The psychosocial aspects of strabismus: correlation between the AS-20 and DAS59 quality-of-life questionnaires

To compare two quality-of-life (QoL) scales and subscales: the Derriford Appearance Scale 59 (DAS59) and the Adult Strabismus-20 (AS-20) scale in a series of strabismic and nonstrabismic patients and to illustrate the differences in results between strabismic and nonstrabismic patients.

The DAS59 is a self-report QoL questionnaire generating an assessment of distress caused by problems of appearance. The AS-20 is a newly developed strabismus specific QoL scale. A prospective, noninterventional study of a series of consecutive adult patients undergoing strabismus surgery and a control group was performed. Patients were given both questionnaires to complete before surgery. The underlying condition, previous number of surgeries, and deviation measurements were recorded.

Thirty-four patients and 30 controls correctly completed both questionnaires. In the strabismus group, the mean AS-20 score was 50.5. The mean DAS59 score was 122.5 (out of 269). There is strong correlation between the scales (r = -0.813; 95% CI, -0.90 to -0.66; p < 0.0001). In the control group, the AS-20 score was 98.8 and the DAS59, 84.4, with both showing significant differences to the strabismic group (t = 12.9 [p < 0.0001] and t = -4.642 [p < 0.0001], respectively).

The AS-20 shows strong correlation to the widely used DAS59. Strabismus patients show significantly more psychosocial distress than controls. The AS-20 is specific to strabismus patients and the result is not influenced by any other systemic factors that can impinge on the more general DAS59 scale.