Sleep Apnea and Glaucoma
Hokkaido University in Japan has a group of scientists who have studied the relationship between obstructive sleep apnea and glaucoma, and have found that there can be damage to the optic nerve in patients with obstructive sleep apnea. But the interesting thing is that the lack of oxygen due to the obstructive sleep apnea does not cause a brief sharp increase in eye pressure. Therefore, these patients with glaucoma have normal eye pressures.
Glaucoma is a disease where the optic nerve is damaged because of increased eye pressure, or is it? This study seems to show that the damage may be caused by something else in patients with obstructive sleep apnea. Glaucoma causes a smaller field of vision and can result in blindness. But patients with obstructive sleep apnea seem to have glaucoma at about ten times the rate of patients who do not have obstructive sleep apnea.
This was a difficult study to perform — to measure eye pressure in sleeping patients, but these scientists were able to do it. Normally, when patients breath out, the eye pressure increases. But in this study, the scientists found that eye pressure decreased when the patients had an apnea event (stopped breathing). This seems to indicate that the optic nerve damage can be from the drop in oxygen without an increase in eye pressure.
This study could help scientists find out why some patients with glaucoma have normal eye pressure. The relationship of obstructive sleep apnea to medical conditions is still unknown to a large extent as this study has shown.