Intraocular pressure – Pressure in the Eye

Mar 6, 2025

Understanding Intraocular Pressure: The Pressure in Your Eyes

Intraocular pressure (IOP) refers to the pressure inside the eye, caused by the fluid present in the eye. Measuring IOP is crucial, as increased pressure can lead to glaucoma and vision loss.

What’s a Normal IOP?

A normal IOP ranges from 10-20 millimeters of mercury (mmHg). Ocular hypertension occurs when the IOP exceeds 21 mmHg in one or both eyes, measured during two or more consecutive office visits.

Causes of Ocular Hypertension

Several factors can contribute to increased IOP:

– Excessive production of aqueous humor, the fluid in the eye
– Poor drainage of the fluid
– Certain medications, such as steroids
– Eye injuries, which may cause increased pressure years later
– Other eye conditions, like pseudo-exfoliation syndrome and corneal arcus
– Age, race, and family history

Low Ocular Pressure: Ocular Hypotony

While less common, low ocular pressure (below 5 mmHg) can cause concerns, particularly if it leads to vision disturbances. Ocular hypotony can result in:

– Corneal swelling
– Macular damage
– Cataracts
– Blurry vision

Glaucoma and Intraocular Pressure

Ocular hypertension may not be a disease itself, but rather an indication of potential glaucoma. It’s often accompanied by optic nerve damage or vision loss.

Diagnosing Intraocular Pressure

To assess IOP, eye care professionals use various tests:

– Visual acuity testing
– Slit lamp examination
– Tonometry (measuring the tone of the eye’s surface)
– Gonioscopy (examining the drainage of fluid from the eye)
– Visual field testing (assessing peripheral vision)

Treating Ocular Hypertension

If symptoms like blurred vision, pain, or seeing halos around lights occur, along with high IOP measurements, treatment may involve:

– Topical medications (eye drops) to reduce IOP

References:

https://en.wikipedia.org/wiki/Intraocular_pressure
https://www.webmd.com/eye-health/intraocular-pressure-eye-health
https://www.medicinenet.com/tonometry/article.htm
https://www.aao.org/eye-health/anatomy/eye-pressure
https://www.allaboutvision.com/en-in/conditions/hypertension/