Laser Activation

Currently there are 2 lasers designed to activate Visudyne, the Opal Photoactivator and the Zeiss VISULAS 690s. These diode lasers facilitate activation by producing a stable power output of red light at a wavelength of 689 nm. Found in clinical trials to be the optimal absorption peak of verteporfin when used for the treatment of CNV, this wavelength in turn allows the verteporfin in the eye to absorb energy quickly and efficiently and thus become active. Both lasers generate a beam spot with an even power distribution, helping to ensure that the drug is activated throughout the desired treatment area. The laser beam is delivered through a slit lamp to the affected area in the retina using a targeting beam of low intensity. The treating ophthalmologist calculates the exact size of area to be treated based on the fluorescein angiography.

Each laser system provides a monochromatic light beam with a large spot size that allows flexibility in treating a variety of CNV lesion sizes. These laser systems have low maintenance requirements, are easy to operate, do not violate the vitreous humor, and, most importantly, do not cause thermal or photocoagulation damage to normal retinal tissue.