Noninvasive detection of collagen regeneration after an isotretinoin treatment and ablative laser surgery in patients with acne scars by Raman spectroscopy

Background: To the date, oral isotretinoin is the most effective treatment for acne scars, and by combining their use with an ablative surgery results in improving the effects of the skin restoration. However, it is highly recommended by dermatologists, to wait for a period of 6 months between the isotretinoin treatment and the laser surgery, and that relative high period of time can lead to negative effects like anxiety or psychological distress in the patients. Our objective is to demonstrate that combining an ablative laser surgery and an isotretinoin treatment at therapeutic doses improves the acne wound healing in a considerably short period of time in comparison with previous studies. Additionally, it is of our interest to evaluate the wound healing due the collagen regeneration by the use of Raman spectroscopy, recently used as a non-invasive medical tool for skin diseases. Method: The study was performed in 9 patients who underwent on an oral isotretinoin treatment due to the presence of acne scars on the face. All patients received one single treatment with a CO2 Ablative Fractional Laser (AFL) on four zones of the face within a range of four weeks after isotretinoin treatment. Additionally, an untreated measurement in the elbow side of the arm acted as a control. Both treatments, the isotretinoin and the ablative surgery, were performed by the same dermatologist. The patients were evaluated by means of Raman spectroscopy before and after the treatment and for the data processing, two different statistical approaches were applied to the Raman spectra with the objective to assess the presence of a specific collagen type. Results: The patients showed normal wound healing post AFL treatments and it was shown that with a therapeutic dose of oral isotretinoin and with one single laser surgery in a relative short period of time, a collagen regeneration was observed. Conclusion: When combined AFL surgery and isotretinoin treatment at therapeutic doses, a regeneration of a type of collagen is observed, which is quantified non-invasively by Raman spectroscopy.