There are currently 120 million contact lens wearers worldwide who are susceptible to sight-threatening infections caused by microorganisms such as bacteria, fungi, and amoeba. There are a variety of chemical disinfection techniques that are commonly used. However, each type has its own advantages and disadvantages. Ultraviolet radiation alone is sufficient for disinfection of most microorganisms but only at doses high enough to cause damage to the lens material.
The antimicrobial effect of UV radiation is enhanced by compounds such as riboflavin, or vitamin B2, a naturally occurring compound and an essential human nutrient, that absorbs UV light and converts it into free radicals. The free radicals are highly reactive against the cell membranes and DNA of infectious organisms that contaminate contact lenses when they come into contact with the eye. Through my research, a combined UV and riboflavin contact-lens disinfection system was created based on the concept that inclusion of riboflavin would significantly reduce the required dose of UV required to kill microorganisms and the risk of affecting the optical properties of the contact lens polymer. This novel lens disinfection method led to the design of a riboflavin and oxygen-enhanced ultraviolet contact lens rapid disinfection device that is more effective at removing bacteria from contact lenses than conventional systems while reducing toxicity to the contact lens and the eye.
What inspired you (or your team)?
In my life, contact lenses have played a significant role as they have enabled me to perform better in my academics and athletics. As I got older, I became an accomplished athlete, but due to my astigmatism, sharp visual acuity would not have been possible without contact lenses. Learning to insert lenses myself was a challenge that was not going according to plan. I had to learn to control my eyelids’ strong protective reflex to close like a clam when the lens approaches. It was taking an eternity to get them in, creating stress. As a result, I mistakenly inserted a lens without neutralizing the peroxide disinfectant solution, causing searing pain in my eye. The chemical burn motivated me to learn more about current contact lens disinfection technology. My research revealed that current methods are not uniformly effective against the wide range of different microorganisms that cause sight-threatening infections, and are also toxic to the delicate surface of the eye. There are many cases of vision-threatening eye injuries every year related to these deficiencies and as many as one million U.S. health care visits for keratitis or contact lens complications occur annually, at a cost of $175 million. This discovery motivated me to develop a method and device that would be a more broadly effective lens disinfectant that would not risk eye injury.