Problems with multipurpose contact lens solutions
There was bad news about multi-purpose contact lens solutions. In Singapore, the ReNu MoistureLoc solution was for ever withdrawn after the outbreak of eye infections in 2006. In fact, multipurpose solutions (MPS) can also result in fungal contamination of the solution. According to a senior consultant ophthalmologist at the Singapore National Eye Center, the underlying cause is the multiple additives in these solutions.
Eye care solutions are originally created to kill germs and bacteria. However, the strong agents in solutions may also damage the natural barrier function of corneal epithelial cells. The term used to describe the danger caused by MPS is cytotoxicity, which indicates the quality of being toxic to cells. Although cytotoxicity is reversible within a few days after the solutions are stopped, cell vitality can be decreased in the process of MPS use.
Although more studies are needed to evaluate the long-term impact of MPS cytotoxicity, some brands of lens solutions are showed to be more harmful to corneal epithelium, which is the natural barrier of the corneal. There is already a study that has compared some brands of MPS, pointing out that the Alcon and Bausch & Lomb solutions are more cytotoxic than others such as the Complete Easy Rub solutions.
Officials from Alcon and Bausch & Lomb fought back that the study was actually an in-vitro test and involved no actual lens wear. They argued that clinical results can not be predicted by in-vitro tests. Bausch & Lomb spokesman also pointed out that their products were assured by stringent quality control systems and approved by the US Food and Drug Administration. In addition, the study was funded by their competitors.
Despite those controversies, there is advisable ways to avoid potential risks of MPS. Some experts recommend saline solutions for lens rinsing after using MPS, which can remove preservatives found in MPS. Furthermore, contact lens solutions should be properly prescribed by lens practitioners.
From: www.eyeoverheard.com