Abstract
Purpose: :
Glaucoma is a major cause of blindness characterized by progressive and irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells and visual deficit associated with glaucoma have been extensively studied, recent evidence suggest that glaucoma can also affected non-image-forming visual functions, such as the control of circadian rhythms. The aim of this study was to evaluate the circadian physiology, particularly sleep/wake cycles in patients with bilateral advanced glaucomatous neuropathy.
Methods: :
Nine normal control subjects from 55 to 80 years and nine age-matched patients with bilateral advanced primary open-angle glaucoma with more than 10 years from diagnosed, were included in this observational, prospective, case-control study. Advanced glaucoma damage was considered as a combination of both an optic nerve with a vertical cup to disc ratio of more than 0,8 and an altered visual field, defined as a mean deviation worse than -12 db. Subjects with neurologic and motor disorders or those who used common hypnotic drugs were excluded. The visual field analysis was performed with a Humphrey Field Analyzer II computer 750 and a core program 24-2. We included only reliable visual fields (fixation losses, false positives and false negatives below 25%) in phakic and pseudophakic patients. Patients were required to record the timing and duration of their sleep and daily activities, and wore an actigraph (MicroMini Motionlogger® Actigraph, USA) on the wrist of the non-dominant arm for 20 days.
Results: :
Although no differences in total minutes scored as sleep were observed between groups, glaucomatous patients showed a significant decrease in the sleep efficiency and the percentage of sleep, whereas the amount of wake minutes and the mean wake episode duration after sleep onset were significantly higher on the glaucomatous patients than in the control group.
Conclusions: :
These results suggest circadian alterations, particularly in the sleep quality, in patients with advanced glaucoma.
Keywords: circadian rhythms • ganglion cells • quality of life