High fluence in laser stapedotomy aggravates transient subjective dizziness.

Background: Laser fenestration in stapedotomy has thermal effect to the vestibule.

Aims/objectives: To evaluate the role of energy density (fluence) in the severity of postoperative vestibular symptoms.

Materials and methods: The retrospective chart-review study included 84 patients with otosclerosis that underwent primary laser stapedotomy. Surgical outcomes, including nystagmus, and subjective vestibular symptoms during one-month follow-up, were compared between potassium titanyl phosphate (KTP) and CO₂ laser. According to this study and literature, we assessed the relationship between laser parameters and the incidence of persistent vestibular symptoms lasting more than one week after surgery.

Results: The KTP and CO₂ laser group included 48 and 36 patients, respectively. Fluence was different between the KTP (637 J/cm²) and CO₂ (141 J/cm²) laser (p < .001). The KTP group showed gradual decrease in dizziness during one-month observation period, while the CO₂ group exhibited a steep recovery curve in the first postoperative week (9 and 4 d of duration, respectively). The incidence of persistent vestibular symptoms was correlated with both fluence (r = 0.80, p = .01) and spot size (r = -0.74, p = .01).

Conclusions and significance: Appropriate setting of parameters with lower fluence is desirable for the efficiency and safety of laser stapedotomy.Abbreviations: ABG: air-bone gap; SD: standard deviation.