Comparing outcome criteria performance in adult strabismus surgery.

PURPOSE: To evaluate the performance of motor, diplopia, and health-related quality of life (HRQOL) criteria when analyzing outcomes of adult strabismus surgery.

DESIGN

Cohort study.

PARTICIPANTS

We studied 159 adults undergoing 171 strabismus surgeries.

METHODS

All patients underwent clinical assessment preoperatively and 6 weeks postoperatively, including completion of Adult Strabismus-20 HRQOL questionnaires. Preoperatively, strabismus was classified as either diplopic (n = 117), nondiplopic (n = 38), or atypical diplopic (n = 16). To assess performance of motor, diplopia, and HRQOL criteria, success was defined a priori and applied separately and in combinations. For success: (1) motor criteria, <10 prism diopters by simultaneous prism cover test; (2) diplopia criteria, none or only rare in primary distance and for reading; (3) HRQOL criteria, exceeding previously reported 95% limits of agreement (LOA).

MAIN OUTCOME MEASURES: Surgical success rate when applying motor, diplopia, and HRQOL criteria alone and in combinations.

RESULTS

Overall, success rates were 90% for motor criteria, 74% for diplopia criteria, and 60% for HRQOL criteria. Combining criteria, the highest success rate was for motor plus diplopia criteria (67%) and the lowest success rate was when combining motor, diplopia, and HRQOL criteria (50%).

CONCLUSIONS

Applying motor criteria alone yields the highest success rates when evaluating outcomes in adult strabismus surgery, but motor criteria do not fully represent the patient's postoperative status. Combining diplopia criteria with motor criteria provides a more clinically relevant standard for judging the success of adult strabismus surgery. For HRQOL criteria, exceeding 95% LOA at 6 weeks postoperatively seems to be a difficult hurdle to clear for some individual patients, and evaluating change in HRQOL score may be more useful in cohort studies.