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What is Glaucoma and Glaucoma Screening?

Glaucoma is a group of diagnosable eye diseases that cause damage to the optic nerve and can result in vision loss. The three most common forms of Glaucoma are open-angle glaucoma, closed-angle glaucoma and normal-tension glaucoma. Currently, it is possible to slow, and in some cases even stop, the progression of glaucoma through medical intervention using a medication, undergoing laser treatment, having surgery or a combination of all three treatments.

Symptoms of Glaucoma

Open-angle glaucoma is in almost all cases completely painless and has very few early symptoms or even acute attacks. This is one of the reasons why regular eye check-ups are exceptionally important because this along with many other eye diseases do not manifest their symptoms immediately, which makes them harder to detect without an eye check-up from an Ophthalmologist. In the case of open-angle glaucoma, the only signs of this disease for the patient will be the gradual and progressive loss of vision as the optic nerve changes and results in an increased cup-to-disc ratio which can be picked up via a fundoscopic examination.


In the case of closed-angle glaucoma roughly 10% of patients present with the following symptoms:


  • Sudden onset ocular pain

  • Visual halos around lights

  • Red-eye or eyes

  • Very high intraocular pressure (>30 mmHg)

  • Nausea and vomiting

  • Sudden onset lowering of vision

  • Fixed, mid-dilation of the affected pupil. 


Please note that in rare cases closed-angle glaucoma can result in an oval pupil. Additionally, opaque specks may occur in the lens affected by glaucoma. These are known as glaukomflecken.


MEDICAL NOTE! Acute angle closure is an emergency and must be treated as such.

What Causes Glaucoma?

Ocular hypertension, which iis increased pressure within the eye, is the major risk factor in most glaucoma’s and can increase the risk of developing glaucoma. Ocular hypertension can be caused by numerous factors, including both ethnicity and genetics.


Ethnicity and Glaucoma

People of East Asian descent are more prone to developing angle-closure glaucoma due to the shallowness of the ocular anterior chamber depths. This has resulted in a higher incidence of angle-closure glaucoma in this section of the world's population.


Genetics and Glaucoma

A positive family history of glaucoma can increase the risk of glaucoma in patients. The risk of primary open-angle glaucoma (P.O.A.G.) is increased by between two- and four-fold for people who have a sibling with glaucoma. This form of glaucoma is associated with mutations in the following genes


  • MYOC

  • ASB10

  • WDR36

  • NTF4

  • TBK1



Please also note that normal-tension glaucoma is also associated with additional genetic mutations in the OPA1 and OPTN genes. Additionally, numerous rare congenital and genetic eye malformations are associated with glaucoma.


Please contact a Top Cape Town Ophthalmologist to find out more.  


Other Causes of Glaucoma

There are various other factors and conditions which can result in glaucoma, all of which are known as "secondary glaucoma" and in most cases severely restrict blood flow to the eye. Some of these conditions and factors are:


  • Prolonged use of steroids

  • Severe diabetic retinopathy

  • Central retinal vein occlusion, which is also known as neovascular glaucoma

  • Ocular trauma (angle-recession glaucoma)

  • Uveitis, which is also known as uveitic glaucoma​

Glaucoma Screening

Glaucoma Screening can be done by an Ophthalmologist and is recommended for anyone over the age of 40 years. This Glaucoma Screening should be done at least once a year and is done using a dilated fundus examination or dilated-pupil fundus examination. This simple diagnostic procedure uses mydriatic eye drops to dilate or enlarge the pupil. This allows for a better view of the fundus of the eye during the eye examination.

If you would like to Book a Glaucoma Screening then please Request an Ophthalmological Examination.

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