BALTIMORE — Laser therapy for photo voltaic lentigines in people with darker pores and skin varieties has lengthy been related to a better threat of postinflammatory hyperpigmentation (PIH), however a small examine in Thailand has proven the 532-nm picosecond laser with a fractional beam microlens array (MLA) had a considerably decrease incidence of PIH than the full-beam therapy with out MLA.
The examine enrolled 27 sufferers with photo voltaic lentigines and Fitzpatrick pores and skin varieties (FSTs) III-IV, Woraphong Manuskiatti, MD, professor of dermatology at Siriraj Hospital, Mahidol College, Bangkok, reported on the annual assembly of the American Society for Laser Medication and Surgical procedure. They obtained the fractional beam therapy on one facet of the face and the full-beam on the opposite facet. At 6 months, the incidence of PIH was about 81% decrease on the fractional-beam facet, Manuskiatti mentioned.
“Prior to now, after we used laser to deal with pigmented lesions, we used the so-called full-beam approach on the pigmented space,” Manuskiatti informed Medscape Medical Information. “From the examine, we discovered that you simply needn’t deal with it at 100%. You may fractionally deal with the pigmented lesion and get a very comparable therapy consequence and, at that lowered beam, much less incidence of postinflammatory hyperpigmentation.”
Examine Design and Outcomes
Of the 27 sufferers within the examine, 12 have been FST III (44%), 14 have been FST IV (52%), and one was FST V (4%). On the fractional-beam facet, the laser was delivered via a 9-mm spot measurement with a median fluence of 0.47 J/cm² at a frequency of two Hz for a complete of two passes with out pulse overlapping. On the full-beam facet, the laser was operated with a 4.5-mm handpiece, with fluence starting from 0.3 to 0.7 J/cm² (utilizing an endpoint of slight darkening of the pigmented lesion) at 2 Hz.
The sufferers obtained a single therapy and had a scientific analysis and shade studying assessments at 2 weeks, 1 month, 3 months, and 6 months after the therapy. Twenty 5 sufferers accomplished the examine.
The researchers discovered no statistically important variations in lesional clearance between the 2 strategies at any of the follow-up assessments, Manuskiatti mentioned. ” This could be one of many different remedies of treating photo voltaic lentigines in dark-skinned sufferers,” he mentioned when presenting the examine outcomes.
He reported the charges of PIH on the full-beam and fractional-beam sides, respectively, on the following intervals have been: 64% and eight% at 2 weeks, 80% and 32% at 1 month, 96% and 36% at 3 months, and 88% and 16% at 6 months.
“The incidence of PIH on the full-beam facet was statistically larger than that on the fractional-beam facet all through the follow-up interval,” he mentioned. Transient and delicate hypopigmentation was noticed in a single affected person (4%) on the fractional-beam facet and in 5 (20%) on the full-beam facet. Manuskiatti added that no different adversarial results have been documented through the examine.
” Usually whenever you use laser to deal with pores and skin sort I or II, you do not have…PIH or darkening of the pores and skin,” Manuskiatti informed Medscape Medical Information, “however when you’ve got pores and skin sort III and above, you run into a very excessive incidence of postinflammatory hyperpigmentation — and treating that with fractional beam can result in a lowered incidence of darkening of the pores and skin afterward.”
A Decrease-Value Possibility
This examine confirmed that the 532-nm picosecond laser with fractional beam MLA is a helpful choice for sufferers with darker pores and skin varieties, Kelly Stankiewicz, MD, a dermatologist who practices in Park Metropolis, Utah, and moderated the session the place these outcomes have been introduced, informed Medscape Medical Information.
“Probably the most difficult factor about treating lentigines in darker pores and skin varieties is stopping potential unwanted side effects, primarily dyspigmentation,” she mentioned after the assembly. “These unwanted side effects are, for probably the most half, non permanent, however they will take 6-18 months to resolve, so it is essential to stop them within the first place.”
She famous that the 532-nm and 1064-nm wavelengths are probably the most generally obtainable for picosecond lasers and that they are simpler to provide and cheaper. “There are picosecond lasers with center wavelengths within the purple gentle to near-infrared vary (650-785 nm) which are higher for darker pores and skin varieties as a result of they’re extra mild but nonetheless efficient at focusing on pigment, however these lasers are dearer and fewer extensively obtainable,” Stankiewicz mentioned.
“The microlens array, used on this examine with the 532-nm wavelength, is a reasonable piece that matches on the finish of the laser,” she added. “So, to have an choice that turns a 532-nm laser right into a safer machine for the therapy of lentigines in darker pores and skin varieties may be very useful.”
Manuskiatti and Stankiewicz had no related disclosures to report.
Richard Mark Kirkner is a medical journalist based mostly within the Philadelphia space.
