Glaucoma

In this lesson we're going to talk about glaucoma.

Glaucoma, by definition, is damage to the optic nerve as a result of increased pressure inside the eye, also known as intraocular pressure, or IOP. In order to understand how that works, we have to take a few steps back and take a look at the eye. The anatomy of the eye functions similarly to a kitchen sink. Part of the iris, call the ciliary bodies, are responsible for producing the aqueous humor in the eye - that’s like the faucet in the sink. The drain portion of the eye is where the iris and the cornea meet, often called the drainage angle. Glaucoma is a result of decreased outflow of that aqueous humor. This is because of a clogged or blocked drainage angle, similar to having a clog in the sink. Because the fluid has nowhere else to go, and since the eyes are confined space, this creates an increased intraocular pressure. Remember the optic nerve sits here at the back of the eye, so as the pressure increases, it can push on the optic nerve, which is what causes damage to the optic nerve.

Now that we have a better understanding of what glaucoma is, we can take a look at different types of glaucoma. There are two common types of chronic glaucoma, which have to do with how to open the drainage angle is. Some people suffer from open-angle glaucoma and some people suffer from narrow angle glaucoma. They are just like they sound. Open-angle glaucoma has a drainage angle that is open but it gets clogged over time. Narrow angle glaucoma has a drainage angle that's closed or narrowed, anatomically. Either way, the fluid can’t flow out like it should. Of these all of these types, the most important one to remember is acute angle closure glaucoma. This happens when the drainage angle suddenly becomes blocked or more narrowed. This can occur as a result of inflammation or trauma or other causes. This is a medical emergency because it can lead to long-term vision loss if we don’t catch it and fix the problem. There's one other type of glaucoma. It's a type of glaucoma in which the pressure inside the eye is normal. However, there is still damage that has occurred to the optic nerve consistent with other types of glaucoma.

Now we're going to take a look at some assessment findings. Things that the patient experiences could be vision loss or vision changes, because of the damaged optic nerve, and eye pain, or headaches from the increased pressure. Things that you as a nurse would see would be things like corneal changes such as a hazy or cloudy cornea like you see here or changes in the white part of the eye (the sclera) that looks similar to being bloodshot. It’s important to realize that bloodshot eyes are not an isolated symptom of glaucoma. But when paired with patient complaints like vision loss and eye pain, and you see a cloudy cornea, you can be suspicious that glaucoma may be the culprit. One of the most important diagnostic tools in determining if glaucoma is actually the problem is something called tonometry which is a measurement of the pressure inside the eye. The important thing for you guys to remember is that the normal pressure is 10 to 21 mmHg.

When we talk about medications we need to think back to how the eye works, again like a sink. There are several different types of medications the focus on controlling the outflow, so think about unclogging the drain. There are also medications that work to decrease the amount of aqueous humor in the eye, much like turning down the kitchen sink. There are also the medications that do both to turn down the sink and to unclog a drain. I've listed some drug classes and some medications as examples into how they can help to control pressure in the eye so make sure you check those out.

When we talk about nursing priorities there are some situations that we want to avoid. These things are like placing your patient in Trendelenburg, the valsalva maneuver, or having a patient bear down, so think constipation. The reason we want to avoid these types of situations that they increase pressure inside the head. This increase in intracranial pressure also increases intraocular pressure, which makes glaucoma worse. So just be mindful if you have a patient that has glaucoma and any time you’re intervening, think about their eye pressure. For example, if you have a patient who couldn’t be turned and had to lay flat AND was constipated, this situation could be problematic for their glaucoma.

Now when it comes to educating our patients there are two main focuses. Medications, and activities of daily living, or ADL’s. When it comes to medications, it's important that the patient understand how to correctly give themselves medication and most importantly patient compliance. The main reason patients have uncontrolled or worsening glaucoma is because they aren't compliant with their meds. So make sure that you reinforce that education component with your patients. When talking about ADL’s, the biggest takeaway is safety. Encourage your patient or if you have the opportunity, make sure that your patient’s home is safe because they have limited vision or their vision could get worse at any given moment. Because of this, make sure that they don’t move their furniture, they remove throw rugs, and do an overall safety assessment to look for tripping hazards. Additionally, finding ways for patients to see easier like large text telephones, can help improve their ADLs at home.

I just want to quickly cover some nursing concepts. Safety is important because you need to make sure that your patient is safe at home because they have decreased sensory and visual perception. Also be sure to consider patient’s comfort levels because glaucoma can occasionally be painful.
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Okay guys, quick recap. Remember that glaucoma is about increased pressure inside the eye. Increasing that pressure can cause vision changes, vision loss, and retinal damage. The eye is like a kitchen sink, so if you have increased pressure you need to unclog the drain. Remember the medications can turn down the faucet, unclog the sink, or do both. As a nurse, you want to avoid interventions that are going to increase pressure inside the head or the eye. And lastly, educate your patients on medication compliance and make sure they properly understand how to give themselves a medication.

So that’s it for glaucoma, make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!