2.1 Study subjects
Patients with hoarseness as their chief complaint undergoing laryngoscopy from January 2009 to December 2020 were selected. Patients with vocal cord leukoplakia were included. All patients had a definite pathological diagnosis. The exclusion criteria were as follows: (1) patients with obvious cauliflower or ulcerative masses, polyps, cysts, Reinke’s edema, and papilloma on the surface of vocal cords; (2) lesions without definite pathological diagnosis; (3) patients with low-quality laryngoscope images that did not meet the requirements for morphological assessment; and (4) patients with lidocaine allergy, severe uncontrolled dyspnea, unstable angina, uncontrolled hemorrhagic disease, or the inability to understand and sign informed consent. This study was approved by the Medical Ethics Committee of the hospital. All patients provided written informed consent before the examination.