PACK-CXL may play role in treating infectious keratitis
WAIKOLOA, Hawaii — Photoactivated chromophore for keratitis corneal cross-linking could be useful in infectious keratitis in under-developed countries where access to antimicrobial therapies and antibiotics is lacking, according to Jay S. Pepose, MD, PhD, at Hawaiian Eye 2019.
“Research has shown that only 50% of eyes with microbial keratitis have a good visual outcome if antibiotic treatment is delayed, and drugs may not be readily available,” Pepose said.
In industrialized countries, the biggest risk factor for microbial keratitis is contact lens wear, he said. Other factors include ocular trauma, recent eye surgery, ocular surface disease, lid deformity, impairment of corneal sensation, chronic use of topical corticosteroids and systemic immunosuppression.
“The mechanism of action for photoactivated chromophore for keratitis (PACK) is the riboflavin with the nucleic acids of the pathogen and inhibition replication,” he said.
“Damage to the pathogen’s cell walls is caused by massive amounts of reactive oxygen species. Then, changes in the tertiary structure of the surrounding stromal collagen fibers make it difficult for the collagenases to dock their cleavage sites and exert their function and cellular apoptosis related to PACK-CXL could influence the immune response.”
As for future developments in this area, “there’s a lot of interest in varying treatment time and light intensity,” Pepose added.
Alternative chromophores to riboflavin are being explored as well as using different UV wavelengths, UV-C rather than UV-A. Studies are also looking at the application of this at the slit lamp, Pepose said. – by Abigail Sutton
Reference: Pepose JS. Crosslinking for infectious keratitis: PACK-CXL. Presented at: Hawaiian Eye; Jan. 19-25, 2019; Waikoloa, Hawaii.
Disclosures: Pepose reports consulting with Bausch + Lomb and Shire and an ownership interest in Okogen.