Keratoconus and Pellucid Marginal Degeneration (PMD)
make up the group of eye disease called corneal ectasia.
Ectasia is defined as the expansion or distention of
body tissue, in this case the cornea - the clear dome
covering the colored part of the eye. The cornea’s
primary responsibility is focusing light onto the retina
to create clear, sharp vision. When the cornea
thins, or becomes ectactic, it distorts the vision
causing blur, multiple images, glare, haloes, dry eyes,
light sensitivity and other undesirable visual
phenomena.
Keratoconus is a cone-like a thinning and distortion of
the central cornea, while PMD is a broader thinning that
affects the peripheral cornea. In our experience
many cases of PMD are improperly diagnosed as
keratoconus or high astigmatism.
Glasses, and in most cases, soft contact lenses, cannot
correct the blurred vision caused by this distortion.
Specialized rigid or hybrid contact lenses are the only
treatment option. Generally, keratoconus is easier
to treat than PMD, which requires more specialized and
complex contact lens designs. While the majority of
patients can be treated with contact lenses, in severe
cases, both disorders can lead to the need for a corneal
transplant.
FDA trials are currently underway for a procedure called
corneal cross-linking. It involves placing
vitamin-A drops in the eye and exposing it to a certain
wavelength of ultraviolet light. While this
doesn't correct or reverse the condition it has been
shown to significantly strengthen the cornea to keep it
from getting worse.
Even in the hands of the most skilled physicians,
ectasia can be induced by refractive surgery (LASIK,
PRK, RK, etc.). While some of these patients
actually had undiagnosed keratoconus or pellucid
marginal degeneration prior to surgery, many cases are
thought to be caused by the biomechanical effects of the
surgery. Once again, highly specialized contact
lenses can be used to treat these disorders.
Battleground Eye Care has the high tech equipment
necessary to successfully diagnose and treat these
conditions.
If you have been diagnosed with keratoconus or pellucid
marginal degeneration and would like to schedule a
consultation, please use our online appointment request
or call 336-282-2273. We look forward to helping
you.