EPOS
European Paediatric Ophthalmological Society
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How to Avoid Ptosis after Botulinum Toxin Injections in Treatment of Childhood Strabismus
Bodla Ali11University Hospital, Coventry, UK
Introduction:We compare the incidence of ptosis in childhood strabismus treated in either supine or sitting up position under ketamine anaesthesia. Methods:A retrospective, interventional and comparative case series with a total of 9 patients. Age at the time of presentation ranged from 9 to 108 months. Acute onset exotropia was found in 3 (33%) patients while rest (66%) had a diagnosis of infantile esotropia. Group A(55.5%) had BTXA injection in supine while group B (44.4%) had same treatment in sitting up posture under ketamine anaesthesia. Same position was assured post treatment in group B for 90 minutes post treatment. Main measured outcomes were pre and post treatment visual acuity, angle of deviation and incidence of ptosis. Extent of ptosis was consistently recorded in clinic visits. Results:BTXA injections were effective in reducing the mean preinjection deviation of 45 PD to 17PD. Four patients (44.4%) required more than one injection while two (22%) latter had surgical correction. One patient (11%) did not had any effect of BTXA on ocular deviation despite of consecutive injections. Overall 3 patients from Group A (60%) developed ptosis while no one from Group B had this complication. Though ptosis was transient with complete resolution in 2 months, it was significant with the lid drooping to 5 mm in 2 patients(66.6%) covering visual axis for approximately 2 weeks. In no case did any degree of ptosis-related amblyopia ensue. Conclusion:Botulinum toxin is an effective, rapid and less invasive treatment modality in childhood strabismus. Reduction in ocular deviation is significant which helps preserve the binocular potential. A significant noumber of patients require more than one injection in order to achieve an acceptable alignment. Treatment was equally effective in infantile esotropia and exotropias. Ptosis was the most frequent complication because, without patient co-operation to move the eyes to record a strong EMG signals, the localisation of recti is less accurate resulting in levator infiltration while in supine position. Ptosis can be avoided with carrying the procedure in a sitting position. Optimum posture can be achieved by positioning the patient in a child’s car seat during the procedure as done in our regular practice.