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Causes of Glaucoma

The truth is that conventional medicine and eye-doctors do not definitively know what causes Glaucoma, though there are many theories. Ocular Hypertension is closely associated with it and is considered the primary indicator / risk-factor of most Glaucoma. The theory being that high interocular Pressure associated with Ocular Hypertension damages the Optic Nerve causing glaucoma.

This does not however explain normal tension Glaucoma where Ocular Hypertension is not present but optic nerve damage still occurs.

With such delicate tissues as the retina and optic nerves even slight dysfunctions can have serious effects. It is likely that there are many causes and scenarios that can lead to Glaucoma. No one knows what actually kills the optic nerve cells (Apoptosis). High IOP clearly plays a role, but what actually causes the cell death in the optic nerves – high IOP, glutamate, poor blood flow, insufficient oxygen or nutrients or some genetic factor is the main question that remains unanswered. And whilst high IOP is clearly a major risk factor, no causal link has yet been made. Millions of people who have Ocular Hypertension never develop Glaucoma.

Causes of Closed Angle Glaucoma ( Narrow-Angle Glaucoma )

This form of Glaucoma is caused by a structural defect in the eye that creates a narrow angle between the the iris and the Cornea. If the Iris slips forward it can block the fluid drainage angle. This can be caused by eye trauma or it can be triggered by medications that dilate the pupil, such as antihistamines and tricyclic antidepressants. It can also occur naturally, when the eye dilates in low light.

Causes of Congenital Glaucoma

Nearly 85 percent of congenital glaucoma cases can be attributed to an inherited genetic defect. In particular the LMX1B gene is believed to cause some cases of inherited glaucoma. Other factors can include parental health and birth trauma.

Causes of Secondary Glaucoma

Secondary glaucoma is associated with a previous illness, injury, or disease. There are many secondary causes of glaucoma. Secondary glaucoma can be either of the open-angle or closed-angle variety, and are associated with:

  • Developmental glaucoma, where developmental problems interfere with the proper drainage of the eyes.

  • Ocular disease – pigment dispersion and vascular growth as a result of other eye-diseases.

  • Systemic diseases and drugs – Diseases such as Diabetes or the use of steroids such corticosteroids can cause glaucoma

  • Inflammation – uveitis

  • Eye Trauma causing angle recession, RBC associated glaucoma

  • Ocular surgery – aphakic glaucoma, aqueous misdirection

 

Causes of Open Angle Glaucoma

For the purposes of this section, normal tension Glaucoma is included as a sub-category of open Angle Glaucoma. Below is a list of issues that may be causal factors in the development of Glaucoma.

 

  • High Interocular Pressure ( not for Normal-Tension Glaucoma )

  • Brain chemical abnormalities - Elevated level of glutamate (a neurotransmitter) in the vitreous humor of the eye can kill nerve cells[7]

  • Genes - Several genetic factors can contribute to glaucoma. Mutations in the GLC1A gene cause it to overproduce a substance that clogs the angle where fluid drains from the eye.

  • Nitric oxide deficiencies - Low levels of nitric oxide contribute to unhealthy blood vessels, which in turn elevate intraocular pressure.

  • Poor Diet & Nutritional deficiencies

  • Reduced blood flow [9] – insufficient delivery of oxygen and nutrients to the eye – specifically the optic nerve.

  • Nerve irritation

  • Autoimmune disease – where the bodies defensive system is incorrectly triggered and it attacks healthy cells.

  • Exposure to toxins and certain medications