Background and objective: The authors evaluated the feasibility of merging free-dye angiography and the fluorescent vesicle technique to achieve the best characteristics of both.
Materials and methods: Fluorescent vesicles encapsulated with either indocyanine green or carboxyfluorescein were mixed with free indocyanine green or free sodium fluorescein, respectively, and imaged with a scanning laser ophthalmoscope in both an in vitro model and primate and rabbit models.
Results: In the in vitro model of the sodium fluorescein combination, optimal viewing of vesicleen capsulated dye and free dye was at a ratio of 150:1; for indocyanine green, the ratio was 50:1. In vivo, high-quality fluorescent vesicle angiograms were obtained that demonstrated leakage of free dye from choroidal laser spots.
Conclusions: Free dye and fluorescent vesicles can be combined to obtain an angiogram with all of the advantages of a traditional angiogram, while allowing the operator to assess the changes in retinal or choroidal circulation directly.