Abstract
Purpose: :
A phase II study was planned to compare efficacy of choroidal neovascular membrane (CNV) feeder vessel treatment (FVT) preformed by application of 810 nm laser energy during indocyanine green (ICG) dye transit through the feeder vessels (i.e., DEP) to application of the laser energy alone.
Methods: :
A fundus camera was modified for ICG angiography by replacing its xenon flash lamp with an 810 nm wavelength diode laser. Live ICG images were acquired by a CCD video camera and displayed on a LCD monitor located above the patient's eye. The output fiber optic of an 810 nm laser photocoagulator was mounted on a joystick–controlled micromanipulator in the fundus camera's optical system for positioning the photocoagulator laser beam on the fundus while viewing live ICG video images of the choroidal vasculature. The device makes possible precise delivery of photocoagulation energy to CNV FVs upon arrival of a secondarily–injected, high–concentration ICG dye bolus in a targeted FV. Patients with minimally classic or other choroidal lesions were randomized to ICG–DEP FVT or FVT alone.
Results: :
40 patients randomized (20 FVT / 20 ICG–DEP FVT). Data at 12 months showed only 1 case treated with FVT with choroidal hemorrhage (2.5 %). Closure of choroidal neovascular membrane was achieved in 87,5% and maintained after 12 months in 71.4% in ICG–DEP arm and 64.2% and 55.5% respectively in FVT arm. The number of laser burns to achieve the closure with DEP FVT were less than FVT (3 to 9 vs. 100 to 300). Four patients droped out or changed type of treatment (1 ICG–DEP and 3 FVT). Mean treatments for each case was 3,88 (1 to 7).
Conclusions: :
Preliminary data analysis suggests that feeder vessels are identifiable and treatable during the dye transit. ICG–DEP appears to be a safe procedure. It also facilitate FVT by reducing the number of burns necessary for vessel closure and makes the treatment of larger diameter new vessels possible.
Keywords: laser • choroid: neovascularization