What can Cause Glaucoma?

Glaucoma occurs due to damage to the optic nerve that connect eyes to the visual cortex of brain. As optic nerve damage gradually deteriorates (due most commonly to rise in intraocular pressure), blind spots develop gradually in your field of vision. Exactly how raise in intraocular pressure of eyes lead to damage of optic nerve is not well understood. The intraocular pressure rises when there is excess production of fluid inside eye (aqueous humor) or if the drainage system for the fluid is defective and unable to drain normal amount of fluid. As a result, fluid buildup occurs and intraocular pressure rises.

There are various types of glaucoma and the causes of such types can also vary. These include,

  • Causes of open-angle glaucoma:

This is the most common type of glaucoma. The drainage angle formed by iris and cornea remain normal, however, the trabecular meshwork that also help drain aqueous humor may be partially damaged. This lead to accumulation of aqueous humor inside eye and pressure inside eye gradually builds up, leading to optic nerve damage and glaucoma symptoms. The nerve damage and symptoms develop very slowly and the patient may not even be aware of the problem and it may be too late to treat satisfactorily in some patients. Hence, it is important to get regular eye check done by your eye doctor.

  • Causes of angle-closure glaucoma:

In this type the angle between iris and cornea that help drain aqueous humor is narrow. As a result the fluid drainage is obstructed and intraocular pressure rises. This type can occur suddenly (acute angle-closure glaucoma) and is an acute medical emergency and need immediate lowering of intraocular pressure to preserve optic nerve from damage. It can also develop gradually (chronic angle-closure glaucoma) and in such case it may be difficult to differentiate from open angle glaucoma.

  • Normal tension glaucoma:

In this type of glaucoma, the intraocular pressure is normal, but optic nerve is damaged. The reason of optic nerve damage is not clear. The reason may be lack of blood supply to optic nerve due to atherosclerosis of the blood vessel that supply to optic nerve.

  • Pigmentary glaucoma:

In this type of glaucoma, pigment granules are buildup in the drainage channels, mostly from iris and slow down or block aqueous humor flow and intraocular pressure buildup, leading to damage to optic nerve.

  • Glaucoma in children:

Sometimes glaucoma may be present among children. It may be present since birth or may develop in the first few years of life. The causes may not be found or it may be due to the same causes that lead to glaucoma in adults.


Image courtesy of [patrisyu] at FreeDigitalPhotos.net

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