Comparing the extent of protein build-up on several disposable lenses by two spectrophotometric methods

This study aims to quantify levels of protein build-up on high-water ionic (Type IV) disposable contact lenses worn by patients, by two spectrophotometric methods, previously validated only with conventional lenses. Forty lenses were analyzed and the related results were compared. The Ninhydrine-Lysozyme method and the Coomassie Blue Albumin one agreed in identifying the most spoiled lenses. Etafilcon A attracted significantly more protein than the other materials tested, which were in the following decreasing order of protein spoilation: Ocuflcon D, Ocufilcon A and Vasurfilcon A. These similar findings suggest that it is possible to use the above mentioned analysis methods for an accurate evaluation of the contamination of several materials of disposable/frequent replacement lenses as for conventional lenses.