What is hypotony in the eye?

What is Hypotony in the Eye?

Hypotony, or ocular hypotony, refers to an abnormally low intraocular pressure (IOP) within the eye. The intraocular pressure is the fluid pressure inside the eye, an important factor in maintaining the eye's shape and proper function. Normal IOP ranges between 10 to 21 mmHg. When the pressure falls below this range, usually under 6 mmHg, it is referred to as hypotony.

Hypotony can occur due to various reasons such as surgical complications, trauma, inflammation, or diseases that affect the eye, including uveitis or retinal detachments. Another common cause is fluid leakage from surgical wounds after procedures like cataract surgery or glaucoma surgery. In some cases, certain systemic diseases or the use of specific medications can also lead to hypotonic conditions.

Low ocular pressure can lead to a range of symptoms and complications. People with hypotony may experience blurred vision, distorted vision, and discomfort within the eye. In more severe cases, hypotony can result in more significant visual impairment or loss. This is often due to structural changes in the eye caused by the lower pressure, such as the flattening of the cornea or choroidal detachment (separation of the retina from the choroid, which is the middle layer of the eye).

Diagnosing hypotony involves measuring the intraocular pressure using a tonometry test. This is often accompanied by a comprehensive eye examination to assess any associated damage or underlying causes. Detecting hypotony early is crucial in preventing potential vision complications and addressing the underlying causes appropriately.

Treatment for hypotony largely depends on the underlying cause. If it results from surgical interventions, the condition may resolve on its own or require further surgical correction. In cases where inflammation or leakage is identified as the cause, topical treatments or medications may be necessary to address these issues. While managing hypotony, the overarching goal is to restore normal pressure levels while preserving vision and preventing further ocular damage.

Hypotony should not be confused with conditions associated with high intraocular pressure, such as glaucoma, which can also cause vision problems but through entirely different mechanisms. While elevated IOP is a direct risk factor for glaucoma, hypotony poses its own set of challenges and risks that necessitate prompt and often individualised intervention.

If you suspect hypotony or experience sudden changes in vision, it is crucial to seek an evaluation by an eye care professional. Managing the condition effectively involves both addressing the symptoms and targeting the root cause to mitigate long-term effects on vision and eye health.