CXL cytotoxicity digs deep

New Orleans-Often forgotten in the buzz over corneal crosslinking (CXL) is that the procedure kills cells down to 300 µm deep, knocking out everything in its path, including microorganisms and keratocytes, said Theo Seiler, MD, PhD.

"This is a powerful method of killing germs inside the cornea,” said Dr. Seller, professor of ophthalmology at the University of Zurich and chairman of IROC, Zurich. "The loss of cells is persistent-there is still a loss after 3 years.”

Dr. Seiler, who introduced CXL, said he sees tremendous applications for melting diseases.

"In these diseases, there is a constant thinning, a loss of tissue, but if you can delay that-or make the collagen more resistant-the equilibrium can shift between catalysis and synthesis to where there’s augmentation," he said.

Separate studies released this year in Iran and Europe continue to suggest that CXL is an effective procedure with long-term results, Dr. Seller said.    

Complication rates for these new studies ranged from 0% to 13%, with a failure rate of 2%. Other studies support these findings, as there is almost complete absence of adverse reactions to the treatment, he said.

During CXL, new chemical bonds are created between molecules, translating not only to well-documented stable bridges that reinforce the corneal structure, but also, as Dr. Seiler emphasized, making the collagen more resistant against digestive enzymes.

“It is not correct to call this procedure collagen crosslinking,” he said, “but corneal crosslinking, as the changes are not only in the skin collagen.”

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