In this study, the efficacy and safety of Photodynamic Therapy were evaluated in patients with occult lesions (Table 2).

Results after 12 months were somewhat disappointing; however, efficacy was demonstrated in the treated group at 24 months (46.2% versus 33.3%).

Subgroup analysis led to the conclusion that greater benefits were achieved in patients with small lesions (less than 4 disc areas) and/or visual acuity worse than 20/50.

In these patient subgroups, the differences between the PDT group and the placebo group had greater statistical significance (51% versus 25%).