The Role of Corneal Sensation in Facial Nerve Paralysis

PURPOSE: Patients with facial nerve paralysis (FNP) can have corneal decompensation resulting in poor visual outcomes. Here, we measure the associations between clinical parameters and corneal epitheliopathy in FNP. METHODS: In this cross-sectional cohort study, FNP patients from a 6-year period were reviewed. Etiology of FNP, visual acuity, grade of corneal epitheliopathy, and corneal sensation were recorded. Multivariate analysis was completed to assess the association between severe epitheliopathy and 4 ocular protective mechanisms: corneal innervation, House-Brackmann orbicularis score, Bell's phenomenon, and lagophthalmos. RESULTS: Forty patients (mean age 58.7 years) were included: 38% had an underlying central etiology, while 22% had peripheral causes and 40% Bell's palsy. Mean logMAR visual acuity on the ipsilateral side of FNP was 0.49. Severe epitheliopathy was identified in 18%. However, 35% of patients had decreased corneal sensation. Best corrected visual acuity was worse in patients with severe corneal epitheliopathy (p = 0.0003), and the rate of decreased corneal sensation was 4 times higher than in patients with normal corneas (p = 0.001). Multivariable analysis demonstrated a significant association between severe epitheliopathy and decreased corneal sensation (odds ratio [OR] = 14.97; p = 0.04), but not with House-Brackmann grading (OR = 1.86; p = 0.31), poor Bell's phenomenon (OR = 7.19; p = 0.13), or lagophthalmos (OR = 0.99; p = 0.95). Compared with patients with normal corneal sensation, those with reduced sensation had worse best corrected visual acuity and degree of corneal epitheliopathy (p = 0.005, p = 0.0003). CONCLUSIONS: Reduced corneal sensation was the most significant independent predictor of severe corneal epitheliopathy. Corneal sensitivity can affect visual outcomes and is an important variable to measure in patients with FNP.