Protective ptosis by botulinum A toxin injection in corneal affectations

Abstract

Botulinum toxin A has been introduced as a local injection therapy of different conditions with focal muscular hypercontractions. In the ophthalmologic field the toxin has proven its efficacy in the therapy of blepharospasm and hemifacial spasm. There are only few reports on the use of a botulinum toxin A to induce a protective ptosis in patients with persistent corneal ulcers. 21 patients who failed to respond to conservative therapy of corneal erosions or ulcers of different origin received a botulinum toxin A injection into the levator palpebrae superioris muscle. The ptosis began after a mean of 1.5 days (1-3 days) and was complete after a mean of 5.1 days (3-12 days) after injection. Complete recovery of the levator function could be observed after a mean of 12.4 weeks (4-24 weeks). In 13 patients (61.8%) the botulinum toxin A induced protective ptosis lead to a complete healing of indolent ulcers or erosions, in 4 patients (19%) an additional tarsorrhaphy was necessary. In 3 patients no healing could be observed during follow up, in one patient (with neuroparalytic ulcer) the injection was given prophylactically. The period of healing on average was 3.8 weeks. There was no relationship between the healing rate and the duration of the corneal disease prior to the botulinum toxin injection. The mean healing rate of younger patients was higher (75%) than that of older patients (53.8%) and higher in erosions (70%) than in ulcers (30%). No side effects were observed besides in one patient the undesirable duration of the ptosis of a half year. The induction of a protective ptosis with botulinum toxin A injection is an efficacious treatment alternative in persistent corneal erosions and ulcers before performing a tarsorrhaphy. This method is preferrable especially in patients with lagophthalmos due to facial nerve paresis with potential recovery.