Choroidal neovascularization secondary to age-related macular degeneration is a leading cause of vision loss in adults. Although most patients present with occult CNV, treatment has focused on the small percentage of eyes with well-delineated, classic CNV. Transpupillary thermotherapy is a recent advancement in the management of occult CNV. Transpupillary thermotherapy acts in a subthreshold manner by slightly raising the choroidal temperature. A recent pilot study demonstrated that 56% of treated eyes remained stable one year after treatment with only 25% losing two lines of visual acuity. The TTT4CNV study will further evaluate the effectiveness of transpupillary thermotherapy in a randomized, double-blind trial.