Researchers from Brasil1 believe they have identified a link between glaucoma and sleep quality. They compared 32 patients with glaucoma to 13 subjects without and measured quality of sleep using polysomnography. They found patients with glaucoma have significantly lower total sleep time, sleep efficiency and oxyhemoglobin saturation (the molecule that carries oxygen from your lungs to the rest of your body) compared to healthy subjects.
To help explain this phenomenon, the researchers in the same study also assessed the function of retinal ganglion cells (RGC), a type of cell in the retina vital for carrying information about vision from the eye to the brain which is reduced in number in glaucoma patients. Not surprisingly they found that RGC function was reduced and speculate that this is the reason from impaired sleep.
Information from the eye is important for your body’s ability to regulate it’s normal day-night cycle. If this information is impaired in some way, it stands that your body’s day-night cycle may also be impaired. Blindness is an extreme example where vision impairment has a known association with sleep disturbance. What the study of Gracitelli et al shows is that individuals with glaucoma may have a similarly affected sleep pattern even though they maintain functional vision. These findings suggest clinicians (and patients) should be alert to the possibility that glaucoma is reducing sleep quality. Whether glaucoma treatment has positive influence on this finding remains to be seen.
1. Gracitelli CP et al. Intrinsically Photosensitive Retinal Ganglion Cell Activity Is Associated With Decreased Sleep Quality in Patients With Glaucoma. Ophthalmology 2015 Apr 06;[EPub Ahead of Print]