Neurological Basis of Charles Bonnet Syndrome
This
is a very interesting study both for scientific and clinical reasons.
The idea to investigate spontaneous "resting-state" fluctuations in the
brain via patients with Charles Bonnet syndrome is excellent. These are
patients who experience visual hallucinations, "phantom vision" if you
will, after losing sight. Their eyes no longer send input to their
brain, but these patients can still "see" with their intact visual
cortex. Of note is the finding that brain wave activity reminiscent of
slow spontaneous fluctuations emerged just before onset of the
hallucination, indicating that the hallucinations were evoked internally
and not from external stimuli. Limitations of the study include its
small sample size of only five patients with Charles Bonnet syndrome.
However, the news coverage of Charles Bonnet syndrome is an excellent
opportunity to call attention to this condition. As you can imagine,
hallucinations can be a frightening and isolating experience. So
awareness of Charles Bonnet syndrome for both trainees and the public
increases assurance if they encounter the situation.
Anti-fibrotic Therapy for Glaucoma
In
this study, researchers at the University of Burmingham in the U.K.
investigated the use of anti-fibrotic low molecular weight
dextran-sulphate (ILB) as a potential therapeutic for open-angle
glaucoma (OAG) in preclinical rodent models. The researchers state,
"[W]e demonstrated that ILB acts, in part, by
downregulating transforming growth factor (TGF) β signaling genes and by
altering gene expression relating to extracellular matrix dynamics,
leading to tissue remodeling, reduced fibrosis and functional tissue
regeneration. These observations indicate the potential of ILB® to
alleviate fibrotic diseases." To my knowledge, that would be a novel
mechanism to treat OAG by reducing fibrosis of the trabecular meshwork. A
major limitation of the approach, however, is that ILB as currently
formulated is delivered by daily subcutaneous injection. The researchers
are planning to work on a topical "shear thinning fluid gel" as a
delivery method.
Early Detection of Cognitive Decline in Type 1 Diabetics
Ocular
Coherence Tomography (OCT) and its most recent additional function of
angiography (OCTA) have been explored in recent years as a means of
early detection of neurodegenerative diseases such as Alzheimer's. The
retina, being an extension of the brain (specifically the diencephalon),
allows for a unique, noninvasive, and comparatively inexpensive view
into conditions that affect the central nervous system. What was new to
me, i.e., what this article introduced me to, is the potential
connection between diabetes and Alzheimer's disease. The researchers
found associations between proliferative diabetic retinopathy (PDR) and
certain memory and psychomotor tasks. The small and somewhat cloistered
study, comprising 129 participants, investigated the link for people
with Type 1 diabetes, but the researchers plan on future studies for the
larger population of people who are affected by Type 2 diabetes.
Ultra-Thin Sensor for Smart Contact Lenses
Smart
contact lenses "could soon become" mainstream for a long time now. I
don't think there is actually anything exciting about this paper. Their
contact lens is a prototype design, from an engineering approach, that
has not progressed to testing in animal (rabbit) models yet. I suppose
thin electrical components would indeed be very important for a device
that would sit against a very sensitive ocular surface, but let's say
that this design is still in a very early phase at this point.
In the News
An
interesting read. A more experienced version of my own thoughts
generally, except for the following: “I sometimes tell a patient with
complex disease, ‘I’ll teach you something about your disease at every
visit, and eventually you’ll have a PhD in glaucoma.’ I’ve even been
known to assign homework.” This is a great joke! And I think it’s a
great example to show the devaluing of doctoral degrees across the
board. Just as it is a rigorous process to earn an MD, it is a rigorous
process to earn a PhD. For one, a PhD requires generating new knowledge,
not merely disseminating existing knowledge that (prior) PhDs have
produced. I don’t want to go as far as to say that it is ironic, but
this is something to be mindful of as well.
In Other News
1) Aphantasia
2) Optical illusions and dogs
3) Magnetic sense in birds
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