Page 21 - Characterization of genetic neurodevelopmental disorders at adult age, with a focus on 22q11.2 deletion syndrome - Emma Boersma

General introduction
There have been a few studies that reported on visual acuity and ocular
findings in individuals with 22q11.2DS, mainly children, showing high
prevalence rates of hyperopia, strabismus and amblyopia. 71-74 Visual acuity
was (near) normal in most individuals, although in rare cases visual acuity
was affected by a Peters anomaly,74 or cataract.75 Other common findings
were retinal vascular tortuosity and posterior embryotoxon, that do not
affect visual acuity or require any treatment.71, 73, 74
The eye as a window to the brain
Studying brain development and brain disorders, especially in individuals
with a GND, is challenging but very important for understanding the
pathophysiology of brain disorders and may help identifying individuals
that are at increased risk at an early stage. Non-invasive and fast methods
would facilitate the study of brain disorders in individuals with a GND.
Because retinal and cerebral tissue share embryological, physiological,
and anatomical characteristics, retinal blood vessel morphology (referred
to as retinovascular parameters) and retinal layer thickness (retinoneural
parameters) have been proposed as non-invasive biomarkers for psychiatric
and neurodegenerative disorders.76-81 Since the retina is the only part of the
central nervous system that can be examined from the exterior, the eye may
serve as a window to the brain. Retinovascular and retinoneural parameters
can be studied using non-invasive and fast methods such as fundoscopy
and optical coherence tomography (OCT). Fundoscopy can be used to study
retinovascular parameters such as branching pattern and vessel density,
and OCT can be used to study retinoneural parameters such as thickness
of the retinal nerve fiber layer and macular layer, covering different regions
of the retina.82
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Differences in these retinovascular and retinoneural parameters between
adults with 22q11.2DS and controls have not been studied yet, but may
help to the identify predictive biomarkers for psychiatric disorders such
as schizophrenia and neurodegenerative disorders such as Parkinson’s
disease.
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