Studies on Microbial Adherence to Hydrogel Contact Lens Surfaces+

Grant Winners

Deans

Abstract

A large segment of the American and global population with refractive errors has made contact lenses their choice of vision corrective device. In fact, more than 32 million individuals are presently wearing contact lenses in the United States. Most of these individuals are wearing hydrogel or soft contact lenses, which consist of a flexible plastic that contains anywhere from 36% to 74% water. The advantage of soft contact lenses when compared with rigid gas permeable lenses is their ease of use and greater comfort for most people. A disadvantage of soft contact lenses is that proteins and lipids tend to form deposits on their surface. Moreover, these deposits together with the microorganisms inhabiting the overlying biofilm comprise the major factor leading to corneal diseases associated with contact lens wear. The microorganisms that are indigenous to the ocular tear film include bacteria and yeasts. Poor cleaning and disinfection of contact lenses, including the use of tap water, can lead to acanthamoeba infections of the cornea. The goal of the proposed studies is to examine ways to limit microbial adherence to these surface deposits and to the ocular biofilm. Our experimentation will involve the study of biofilm formation and the ability of a non-steroidal anti-inflammatory drug, sodium salicylate, to retard or alter biofilm formation on a hydrogel contact lens. We will also measure whether or not microbial growth in the biofilm and microbial adherence to the contact lens surface is reduced. Quantitative analysis of the data obtained will be performed using the Chi Square Test and Analysis of Variance (ANOVA),as well as by descriptive analysis. New information regarding the formulation for hydrogel contact lens design and disinfection systems may help to reduce the risk of infectious keratopathies.