The House-Brackmann system and assessment of corneal risk in facial nerve palsy.

PURPOSE: The House-Brackmann (HB) facial nerve grading system is widely used by ENT/head and neck surgeons, but is perhaps of less value to the ophthalmologist. Our aim was to assess the value of the numeric portion of this system in identifying those patients with facial nerve palsy who are at risk of corneal complications. We also sought to identify other factors that might be predictive of such complications.

METHODS

Forty-two patients (43 palsies) were studied prospectively. The HB grade was recorded together with measurements of levator function, upper lid closure, Bell's phenomenon, lagophthalmos, ectropion, lower lid retraction and corneal sensation. Conjunctival injection and corneal staining were also graded. ROC (receiver operating characteristic) curves were used to assess the value of each parameter as a screening test for corneal complications.

RESULTS

There was no cut-off of HB grade, levator function, Bell's phenomenon, ectropion or lower lid retraction that was sufficiently sensitive and specific to screen for corneal complications. However, on assessing lagophthalmos and upper lid closure, cut-offs with more favourable sensitivities and specificities were identified.

CONCLUSIONS

The numeric portion of the HB grading system is not a useful guide in identifying those patients with facial nerve palsy who are at risk of corneal complications. Measurements of lagophthalmos and upper lid closure, alone or in combination with other tests, may be of more value.