Early vascular changes induced by transpupillary thermotherapy of choroidal neovascularization

Objective: To study early direct effects of transpupillary thermotherapy (TTT) on choroidal neovascularization (CNV) and choroid. Design: Retrospective, noncomparative interventional case series. Participants: Sixty-four eyes with subfoveal CNV. Intervention: TTT was delivered using a diode laser at 810 nm through a contact lens. Exposure time was 60 seconds with a power/diameter ratio of 247 mW/mm. The end point was an invisible treatment with no color change at the retina level. Main Outcome Measures: Fluorescein and indocyanine green angiographic findings within 1 hour, and at 1, 2, and 4 weeks after TTT. Results: Fluorescein angiography (FA) and indocyanine green angiography (ICGA) performed within 1 hour after TTT showed increased leakage of CNV and choroidal vessels. Follow-up at 1 and 2 weeks demonstrated a hypofluorescent area corresponding to the laser spot and absence of angiographic leakage seen on FA and ICGA. At 4 weeks after TIT FA showed mottled hypofluorescence-hyperfluorescence of the TTT-treated area and absence of angiographic leakage. Conclusions: TTT induces a characteristic dynamic sequence of vascular changes. Treatment with TTT can lead to absence of angiographic (FA and ICGA) leakage for 4 weeks. Determination of the long-term efficacy and visual implications awaits the results of clinical trials. Ophthalmology 2002;109:1098-1104 (C) 2002 by the American Academy of Ophthalmology.