Risk factors for visual impairment in facial nerve palsy
Reviewed by Hetvi Bhatt

Facial nerve palsy (FNP) is known to be associated with corneal exposure due to the nature of the condition, but how many of those will go on to develop severe visual impairment (SVI)? This study investigates the risk factors associated with SVI and ocular surface exposure by analysing electronic patient records of 1870 patients with facial nerve palsy. Underlying aetiology included: Bell’s palsy (68.9%), traumatic (12.9%), neoplastic (10.6%), congenital (3.1%), surgical (2.3%) and stroke (2.1%). Neoplasia, poor Bell’s phenomenon, and older age were significantly associated with ocular surface exposure. For SVI, significant factors included corneal scar, corneal ulcer, poor Bell’s, more than 10mm lagophthalmos, older age and male patient. Interestingly, patients with FNP of less than one year were more likely to have poor Bell’s and therefore higher rates of ocular surface exposure. The authors therefore suggest more frequent follow-up is required for these patients in the first year to reduce the risk of corneal damage. They have also found that presence of ectropion did not influence visual outcome. Unfortunately, the change in visual acuity from pre to post-FNP was not studied in this paper. This would have been useful to assess the true effect of each of the above-mentioned factors on SVI.

Ocular involvement in facial nerve paralysis: risk factors for severe visual impairment and ocular surface exposure in 1870 patients.
Singh S, Das AV, Ali MH.
ORBIT
2022 July; Epub ahead of print.