Method and apparatus for treating dermal melasma

An apparatus for selectively affecting a pigmented region in a layer of a skin tissue, comprising:

• a radiation arrangement including at least one laser configured to emit at least one electromagnetic radiation (EMR) beam;
• an optical arrangement including at least one lens configured to direct and focus the at least one EMR beam as a convergent beam into at least one focal region having a width less than 100 μm within a dermis layer of the skin tissue containing pigmented and unpigmented regions;
• a sensor configured to detect a speed of a translation of the apparatus over the surface of the skin tissue, and provide signals which are based on the detected speed to affect at least one property of the at least one EMR beam;
• and
• a controller configured to receive the signals from the first sensor and to control:
• a power output of the radiation arrangement so as to provide a fluence of the at least one EMR beam between 10 and 1000 J/cm2 in the at least one focal region when the signals indicate that the apparatus is in motion over the surface of the skin tissue, and
• at least one of the radiation arrangement or the optical arrangement so as to scan the at least one EMR beam over an entirety of a treatment area of the skin tissue within the dermis layer,
• wherein a dwell time of the at least one EMR beam at the at least one focal region is 2 ms or less, and
• wherein, in operation, the at least one EMR beam (i) provides selective energy absorption by the pigmented regions of the skin tissue within the treatment area, and (ii) damages the pigmented regions while preventing damage to the unpigmented regions of the skin tissue within the treatment area and within an epidermal layer of the skin tissue overlying the at least one focal region.