Michal Schwartz, Professor of Immunology at the Weitzman Institute of Science in Israel, has built a career on shattering the myths that many of us were taught about the blood/brain barrier. The work in her laboratory centered in part on changes in the retina and optic nerve based on their intimate properties as central nervous system tissue. Although her publications stemmed from work on mouse models, her views have already helped revolutionize how we conceptualize the glaucomas, and earned her ARVO’s prestigious Friedenwald Award in 2002.
If you don’t have the time to watch the entire 76 minute presentation above, listen to the first 7 minutes during which you’ll get a sense of how much resistance Professor Schwartz had to overcome in dealing with dogma. Many years ago in practice, as I was evolving toward a more holistic model of care, I wondered about so-called normal tension glaucoma and in particular why we primarily treated patients with topical pharmaceuticals to lower IOP when IOP clearly wasn’t the problem in the first place. Common thinking was that these patients simply couldn’t sustain a normal IOP, and required drops to drive their IOP as low as possible. Yet a cynic would say that this fell into the category of “if all you have is a hammer, everything looks like a nail”. And in reality, all these years later, not that much has changed how we treat glaucoma. But if you’ve heard of the drive toward the use of neuroprotective agents, you can credit Dr. Schwartz’s pioneering research.
Michal co-authored a paper in Nature Reviews – Neurology in 2013 entitled The Retina as a Window to the Brain – from Eye Research to CNS Disorders, and you can gain a sense of its profundity from the abstract:
“Philosophers defined the eye as a window to the soul long before scientists addressed this cliché to determine its scientific basis and clinical relevance. Anatomically and developmentally, the retina is known as an extension of the CNS; it consists of retinal ganglion cells, the axons of which form the optic nerve, whose fibres are, in effect, CNS axons. The eye has unique physical structures and a local array of surface molecules and cytokines, and is host to specialized immune responses similar to those in the brain and spinal cord. Several well-defined neurodegenerative conditions that affect the brain and spinal cord have manifestations in the eye, and ocular symptoms often precede conventional diagnosis of such CNS disorders. Furthermore, various eye-specific pathologies share characteristics of other CNS pathologies.”
Although the full text of the paper itself is not in public domain its key figures are, and I reproduce one of them here.