The objective of this study was to determine the efficacy of photodynamic therapy in minimally classic membranes (where the classic component represents less than 50% of the neovascular lesion) sized below six disc areas (Table 2).

Additionally, the efficacy of reducing fluence to 50% (25J/cm2) relatively to standard parameters (50J/cm2) was also analysed.

In the standard laser light activation protocol, a wavelength of 689 nm and an intensity of 600 mw/cm2 are used for 83 seconds to achieve a fluence value of 50J/cm2.

In this study, no statistically significant efficacy was found at 12 and 24 months in the group of patients treated with the standard protocol.

On the contrary, better results were observed for patients treated with the reduced fluence protocol, in terms of the primary endpoint (loss of visual acuity of less than 15 letters).

Based on these results, the study authors advise treatment of small minimally classic lesions with PDT, concluding that the reduced fluence protocol may be beneficial.

The percentage of conversion of minimally classic lesions into predominantly classic lesions was also studied and treatment efficacy was demonstrated, irrespective of the fluence used.

The reduced fluence issue will also be referred in the Denali study.

This study investigates the efficacy and safety of combined therapy involving PDT and antiangiogenic drugs, namely ranibizumab 0.5 mg, administered intravitreally.

Patients were randomized to receive intravitreal injections of ranibizumab 0.5 mg, in monotherapy or combined with PDT, with standard or reduced fluence.

This study, which started in May 2007, includes 321 patients and is currently in course in the United States and Canada.

The results of the Denali study are not yet available.

Two other studies – VALIO (Verteporfin Therapy with Altered Light in Occult choroidal neovascularization) and VER (Verteporfin Early Retreatments) were also performed.

In the VALIO study, the efficacy of laser treatment at 15 and 30 minutes was evaluated and compared.

Since no statistically significant differences were observed between these two therapeutic modalities, it was decided to maintain the 15 minutes used in standard treatment.

The objective of the VER study was to determine whether it would be beneficial to reduce treatment intervals to 6 weeks in the first 6 months.

Since no increase in efficacy was found relatively to the standard regime (treatment every 3 months), it was advised that the usual treatment regime be maintained.