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.
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.
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.
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