Purpose:
The current understanding of circadian regulation disorders and their involvement in
glaucoma pathophysiology are poorly understood, yet they may have a substantial impact on the onset and progression of
glaucoma. Herein, we review and summarize all the available literature on
circadian rhythm disorder and
glaucoma to uncover the impact on
glaucoma risk, and we highlight future research and potential novel targets for
glaucoma management.
Materials and Methods:
A review of the relevant literature was performed through PubMed through August 1, 2019.
Results:
Within a normal
circadian rhythm, intraocular pressure (IOP) peaks at night, whereas blood pressure (BP) troughs at night. High nocturnal IOP coupled with low nocturnal systemic BP results in low ocular perfusion pressure and potential for unobserved damage to retinal tissues and the optic nerve. Circadian-related melatonin and
sleep disorders also result in changes in IOP and ocular perfusion pressure that lead to the progression of
glaucoma. In addition, impaired perception of light input due to
glaucoma can subsequently lead to abnormal serum levels of melatonin, resulting in
circadian rhythm misalignment. This disruption of the
circadian rhythm also contributes to sleep and mood disorders, common in individuals with
glaucoma. As regards treatment,
glaucoma medications that lower nocturnal IOP without influencing nocturnal BP or diminishing circadian variation seem most effective.
Conclusions:
Glaucoma progression is influenced by multiple physiological factors regulated by the
circadian rhythm. Progression of the disease may also cause physiological changes that lead to circadian-related issues. Further research is warranted on the diurnal cycle, melatonin-mediated processes, and their influence on
glaucoma management.
