Effects of primary glaucoma on sleep quality and daytime sleepiness of patients residing at an equatorial latitude

AIM:To investigate the impact of primary glaucoma on sleep quality and daytime sleepiness of patients.METHODS:Prospective cross-sectional study with consecutive sampling in South-East Asian population was performed.Validated questionnaires:the Pittsburg Sleep Quality Index(PSQI)and Epworth Sleepiness Scale(ESS)were administered prospectively.Subjects with nonglaucomatous optic neuropathy or concomitant retinal pathology were excluded.Glaucoma severity was based on HVF 24-2 perimetry.Binocular single vision was represented based on the better eye.Frequency of and predictive factors for poor sleep quality and excessive daytime sleepiness were compared.RESULTS:A total of 79 primary open angle glaucoma(POAG),27 primary angle-closure glaucoma(PACG)patients,and 89 controls were recruited.PACG patients had higher median PSQI scores(P=0.004)and poorer sleep quality(P<0.001).Compared to controls,PACG patients were 3.34 times more likely to have poor sleep quality(P=0.008),which remained significant after adjustment for demographics(P=0.016)and predictive variables(P=0.013).PACG patients have poorer sleep quality when visual acuity(VA)was 6/15 or worse(P=0.009).Univariate and multivariate analysis of predictive variables for poor sleep quality and daytime sleepiness did not find statistical significance.CONCLUSION:PACG patients have poorer sleep quality but not daytime sleepiness.This is important in South-East Asian population with heavy disease burden.Evaluations on sleep disturbances can be considered to provide more ho istic care.

ipRGCs: possible causation accounts for the higher prevalence of sleep disorders in glaucoma patients

Sleep accounts for a third of one＇s lifetime, partial or complete deprivation of sleep could elicit sever disorders of body function. Previous studies have reported the higher prevalence of sleep disorders in glaucoma patients, but the definite mechanism for this phenomenon is unknown. On the other hand, it is well known by us that the intrinsically photosensitive retinal ganglion cells（ip RGCs） serve additional ocular functions, called non-image-forming（NIF） functions, in the regulation of circadian rhythm, melatonin secretion, sleep, mood and others. Specifically, ip RGCs can directly or indirectly innervate the central areas such as suprachiasmatic nucleus（SCN）, downstream pineal gland（the origin of melatonin）, sleep and wake-inducing centers and mood regulation areas, making NIF functions of ip RGCs relate to sleep. The more interesting thing is that previous research showed glaucoma not only affected visual functions such as the degeneration of classical retinal ganglion cells（RGCs）, but also affected ip RGCs. Therefore, we hypothesize that higher prevalence of sleep disorders in glaucoma patients maybe result from the underlying glaucomatous injuries of ip RGCs leading to the abnormalities of diverse NIF functions corresponding to sleep.