The procedure's advantages over traditional PK can be divided into two categories, according to OSN Cornea/External Disease Section Member Thomas John, MD.
"First, the fact that we're taking the full-thickness corneal wound and sutures out of the equation has advantages.With PK, because of the wound, significant astigmatism occurs.Second, with PK, the wound never heals entirely.So if the patient has an accident or trauma, that's the spot where the eye will rupture," Dr. John
trephined the posterior part of that split cornea 360° and then removed the disc," Dr. John
surgically created a donor disc consisting of the posterior corneal stroma, Descemet's membrane and the healthy endothelium all in one disc.This disc was brought into the anterior chamber of the patient's eye and placed to close the space that was surgically created in the patient's cornea, much like closing a manhole lid," he
described Dr. Melles' technique as a "huge step forward," but noted that it did not become popular among corneal surgeons.
"The disc was placed on the inner corneal surface and was only held with the air bubble, much like taking a pizza and slapping it onto the ceiling," Dr. John
...Thomas John, MD, can be reached at 16532 S. Oak Park Ave., Tinley Park, IL 60477; 708-429-2223; fax: 708-429-2226.