Local and systemic effects of low-level light therapy with light-emitting diodes to improve erythema after fractional ablative skin resurfacing: a controlled study

Therapy with light-emitting diodes (LED) has been associated with the reduction of erythema and accelerated wound healing. LED phototherapy has been used in various clinical practices including post-laser wound healing enhancement. Fractional laser resurfacing is one of the popular dermatological procedures; however, the duration and degree of downtime may limit daily life activity and studies on the effect of LED low-level light therapy (LED-LLLT) on post-ablative laser wound care are still limited. To evaluate local and systemic effects of LED-LLLT on post-ablative laser erythema and wound healing acceleration after fractional ablative laser resurfacing. The study was divided into two arms. First, a prospective split-face randomized controlled and single-blinded study involved 17 patients (split-face group) to determine the local and systemic effect of LED-LLLT. Patients with acne scars or rhytides were treated with a single session of fractional CO₂ laser followed by 830/590 nm LED-LLLT on one side of their faces. The duration of post-laser erythema, the erythema index, and transepidermal water loss were collected at baseline, and compared with 7-daily follow-up visits posttreatment for the non LED- and LED-treated sides. The second controlled arm of the study was performed on an additional 19 subjects (CO₂ group). The patients received a single fractional CO₂ laser treatment without any LED-LLLT with the same follow-up protocol. All measurements were compared with the results from the patients from the split-face group. In the split-face group, the duration of erythema post laser was equal (7.4 ± 2.8 days). No significant reduction in the erythema index and transepidermal water loss was seen in the LED-treated vs the non-treated side (p values = 0.99 and 0.78 respectively). For the second part of the study that compared the results between the split-face group and the control CO₂ only group, the duration of the post-laser erythema was comparable (p value = 0.32). However, the percentage difference of the erythema index from baseline in the split-face group was significantly lower than the CO₂ group on days 1, 4, 5, and 7 post-laser treatment (p value = 0.03 on days 1, 4, 5, and 0.04 on day 7) and the LED-treated side provided the lowest percentage difference of the erythema index followed by the non LED-treated side compared with the control CO₂ only group. 830/590 nm LED-LLLT may provide both local and systemic effects on the degree of post-ablative laser erythema in human skin, however, appropriate protocol settings should be considered to achieve a significant clinical outcome.