Richard F. Spaide

Choriocapillaris Flow in Health and Disease

Richard F. Spaide, MD


The choriocapillaris is a critical vascular layer in the eye, but analysis of blood flow there has been very challenging. With optical coherence tomography angiography we have been able to create maps of the flow in the choriocapillaris. This flow appears to follow a simple but powerful pattern. The choriocapillaris shows areas of flow and small areas of absent flow signal. This pattern can change slightly from moment to moment. However, the pattern at any given time corresponds to a simple, but powerful mathematical association known as a power law relationship. This same mathematical relationship is the underpinning of many processes in the universe from avalanches to earthquakes to the structure of language. This same relationship is seen in how atoms and molecules align during phase transitions and forms part of the foundation of fractals. Alterations in the power law relationship in choriocapillaris flow occur with aging, hypertension and having late age-related macular degeneration in the fellow eye. This observation has numerous physiological and even philosophical implications. Finally, a model will be shown that attempts to emulate changes in choriocapillaris flow with aging.