Abstract
Abstract: :
Purpose: To evaluate the histological findings after photodynamic therapy ( PDT) of experimental choroidal neovascularization ( CNV). Methods: CNV was induced in 56 pigmented C57BL/6 mice using a krypton laser. The CNV lesions were then treated with verteporfin ( 6.0 mg/m2) using a diode laser ( Opal Coherent Photoactivator) with a slit lamp adaptor delivering a 1,5 mm spot of 689 nm light with laser delivery times of 32 seconds, 64 seconds and 83 seconds. Eyes were enucleated 13 days after CNV induction and the height of CNV formation was measured. Results: PDT treatment of control eyes without CNV revealed a time–dependent progressive damage to the neural retina, RPE and choroid with minimal damage using a delivery time of 32 seconds and complete photoreceptor loss using 83 seconds. When PDT was applied over the laser–induced CNV lesion the height of lesions was significantly reduced using all three laser delivery times ( 32 seconds, 64 seconds, 83 seconds). Conclusions: The results show that PDT can decrease the experimental CNV complex and that a pattern of greater damage to the neural retina, RPE and choroid is seen with increasing light doses which corresponds well with the known features of verteporfin ( PDT).
Keywords: pathology: experimental • retina