The subject's neck thyroidectomy incision was bisected along the anterior midline. One side received 1565 nm non-ablative fractional laser treatment, designated as the study side, according to a computer-generated randomization scheme, while the other side received a sham treatment (the laser device emitted sound only, without delivering any energy), serving as the control side. Outcome indicators were recorded during follow-up, along with any related adverse events and/or reactions occurring during and after the treatment. The aim was to evaluate the effectiveness and safety of the 1565 nm non-ablative fractional laser in the treatment of postoperative thyroid scars.

Inclusion Criteria:

1. The patient is conscious, with no intellectual disability or cognitive difficulties, and understands and signs the informed consent form.
2. Healthy male and female subjects aged 18 to 70 years.
3. Fitzpatrick skin types I to V.
4. Women of childbearing age have used contraceptive measures within three months before enrollment.
5. The patient has undergone traditional thyroidectomy through the anterior neck approach within 15 days, with a surgical incision visible in the midline of the neck, symmetric along the anterior midline of the body surface; or the patient has undergone traditional thyroidectomy through the anterior neck approach within one year, with a linear hypertrophic surgical scar visible in the midline of the neck, symmetric along the anterior midline of the body surface.
6. The patient is able to comply with all the plans and requirements for visits, treatments, and assessments.requirements.

Exclusion Criteria:

1. Need for modified radical neck dissection or reoperation, or other surgical plans that may affect treatment and follow-up during the trial period;
2. Previous neck surgery;
3. Pregnant, planning to become pregnant during the study period, less than three months postpartum, or less than six weeks after completing breastfeeding;
4. History of keloid or delayed wound healing;
5. Uncontrolled systemic diseases;
6. History of mental disorders;
7. Presence of skin tumors or skin inflammation in the treatment area;
8. Active infection in the neck area or systemic infection;
9. Use of oral photosensitizing drugs or retinoids within six months before screening;
10. Use of anticoagulants, corticosteroids, immunosuppressants, or other drug treatments within three months before screening;
11. Exposure to strong ultraviolet radiation causing desquamation, erythema, or other conditions in the neck within one month before screening;
12. Participation in other drug/medical device clinical trials within one month before screening or planned participation during the study period;
13. Use of any other treatment methods for post-thyroidectomy scars except for silicone gel sheets and topical drugs before and during treatment;
14. Use of silicone gel sheets and topical drugs for post-thyroidectomy scars within seven days before starting treatment;
15. Patients allergic to compound lidocaine cream or its components, and no alternative to this drug is available;
16. Patients who, in the investigator's opinion, have other conditions that may affect compliance or are not suitable for participating in this study.