Assessment of the effects of cetypyridium chloride on water content of the collagen-keratocyte matrix of the mammalian corneal stroma ex vivo

Abstract

The effects of cationic surfactants on the time-dependent increases in hydration of the corneal stroma were investigated to assess if the contribution of the proteoglycans could be titrated and how it might relate to the maximum and minimum swelling properties of the corneal stroma. From recent post-mortem eyes from adult sheep, square (8×8 mm) samples of corneal stroma were prepared and incubated in isotonic neutral pH mixed salts solution with added glucose, or pure water, at 37°C. The time-dependent changes in wet mass were assessed over 24 h in the absence or presence of 0.001–2% w/v cetylpyridium chloride (CPC) or benzalkonium chloride (BAC). The rate and magnitude of stromal swelling was reduced in a concentration-dependent fashion by the surfactants. In mixed salts solution, 100% inhibition of swelling could be achieved at 2% CPC and BAC. In pure water, the relative swelling was much more substantial and could only be attenuated by CPC.