The eye is like a kitchen sink – Basic structure of the eye

  • November 23, 2021
  • Conditions

The eye is like a kitchen sink – Basic structure of the eye

The eye is a complex organ which involves a lot of structures and systems working together. When they all work as they should, the eye functions normally.

One of these is the drainage system. It operates somewhat like a kitchen sink, keeping the pressure in the eye at a safe level. Here’s how it works.

Posterior Vitreous Detachment - Coastal Eye Surgeons

How the drainage system works

The front of the eye is full of fluid. It’s easiest to think of it like a sink.

The ciliary body works like a tap. It’s located behind the eye’s iris (coloured part) and lens (clear part). The ciliary body produces fluid called aqueous humour which fills up your eye and flows through the pupil.

The trabecular meshwork is a section of spongey tissue which works like a drain. Aqueous humour can flow through it to exit the eye. Once it does so, it gets absorbed into small channels and then into veins, making its way back into the body’s circulatory system.

When these two structures work together properly, it’s like turning on the tap in an unplugged sink. Fluid can fill the sink and exit at about the same rate, so the amount of fluid present stays similar. If they don’t work as intended, severe vision problems can result.

What can go wrong?

Much like a sink, the eye can have problems which affect its ability to fill and drain properly.

If the drain gets blocked, fluid cannot leave the area. As a result, it can build up and cause pressure inside the eye.

If the tap is broken, the eye can get more fluid than it can drain. This can also cause increased intraocular pressure (IOP) and damage the optic nerve.

This leads to optic nerve damage and serious vision problems like glaucoma. Since vision loss caused by a damaged optic nerve can’t be recovered, problems with the eye’s drainage system are sight-threatening and need to be addressed as soon as possible.

How do these things get fixed?

In this case, an ophthalmologist works like a plumber to correct problems and restore normal IOP. There are a few ways we can do this.

High IOP can be treated with eye drops or medications. These work by improving drainage, similar to a plumber flushing the sink with drain cleaner to unblock it. Other types of drops work by decreasing aqueous humour production.

If these are not effective, a  laser or surgical procedure may be used to decrease the eye pressure. These work by opening the drainage passages or creating new ones, similar to a plumber unblocking your drain or installing a new one. In some cases, these procedures are performed in an emergency setting.

If drops or laser treatments don’t manage eye pressure, a surgeon can implant a glaucoma drainage device. These essentially make a new drainage system in the eye, like a plumber installing new pipes underneath your sink. If you need one, your surgeon will discuss the types available with you and select one that best meets your needs.

If the ciliary body is producing too much fluid and medications don’t help it, it can be destroyed using a laser or freezing procedure. This is known as cyclodestruction, and it’s like a plumber fixing a very leaky tap by removing it.

Seeking help

Glaucoma is sight-threatening, but it’s well understood and prompt treatment can go a long way in saving sight. If you think you may be affected, it’s critical to see your eye doctor straight away to start treatment.

Located on Hope Island (near the Gold Coast), Coastal Eye Surgeons is experienced in diagnosing and treating glaucoma and can provide a range of options.

You can learn more about how the eye works, glaucoma, and how it’s treated by following the links below

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