Strabismus in adults with uveal melanoma following episcleral plaque brachytherapy

PurposeTo ascertain the incidence of persistent strabismus in patients treated with plaque brachytherapy and its subsequent treatment.MethodsA single center retrospective case note review of adult patients with persistent diplopia or strabismus following plaque brachytherapy for all types of intraocular tumors between 1996 and 2004.ResultsA total of 929 consecutive adults underwent plaque brachytherapy during the study period at a single center. Sixteen patients (1.7%) with treated uveal melanoma developed persistent diplopia or strabismus. In 11 patients (69%) the timing of onset was in the first year, in 2 (13%) in the second year, and one each (6% each) in years 5, 7, and 8. Two patients (13%) did not require any intervention. Fourteen patients (88%) required treatment: 7 (50%) were treated with prisms only, 3 (21%) underwent botulinum toxin (BTXA) injections, and 4 (29%) were treated with extraocular muscle surgery (3 required one operation and one required 2 procedures).ConclusionsThe incidence of ocular motility disorders following plaque brachytherapy in our cohort was 1.7% over 8 years and we include this in the consent process for conservative treatment of intraocular tumors. Options for treatment for persistent diplopia or strabismus include prisms, botulinum toxin injection, or surgery.