Being told you have high eye pressure can sound alarming, especially if glaucoma is mentioned at the same appointment. But high eye pressure and glaucoma are not the same thing. Elevated eye pressure is an important risk factor for glaucoma, but some people have higher-than-normal pressure without ever developing glaucoma. The reverse can also happen: glaucoma can develop even when eye pressure falls within what is generally considered a normal range.
For that reason, an eye pressure reading is only one part of a glaucoma evaluation. At Paragon Eye Associates, we also look closely at the optic nerve, peripheral vision, corneal thickness, family history and other factors that help us understand whether a patient’s vision is at risk.
What Does Your Eye Pressure Actually Tell Us?
Your eye continuously produces a clear fluid called aqueous humor. That fluid needs to circulate and drain properly to maintain a healthy pressure inside the eye. If it does not drain efficiently, intraocular pressure, commonly called IOP, can rise.
Eye pressure is measured in millimeters of mercury (mmHg), and approximately 10 to 21 mmHg is commonly referenced as the normal range. However, there is no single number that separates a healthy eye from an unhealthy one. A pressure of 22 or 24 may not cause damage in one patient, while another patient may develop glaucoma at a lower pressure.
Instead of looking only at whether a number falls above or below 21, we want to know what that pressure means for that particular patient’s eyes.
High Eye Pressure vs. Glaucoma
If your pressure is elevated but your optic nerve remains healthy and testing does not show glaucoma-related vision loss, you may be diagnosed with ocular hypertension. This means your eye pressure is higher than expected, but you do not currently have evidence of glaucoma.
Ocular hypertension does increase the risk of developing glaucoma, so it should not be ignored. Depending on your pressure and other risk factors, we may recommend regular monitoring or treatment to lower the pressure before damage occurs.
Glaucoma is different because there is damage to the optic nerve. Over time, that damage can affect peripheral vision and eventually more of a person’s sight if the disease progresses. Since vision already lost to glaucoma cannot be restored, detecting changes early is particularly important.
What If My Eye Pressure Is 22, 24 or 25?
We hear versions of this question frequently, and the number by itself is not enough to answer it.
If your pressure measures 24 mmHg, for example, we would not automatically conclude that you have glaucoma. We would want to know what your optic nerve looks like, whether your visual field is normal, how thick your cornea is, whether your pressure has changed over time and whether you have other glaucoma risk factors.
Family history also matters. If a parent or sibling has glaucoma, that information may change how closely we monitor an elevated pressure reading.
This is also why comparing your pressure to someone else’s is not particularly helpful. What matters is whether your current pressure is safe for your eyes.
Can You Have Glaucoma With Normal Eye Pressure?
You can. Normal-tension glaucoma causes optic nerve damage even though a patient’s measured eye pressure does not exceed the typical normal range.
It is a good example of why glaucoma screening involves more than the familiar “air puff” or pressure check. A normal pressure reading does not necessarily tell us that the optic nerve is healthy, just as a higher reading does not automatically tell us that glaucoma is present.
How Do We Check for Glaucoma?
When there is concern about glaucoma, several pieces of information are considered together. In addition to measuring intraocular pressure and examining the optic nerve, testing may include a visual field test to check peripheral vision, measurement of corneal thickness and optical coherence tomography (OCT).
OCT gives us detailed images and measurements of structures around the optic nerve and retina, including the retinal nerve fiber layer. These measurements are especially valuable when they are followed over time. Comparing today’s results with earlier exams can reveal subtle changes that may not yet be noticeable in everyday vision.
For many patients with elevated eye pressure, that long-term comparison is just as important as the pressure reading taken during any single visit.
When Does High Eye Pressure Need Treatment?
Not everyone with ocular hypertension needs to begin treatment immediately. If the optic nerve is healthy and the overall risk of developing glaucoma is relatively low, monitoring may be appropriate. Someone with higher pressure, suspicious optic nerve changes or additional risk factors may benefit from treatment sooner.
When treatment is recommended, there are now several ways to lower eye pressure. Prescription eye drops remain a common option, but they are no longer the only one. Depending on the patient’s diagnosis and needs, treatment may also include laser procedures, sustained-release medication or glaucoma surgery.
iDose® TR, for example, is an implant that delivers glaucoma medication from inside the eye over an extended period. For appropriate patients, it can reduce the burden of using glaucoma drops every day.
Another option for certain glaucoma patients is Minimally Invasive Glaucoma Surgery (MIGS). Procedures such as iStent® are designed to improve the eye’s natural drainage and lower pressure through a minimally invasive approach. MIGS may also be performed at the time of cataract surgery for some patients.
There is no single glaucoma treatment that is right for everyone. The decision depends on the type and stage of glaucoma, the amount of pressure reduction needed, current medications, previous treatment and the health of the eye.
Don’t Ignore High Eye Pressure Just Because Your Vision Seems Fine
One reason glaucoma can be difficult to detect is that early disease often does not change the way you see or feel. Elevated eye pressure itself usually does not cause noticeable symptoms either. You can have excellent central vision and still have early changes developing in the optic nerve.
If you’ve been diagnosed with ocular hypertension or identified as being at higher risk for glaucoma, keeping up with recommended follow-up exams gives your doctor the opportunity to spot those changes early. The goal is not simply to keep an eye on a pressure number. It is to make sure the optic nerve and your vision remain stable.
High Eye Pressure and Glaucoma Evaluation in Arlington and Mansfield, TX
If you’ve recently been told that your eye pressure is high, don’t assume that you have glaucoma. An elevated reading deserves further evaluation, but the health of your optic nerve and the results of glaucoma testing tell us much more about your actual risk.
At Paragon Eye Associates, we evaluate and treat glaucoma for patients throughout Arlington, Mansfield and the surrounding North Texas area. Depending on what we find during your examination, the right plan may be continued monitoring, medication or a more advanced glaucoma treatment such as iDose TR or MIGS with iStent.
If you have elevated eye pressure, a family history of glaucoma or questions about a recent eye exam, schedule an appointment with Paragon Eye Associates for a comprehensive evaluation.
