Diabetic retinopathy, a disease of the eye that arises as a complication of diabetes, affects up to 80% of long-term diabetic patients and accounts for 12% of new cases of blindness each year. The blindness associated with this disease occurs due to leakage from the blood vessels feeding the retina. Diabetic retinopathy has few early warning signs, and there are relatively few diagnostic methods that can accurately detect leakage in the blood-retinal barrier (BRB). Multiple studies have indicated that early diagnosis of diabetic retinopathy could lead to the successful prevention of blindness in up to 90% of cases. This technology, polychromatic angiography (PCA), uses multiple fluorophores associated with small, biocompatible particles of different sizes. By using particles of different sizes, PCA can detect and differentiate between large and small leakages in the blood-retinal barrier. The ability to detect small leakages, the hallmark of early retinopathy, may allow clinicians to intervene early, before much of a patient's vision has been affected.
Currently available diabetic retinopathy diagnostic tools use fluorescent dyes to diagnose leakage in the blood vessels of the eye; however, small and large leakages cannot be distinguished so the progression of the disease cannot be monitored accurately. By using differently tagged particles of multiple sizes, polychromatic angiography allows for fine-grained diagnosis of diabetic retinopathy. For example, in cases where the blood-retinal barrier has been slightly damaged, only the smallest of the particles will leak out of the blood vessels, and a specific fluorescent signal will be detectable. In cases where the blood vessels have experienced heavier damage, the larger particles will leak through, emitting a distinct fluorescent signal. This technology may enable clinicians to detect diabetic retinopathy and other BRB-related disorders far earlier than fluorescein angiography and may be a useful tool to monitor progression of the disease over time in a quantitative manner.
This technology has been tested in vivo in rabbit models of BRB dysfunction.
Patent Issued (AU2007269609)
Patent Issued (CN101616692 B)
Tech Ventures Reference: IR 1992