Stroboscopy versus high-speed glottography: A comparative study

Objectives: To evaluate and to compare the diagnostic value of videostroboscopy (VS) and high-speed glottography (HGG) in dysphonic patients. Study Design: Randomized, prospective study. Methods: A total of 162 patients underwent indirect laryngoscopy using both methods (VS and HGG). The resulting 324 films were evaluated by two professionals (laryngologists, MDs) using a standardized protocol containing established criteria to classify vocal fold vibratory movement qualities. Results: The rating "not assessable" was mentioned significantly more often in VS than in HGG (P <.001). In HGG, methodologic failures were less frequent, and the length of investigation was shorter. Even if the agreement between the two raters was higher in HGG (54%) compared with VS (42%, both percentage values show a low accordance in diagnostic findings. Conclusions: Regardless of the method used (VS or HGG), perceptive evaluations of vibratory movements of vocal folds revealed a higher variability than assumed. This result supports the need for objective methods to analyze vocal fold vibratory movements. Therefore, realtime imaging of vocal fold vibratory movements using HGG will be necessary.