Intrastromal corneal ring has immune benefit, surgeon finds

MONTE CARLO, Monaco — Implanting an intrastromal corneal ring in patients who undergo corneal transplant might reduce the chance of immune reaction, according to the surgeon who designed the ring. Jörg Krumeich, MD, offered his observations about several cases in which he implanted the Krumeich intrastromal corneal ring, produced and distributed by Humanoptics.

“I made and implanted these rings to reduce astigmatism, stabilize the wound and improve healing,” Dr. Krumeich said. “Quite unexpectedly however, I observed that for some reasons these patients had fewer immune reactions. We therefore investigated this aspect and confirmed that the intrastromal corneal ring possesses immune-suppressing properties.”

Dr. Krumeich described a multicenter study that compared patients undergoing corneal transplants with or without implantation of the ring. Results in 179 patients implanted with the ring showed a significantly lower rate of immune reaction (1%) compared with patients who were not implanted with the ring (6%), Dr. Krumeich said.

He added that the device “seems to stop the recurrence of immune reaction” in patients with a previous history of one or more transplant failures.

“In nine cases that I reoperated after several failures, only one had a new rejection, while the remaining cases are showing no sign of immune reaction over a follow up of 1 to 8 years,” Dr. Krumeich said.

According to Dr. Krumeich and other speakers involved in the discussion here during the European Society of Cataract and Refractive Surgeons Winter Refractive Surgery meeting, the immune-suppressive effect may be connected with the properties of the material of which the ring is made, an alloy of titanium, molybdenum and cobalt. A study to find the cause of the immune-suppressive effect will soon be started, Dr. Krumeich said.

“At this stage we only have the observation, and not yet the cause of the phenomenon,” he said.