Page 185 - Characterization of genetic neurodevelopmental disorders at adult age, with a focus on 22q11.2 deletion syndrome - Emma Boersma

The eye as a window to the brain
inferior segment, as compared to controls. In addition, we found negative
correlations of age with FD and RNFL thickness in the global, temporal
inferior and temporal superior segments in adults with 22q11.2DS, that
were not found in controls.
Retinal vascular morphometric abnormalities
Increased retinal vascular FD and tortuosity in the peripapillary region have
been also reported in patients with community-based schizophrenia, 16, 20
a psychiatric disorder that affects about 1 in 4 patients with 22q11.2DS.5
However, findings in this new research area are inconsistent. For example,
lower macular FD has also been found in an independent sample of patients
with schizophrenia.17 Similarly, both smaller and wider arterioles, and wider
venules, have been reported in patients with schizophrenia.12, 16, 17 Wagner
et al. recently discussed possible explanations for the inconsistent findings
between studies, like the complex relationship between disease duration,
retinovascular parameters, age, and comorbidities such as diabetes and
hypertension.17 Another contributing factor in this regard might be the
retinal region studied, i.e., macular or peripapillary region, in the concerning
studies.
6
The finding of a negative correlation of FD with age in adults with
22q11.2DS is consistent with studies in much older adults in the general
population with (mild) cognitive impairment and Alzheimer’s disease.13, 28
This raises the question to what extent this finding indicates premature
neurodegenerative processes, that may underly cognitive decline and early-
onset Parkinson’s disease in 22q11.2DS.6, 8 Interesting in this context is that
studies in a mouse model of aging have shown a negative relationship in
retinal branching with age.29, 30
Retinal nerve fiber layer thickness
Thicker RNFL of the nasal, and a trend for thinner RNFL in the nasal inferior,
segments in 22q11.2DS were found compared to controls. Findings from
studies examining RNFL in idiopathic schizophrenia spectrum disorders
have been inconsistent. Some studies found the RNFL to be significantly
reduced, specifically in the nasal and superior segments,15, 31 but not all.17,
32, 33
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