Early deposition trends on group I (Polymacon and Tetrafilcon A) and group III (Bufilcon A) materials

One of the problems with hydrophilic contact lenses is that they are susceptible to spoilage. This study investigated the degree of spoilage associate with lenses of various surface changes during the early stages of wear and the effect of surfactant cleaning of lenses at this stage. Ten patients wore a control HEMA lens on one eye and either an ionic (Bufilcon A) or non-ionic (Tetrafilcon A) lens on the other for one week and used a peroxide system for disinfection. The lenses were then replaced with identical lenses, which were also worn for 1 week, with surfactant cleaning added to the care regimen. The lenses then were examined by fluorescence spectroscopy in order that the extent of lipid and protein deposition could be assessed. The results indicate that protein accumulation is highly material dependent, whereas lipid deposition is primarily patient dependent. Also the term "ionic" does not necessarily indicate equally enhanced deposition in all lenses so termed. Surfactant cleaning appears to be of little benefit in reducing deposits during the early stages of wear, its benefit in the long-term being of much greater significance.