The role of meibomian gland dysfunction on the development of dry eye disease in patients with facial nerve palsy.

PURPOSE To investigate whether meibomian gland dysfunction is the cause of dry eye in facial nerve palsy and to identify the possible relationship between the grades and durations of facial nerve palsy and meibomian gland dysfunction. METHODS This prospective observational study included 63 patients with unilateral facial nerve palsy. Facial nerve function and severity were assessed using the House-Brackmann grading system. Unaffected contralateral eyes were used as the control group. The following parameters were compared: tear breakup time, Schirmer 1 test score, area and density scores for corneal fluorescein staining, eyelid abnormality, meibomian gland expression, meibography scores, and areas of meibomian gland loss. A Pearson correlation analysis was performed between the grades and durations of facial nerve palsy and meibomian gland dysfunction. RESULTS The eyes affected by facial nerve palsy demonstrated significantly lower tear breakup time (p<0.001) and significantly higher values for corneal fluorescein staining (p<0.001), Schirmer 1 test score (p=0.042), lid abnormality score (p<0.05), meibomian gland expression level (p=0.005), meibography scores (p<0.05), and areas of meibomian gland loss (p<0.05). The grade and duration of facial nerve palsy significantly correlated with meibomian gland dysfunction (p<0.05). CONCLUSIONS Meibomian gland dysfunction has a significant contribution to the development of dry eye disease after facial nerve palsy. Furthermore, a strong correlation was observed between the grades and durations of facial nerve palsy and meibomian gland dysfunction.