Fractional Erbium laser in the treatment of photoaging: randomized comparative, clinical and histopathological study of ablative (2940nm) vs. non-ablative (1540nm) methods after 3 months.
BACKGROUND
Fractional non-ablative lasers keep the epidermis intact, while fractional ablative lasers remove it, making them theoretically more effective.


OBJECTIVE
To evaluate the clinical and histological alterations induced by fractional photothermolysis for treating photoaging, comparing the possible equivalence of multiple sessions of 1540nm Erbium, to one session of 2940nm Erbium.


METHODS
Eighteen patients (mean age 55.9) completed the treatment with three sessions of 1540nm fractional Erbium laser on one side of the face (50 mJ/mB, 15ms, 2 passes), and one session of 2940nm on the other side (5mJ/mB, 0.25ms, 2 passes). Biopsies were performed before and 3 months after treatment. Clinical, histological and morphometric evaluations were carried out.


RESULTS
All patients presented clinical improvement with no statistically significant difference (p> 0.05) between the treated sides. Histopathology revealed a new organization of collagen and elastic fibers, accompanied by edema, which was more evident with the 2940nm laser. This finding was confirmed by morphometry, which showed a decrease in collagen density for both treatments, with a statistical significance for the 2940nm laser (p > 0.001).


CONCLUSIONS
Three 1540nm sessions were clinically equivalent to one 2940nm session. The edema probably contributed to the positive results after three months, togheter with the new collagen and elastic fibers organization. The greater edema after the 2940nm session indicates that dermal remodeling takes longer than with 1540nm. It is possible that this histological superiority relates to a more prolonged effect, but a cohort longer than three months is needed to confirm that supposition.
Santa Casa de Misericórdia do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Juliano
J
Borges
Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Tullia
T
Cuzzi
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Carlos Alberto
CA
Mandarim-de-Lacerda
Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Mônica
M
Manela-Azulay
D001706:Biopsy; D003094:Collagen / Q000528:radiation effects; D019583:Dose Fractionation, Radiation; D004487:Edema / Q000473:pathology; D004547:Elastic Tissue / Q000528:radiation effects; D005145:Face / Q000528:radiation effects; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008875:Middle Aged; D010147:Pain Measurement; D011594:Psychometrics; D012867:Skin / Q000473:pathology / Q000528:radiation effects; D015595:Skin Aging / Q000528:radiation effects*; D013997:Time Factors; D016896:Treatment Outcome
D003094:Collagen