Laser toning: in a 39-study analysis the top-ranked option was not laser alone but laser plus a topical

A 2022 prospective split-face study in Korea. Twenty Korean patients with facial melasma were randomly assigned 1,064 nm picosecond Nd:YAG on one side of the face and 1,064 nm Q-switched Nd:YAG toning on the other, five sessions at two-week intervals.

The results in order:

• Both sides showed significant clinical improvement and decreased mMASI scores from baseline.
• At no time point was there a significant difference in mMASI between the two techniques.
• The melanin index showed no significant improvement in either group.
• Patient satisfaction and visual analogue scores did not differ between the two either.

It matters not to skip the third line. mMASI is a score a person assigns by eye; the melanin index is a reading from an instrument. The eye-assigned score improved while the instrument-measured pigment did not change significantly.

Which to believe when they diverge is not simple. The clinical grade may be the outcome that matters more to a patient; the instrument may be more objective. But quoting one erases the other.

The authors' conclusion is exact: the picosecond laser is as effective and safe as the conventional Q-switched laser, but no superior outcome was observed.

And here too the control is another device. It is not a comparison against having no treatment.

The 2023 network meta-analysis collected randomised controlled trials up to November 2022: 39 studies, 1,394 participants. It compared laser-related therapies for melasma on MASI improvement in a single framework.

The important part of the result is what beat what.

Q-switched Nd:YAG plus topical medications was significantly superior to:

• Q-switched Nd:YAG alone [MD = −4.21 (−6.80, −1.63)]
• Er:YAG plus topical medications [MD = −3.52 (−6.84, −0.19)]
• Topical medications alone [MD = −5.22 (−9.20, −1.23)]
• Picosecond laser plus topical medications

The top of the SUCRA ranking:

1. Q-switched Nd:YAG + topical medications — 85.9%
2. Oral tranexamic acid — 80.1%

Two things to take from this.

First, laser ranks higher combined with a topical than it does alone. That combination significantly beating monotherapy is the central number of this analysis.

Second, second place is not a laser. It is oral tranexamic acid. On this site's tranexamic acid page we wrote that the topical route was not significant and only the oral route was. Two conclusions from entirely separate bodies of data point the same way.

Network meta-analysis rankings are built from indirect comparisons, not head-to-head ones, so they should not be read as a straight league table. But the simple picture of 'melasma means laser' does not match the data.

This may be the most practically useful item on the page.

The background sentence of the 2021 paper says it outright: Q-switched Nd:YAG toning has been used successfully for melasma, especially in dark phototypes, but punctate leukoderma was found to be a frequent complication that reduced the safety of this procedure.

Punctate leukoderma is small white spots left where pigment removal has gone too far. It trades melasma for a pigment problem in the opposite direction, and it is hard to reverse.

That study tested a way to reduce it. Thirty patients with bilateral symmetrical melasma were randomised split-face: one side received Q-switched Nd:YAG toning (nine sessions, every two weeks), the other a combination including low-power fractional CO2 (three sessions, every four weeks). Assessment used mMASI, spectrophotometry (melanin and erythema indices), photography, blinded physician assessment and patient satisfaction, at baseline, one week after the last session, and 8–12 weeks after.

That this trial exists is itself information. A complication has to be common enough to be worth a dedicated study on reducing it.

Note the session count too: nine sessions at two-week intervals. Toning is not a one-visit procedure, and cumulative exposure is not unrelated to leukoderma risk.