OBJECTIVE: To determine the effectiveness of picosecond KTP in reducing peri-ocular dark circles caused mainly by excessive pigmentation and to compare Picosecond KTP with Thulium laser ability in reducing the intensity and extent of peri-ocular dark circles.
METHODS: This split-face prospective study included twelve women with periorbital dark circles (pigmented or mixed-pigmented type). The left lower eyelid was treated using the PicoHi machine (HIRONIC Ltd), a full beam Q-switched Nd-YAG provided by KTP crystal (523 nm) at settings of 0.3 J/cm2, 5 mm, 5 Hz, and 300 Ps. Whereas the right lower eyelid was treated using the Lavieen machine (WON TECH Co., Ltd), a fractional Thulium laser (1927 nm) at setting 1320 mJ/cm2, 30 × 15 mm, 1500 microseconds. Patients received a series of 3 treatment sessions, given at 4-week intervals.
RESULTS: The 532-nm full beam Q-switched KTP and fractional Thulium lasers were more likely to induce post-inflammatory hyperpigmentation rather than decrease the pigmentation. The risk is higher with a Q-switched KTP laser, which may be attributed to the skin tone of the participants. Nonetheless, some improvement in the pigmented type of PDCs, although not detected clinically, was documented by the VISIA software.
CONCLUSIONS: No solid conclusion can be drawn from the results of the study. Picosecond KTP and Thulium lasers may have a role in reducing PDCs yet more studies should be performed in order to determine the exact impact these lasers have.

BACKGROUND: Periorbital dark circles (PDC) is one of the most common cosmetic issues in today\'s society. Only moderate degree of improvement has been achieved by various available treatment options. The present study aimed to compare the clinical efficacy of carboxytherapy and fractional CO2 laser therapy in the management of PDC.
METHODS: In this split face study, 30 patients with bilateral PDC aged between 23 and 52 years were recruited who underwent carboxytherapy (n = 30) on PDC of one side of the face and fractional CO2 laser therapy (n = 30) on the PDC of other side. The entire treatment comprised of four sessions of each therapy with an interval of 2 weeks each time. The assessment was based on both subjective methods (patients\' satisfaction and physician\'s judgment) and objective method (based on digital standard photographs). The degree of improvement from the patient\'s point of view (patient satisfaction) and physician\'s point of view (physician satisfaction) was assessed in different therapy sessions in comparison with the improvement after first session.
RESULTS: The study included 30 patients with mean age of 38.22 ± 8.3 years. The mean disease duration was 45 ± 12.3 months. After the second therapy session, patients\' satisfaction was remarkably better in the fractional CO2 laser therapy group than the carboxytherapy group, over the time. According to the physician satisfaction, the improvement rate was higher after the second and sixth weeks in the fractional CO2 laser therapy group than the carboxytherapy group; whereas in other sessions, there were no statistically significant differences. There were no significant side effects observed in either group post-treatment each time.
CONCLUSIONS: Fractional CO2 laser therapy is a better option to treat PDC than carboxytherapy. Also, mild side effects (including erythema, pain, and discomfort) were reported in both groups; with no significant difference between the groups.

BACKGROUND: Numerous therapeutic techniques for periorbital hyperpigmentation have been suggested.
OBJECTIVE: In this comparative intrapatient study, the effectiveness of combination therapy included fractional Er: YAG laser and autologous platelet-rich plasma (PRP) compared to Er: YAG laser in periorbital hyperpigmentation treatment.
METHODS: Thirty-two patients were enrolled. The right periorbital sides of patients received combination of Er: YAG laser and autologous platelet-rich plasma (PRP) and the left side received Er: YAG laser (three sessions with 4 weeks\' intervals). PRP was used in two ways included injection and topical. Patients were evaluated by biometric characteristics, patients, and physician assessments. Also, the patient\'s satisfaction was assessed and side effects were evaluated.
RESULTS: The mexameter results showed that the melanin content in the right side of the periorbital of the patients was significantly decreased compared to left side. Also, significant increase was observed in the skin lightness of the right side in compare to left. The visioface results showed the decrease in the percent change of the color and wrinkle in both sides, but in the right side these changes were significantly more than left side. The patients and physician assessment confirmed the measured results.
CONCLUSIONS: Combination of Er: YAG laser and PRP is significantly effective for periorbital hyperpigmentation.

Treatment of the periorbital dark circles (PDCs) is a current challenge, with most treatment methods failing to yield promising results. The effectiveness of two common methods for periorbital dark circle treatment was compared in 28 patients with PDC. The patients were randomly divided into two groups of equal numbers: the first group received carboxy therapy, and the second group fractional 10,64 nm Q-switched Nd:YAG laser. In the carboxy therapy group, the treatment was performed six times, with 1-week intervals between sessions. In the group treated by Nd:YAG laser, the treatment was conducted in four sessions, with 1-month intervals between sessions. The results were evaluated through biometric evaluation, scoring on the visual analog scale (VAS) by both physicians and patients, and patients\' satisfaction. Side effects of the treatments were also evaluated. The results showed that both carboxy therapy and Nd:YAG laser are effective in the treatment of periorbital dark circles, but carboxy therapy is significantly more effective. An increase in the skin lightness and a decrease in the melanin content of the periorbital skin was observed in the group receiving carboxy therapy, and these changes were more pronounced in this group compared to the group of Nd:YAG laser. In addition, side effects, such as erythema and post-inflammatory hyperpigmentation, were less in carboxy therapy than in Nd:YAG laser. Furthermore, the procedure was less expensive and easier to perform compared to Nd:YAG laser. Carboxy therapy is significantly more effective than Nd:YAG laser in PDC treatment.Trial registration: IRCT20080901001159N24.