532-nm and 1064-nm Q-switched Nd:YAG laser therapy for reduction of pigmentation in macular amyloidosis patches.

BACKGROUND: Macular amyloidosis is a primary form of skin amyloidosis with deposition of small to moderate amyloid material in the upper dermis and mild pigmentary incontinence with resultant clinical hyperpigmentation. OBJECTIVES: To determine the efficiency of Q-switched Nd:YAG laser (532 and 1064 nm) in reducing the pigmentations due to skin macular amyloidosis. METHODS: A prospective, side by side, controlled, clinical trial study was designed. Twenty subjects with clinical diagnosis and pathology confirmation of macular amyloidosis were treated with Q-switched Nd:YAG laser: 532 nm in a part of their plaques and with 1064 nm in another part of their plaques. Assessment of efficiency was done by colorimetric scores based on Mexameter measurement and also digital photographs before laser therapy and 8 weeks after treatment. RESULTS: Mexameter-based data analysis showed that the two lasers (Q-switched 532 and 1064 Nd:YAG) are effective in reducing the degree of macular amyloidosis patches pigmentation, and 532 nm is meaningfully more effective than 1064 nm in this matter. Photograph-based analysis showed that 90% of cases treated by 532 nm had good or very good response, and for the 1064 nm-treated patches, 60% of cases had the good or very good response. CONCLUSIONS: The results of study showed the net positive effect of Q-switched Nd:YAG laser, either 532 nm or 1064 nm, in pigment reduction of macular amyloidosis patches, but the 532-nm laser was more effective than 1064 laser.