Long-term efficacy and safety of carbon dioxide (CO2) array laser versus erbium-doped yttrium aluminum garnet (Er:YAG) laser for acne scars.

Abstract

Background: Acne vulgaris is a prevalent skin condition that often leads to facial scarring, significantly affecting patients' quality of life. Laser therapies, particularly carbon dioxide (CO₂) array laser and erbium-doped yttrium aluminum garnet (Er:YAG) laser, are widely used for acne scar management. This study aimed to compare the long-term efficacy and safety of these two laser systems for the treatment of acne scars.

Methods: A retrospective analysis was conducted on 254 patients with acne scars who were treated between January 2021 and January 2024. Among them, 124 patients received CO₂ laser treatment, while 130 received Er:YAG laser treatment. Clinical data encompassing demographics, scar improvement, inflammatory markers, and patient satisfaction, were collected over one year. Evaluations were based on Extended Cook's Corrected Acne Scarring (ECCA) scores, VISIA Skin Analysis, and Dermatology Life Quality Index (DLQI).

Results: Er:YAG laser demonstrated significantly lower intraoperative pain (VAS: 3.12 ± 0.23 vs. CO₂: 3.19 ± 0.21; P = 0.011) and shorter erythema resolution time (2.93 ± 0.64 vs. 3.11 ± 0.7 weeks; P = 0.029). Post-treatment INF-γ levels were higher in the Er:YAG group (853.68 ± 113.56 vs. 815.3 ± 120.28 pg/mL; P = 0.009). CO₂ laser showed superior long-term scar reduction (ECCA), with the most pronounced improvement observed at 12 months (39.84 ± 3.26 vs. Er:YAG: 41.31 ± 4.88; P = 0.005). VISIA analysis revealed better outcomes for CO₂ laser in pore size (7.55 ± 1.86 vs. 8.16 ± 1.14; P = 0.002) and porphyrins (81.33 ± 4.11 vs. 83.24 ± 5.24; P = 0.001). Treatment efficacy favored CO₂, with significantly lower ineffective response rates (5.65% vs. 16.92%; P = 0.017), although persistent erythema was more common with CO₂ (6.45% vs. 0.77%; P = 0.035). At 12 months, DLQI improvement was superior greater in the CO₂ group (11.25 ± 1.98 vs. 12.01 ± 2.02; P = 0.003).

Conclusion: The CO₂ laser demonstrated superior long-term efficacy for reducing acne scars compared to the Er:YAG laser, at the cost of increased persistent erythema. Conversely, the Er:YAG laser offered a better recovery profile with fewer adverse reactions.