Glaucoma – Not always so benign

tfcoates (55)in #steemstem • 6 years ago

G’day team,

Today I’m doing a post to enter the @medicolife science contest, and talking about a rather common and misunderstood condition of the eye, glaucoma.

What is Glaucoma

Glaucoma is a condition where pressure builds up in the eye, its usually chronic condition which progresses slowly over time, but a rapid onset version exists that can be extremely painful and threaten vision. To really understand Glaucoma, however, we have to first understand a bit about the eye.

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The eye is split into two segments, the anterior or front segment contains the lens, iris and ciliary muscles which are responsible for filtering and focusing light. The posterior, or back, segment contains the retina, arteries and the optic nerve which are responsible for processing light information and delivering it to the brain.

Now the anterior segment, itself, is broken into two further segments. An anterior chamber in front of the iris and a posterior chamber behind it.

As it's our window to all the light in the world, obviously, this region of the eye can’t have blood flowing through it. However it does still need some form of nutrient supply, so in the ciliary body behind the iris Aqueous Humour is produced, which flows forward into the anterior chamber and out through a drain called the Trabecular Meshwork.

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Two Types of Glaucoma

Now we understand a little about how the eye works, we can look at the two problems that arise and cause our two distinct types of glaucoma.

Open Angle Glaucoma

Now, this is the most common cause of Glaucoma, it’s a chronic condition which is caused by a failure of the Trabecular Meshwork to properly drain the Aqueous Humor produced by the ciliary body. For anyone who knows just a little bit about physics, if we think of the eye as a fixed volume and we’re adding more liquid to this volume than we’re draining out, the pressure inside begins to rise. High pressure in the eye is a bad thing, especially for the small arteries which are trying to squeeze blood in to supply the retina and optic nerve. As the blood supply dwindles, we see the death of the outer retina and the optic nerve.

This will ultimately result in a long-term vision loss, beginning in the peripheries and working towards the center.

Acute Angle-Closure Glaucoma

Unlike it’s slow but relentlessly moving counterpart, acute angle closure glaucoma is both a rapid and treatable condition. It occurs when the angle between the iris and cornea closes (where the iris is pushed forwards), actively blocking the entire Trabecular Meshwork. This results in a rapid and rather extreme build-up of pressure in the eye which can cause a direct damage to the retina and ultimately lead to blindness.

While treatment options are available for Acute Angle-Closure Glaucoma, they are not always administered in time and long-term vision impairment is a common outcome.

Prevention is Better than Cure

As the old adage goes, prevention is the name of the game when it comes to both forms of Glaucoma, as well as understanding what our individual risks are. Open0angle glaucoma is more common in Black populations than Caucasians and the most common risk factor is hypertension, so having a healthy diet and lots of exercise is the best option to hold off the disease. Acute Angle-Closure Glaucoma is more common in women, Asians and least common in Black populations. People with hyperopia are also more likely to get Acute Angle-Closure Glaucoma, in this scenario there’s not much one can do to control the risk factors.