Treatment of Melasma Using Q-switched Nd: YAG Laser and Fractional CO2 Laser Separately and in Combination

* All participants will be divided into 2 groups : Group A \& Group B. * Group A will be subjected to 3 consecutive sessions of Q-switched 1,064 nm Nd: YAG laser to one side of the face \& fractional co2 laser to the other side of the face with one month interval between sessions. * Group B will be subjected also to 3 consecutive sessions of Q-switched 1,064 nm Nd: YAG laser to one side of the face \& an additional fractional co2 laser to the other side of the face using the above mentioned parameters with one month interval between sessions. * Response to treatment will be assessed using the Melanin Index (MI) score, Melasma Area and Severity Index (MASI) score, spectrophotometer ( Derma catch, colorix, Neuchatel, Switzerland ) and a subjective self-assessment method.