Abstract
Purpose :
Indocyanine green (ICG) is commonly used to aid in the diagnosis of diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration. ICG injection is required in order to obtain fluorescent images of blood flow. Hence, there is little opportunity to practice the measurement sequence of image capture for beginning fundus photographers and technicians.
To solve this problem, we have developed a model eye that emits fluorescent wavelengths equivalent to ICG.
Methods :
The model eye is equipped with a lens component and a pseudo-fundus component. The lens component has an optical power equivalent to the refractive power of the human eye. The pseudo-fundus components contain a fluorescent component that emits wavelengths equivalent to ICG. The fundus component also contains a substance that emits a wavelength equivalent to fluorescein.
The fluorescent components are made from a resin material. The material was dissolved in an organic solvent, then solidified to emulate retinal blood vessels.
Results :
Fluorescence of the appropriate intensity was obtained by adding colorless resin pellets (PMMA in this report) to resin pellets containing a pigment exhibiting fluorescence characteristics equivalent to ICG. Subsequently, the pellets were dissolved in an organic solvent. A variety of solvents may be used as the solvent (for example, chloroform, acetone, and THF). In this study, we determined that chloroform was the best choice because of the high speed of dissolution and requires only a small amount of solvent.
As a test, the resin material dissolved in the organic solvent, was poured into grooves, and solidified by drying only the organic solvent. After confirming the successful solidification of the resin material, the dissolved resin material was poured into the grooves made in the pseudo-fundus component of the model eye to form simulated blood vessels.
This model eye allowed the successful imaging of fluorescent images resembling those captured in human eyes.
Conclusions :
The ICGA model eye enables easy imaging of fluorescent blood vessel images, circumventing the need to inject ICG in humans or animals to practice retinal photography/angiography.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.