Dependence of clinical signs of paralytic lagophthalmos on level and duration of facial palsy

Abstract

The path of the facial nerve is associated with multiple nerves, bones and soft tissues, including n. trigeminus, n. intermedius, petrosal bone and parotid gland. Due to this fact, facial palsy results not only in lagophthalmos but also in dysfunction of tear production and even vision lost in some cases. The aim of the study is to compare clinical signs of lagophthalmos in patients with various levels and duration of facial palsy. We analyzed 120 cases of lagophthalmos in patients aged 5–90 y.o. with duration of facial palsy from 2 month to 90 years. The patients were divided into 4 groups according to the level of nerve damage: 1 – in the cerebral part of the nerve, 2 – in petrosal bone, 3 – in the area of parotid gland, and 4 – indefinite. The light forms of keratopathy were dominant in all of the groups (72.5 %). There was a very weak correlation between the duration of facial palsy and margin to the low limb distance (r = 0.190; p < 0.05). The width of the eye fissure was significantly different between 1st and 3rd groups (p = 0.019), 1st and 4th groups (p = 0.042), 2nd и 3rd (p = 0.038), 2nd and 4th (p = 0.043). Although the results of Schirmer 1 tests was significantly different only between 1st and 3rd groups (p < 0.001). Severity of clinical signs in paralytic lagophthalmos depends in most on the level of facial nerve damage and can be due to concurrent damage of n. trigeminus. The duration of the facial palsy and involvement of n. intermedius do not play any significant role. Keywords: n. facialis, n. trigeminus, n. intermedius, neurotrophic keratopathy, exposure keratopathy, exposure keratitis