Choriocapillari photodynamic therapy uing indocyanine green

PURPOE: To evaluate the potential of photodynamic therapy uing indocyanine green for occluion of choroidal neovacularization, the author tudied efficiency and collateral damage of photodynamic therapy–induced photothromboi in the rabbit choriocapillary layer. METHOD: Fundu photography, fluorecein angiography, and light and tranmiion electron microcopy were ued to tudy the efficiency of photodynamic therapy–induced photothromboi uing indocyanine green a the photoenitizer, and to ae the reultant collateral damage. The delivery ytem conited of a modified infrared diode laer tuned to 810 nm, near the maximum aborption peak of indocyanine green. REULT: Choriocapillary occluion wa achieved at indocyanine green doe of 10 and 20 mg/kg and a radiant a low a 6.3 J/cm2. When photodynamic therapy wa performed with indocyanine green doe of 10 mg/kg, damage to the neural retina wa minimal. Only inner photoreceptor egment howed degeneration, probably econdary to choroidal ichemia. Bruch membrane remained intact. Retinal pigment epithelium wa invariably damaged, a een with other photoenitizer. Temporary occluion of large choroidal veel occurred at both dye doe. CONCLUION: In thi experimental tudy, photodynamic therapy uing indocyanine green and 810-nm light irradiation produced endothelium-bound intraluminal photothromboi, with preervation of the retinal architecture and minimal lo of viual cell. Membrane targetability, hydrophilic and fluorecent propertie, and activation at 805 nm ugget indocyanine green a a potential photoenitizer for choroidal neovacularization. Thee combined conideration point toward further tudy of photodynamic therapy uing indocyanine green for the treatment of choroidal vacular dieae.