PK has higher long-term endothelial cell loss than DALK, study finds

ROME — A comparison of penetrating keratoplasty and deep anterior lamellar keratoplasty outcomes in a large series of patients over 5 years showed comparable best corrected visual acuity but a significant difference in endothelial cell count favoring DALK.

The study, which included 252 DALK eyes and 590 PK eyes, was conducted at the Clinic Krumeich in Bochum, Germany. All transplants were performed by the same surgeon using the water pillow technique of Jörg Krumeich, MD. This technique "allows the surgeon to obtain a bare Descemet's. If this membrane is really bared completely, the posterior layers are smoother than with any other technique," Dr. Krumeich said at the winter meeting of the European Society of Cataract and Refractive Surgeons.

All grafts were performed with the same guided trephine system, and special Geuder instruments were used for DALK. Double-running anti-torque sutures were used for fixation.

"Concerning BCVA or cylinder values, statistically significant differences could only be found for the first 3 months, during which the results of DALK were superior. From month 6 through to 5 years, no significant difference was found," Dr. Krumeich said.

However, a significantly higher loss of endothelial cells was found in the PK group from 6 months onward.

Dr. Krumeich said that DALK is not an inferior procedure to PK. On the contrary, DALK is a procedure that provides a permanent healing of a disease, but PK can only be called a temporary procedure because it has to be repeated after 12 year to 15 years, he said.