Incorporating Health-related Quality of Life Into the Assessment of Outcome Following Strabismus Surgery

Purpose: To evaluate changes in health-related quality of life (HRQOL) in adult strabismus patients classified as surgical failures by standard motor and diplopia criteria. Design: Prospective cohort study evaluating outcomes. Methods: Adults undergoing strabismus surgery in a single clinical practice, with preoperative and 1-year-postoperative Adult Strabismus-20 HRQOL questionnaires, were included. Motor and diplopia criteria were applied to classify outcomes (success, partial success, or failure). For those classified as failure, the medical record of the 1-year examination was reviewed to determine whether the patient reported subjective improvement. We evaluated improvement in HRQOL, defined as exceeding 95% limits of agreement on at least 1 of the 4 Adult Strabismus-20 domains. We compared proportions exceeding 95% limits of agreement in those reporting subjective improvement vs those who did not. Results: Forty of 227 patients (18%) were classified as failure by motor and diplopia criteria, with 39 of 40 able to exceed Adult Strabismus-20 95% limits of agreement. Overall, 21 of 39 (54%) showed improved HRQOL by exceeding 95% limits of agreement on at least 1 of the 4 Adult Strabismus-20 domains (54% vs predicted 10% by chance alone; P <.0001). Twenty-five patients (64%) reported subjective improvement, of whom 16 (64%) showed improved HRQOL exceeding 95% limits of agreement. Conclusions: Many apparent surgical failures report subjective improvement, often reflected in improved HRQOL scores. We propose incorporating quantitative HRQOL criteria into the assessment of strabismus surgery outcomes, defining success as either meeting motor and diplopia criteria or showing improvement in HRQOL beyond test-retest variability.