Causes and prevention of Ptosis after Temporal muscle transfer in Lagophthalmos in the Patients with leprosy

Ahn, Sung Yul; Park, Hyang Joon; Kim, Jong Pill

Abstract

Facial nerve paralysis in leprosy adversely affects facial regions from the forehead to the lip. In particular, lagophthalmos in patients with leprosy causes exposure keratitis, corneal and conjunctival dryness which can progress blindness and disfigurement. The function of the eyelids is controlled by the oculomotor nerve and the facial nerve. In leprosy patients the oculomotor nerve continues to function causing the levator muscle to lift the eyelids. However, paralysis of the facial nerve prevents the orbicularis oculi muscle from closing the eyelids, resulting in lagophthalmos. Various methods were developed to correct lagophthalmos, one of which was temporal muscle transfer(TMT) reported in 1934 by Gillies. Since we noted relatively high occurrence of ptosis as a complication in patients treated previously with the TMT, we performed other surgical procedures for laglphthalmos over 15 years, not to make the ptosis. Although most of the patients quite improved post-operatively, partial lid-gap frequently persisted. It may be related to involutional changes and paralyzed orbicularis muscle. Recently, we conducted 4 different TMT methods for last 4 years to reduce ptosis. The methods used included Brown & McDowell, McCord & Codner, modified Gillies & Anderson, and modified Gillies. Seventy-five TMT operations in 60 patients(26 males and 34 females) were done between 2011 and 2014. The age range of the patients was 54~87 years(the mean was 70.1). Fifteen patients had bilateral TMT procedures. As a result, ptosis appeared in 14(18.7%) out of 75 TMT procedures for 4 years. Four technical points should be considered for the initial assessment to prevent or reduce the incidence of ptosis. The first is the increase of the length of temporalis muscle flap to approximately 8cm with a parallel course to the lateral canthus, which will reduce the oblique pull. Second, the width of the fascia sling in the upper eyelid is narrow(3~4mm) to reduce weight on the eyelid. Third, the fascia sling in the upper lid is not tied with that of the lower lid at the medial canthal tendon to reduce tension. Lastly, the fascia sling in the upper eyelid is shallow(subdermal level) in location and as near as possible to the lid margin.