The nerve fibers that make up the optic nerve connect the retina to the brain. The loss of nerve fibers causes blind spots in the visual field, also known as visual field defects. The ophthalmologist can see that the optic nerve gradually starts to look different. Due to the loss of nerve fibers, the optic nerve becomes eroded or “excised”. If the disease is not treated or inadequately treated, the visual field defects will become larger and, at a late stage, sharp vision may also be affected.
Risk Factors
The mechanism that leads to the deterioration of the optic nerve in glaucoma is still not known in all its details. However, many factors are known to significantly increase the likelihood of glaucoma occurring (risk factors):
- Elevated eye pressure. This is by far the most important risk factor. A statistically normal eye pressure is between 11 and 21 mmHg. The higher the eye pressure, the more likely it is to occur.
- Glaucoma runs in the family. If glaucoma occurs in someone’s closest (1st and 2nd degree relatives), the chance of it occurring is 10 times higher than for someone without glaucoma in the family.
- High Age (older). In old age, glaucoma is much more common (4% of people older than 80 have glaucoma).
- Strong nearsightedness or farsightedness.
- Abnormalities of the blood vessels near or within the eye.
Types of glaucoma
The most common type of glaucoma is high-pressure glaucoma. In this process, the drainage system of the eye becomes clogged. This increases the eye pressure and eventually damages the optic nerve causing visual field loss.
In what is known as “closed chamber angle” glaucoma, the construction of the eye is such that through the iris (the rainbow membrane), the drainage system of the eye can be blocked, preventing the eye fluid from leaving and increasing eye pressure. This form can be acute or chronic. The acute form is usually accompanied by blurred vision, a red eye, headache, nausea and vomiting. These symptoms are caused by very high eye pressure. Prompt treatment is required to prevent damage to the optic nerve.
The chronic form is more common and can be treated well in the early stages. People who are farsighted, with strong plus glasses, are more likely to have this form of glaucoma.
Do you have any questions about glaucoma? Don’t wait and come by our store so we can see if we can help you. We can also put together a referral letter with findings to give to the family doctor or ophthalmologist.
