Sleep Apnea and Glaucoma | Driving with Dr. David Richardson Ep 03

Good morning. I’m Dr. David Richardson. I’m a cataract and glaucoma surgeon that practices in Southern California. I’ve been playing with a video idea; basically, take a little bit of time I’ve gotten in my day that’s free to share some of the knowledge that I have about glaucoma that may not be commonly available online.

Right now, I’m discussing systemic issues that can be associated with glaucoma as part of a holistic approach to treating glaucoma; not limited just to addressing intraocular pressure or IOP. One of the things I mentioned in the first video was sleep apnea. So, I’d like to discuss a little bit about sleep apnea. Let’s get going and chat.

Sleep Apnea and Importance of Oxygen to Tissues

The first thing is to address some misconceptions about sleep apnea. Sleep apnea is not just an issue with bad snoring. Sleep apnea is, essentially, a condition where someone during sleep is unable to breathe for a period of time or rather just stops breathing.^[1] And there are multiple potential mechanisms of this. We don’t really need to get into but point is, that for a period of time, which can be an extended period of time, there is no breathing occurring. And if there is no breathing occurring, there is no oxygenation of the tissues in the body; including the retina, optic nerve, and other ocular or eye-related tissues.^[2] Now, it’s of interest that the retina is considered to be one of the most metabolically active structures in the body and what that means is that it requires a lot of energy in order for it to function well.

The retina is essentially the sports car of the eye. Just as you would not attempt to drive a sports car using low octane fuel or at least not expected to perform well, one cannot expect that the retina is going to perform well if it does not have a good blood supply or is not getting oxygen in the blood, because oxygen is the fuel that our tissues need. Now, you might be wondering, “Well, what does the retina have to do with the optic nerve?” We’re talking about glaucoma. Glaucoma is a condition of optic nerve pathology. Well the optic nerve is made up of axons from cells, which are in the retina. These cells are called the ganglion cells and it’s important that these ganglion cells get the oxygen they need in order to perform the metabolic activity or functions that are going on.

So, all of this is just to state that you need to have good oxygenation as well as good perfusion (as we talked about in the last video). So, you need to have a blood supply but the blood itself has to be oxygenated. Both of those things are critical. And in those with sleep apnea, there is “not good oxygenation” during the night. So, all of this is just to point out that sleep apnea, again, is not just an issue of snoring, it’s not just something that makes people tired the next day… it’s a condition that actually slowly destroys the tissues in the body—the eye, being one of them. And in particular, the ganglion cells and associated optic nerve.

So, although it can be quite challenging, and annoying, and inconvenient to obtain a workup for sleep apnea, and a treatment (an effective treatment) for sleep apnea—it, really, is worth the effort.

There are a couple of types of glaucoma, in particular, where it seems to be worth the effort. So, although I recommend for all of my patients who have symptoms of or who at risk of sleep apnea—and what are some of the risks? Well, obesity (or doesn’t even have to be obesity), it just can be extra tissue around the neck or within the oral pharynx (so, basically the back of the mouth the tongue the the mouth the back of the mouth)…all these things, which can be addressed from weight loss to special devices that are placed in the mouth to orthodenture. I mean, so there really is a full range of potential treatments ^[3]—I do recommend that any of my patients with glaucoma who are at risk for sleep apnea get worked up for it. And those that have it documented, actually, be treated for it.

Normal Tension Glaucoma and Sleep Apnea

There is a subsets of patients that have what is called, “normal tension glaucoma” (sometimes called low tension glaucoma)^[4] in which they have all of the signs and symptoms of glaucoma in terms of the typical loss of nerve fiber layer a loss of visual field but their pressures are fine or at least every documented pressure has been fine. In these patients, it really is felt that, the problem is not primarily with the intraocular pressure but rather perfusion of the optic nerve or oxygenation. And these patients tend to be particularly susceptible to damage from sleep apnea. So anyone who has normal tension glaucoma and is at risk of sleep apnea or developing sleep apnea, in my view, really needs to be worked up and treated for it.

So I think that’s enough on sleep apnea, today. Again, I’m not going to get into all of the methods of how to diagnose and treat it. That’s for another specialist to discuss. I’m sure there’s some video out there on that, as well, online. But I did want to pay particular attention, today, to that element of a holistic approach to glaucoma. Eventually we’ll get to intraocular pressure—but not yet.

All right, so have a great day and I’ll see you on my next commute.

References

¹ Berry RB, Budhiraja R, Gottlieb DJ, Gozal D, Iber C, et al. (2012) Rules for scoring respiratory events in sleep: update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events. Deliberations of the Sleep Apnea Definitions Task Force of the American Academy of Sleep Medicine. J Clin Sleep Med 8: 597–619.

² Karakucuk S, Goktas S, Aksu M, Erdogan N, Demirci S, et al. (2008) Ocular blood flow in patients with obstructive sleep apnea syndrome (OSAS). Graefes Arch Clin Exp Ophthalmol 246: 129–134. https://www.researchgate.net/publication/6163734_Ocular_blood_flow_in_patients_with_Obstructive_Sleep_Apnea_Syndrome_OSAS

³ Treatment of Obstructive Sleep Apnea Syndrome https://www.uptodate.com/contents/management-of-obstructive-sleep-apnea-in-adults

⁴ Lin PW, Friedman M, Lin HC, Chang HW, Wilson M, et al. (2011) Normal tension glaucoma in patients with obstructive sleep apnea/hypopnea syndrome. J Glaucoma 20: 553–558. https://www.ncbi.nlm.nih.gov/pubmed/20852436

⁵ Mojon DS, Hess CW, Goldblum D, Fleischhauer J, Koerner F, et al. (1999) High prevalence of glaucoma in patients with sleep apnea syndrome. Ophthalmology 106: 1009–1012.

⁶ Geyer O, Cohen N, Segev E, Rath EZ, Melamud L, et al. (2003) The prevalence of glaucoma in patients with sleep apnea syndrome: same as in the general population. Am J Ophthalmol 136: 1093–1096.

⁷ Lin CC, Hu CC, Ho JD, Chiu HW, Lin HC (2013) Obstructive sleep apnea and increased risk of glaucoma: a population-based matched-cohort study. Ophthalmology 120: 1559–1564.

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