A new study presented at the virtual 2021 Annual Meeting of The Association for Research in Vision and Ophthalmology (ARVO) points to the cause of high incidence of sleep disorders in patients with glaucoma.
A recent study of more than 6,700 people showed that glaucoma patients have a high incidence of sleep disorders. Intrinsically photosensitive retinal ganglion cells (ipRGCs), which are involved in circadian rhythms, are also known to be injured in glaucoma. The ipRGCs provide input to the ventrolateral preoptic nucleus (VLPO), a major sleep-inducing subcortical structure. Ventrolateral preoptic nucleus induces sleep by delivering inhibitory signals to the subcortical arousal systems and the cortex.
Inspired by these findings, Ji Won Bang, PhD, and her team at the New York University Grossman School of Medicine, investigated whether the sleep-regulating subcortical systems involving ventrolateral preoptic nucleus and their inhibitory projections to the cortex are impaired in glaucoma.
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The study’s 38 glaucoma patients and 22 healthy subjects underwent 3T anatomical MRI and resting-state functional MRI (fMRI) with eyes closed. Additionally, 25 glaucoma patients and 7 healthy subjects were scanned for 3T anatomical MRI and proton magnetic resonance spectroscopy (MRS). Results showed that the sleep-regulating subcortical systems involving ventrolateral preoptic nucleus and their projections to the occipital cortex are impaired under glaucoma. Such alterations may underlie the high occurrence of sleep disorders in glaucoma.
As intraocular pressure is currently the only clinically modifiable risk factor for glaucoma, Bang hopes this research may lead to a better understanding of glaucoma pathogenesis in relation to sleep problems in the brain, which could contribute to better strategies to target glaucoma treatment beyond intraocular pressure control.
Bang says in a release, “We expect our study will bring attention to research that investigate changes in the brain and their behavioral relevance in glaucoma. We wish our study will contribute to developing more targeted therapeutic interventions for glaucoma patients who suffer from sleep problems.”
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