PELLUCID MARGINAL DEGENERATION

Pellucid Marginal Degeneration is somewhat like keratoconus but begins later (usually 20's to 40's) and doesn't have Fleischer rings or Vogt stria. It is characterized by a 1-2mm wide arc of corneal thinning extending from 4 o'clock to 8 o'clock, and with increasing severe flattening in the vertical meridian. Best spectacle-corrected VA on average is a little worse than 20/30.

According to this article in the December Ocular Surgery News, these patients are able to obtain nearly 20/20 vision on average with:

"bitoric gas-permeable contact lenses with a larger overall diameter"

Sounds like another case for Jim Slightom at ABBOptical!