Role of botulinum toxin A in surgically overcorrected exotropia

Purpose: The purpose of this study was to define the role of botulinum toxi n type A (BTXA) in surgically overcorrected exotropia. Methods: A retrospec tive review was performed using the BTXA clinic database of more than 3500 patients to identify patients with a consecutive esotropia, Results: Sixty patients met the inclusion criteria; the patients' ages ranged from 5 to 80 years. Before toxin treatment, an average of 1.8 operations had been perfo rmed per patient, The mean distance deviation was 17 PD base out and near d eviation was 18 PD base out. The time from the last operation to an injecti on of BTXA averaged 28.3 months. We divided our patient population into 2 g roups: those with fusion potential and those with no expected fusion potent ial. Of the 36 patients with fusion potential, 15 patients achieved and mai ntained good ocular alignment and resolution of their diplopia with an inje ction of BTXA, In the 24 patients with no expected fusion potential, 4 pati ents (17%) achieved and maintained good alignment with an injection of BTXA . Although they were not cured, 10 additional patients chose to have repeat ed BTXA injections to maintain their ocular alignment, whereas only 2 patie nts required occlusive methods to eradicate intractable diplopia, Five pati ents had additional surgery, of which 3 patients obtained a functional resu lt, Conclusions: BTXA has a role in surgically overcorrected exotropia for patients in whom a functional result may be obtained, BTXA is of less value for patients with poor binocular function. It has proved especially useful as a treatment given only once for 42% of patients who could regain high-q uality stereopsis. The safety and ease of administration of this treatment add to its merit.