OVERVIEW OF GLAUCOMA

Glaucoma is the prominent cause of permanent blindness across the globe. According to the World Health Organization, glaucoma remains the second leading cause of blindness worldwide. Over the course of time, researchers have linked glaucoma to a poor quality life. People with glaucoma have been reported to show an increase in anxiety, lower self-esteem, less emotional well-being and reduced confidence in health care procurement. The impact of this disease is indisputably grave. Thankfully, certain diagnostic, preventive and treatment measures have been put in place to intercept any long term effects.

WHAT EXACTLY IS GLAUCOMA?

Glaucoma is a disease that affects the eye usually damaging the optic nerve. The optic nerve is responsible for sending information from the eye to the brain for processing. Glaucoma is characterized by abnormally elevated fluid pressure within the eye, known as intraocular pressure. This intraocular pressure within the eyes, if left untreated for a long time can cause permanent damage to the optic nerve. Eventually, it may progress into a long-lasting vision impairment.

PREVALANCE

60.5 million of the world’s population had glaucoma in 2010. Rather alarming research, further projects an increase in the occurrence of glaucoma to 111.8 million by 2040. 

In Sub Saharan Africa, glaucoma poses a major health challenge with open-angle glaucoma being the most common. Africa is found to be the domain with the highest occurrence of glaucoma associated blindness compared to other regions worldwide. 15% of blindness in Africa results from glaucoma. Africa, unlike other continents, the burden of glaucoma tends to be incredibly high. This is mostly due to the lack of understanding surrounding this disease.

In addition, due to this poor understanding, manifestation is usually late; with up to 50% of patients blind in one eye at the time of diagnosis. More so, close to 90% of the African population doesn’t even know they have the disease. 

In virtue of the Ghana Glaucoma Association, about 700 000 of the total population of Ghana have glaucoma. From this, 250 000 are unaware of their situation whereas 60 000 people have long been blind.

Eye surgeries were conducted in 5 communities of Tema, Ghana from 2006- 2010. This surgery discovered that 6.8% of people over the 40 years had primary open-angle glaucoma. Then after, it increased to 14.6% amongst those the ages of 80 and above. Also, Dr. Mike Gyasi, the Vice President of the ophthalmological society of Ghana, suggests 1 of every 10 Ghanaians under 40 is likely to get the disease.

WHO IS AT RISK OF GLAUCOMA?

Everyone is susceptible to glaucoma but certain factors make others more liable.

  • Family history – a person with a family history of glaucoma is at risk for the disease.
  • Age – people over age 60 are likely to have glaucoma.
  • Backgrounds – glaucoma is common amongst Africans, Hispanics, and Asians.
  • Diabetic patients – 35% of people with diabetes have an increased risk of developing open-angle glaucoma.
  • Nearsighted people.

How GLAUCOMA REALLY OCCURS.

The eye like most spherical bodies requires pressure to maintain a healthy balance and shape.  This pressure is derived mostly from the fluid component of the eye; aqueous and virtuous humour.  These fluids are produced by nearby tissues and exit the eyes through drainage channels. When these channels get blocked, serious damage to the eye may occur including glaucoma.

In front of the eye is an area called the anterior chamber. Fluid (aqueous humour) produced by eye ( ciliary body) flows into this area in order to maintain eye pressure, as well as nourish nearby tissues. More so, the fluid is drained through channels at an angle created by the iris and cornea. If for some reason these channels are blocked, it can lead to an abnormally elevated fluid pressure in the eye (intraocular pressure). This abnormal increase in pressure destroys the optic nerve causing glaucoma.

CAUSES OF GLAUCOMA

The main cause of glaucoma is an increase in intraocular pressure. For that reason, anything that causes the fluid pressure within the eye to increase is a viable cause for glaucoma. Some of these include

  • Trauma to the eye.
  • Certain diets such as saturated fats and sugar-sweetened beverages.
  • Low blood supply.
  • Certain medications such as steroids, cold medications, and allergic medications.
  • Cataract surgery.
  • Damage to the optic nerve.

It should be noted that not everyone with increased intraocular pressure is at risk of developing glaucoma. This due to the fact that some people are more tolerant than others.

TYPES OF GLAUCOMA

There exist three common types of glaucoma, which are marked by elevated fluid pressure within the eye.

Open-angle glaucoma also known as primary or chronic glaucoma is responsible for over 90% of all glaucoma cases. This happens when the drainage angle for fluid (aqueous humour) within the eye is wide open more than usual. Open-angle glaucoma progresses at a slow rate and has a long-lasting effect.

Narrow-angle glaucoma – In this case, the drainage angle for fluid within the eyes is relatively restricted than usual. As a result, fluid exits through the eye slowly creating a much higher pressure within the eye. Narrow-angle has the tendency to progress into angle-closure if not cured at the initial stages.

Angle-closure glaucoma also known as closed-angle glaucoma occurs when the drainage angle is completely blocked. This is due to the fact that the iris pushes slightly forward, blocking the drainage channels as well as increasing intraocular pressure. Compared to open and narrow-angle glaucoma, angle closure-glaucoma develops at a fast rate and requires immediate treatment measures.

Other types of glaucoma include;

  • Normal-Tension Glaucoma- occurs even when the fluid in the eye is normal. The cause is due to optic nerve damage
  • Congenital Glaucoma – occurs when the drainage channels of a baby’s eye failed to develop properly

SIGNS AND SYMPTOMS

The signs and symptoms of glaucoma are different depending on the type of glaucoma you have.

People with persistent open-angle glaucoma show no remarkable symptoms at the initial stages. The condition progresses slowly and eventually leads to vision loss and a painful eye sensation.

On the contrary, symptoms of acute angle-closure glaucoma are noticeable right from the start.  The symptoms include

  • Nausea
  • Hazy cornea
  • Blurred vision
  • Severe pain
  • Sensitivity to light

However, In chronic angle-closure glaucoma and normal-tension glaucoma, affected persons show no symptoms unless they start to lose their vision.

Congenital glaucoma presents with; bulging eyes, cloudy corneas, extensive tearing and sensitivity to light.

DIAGNOSIS OF GLAUCOMA

Early diagnosis is the best approach to protecting your eye from vision complications associated with glaucoma. Glaucoma can be diagnosed using a series of eye examination tests. These tests are done to check the fluid pressure, as well as any changes in the eye that predisposes one to glaucoma. The common tests are:

  • Visual field tests (perimetry): to survey the vision area and detect any blind spot in a patient’s line of vision.
  • Dilated eye exam (ophthalmoscopy): used to detect optic nerve damage by carefully observing the pupils. Eye drops are used to cause pupil dilation for proper examination.
  • Tonometry: done to measure the fluid pressure in the eye (intraocular pressure).
  • Pachymetry: evaluates the thickness of the cornea.
  • Gonioscopy: used to draw a distinction between the major types of glaucoma. It determines whether the drainage angle is wide or open.

Treatment

When it comes to the treatment of glaucoma, eye drops are typical, compared to pills. Several treatments are used to correct the damages caused by glaucoma.

The purpose of glaucoma treatments is to reduce fluid production. Other treatments are used to decrease the diameter of the pupils and increase flow drainage from the eye. However, surgery is resorted to when other treatments fail to work.

  • Alpha-adrenergic agonists.
  • Beta-blockers.
  • Miotics
  • Carbonic Anhydrase Inhibitors.
  • Prostaglandin related drugs.
  • Laser therapy.
  • Surgery .