Sub-threshold Micro-Pulse Laser Therapy for Drusen of Dry AMD

Inclusion Criteria: 1. Older than 50 years of age. 2. Male or female patients with nonexudative AMD with a drusen diameter of at least 125um in the central 3mm circle 3. clear media to perform colour, red-free imaging and fundus fluorescein angiography, fundus autofluorescence imaging and OCT. 4. Able to give an informed consent. Exclusion Criteria: 1. Presence of other macular disease such as epiretinal membrane, macular telangiectasia. 2. unclear media that no clear colour, red-free imaging and fundus fluorescein angiography, fundus autofluorescence imaging and OCT can performed. 3. Ocular or periocular infections.