Adverse events were reported in 4 s

Adverse events were reported in 4 studies. One study22 observed an asymmetrical smile on day 7 postoperatively.One study17 reported local pain and pruritus in the BTXA group, and the adverse events rapidly disappeared without special treatment. One study23 reported that 1 patient in the control group had mild headaches during the 6-month follow-up. One study13 reported a mild drooping lid on the third day after BTXA injection. The drooping distance of the eyelid was approximately 0.5 mm compared with that in the control group; the affected patient was diagnosed with mild blepharoptosis. Symptoms gradually resolved within 6 weeks without any treatment.