Glaucoma Latest Facts: Causes, Symptoms, Risk Factors, Treatments and Prognosis

Glaucoma is an eye disease that leads to an irreparable limitation of the visual field occurring due to damage to the optic nerve. The peripheral vision is primarily affected. Those affected can go blind if they do not receive treatment. In addition, glaucoma is the second cause of blindness after cataracts in the world’s least developed countries.

Glaucoma Surgery

Glaucoma Surgery

In most cases, glaucoma is associated with increased intraocular pressure (IOP). Normally this value should not exceed 21 (mmHg).

However, it has been found that almost 1 in 3 people experience symptoms of glaucoma, even when intraocular pressure is normal. A decrease in the blood supply to the optic nerve, caused by atherosclerosis in the vessels that irrigate that nerve, maybe the cause. Regardless of whether the pressure inside the eye is too high or not, the treatment remains the same.

Who is affected?

In the US more than 3 million Americans over 40 (> 1%) are affected. This percentage rises to 5% for people over 70 and 10% for people over 80. However, glaucoma can occur at any age.

Causes

It is often unclear why glaucoma occurs. Heredity is the main risk factor. Certain anatomical features may also play a role.

For example, sometimes glaucoma is associated with a specific problem:

  • Blunt force trauma to the eye
  • Another vision problem: cataracts, severe myopia, chronic uveitis
  • Certain diseases: diabetes, high blood pressure, cardiovascular disease, uncontrolled hypothyroidism.

Taking certain drugs also increases the risk of glaucoma. This is the case with corticosteroids, for example, which are administered directly into the eyes or taken orally.

Note: Corticosteroid pumps for asthma and corticosteroid creams or ointments for eczema have no effect on glaucoma.

Why is the pressure increasing?

Inside the eye, between the cornea and the iris, there is a space called the anterior chamber. This space is filled with a fluid called aqueous humor. This transparent liquid has several functions: It maintains intraocular pressure, gives shape to the eyeball, and nourishes the cornea and lens. The aqueous fluid is constantly renewed and circulates through the eye.

In most cases of glaucoma, there is a decrease in the excretion of aqueous humor via its drainage canal. Fluid excretion is gradually slowed, gradually leading to open-angle glaucoma, or quickly blocked, causing closed-angle glaucoma.

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Since the aqueous humor does not drain as it should, the pressure inside the eye increases. The high pressure causes the optic nerve head to be excavated, altering, and gradually destroying the optical fibers of the retina. This leads to a disturbance of the peripheral visual field, which is normally not perceived by the patient.

Types of Glaucoma

Open-angle glaucoma

This type of glaucoma, which accounts for 80% to 90% of cases (in whites, blacks, and Hispanics), develops slowly, without causing symptoms, over a period of 10 to 20 years. The “angle” referred to is the angle formed by the connection between the iris and the cornea. It is called the iridocorneal angle. Usually, both eyes are affected. An important warning sign is a gradual increase in pressure inside the eye. Normally this should not exceed 21 (mmHg). The intraocular pressure can be determined by an eye examination.

Angle-Closure Glaucoma

It occurs less frequently (except in Asians, where it is common) as a result of a sudden increase in pressure in the eye. This is a medical emergency. It causes extreme eye pain and other visible symptoms such as decreased vision and colored halos around lights. The intraocular pressure sometimes rises to 80 mmHg. Such attacks typically occur at night when the light is dimmed and the pupils dilate. If this type of glaucoma is not treated quickly, the person may go blind. If treated early enough, the risk of blindness is greatly reduced.

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Angle-Closure Glaucoma usually affects only one eye at first, and then the other within 5 years if it is not properly controlled.

Two factors are required for an attack to occur:

  • An anatomical predisposition.
  • Dilation of the pupil (the central opening of the iris through which light rays pass). It can occur as a result of long periods of darkness, stress, or the use of dilating agents such as anticonvulsants, antihistamines, antidepressants, and nitrates.

Congenital glaucoma

It can occur at birth or take several months to appear. Most often both eyes are affected. Sometimes it is hereditary, maybe an isolated problem, or can be explained by an eye malformation (usually a congenital cataract) or certain rare diseases. Also in this case the outflow of the aqueous humor is blocked.

Glaucoma Diagnosis

Here are the most frequently performed tests.

Tonometry test

This is the first test that is normally performed. The tonometer measures the pressure inside the eye. Two techniques are used: A jet of compressed air is directed at the open eye, known as pulse air tonometry, or after an anesthetic drop is instilled into the eye, a probe is put on the cornea, known as plane tonometry. This test is both quick and painless. The normal intraocular pressure is between 8 mmHg and 21 mmHg.

Measurement of the corneal thickness

It is important to measure corneal thickness as it influences the result of the tonometry test. If the cornea is thick, the pressure is overestimated; if the cornea is thin, the pressure is underestimated.

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Examination of the eye

Optical nerve damage can be seen with a device that directs light to the eye.

Examination of the visual field

To assess the extent of the field of vision, the person is asked to fix a target in the center of an illuminated sphere, and then dots of light appear at different areas in the field of vision.

When to consult a doctor?

  • Consult a doctor urgently if you feel considerable pain in your eye and your vision is deteriorating rapidly.
  • Consult an eye doctor regularly to prevent eye diseases.
  • Consult a doctor if you have problems with contact lenses.

Glaucoma symptoms

Open-angle glaucoma

No symptoms for 10 to 20 years.

Then blurred peripheral vision.

Sometimes eye pain and headaches.

Blindness, in advanced stages.

NB: Usually both eyes are affected.

Angle-Closure Glaucoma

Very severe eye pain.

Sudden blurred vision.

A vision of colored halos around light sources.

Eye redness.

Nausea and vomiting.

NB: Permanent vision loss may occur within one day after the attack, so it is important to get treatment as soon as possible. The attack usually affects only one eye.

Congenital glaucoma

Big, often watery eyes.

An iris with blurred details.

Increased sensitivity to light.

NB: Symptoms may not appear until several months after birth.

Individuals at risk and risk factors for glaucoma

People at high risk

  • People with a family history of glaucoma.
  • People aged 60 years or older.
  • Black populations have a higher risk of open-angle glaucoma. Their risk increases already at the age of 40.
  • Mexican and Asian populations are also at greater risk.
  • People with diabetes or hypothyroidism.
  • People with low or high blood pressure and people who have had heart problems in the past.
  • People with other eye problems (pronounced myopia, cataracts, chronic uveitis, pseudoexfoliation, etc.)
  • People who have suffered a serious injury to one eye (e.g. a blow directly to the eye).

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Risk factors

  • The use of certain drugs, especially those based on corticosteroids (in open-angle glaucoma) or those that dilate the pupil (in closed-angle glaucoma).
  • The consumption of coffee and tobacco can temporarily increase the pressure inside the eye slightly.

Prevention of glaucoma

Basic prevention measures

People with an increased risk of glaucoma (due to age, family history, diabetes, etc.) should have a complete eye exam every year, possibly starting at age 40. The earlier an increase in intraocular pressure is detected, the less likely they are to lose sight.

Maintain a healthy weight and normal blood pressure. Insulin resistance, often associated with obesity and high blood pressure, contributes to increased intraocular pressure.

Finally, you should always wear safety glasses to protect your eyes during risky activities (handling chemicals, welding, squash, fast sports, etc.).

Measures to prevent a recurrence

General precautions

  • Avoid the use of certain drugs – especially corticosteroids in the form of eye drops or oral steroids – or consider their potential risks.
  • Eat a diet rich in fruits and vegetables to meet your vitamin and mineral needs as much as possible.
  • Drink small amounts of fluids at once to avoid sudden increases in intraocular pressure.
  • Limiting or avoiding the consumption of caffeine and tobacco can be beneficial.
  • Regular exercise can relieve some of the symptoms of open-angle glaucoma, but it does not affect closed-angle glaucoma. It is best to consult a doctor to choose the right exercise. Beware of exercises, some yoga postures that can increase pressure in the eyes.
  • Protect your eyes from ultraviolet rays in the sun by wearing glasses with colored lenses that filter out 100% of UV rays.

Prevent another Angle-Closure Glaucoma attack

  • Stress can trigger an acute attack of Angle-Closure Glaucoma. It is necessary to pay attention to the factors that cause stress and to try to find solutions.
  • After an initial attack of Angle-Closure Glaucoma, laser treatment helps to prevent a recurrence. This treatment consists of drilling a small hole in the iris with a laser beam so that the aqueous humor trapped behind the iris can drain. In most cases, it is indicated to have the other eye treated preventively.

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Medical treatments for glaucoma

Unfortunately, there is no cure. The visual acuity lost through glaucoma cannot be restored. The purpose of treatment is therefore to prevent or delay consequential damage. To this end, in many cases, the pressure inside the eye is reduced by improving the circulation of the aqueous humor.

The ophthalmologist, a doctor that specializes in treating eye conditions, draws up a treatment plan, and regularly monitors vision. Possible interventions include eye drops, oral medication, laser treatment, and, if necessary, surgery. In many cases, the medications should be taken for life.

If the cause of glaucoma is identified, it is important to treat it. In addition, corticosteroid therapy of the eyes is contraindicated in people with glaucoma. It is therefore advisable not to start or discontinue this type of treatment. In some cases, its use cannot be avoided. It is therefore necessary to have a very good follow-up with an ophthalmologist.

For open-angle glaucoma

Eye drops reduce the pressure on the eye. Drops are often prescribed because they cause fewer side effects than oral medications.

Different types of eye drops are used. The most common include beta-blockers, alpha-adrenergic agents, prostaglandin analogs, carboanhydrase inhibitors, and Cholinergic. Most of these drugs work by reducing the production of aqueous humor in the eye and increasing its excretion.

Side effects vary from one type of drop to another. These may include dry mouth, low blood pressure, slow heart rate, eye irritation, redness around the eyes, or fatigue. It is best to inform your doctor or health care professional of any side effects that occur.

It is important to follow your dosage carefully. This treatment is very effective as long as it is done daily and for life.

Oral medications

If the drops do not sufficiently lower the intraocular pressure, which is rare, oral medication (e.g. carbohydrase inhibitors) may be prescribed. However, these drugs are more likely to cause side effects that are more serious than with eye drops.

Laser treatments

This procedure, called trabeculoplasty, is being performed more and more frequently. Sometimes it is even offered before the application of eye drops. It can also be done if glaucoma worsens despite treatment or if medication is poorly tolerated.

This laser treatment aims to promote the circulation of aqueous humor in the eye. The procedure is painless and quick: it is performed in one or two 5-minute sessions. A laser beam is directed at the trabeculum. It is not exactly clear why it reduces the pressure.

Even if a laser procedure is performed, the medication (usually eye drops) must be taken for life.

Conventional Surgery

This eye operation is called a trabeculectomy. The procedure is intended to create a new form of aqueous humor drainage by removing a small segment of the trabeculum. The placement of tubes is common. The tube leads the aqueous humor into a reservoir behind the eye. About 80% of people who undergo this operation do not need eye drops afterward.

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Other types of surgery are being currently tried. Eventually, they may replace the trabeculectomy. However, it will take several years before their effectiveness can be determined. Examples include Ex-Press®, canaloplasty, Gold Micro-Shunt Implants, and iStent inject®.

For Angle-Closure Glaucoma

Emergency treatment is required. Several drugs are used to quickly reduce intraocular pressure.

Once the pressure is lowered, the ideal solution is to open a passage through the iris with a laser beam. This procedure is called a peripheral iridotomy. This treatment allows aqueous humor to drain to prevent a recurrence. First, anesthetic drops are applied to the eye and a contact lens (which is removed after treatment). After treatment, anti-inflammatory drops are prescribed, which should be applied to the eye for a few days. Other treatments may be necessary.

For congenital glaucoma

Only surgery can correct this kind of glaucoma. It is generally done within the first weeks of life.

Important Advice

There’s good news and bad news when it comes to treating glaucoma. Let’s start with the good news! With current treatments, most people with glaucoma are able to maintain functional vision.

The bad news is that there is no cure for glaucoma and no way to restore lost vision. In addition, the treatments can cause side effects. Most patients stop treatment or do not use the drops regularly because they show no improvement, are expensive and have side effects.

But many patients go blind because they have stopped treatment. If you have a problem with your current treatment, It is strongly advised that you discuss it with your ophthalmologist before stopping the treatment. There are other options available to you.

Read Also: Corneal Perforations Can Now Be Fixed Permanently Without the Need for a Transplant According to University of Montreal Researchers

Glaucoma – complementary approaches

In prevention

Some clinical studies conducted on a small number of individuals suggest that the use of eye drops containing 1% forskolin, a substance extracted from the coleus root, would help reduce intraocular pressure in healthy people.

For supportive treatment

Blueberries and bilberries are traditionally used to prevent and relieve the symptoms of certain eye diseases such as glaucoma and cataracts. Although their efficacy has not been demonstrated in human studies and no competent authority has recognized its value, clinicians, particularly in Europe, use them.

Alternative medicine professional J.E. Pizzorno advises paying attention to substances (food or other) to which the person concerned could have an allergic reaction to, in order to avoid them. The allergic reaction can alter the permeability of the vessels, which in his opinion could contribute to the development of glaucoma.

It would be important to reduce the stress associated with vision loss or anxiety in this respect. At the Mayo Clinic, it is therefore recommended that ways be found to deal with the stress.

Some preliminary research suggests that alpha-lipoic acid, Ginkgo Biloba, and vitamin C supplements may have a positive effect on symptoms of glaucoma.

NB: There is no scientific evidence that naturopathic medicine has any effect on glaucoma.

Read Also: Age-related Close-up Vision Loss- How do I rid myself of reading glasses?

References

https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma

https://www.glaucoma.org/glaucoma/

Ginkgo Biloba Extract Increases Ocular Blood Flow Velocity

Long-term Treatment of Circulatory Disturbances of the Retina and Optic (Author’s Transl)

Lipoic Acid as a Means of Metabolic Therapy of Open-Angle Glaucoma

 

 

 

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