An infection of toenail fungus, or onychomycosis, typically occurs when fungi (most commonly dermatophytes) infect the nail, but may also be caused by yeasts and molds. The nail fungal infection usually begins as a white or yellow spot under the tip of the toenail and then spreads deeper into the nail causing discoloration, thickening and the development of crumbling edges to the nail which can be unsightly and painful and may produce serious physical and occupational limitations. Onychomycosis can also have a detrimental effect on an individual's quality of life, affecting their psychosocial and emotional wellbeing.~Onychomycosis can be difficult to treat, and infections recur easily. Toenail fungus affects approximately 23 million adults (about 10%) in the United States. It is more common among older adults and tends to affect men more than women. Potential complications of onychomycosis include pain, permanent damage to the nails and serious infections that can spread beyond the feet.~Currently available treatments for onychomycosis include oral antifungal medications (Lamisil, Sporanox); antifungal nail polish (Penlac); topical over-the-counter antifungal creams; photodynamic therapy and in more severe cases, surgery to remove the nail. However, there is no perfect cure for toenail fungus. Even the most effective oral medications are only successful about half of the time, and topical medications are successful less than 10% of the time. In addition, clearance of the infection and growth of new clear nail can be slow, and the rate of recurrence of infection is high. Antifungal drugs may also cause side effects ranging from skin rashes to liver damage.~Therefore, the need for a more effective and lasting cure is evident. Recently, research has found laser therapy to show promise as a novel alternative treatment for toenail onychomycosis. Unlike medication-driven treatments, laser therapy presents minimal risk of side effects. Laser therapy is applied to toenail onychomycosis by shining a laser light through the toenail. The laser light vaporizes the fungus while leaving the skin and surrounding tissue unharmed.~Low level laser light therapy operates under the principle of photochemistry with a photoacceptor molecule absorbing the emitted photons and inducing a biological cascade. Like our eukaryotic cell, fungi contain the highly complex organelle the mitochondria, which is responsible for the manufacturing of the energy molecule Adenosine triphosphate (ATP). Within the inner mitochondrial membrane is cytochrome c oxidase, an identified photoacceptor molecule. It is believed that laser therapy could perhaps provide a means to photo-destroy the fungi responsible for onychomycosis by inducing the release of highly reactive superoxides. Moreover, laser therapy has been shown to promote superoxide dismutase (SOD), a process responsible for the destruction of foreign invaders. Extracellular release of low levels of mediators associated with SOD can increase the expression of chemokines, cytokines, and endothelial leukocyte adhesion molecules, amplifying the cascade that elicits the inflammatory response. The physiologic function of hydrogen peroxide, superoxide anion, and hydroxyl free radical is to destroy phagocytosed microbes. By enhancing the natural processes of the immune system and impacting the structural integrity of the fungi strain, it is believed that laser therapy may provide a means for clinicians to effectively treat onychomycosis without the onset of any adverse events.
The purpose of this study is to determine whether low level laser light therapy is effective in the treatment of toenail onychomycosis.