Major Complications following Strabismus Surgery: Nine-year Data from the IRIS® Registry.

PURPOSE: We aimed to identify occurrence rates and associated risk factors of major complications after strabismus surgery in a large cohort. DESIGN: This is a retrospective analysis of patients from the IRIS® Registry (Intelligent Research in Sight) undergoing strabismus surgery over a 9-year period. PARTICIPANTS: The subjects were 89 339 patients who underwent surgery on 134 635 eyes between January 1, 2013, and December 31, 2021, and experienced a major complication within 60 days of the procedure. METHODS: We analyzed subjects' diagnostic and procedural codes for eye muscle surgical procedures and postoperative occurrence of bacterial keratitis, orbital infection, endophthalmitis, and surgery for lost or slipped muscle. MAIN OUTCOME MEASURES: Primary outcomes were frequency of occurrence of complications and any associated risk factors. Secondary measures included temporal profiles of presentation and visual outcomes at 60 days postoperatively. RESULTS: One or more of the 4 surveyed complications occurred in 0.115% of patients. Corneal ulcers and orbital infection occurred in 0.03% each, endophthalmitis occurred in 0.01%, and lost or slipped muscle occurred in 0.04%. Increasing age was associated with every complication except orbital infection. Independent risk factors for any complication were combined vertical and horizontal muscle surgery (as opposed to horizontal or vertical alone) and number of add-on procedural codes. Female sex and age >65 years were independent risk factors for endophthalmitis. Approximately half of the cases of endophthalmitis and orbital infection presented within 5 days of surgery. Visual loss was present in a majority of patients with complications. Mean visual loss in endophthalmitis was 0.58 logarithm of the minimum angle of resolution and averaged 0.11 logarithm of the minimum angle of resolution in the other complications combined. CONCLUSIONS: These data will allow physicians to obtain a more comprehensive informed consent for strabismus surgery. We recommend a postoperative assessment within 5 days of surgery to identify major complications as early as possible. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.