About Glaucoma

What is Glaucoma?

Glaucoma is a progressive disease, which causes optic nerve degeneration over time. The optic nerve is the main nerve responsible for vision. It is like a cable connecting the eye to the brain. As it degenerates, vision loss occurs. This loss may be very subtle at first, and therefore may not be noticed until much later in the disease. Like a "thief in the night", glaucoma damage may creep up on people without being noticed.

What causes Glaucoma?

There are many different types of glaucoma that have many different causes. The most common types are inherited or run in families. This means that if you have a relative (especially a parent) who has glaucoma, you should be checked to see if you have any signs of early glaucoma. Some people with diabetes who develop retinal eye disease may develop neovascular glaucoma. Uveitis or eye inflammation can cause glaucoma as well. Some people are born with glaucoma.

If I have glaucoma does that mean I will be blind during my lifetime?

In most cases, glaucoma takes years to develop. There are also many different types of glaucoma and a spectrum of disease from borderline to an advanced stage. "Knowledge is power" in the case of glaucoma. The best way to prevent ongoing damage from glaucoma is to pick it up early enough to treat. You should have a good screening eye exam by an Optometrist, especially if you have a family history of glaucoma or other diseases, like uveitis (eye inflammation) or diabetes. Your Optometrist will be able to tell you if you are at risk for developing glaucoma, and may refer you to an Ophthalmologist or Glaucoma Specialist for further testing.

What are the key risk factors for glaucoma?

• High eye pressure
• Family history of glaucoma
• Increasing Age
• Race: African or Asian Descent
• Females > Males
• Vascular factors (affecting the circulation to the eye): (eg Migraines, Vasospastic or Raynaud's disease, low blood pressure, high blood pressure)
• Thin corneas (pachymetry measurement)
• Myopia (near-sightedness) - for open angle glaucoma
• Hyperopia (far-sightedness) - for narrow or closed angle glaucoma

Does glaucoma only affect older people? What are some of the types of glaucomas?

Glaucoma can affect all ages, from newborns to the very elderly. Newborns can be affected by congenital glaucoma which is a type of glaucoma that they are born with. Children or young adults can be affected by juvenile glaucoma. People diagnosed with glaucoma in their 30's and upward usually have other delayed onset types of glaucoma such as Primary Open Angle Glaucoma (POAG), Pseudoexfoliation (PXF) Glaucoma, Pigmentary Glaucoma, Acute or Chronic Angle Closure Glaucoma (A/CACG) and Mixed Mechanism Glaucoma. Glaucoma worsens with time and increasing age, and at a faster rate if left untreated. There are other types of glaucoma that are associated with diseases like diabetes, such as neovascular glaucoma (NVG) and rheumatoid illnesses, such as uveitic glaucoma. Glaucoma can also be caused by chronic use of steroids: steroid-induced Glaucoma.

Why is it important to lower eye pressure in glaucoma?

One of the main risk factors that can cause progression of glaucoma and vision loss is high eye pressure. Normal eye pressure runs between 10 and 21 mmHg. In patients with glaucoma, this pressure is often higher than 21 and needs to be lowered. However, not all patients with glaucoma have high eye pressures. This type of glaucoma is often called Normal Tension Glaucoma, but is likely just another form of Primary Open Angle Glaucoma. Even with this type of glaucoma, the best way to prevent progression of the disease is to lower the eye pressure sometimes to slightly subnormal range (eg. 7-9mm Hg). Really low pressures are not healthy either (eg. 6 or lower) since they can cause wrinkling of the inner eye layers, and poor vision as a result, along with other problems.

If eye pressure is high in glaucoma, wouldn't I be able to tell?

When eye pressure increases gradually, people often have no symptoms at all, apart from occasional eye discomfort or slightly foggy vision. Often these people are discovered to have high pressures on a routine eye examination. Having a routine eye exam is very important, since diseases like glaucoma cannot be diagnosed early without proper screening because there are often no warning signs before its too late. Glaucoma is like "a silent thief in the night" for this reason.

However, if there is a sudden rise in the pressure, which can happen with certain types of glaucoma (for example, angle closure glaucoma or neovascular glaucoma), there are symptoms of intense pain, headache, decreased vision and can even nausea and vomiting. This type of problem needs emergent attention and anyone experiencing this should go to his/her local emergency department.

Many over the counter drugs advise not using them if you have glaucoma. Should I avoid all these drugs if I have glaucoma?

If you have narrow angles or angle closure glaucoma, then you should not be using these over the counter medications. However, if you have had laser or surgery to fix the narrow drainage canals, then it is safe for you to use them. These drugs often have components in them that can cause dilation of the pupils. Dilation of pupils can cause the drainage canals to completely close in people who have untreated narrow canals (angles). If they close completely, this can cause the eye pressure to suddenly rise and cause pain, headache, loss of vision, nausea, and vomiting. If this happens, you should go to your nearest emergency department immediately.