Microbe warning over contact lens solutions

Acanthamoeba is a leading cause of eye infection on contact lens wearers, particularly in people that use soft lenses. It can cause keratis of the eye and may eventually lead to blindness. In the British Journal of Ophthalmology, K. Hiti and colleagues, from the University of Vienna, Austria, tested the ability of three types of cleaning solutions for soft contact lenses to kill the single-cell organism Acanthamoeba (Br J Ophthalmol 2002, 86:144-146).

The organism has two distinct life stages: trophozoites and the less active cysts. While all three solutions had killed the trophozoites of all the strains of Acanthamoeba, they were not able to kill all the cysts.

Hiti et al. tested a multipurpose storage solution, a one-step 3% and a two-step 0.6% hydrogen peroxide solution. All three solutions were tested for 30 minutes and then eight hours. The two-step 0.6% hydrogen peroxide solution...