Lasers  Med Sci.  2013 Apr 24. [Epub ahead of print]

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

Marinho RR, Matos RM, Santos JS, Ribeiro MA, Ribeiro RA, Lima RC Jr, Albuquerque RL Jr, Thomazzi SM.


Departamento de Fisiologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristóvão, Sergipe, Brazil.


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.