Light therapy for seasonal affective disorder in visual impairment and blindness - a pilot study.

OBJECTIVE Seasonal and non-seasonal depression are prevalent conditions in visual impairment. We assessed the effects and side effects of light therapy in persons with severe visual impairment/blindness who had recurrent depressive symptoms in winter corresponding to seasonal affective disorder (SAD) or subsyndromal SAD (sSAD). RESULTS We included 18 persons (11 with severe visual impairment, 3 with light perception, 4 with no light perception) who met screening criteria for sSAD/SAD in a single-arm, assessor-blinded trial of 6 weeks light therapy. In the 12 persons who completed the 6 weeks of treatment, the post-treatment depression score was reduced (p < 0.001), and subjective wellbeing (p = 0.01) and sleep quality were improved (p = 0.03). In 6/12 participants (50%), the post-treatment depression score was below the cut-off set for remission. In 4 participants with visual impairment, side effects (glare or transiently altered visual function) led to drop-out or exclusion. CONCLUSION Light therapy was associated with a reduction in depressive symptoms in persons with severe visual impairment/blindness. Eye safety remains a concern in persons with residual sight.