the axes show signs of irregular astigmatisms. Raising questions in for Keratoconus. When doctors check for Keratoconus in the Lasik evaluation they look for ” Inferior Steepening.” Corneal Astigmatism appears in the shape of a football compared to a normal cornea that is round and smooth.

Additionally Keratoconus is confused with Pellucid Marginal Degeneration or PMD. PMD was first discovered by an Ophthalmologist in 1957 named Dr. Schalaeppi. Pellucid Marginal Degeneration is a break down of the cornea creating a lobster claw pattern. PMD is also known as the peripheral form of keratoconus. While the disease is in the same family and similar there are some differentiating factors. When viewing in a corneal topography the PMD appears as a steepening from the outer margin of the cornea heading inwards and appearing to pinch the center.

Signs of Pellucid Marginal Degeneration:

No pain reported [compared to keratoconus]
Visual distortions
No vascularization of cornea
No scarring
Lobster Claw formation

In the end the best form of testing for Keratoconus is to have a baseline corneal topography, and regular testing annually. The treatments of keratoconus are advancing and progression of this disease can be treated successfully. Catching the condition early can give you a better result. Checking with your ophthalmologist and getting regular checkups is a must.