Transpupillary thermotherapy alone and enhanced by standard doses of indocyanine green in pigmented rabbits.
OBJECTIVE
To evaluate the chorioretinal effects of transpupillary thermotherapy (TTT) and TTT enhanced by standard doses of indocyanine green (ICG) in pigmented rabbits.


METHODS
In 25 eyes, two retinal areas were irradiated using identical subthreshold diode laser irradiation. The subthreshold diode laser irradiation level was first determined using the other eye. ICG (0.5 mg/kg) was injected before irradiation of the second area. Red-free photographs, fluorescein angiography, and ICG videoangiography were performed after TTT. Specimens were prepared for light microscopy.


RESULTS
In 35% of the cases, ICG videoangiography revealed a hypofluorescent spot in the area irradiated after injection of ICG that disappeared after ICG re-injection. None of the areas irradiated before ICG injection were hypofluorescent. Red-free photographs and fluorescein angiography were normal in most cases. Light microscopy demonstrated patent choriocapillaris and choroid in most areas.


CONCLUSIONS
Subthreshold TTT, whether enhanced by ICG or not, did not cause significant choroidal or choriocapillaris vascular occlusion. Standard doses of ICG had no significant effect on TTT.
Department of Ophthalmology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Reginaldo M Júnior
RM
Mattos
Márcio B
MB
Nehemy
Erika P
EP
Magalhães
Moisés
M
Pedrosa
D000818:Animals; D002829:Choroid / Q000473:pathology; D020256:Choroidal Neovascularization / Q000473:pathology / Q000628:therapy*; D004396:Coloring Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006979:Hyperthermia, Induced / Q000379:methods*; D007208:Indocyanine Green / Q000008:administration & dosage / Q000627:therapeutic use*; D007275:Injections, Intravenous; D011680:Pupil; D011817:Rabbits; D012160:Retina / Q000473:pathology; D014741:Video Recording
D004396:Coloring Agents; D007208:Indocyanine Green