Page 21 - Demo

General introduction191 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, 74The eye as a window to the brainStudying 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 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.