The main cause of glaucoma is damage to the optic nerve.
While elevated intraocular pressure (IOP), or eye pressure, is a significant risk factor, it is not always the sole cause. The optic nerve, which transmits visual information from the eye to the brain, becomes damaged, leading to progressive vision loss and potentially blindness if left untreated.
Here's a breakdown of factors related to glaucoma:
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Elevated Intraocular Pressure (IOP):
- An imbalance in the production and drainage of fluid (aqueous humor) within the eye can lead to increased IOP.
- This elevated pressure can damage the delicate fibers of the optic nerve.
- Abnormalities in the eye's drainage system are often the cause of this fluid buildup.
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Optic Nerve Damage Without Elevated IOP (Normal-Tension Glaucoma):
- Some individuals develop glaucoma even with normal IOP readings.
- The precise cause in these cases is not fully understood, but may involve:
- Increased sensitivity of the optic nerve to normal pressure levels.
- Reduced blood supply to the optic nerve.
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Other Risk Factors:
- Family history of glaucoma.
- Age (risk increases with age).
- Certain medical conditions (e.g., diabetes, high blood pressure).
- Ethnicity (African Americans and Hispanics are at higher risk).
- Myopia (nearsightedness).
- Prolonged use of corticosteroid medications.
In summary, while high eye pressure is a major risk factor, the underlying cause of glaucoma is damage to the optic nerve, regardless of whether high pressure is present or not. Damage to the optic nerve leads to the characteristic visual field loss associated with glaucoma. Early diagnosis and treatment are crucial to preventing further nerve damage and preserving vision.
