Does a corneal transplant always stop the progression of keratoconus? No, not always. In a very, very small number of cases, keratoconus re-emerges years or even decades after surgery.
Fewer than a dozen examples have been described in the medical literature, notes Dr. Rebekah Montes, OD (pictured right), an optometrist practicing in Houston, TX. Theories such as eye rubbing, hard contact lens wear and inherited allergies have been proposed as possibly contributing to the recurrence. Donated corneas are screened for keratoconus, so it is unlikely that the donated tissue carries the disease.
More likely, the keratoconus is a ‘re-emergence’ of the patient’s original condition. Diseased cells remain at the outer edge of the cornea and, over time, cells migrate toward the graft and assimilate within the transplant tissue. The exact mechanism for this has not been determined, or why this is happens so infrequently.
Re-emergence of KC may take longer…
Dr. Montes reports that re-emergence of keratoconus may take considerably longer in full thickness transplants – one case described a patient whose symptoms reappeared 30 years after the original surgery – than in those patients who undergo a partial transplant, such as a DALK, where only part of the diseased cornea is removed.
Dr. Laurence Sperber, MD, Clinical Professor and Director of the Cornea Service at NYU Langone Medical Center in New York City has only seen one case of a mild recurrence of KC after corneal transplant in his career.
Signs of a KC recurrence would be a significant change in refraction, astigmatism or corneal topography. Even though a recurrence of KC is exceedingly rare, and not a usual risk of transplant surgery, these unusual instances are important reminders for KC patients and their eye surgeons to continually monitor corneal transplants.” – Dr. Sperber, MD
Many patients fear they will need to undergo a corneal transplant when they learn they have keratoconus. In most cases, there will not be a need for a transplant: more than 80% of individuals with KC do not require a corneal transplant.
To learn more about the corneal transplant procedure, watch this short video and talk to your eye care professional.