Potential anti-inflammatory effect of low-level laser therapy on the experimental reflux laryngitis: a preliminary study

The most common cause of laryngitis is the laryngopharyngeal reflux disease. The symptoms of laryngitis can be hoarseness, globus, chronic cough, voice fatigue, throat pain, and dysphagia. Low-level laser therapy (LLLT) is beneficial to reduce the pain and inflammatory response without side effects. Therefore, LLLT may be a useful tool for the treatment of laryngitis. This study proposes to analyze the effect of laser therapy in a model of reflux-induced laryngitis. The animals were randomly put into three groups: control—non-intubated; nasogastric intubation—intubated; and nasogastric intubation with laser therapy—intubated treated with 105-J/cm² laser irradiation. For the induction of laryngitis, the animals were anesthetized and a nasogastric tube was inserted through the nasopharynx until it reached the stomach, for 1 week. Thereafter, measurement of myeloperoxidase activity and the histopathological procedures were performed. In conclusion, we observed in this study that 105-J/cm² infrared laser reduced the influx of neutrophils in rats, and it improved the reparative collagenization of the laryngeal tissues.