News & Events / BME Seminar Series / Past Seminar Speakers / 2019-20David Huang, MD, PhD
BME Seminar Series Winter 2019
Thursday, January 16, 2020 at 4-5 pm
Tech L361
Host: Professor Hao Zhang
Peterson Professor of Ophthalmology and Professor of Biomedical Engineering, Casey Eye Institute, Oregon Health & Science University
Imaging microvascular network without labeling: State of Art & Future Trends
Optical coherence tomographic angiography (OCTA) became available as a clinical instrument in 2014. Since then it has been applied to a wide range of retinal and optic nerve diseases. This presentation will review the current state of the art as well as anticipate future imaging capabilities and clinical applications. One of the important recent advances in OCTA was the development of algorithms to reduce projection artifacts. Projection-resolved OCTA allows visualization of 4 distinct retinal vascular plexuses and improves the diagnosis and classification of optic nerve diseases that primarily affect the superficial plexuses, outer retinal diseases that primarily affect the deeper plexuses, and vascular diseases that affect all plexuses. Commercial OCTA systems have focal spot diameters that are larger than capillaries. Therefore improvement in the transverse optical resolution is needed to accurately measure retinal capillary density. Sensorless adaptive optics (AO) is a practical solution toward this goal. Sensorless AO OCTA has demonstrated improved flow contrast and reduced projection artifacts, as well as improved resolution. Wider field of view is achieved by montaging multiple scans with a high-speed OCTA systems. This has been demonstrated with newer commercial systems as well as experimental prototypes. Improved detection of neovascularization in diabetic retinopathy has been shown with wide-field OCTA. The quality of OCTA is easily degraded by defocus, shadowing, and other signal attenuating aritifacts. Robust detection and quantification of pathologies thus require advanced image processing. Artificial intelligence (AI) and other techniques were used to overcome artifacts and improve the reliability of detecting nonperfusion and neovascularization in retinal diseases. With continued improvements in speed, optics, and algorithms, OCTA is becoming more and more useful in retinal diseases and glaucoma. These major applications are reviewed.