Photonic frontiers in melasma: Navigating layers, risks, and the future of light-based therapeutics

Melasma is a chronic and relapsing hyperpigmentation disease with a multifactorial pathogenesis involving epidermal, dermal, and vascular components. It carries a significant psychosocial burden and affects mostly women, who have an intermediate-to-dark phototype of skin. Light plays a dual role in melasma, which is a factor of both therapy and exacerbation. This narrative review summarizes the latest developments in light-based therapeutic systems, such as intense pulsed light (IPL), Q-switched and picosecond lasers, non-ablative and ablative fractional lasers, and photobiomodulation. IPL and low-fluence Q-switched Nd:Yttrium aluminum garnet lasers would continue to be used in epidermal and mixed melasma, whereas non-ablative fractional lasers would be used on the dermal side since they produce collagen-remodeling effects. The importance of environmental light (high-energy visible light, ultraviolet A-1) in disease persistence is another clinical implication of this review that argues the need to implement effective photoprotective measures. The photonic risk index is a proposed new framework that will help in making device settings more individualized, complication risk stratified, and follow-up intervals better. The future directions mentioned here are artificial intelligence-assisted diagnosis, laser-assisted drug delivery, smart photoprotection 2.0, and heat-minimizing engineering solutions – the future of real precision-guided photodermatology.