Vision Restoration and Brain Functional Connectivity Network Reorganization

Presenter: Bernhard A. Sabel,

University of Magdeburg/Germany and Beijing Tongren Hospital/China 

Host: August Colenbrander, M.D.

Abstract

Although about half of our brain´s cortex controls vision, low vision, and blindness are viewed as exclusively an “eye” issue, with the brain just being an “appendix”. But many visual diseases involve nervous system dysfunction affecting the retina, optic nerve or the brain. A typical “eye” disease, for instance, glaucoma, now also appears to be a brain disease “in disguise”.  

While perimetric and acuity tests can detect eye diseases, higher cognitive functional impairments affecting the “person behind the eye” are missed.  Only by understanding the brain can many ophthalmological diseases be fully grasped. After all, retinal (“bottom-up”) signals have to be interpreted by higher-level (“top-down”) brain networks for the conscious vision to work. 

This has practical consequences: (i)_subjective patient reports of vision impairment or residual vision do not match their “eye” problem, (ii)_normal aging and even some “eye” diseases are associated with brain degeneration, (iii)_ residual vision is sustained by brain network amplification which can be enhanced by attention, (iv) eye movements, controlled by brain centers, are associated with visual disorders, and (v)_brain plasticity, triggered by vision training or brain current stimulation, can improve visual perception.  

Our current method to achieve vision restoration after optic neuropathies is non-invasive alternating current stimulation (ACS). To watch the method check out  www.youtube.com/watch?v=g8p3mWsLvAI. ACS can improve detection performance in visual field testing, acuity and patient reported vision-related quality of life. Physiological EEG changes are increased alpha power in both occipital and frontal brain areas, and brain networks reorganization.  

Our findings confirm that vision loss after optic nerve or brain damage must not be viewed as irreversible. Rather, there is now plenty of reason for optimism of vision improvement through mechanisms of brain plasticity. The brain deserves a better reputation in  ophthalmology which opens new paradigms for diagnosis and therapy.