Abstract
Purpose: :
It is known that the effects of PDT tend to be more severe on monkeys when PDT is performed under the same conditions as those used in patients with a verteporfin dosage of 6 mg/m2 of body surface area. The purpose of this study was to compare the effects of the dosage of verteporfin calculated from the body surface area (mg/m2) to that from the body weight (mg/kg) on photodynamic therapy (PDT) in monkeys under conditions similar to those used in patients.
Methods: :
PDT was performed on one eye of two monkeys. In one monkey, the dose of verteporfin was 6 mg/m2 which is equivalent to that given to patients calculated from the body surface area, and in the other monkey, the dose of verteporfin was 0.16 mg/kg based on the body weight. Verteporfin was administrated by intravenous infusion over 10 minutes. Fifteen minutes after the start of the infusion, a laser at 689 nm and intensity of 600 mW/ cm2 with an irradiation time of 83 seconds was used to irradiate the retina. Fundus photographs and fluorescein angiograms were recorded one week after PDT.
Results: :
When PDT was performed after 6 mg/m2 of verteporfin, there was some whitening (edema) of the retina, and the alterations were more obvious by the leakage in the fluorescein angiograms. When PDT was performed with 0.16 mg/kg of verteporfin, there was clearly less of an effect on the retina and the results were closer to that seen in patients in the clinic.
Conclusions: :
These results suggest that the dose of verteporfin may be more appropriately calculated by body weight than by body surface area when one intends to perform PDT on monkeys under conditions similar to those used for humans in order to obtain effects similar to those in patients.
Keywords: photodynamic therapy • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • macula/fovea