Abstract
Abstract: :
Purpose: Photocoagulation of feeder vessels is under investigation as a treatment for choroidal neovascularization (CNV). This technique is based on the hypothesis that a small number of intrachoroidal feeder vessels supply flow to the entire CNV complex. Therefore, closure of these feeder vessels should result changes in flow characteristics within the CNV. Several clinical studies have reported stability of visual acuity in patients with CNV undergoing feeder vessel closure. While high-speed indocyanine green angiography (HS-ICGA) is typically used as guide to direct laser closure, fluorescein angiography (FA) still remains the imaging modality of choice to follow the subsequent anatomic changes in the CNV. The present study was undertaken to identify the immediate fluorescein angiographic changes in patients undergoing feeder vessel therapy. Methods: Seven patients with CNV underwent pretreatment FA. Feeder vessels in these patients were detected by HS-ICGA and localized by thin plate splines registration of corresponding red-free retinal images. Vessels were treated with either 810 nm diode or yellow wavelength laser photocoagulation. Post-treatment HS-ICGA was used to determine the extent of feeder vessel closure. Immediate FAs were performed and FA's were graded for time to complete filling of the CNV and area of late leakage. Results: Feeder vessels were identified in all seven patients and were closed successfully after treatment with either diode or argon yellow laser. Immediate post treatment fluorescein angiograms revealed a marked decrease in time to filling and a reduction in the area of late leakage. However, late hyperfluorescence of the CNV was detected in all patients. Conclusions: Successful feeder vessel closure can lead to an immediate decrease in perfusion of the choroidal neovascular complex as detected by FA. These angiographic findings support the hypothesis that CNV may be principally perfused through one or more intrachoroidal feeder vessels but that continued slow perfusion may be maintained through non-feeder vessel routes. Photocoagulation of intrachoroidal feeder vessels is a possible therapy in the treatment of CNV.
Keywords: choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • laser