Optometrists may have a new treatment option for a common cause of corneal toxicity. A recent study found 20% human serum to be effective in treating epithelial cytotoxicity caused by benzalkonium chloride (BAK)-containing eye drops.

Researchers exposed human corneal epithelial cells to 0%, 0.002%, 0.02% and 0.2% concentrations of BAK with and without the presence of 20% human serum. After 24 hours, they checked the cells for metabolic activity, proliferation, apoptosis and pro-inflammatory cytokine expression. Additionally, they used topical 20% autologous serum to treat 24 patients with toxic corneal epitheliopathy stemming from use of glaucoma eye drops containing BAK.

In vitro results showed that 20% human serum significantly fostered cell metabolic activity, proliferation and migration, all of which were hindered by BAK exposure. Also, presence of 20% human serum greatly reduced apoptosis in these cells. Of the 24 patients with corneal BAK toxicity, topical treatment with 20% autologous serum decreased corneal punctate epithelial erosions in 20 patients (84% of study participants).

These results provide “a basis for using 20% autologous serum for patients with preservative-induced corneal epitheliopathy,” the study concludes.