Comparative appraisal with meta-analysis of erbium vs. CO₂ lasers for atrophic acne scars

Recent advances in laser technology allowed the development of systems that improve texture, appearance and pliability of skin in acne scars (AS). Currently, comprehensive comparative studies on the efficacy of the most commonly used fractional systems in AS are lacking. Thus, the aim of this work was to appraise and compare the clinical response to erbium versus CO₂ lasers in AS in the form of a meta-analysis. The databases MEDLINE, EMBASE, Cochrane library were searched. Main clinical outcomes were investigator-reported scar improvement and participant-reported scar improvement. Five studies were included in this meta-analysis. Scar improvement was similar for both types of laser in terms of investigator-reported scar improvement (RR: 0.60 95 % CI: 0.35-1.02) and participant-reported scar improvement (RR: 0.99 95 % CI: 0.79-1.25). A sensitivity analysis that excluded studies with high risk of bias found the CO₂ lasers to be superior to the erbium lasers (RR: 0.47 95 % CI: 0.24-0.93): However, the subgroup analysis showed the CO₂ laser not to be significantly different from either the non-ablative erbium (RR: 0.65 95 % CI: 0.34-1.24) or the ablative erbium laser (RR: 0.60 95 % CI: 0.35-1.02). The CO₂ laser produced a slightly greater clinical response compared to the erbium lasers based on the physician's assessment. Overall, the two devices do not differ largely in terms of efficacy but may be complementary, with each resurfacing laser better suited for different clinical tasks.