The Role of Corneal Sensation in Facial Nerve Paralysis

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.

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.

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).

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.