February 3, 2011
One Donor Cornea Solves Pair of Eye Problems
(Ivanhoe Newswire) -- New surgical strategies use a single donor cornea to help two patients with different cornea diseases. The new approach restored good vision to patients who had Fuchs' dystrophy (degeneration of certain corneal cells) and keratoconus (thin, cone-shaped cornea), and also addressed the supply and demand problem for corneas in the U.S.
Advanced keratoconus is often treated with a surgery called deep anterior lamellar keratoplasty (DALK). Fuchs' dystrophy and similar diseases can be treated via several surgical techniques, including the recently developed Descemet's membrane endothelial keratoplasty (DMEK). Dr. Cursiefen and his colleagues noted that, once the tissues needed for DALK were removed from a donor cornea, the tissues needed for DMEK remained. They reasoned that scheduling two patients for surgery on the same day, with the DALK patient always scheduled first, would make it possible to use one cornea for two patients. Since about 80 percent of the cornea diseases that require transplants can be treated with DALK or DMEK, this approach might potentially nearly double the available corneal tissue supply and make quick treatment available to many more patients.
"In this exploratory study, we were able to use one cornea to successfully treat two patients, for 10 of 12 consecutive donor corneas," Claus Cursiefen, MD, was quoted as saying. "Only twice during surgery did we find that a full corneal transplant, rather than DALK, was needed. Our early follow-up with all patients shows good visual outcomes and few complications."
At the six month follow up DALK patients, on average, achieved 20/35 vision, and DMEK patients achieved 20/31 vision, on average. The two patients scheduled for DALK who instead received full transplants achieved 20/50 vision, on average.
Drawbacks of this approach are that both DALK and DMEK are demanding surgeries that currently can only be performed at leading-edge ophthalmic hospitals, and because both techniques are relatively new, longer-term outcomes and effectiveness remain to be determined.
Also, preparation and care of the split corneas requires sophisticated planning and preparation, and access to additional corneas is essential in case full transplants became necessary. Further research will determine whether the approach becomes widely accepted.
SOURCE: Ophthalmology, published online February 1, 2011