Untreated glaucoma commonly causes vision loss called “tunnel vision” and can lead to blindness. A common cause is high aqueous pressure within the front of the eyes. Glaucoma treatment, to be successful, should start.

Untreated glaucoma commonly causes vision loss called “tunnel vision” and can lead to blindness. A common cause is high aqueous pressure within the front of the eyes. Glaucoma treatment, to be successful, should start as soon as the pressure and/or vision loss are detected based on careful diagnosis. For most people with glaucoma, once the pressure reaches acceptable lower levels, nerve damage may slow or stop, but the damage is not reversed. The importance of tailoring treatment to the individual is discussed. Anyone who knows they are in a high-risk category is advised to have their eyes examined regularly.

With glaucoma, what the eye sees in parts of its visual field starts to fade. This loss of vision usually is clustered in zones located around the center of focus. It most often occurs in both eyes, which explains why one symptom in advanced glaucoma is called “tunnel vision.”

Areas or zones of the eye’s light receptors are not sending signals to the brain (the visual cortex). Clusters of the nerve fibers in the retina that link with the receptors start to switch off. In glaucoma, the cornea and lens still focus the light they receive, but the nerve damage cuts off some communication channels to the brain.

Vision loss due to glaucoma is most often gradual. This, perhaps, is one reason why most glaucoma is found in people over 40 years of age. The glaucoma probably developed slowly over several years prior to being diagnosed.

A person with the first stages of glaucoma who has regular and frequent eye examinations has a better chance of having their condition diagnosed early.

The earlier glaucoma is diagnosed, the greater the likelihood that it can be slowed down or even stopped with medication, well before the tunnel-vision stage is reached.

There are more forms of glaucoma than can be mentioned here. Some occur as a result of an accident or a blow to the eye. Since glaucoma most often results from high pressure inside the eye, anything which causes increased intra-ocular pressure (I.O.P.), whether it is an inherited condition, an accident (trauma), or a functional eye disorder, can also result in optic nerve damage.

But the true picture of glaucoma is not so simple. There are individuals with glaucoma whose I.O.P. falls within the “normal” range, and for whom no cause can be found. Others have elevated pressure yet do not experience vision problems.

Each person with glaucoma must have individualized diagnosis and treatment by a qualified eye specialist.

If you have glaucoma, what's next?
The first treatment approach for glaucoma is usually a prescription for eyedrops to be used several times daily. Some cause the eye to make less aqueous (the liquid inside the eye). But usually the eyedrops are to lower pressure by helping unclog the body's natural aqueous drainage system from the eye.

Glaucoma surgery
Surgery, both laser and conventional, can be an effective treatment approach if eyedrops are not working. While laser surgery is the treatment of choice for acute-angle glaucoma (where it normally effects a “cure”), conventional surgery is preferred for most other types. In most common glaucoma conditions, however, surgery is only considered if the eyedrop medications do not achieve the target of stabilizing vision.

With improvements in the science of eyecare, and in the tools of eye doctors, more people are bringing their glaucoma under control. Topical medications, when started early on, are better at lowering I.O.P. The next task is to conquer nerve damage.

Risk factors
Knowing the risk factors for glaucoma gives you a signal (if your risk is high) that you should have regular eye exams to detect it starting earlier in life. Some risk factors are:

• age over 40
• poor health
• African descent
• poor glucose control in diabetics

If you are at risk, have your eyes examined as soon as possible, and set up your next appointment before leaving the clinic.