Glaucoma & Macular Degeneration Vocabulary

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  • 0:01 Loss of Vision
  • 0:27 Glaucoma
  • 2:25 Macular Degeneration
  • 3:07 Lesson Summary
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Lesson Transcript
Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

There are two major conditions that can threaten what some consider your most precious sense. They are called glaucoma and macular degeneration. These conditions and their major types are defined herein.

Loss of Vision

Throughout your day you enjoy all sorts of sounds, smells, sights, and tastes. You have many senses. But the most important sense we have is our vision. I think you'd agree.

Our precious eyesight can be partially or completely threatened by two conditions: glaucoma and macular degeneration. We'll define not only what they are, but also define the different kinds there are.


Glaucoma is a condition characterized by increased intraocular pressure, such that damage to the eye and blindness become a real possibility. Intraocular means within the eye, where 'intra-' means 'within' and 'ocular' refers to the eye.

You may be wondering, what pressure? Well, the inside of your eye is filled with fluid. This fluid, called aqueous humour, is produced by something called the ciliary body, and it flows out of the eye via something called the trabecular meshwork as necessary to keep the pressure normal. If anything obstructs the outflow of this fluid, that means fluid is being produced at a faster pace than it is exiting the eye and so, the pressure within the eye increases.

Just think of a bathtub filling with water. If the drain is open wide enough to accommodate the amount of water flowing into the tub, everything stays the same. If the drain is clogged or blocked, then the tub fills with ever-increasing amounts of water since the rate of outflow is slower than the rate of inflow.

This excess water can spill out onto the bathroom floor, but in the eye, the fluid has nowhere to go and thus, the pressure within the eye increases to the point that it can damage internal structures, namely the optic nerve, the nerve responsible for vision.

There are two major kinds of glaucoma. One is called open-angle glaucoma. This is the most common form of glaucoma where the drainage channels gradually become clogged. It's like a drain in the tub that you can tell is getting clogged over time as it takes longer and longer for the water coming out of the shower to drain.

The other kind is angle-closure glaucoma, where the drainage is blocked very quickly. It's like someone basically puts a bathtub stopper over the drain, and so the water begins to accumulate very quickly within the tub.

Macular Degeneration

The other condition that can lead to vision loss is called macular degeneration, a condition caused by the degeneration of the macula, an area near the center of the retina. This leads to loss of central vision.

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