Abstract
Purpose:
The Adult Strabismus-20 (AS-20) questionnaire assesses health-related quality of life (HRQOL) in patients with strabismus. We have previously reported improvement in HRQOL following successful strabismus surgery, but we are unaware of previous studies that have quantified changes in HRQOL in response to prism. We now compare HRQOL in diplopic patients successfully and unsuccessfully treated with prism.
Methods:
To assess response to prism, we specifically selected patients who presented with diplopia rated as “sometimes” or worse, for reading and/or distance straight ahead, and who completed the AS-20 questionnaire and diplopia questionnaire (DQ) at clinic examinations both prior to prism correction and in prism correction. Prism treatment success was defined as diplopia rated as “never” or “rarely” for reading and distance straight ahead. As controls, prism treatment failures were defined as having worse diplopia, or no change in diplopia, for reading and/or distance straight ahead. For both successes and failures, AS-20 scores (from 100 to 0, best to worst HRQOL) were compared pre- to post-treatment, using signed rank tests. Each of the four Rasch AS-20 subscales (Self-perception, Interaction, Reading Function and General Function) were analyzed separately.
Results:
Twenty-four (67%) of 36 included patients met our criteria for success and 12 (33%) were failures. For successfully treated patients, Reading Function improved from 58.9 to 70.3 (difference: 11.5, 95% CI 2.9, 19.9; p=0.02) and General Function improved from 67.2 to 80.9 (difference: 13.7, 95% CI 4.7, 22.7; p=0.003). Self-perception and Interaction subscale scores remained unchanged (p>0.2 for both). For prism failures, there were no significant changes in AS-20 scores on any of the four subscales (p>0.3 each).
Conclusions:
Successful treatment of diplopia with prism was associated with improvement in strabismus-specific HRQOL, in Reading Function and General Function domains. HRQOL remains unchanged in patients for whom prism treatment was unsuccessful, indicating there was no placebo effect from treatment. In addition, our study further confirms the responsiveness of the AS-20 HRQOL questionnaire to successful treatment of strabismus.
Keywords: 722 strabismus •
669 quality of life