Photo-mediated Ultrasound Therapy (PUT) is a non-pharmacological, highly targeted, non-invasive treatment which selectively disrupts the microvasculature (arteries or veins independently) without catheterization/injection or damage to the surrounding tissue.
Angiogenesis is a hallmark for a spectrum of pathological conditions including cancer, inflammation, and eye diseases. Current research has focused on the development of pharmacologic therapies targeting vascular endothelial growth factor (VEGF) signaling, or non-pharmacological approaches that occlude microvessels through invasive procedures or the injection of foreign substances. While some of these treatments have proven efficacious with significant survival benefits, they are generally expensive, time-consuming, and/or present a risk of toxicity, tissue damage, or other adverse side effects. Thus, there is a need for novel microvascular occlusive methods that can address these limitations.
Initial investigation of this technology has been focused on retinal diseases - particularly those associated with diabetes, a global epidemic affecting 346 million people currently and expected to increase to 552 million people by 2030. Approximately 40% of patients with diabetes have diabetic retinopathy, which can lead to visual impairment and blindness. Diabetic macular edema, the leading cause of decreased vision due to diabetes, is commonly treated with focal laser photocoagulation therapy to cauterize microaneurysms from leaky retinal vessels. Recent results suggest that PUT can be used to occlude microvessels in the retina, providing an effective alternative treatment for diabetic retinopathy and other eye diseases without the risk of damage to the surrounding tissue. Additional research is expected to demonstrate efficacy in inhibiting tumor growth and treating inflammatory disorders such as arthritis.
The technology uses a combination of laser and ultrasound and produces shear stress from oscillating cavitation microbubbles to treat targeted microvessels. Since blood absorbs more optical energy at the target wavelength than the surrounding tissue, cavitation is limited to only blood vessels and therefore PUT is highly localized. It can be further targeted to selectively treat either veins or arteries.
Completely non-invasive, without the need for catheterization or injection. Highly precise, allowing for selective treatment of arteries or veins beyond the skin surface for a depth up to 10 mm. Significant reduction in pain and tissue damage compared with conventional laser therapy, as both the ultrasound and laser pulses are low-power and neither alone can produce damage.
This technology does not rely on pharmacological or thermal effects, so it avoids the adverse side effects of existing treatments. Instead, it promotes mechanical cavitation through non-invasive means - using short laser pulses and ultrasound bursts which can be synergistically applied to maximize vessel occlusion.
The same method may prove effective in cosmetic treatments such as tattoo removal (including color selectivity) and conditions relating to over-vascularization (e.g., varicose veins, spider veins, port wine stain).