In most cases, glaucoma is associated with higher than normal pressure inside the eye. If untreated, glaucoma first causes peripheral vision loss and eventually can lead to total blindness.
According to world health organization, globally, glaucoma is the second leading cause of blindness (behind cataracts). Glaucoma is often known as the silent thief of sight because most types cause no pain and produce no symptoms until observable vision loss takes place. For this reason, glaucoma often progresses undetected until the optic nerve has been permanently damaged with varying degrees of permanent vision loss. One eye may develop glaucoma faster than the other. Glaucoma takes place when the drainage tubes (trabecular meshwork) within the eye become slightly obstructed. This prevents eye fluid (aqueous humour) from draining properly.
There are different types of glaucoma:
Primary open-angle glaucoma: This happens to be the most common type of glaucoma which progresses without the knowledge of the individual.
Acute angle-closure glaucoma: There are symptoms associated with this type of glaucoma, which include eye pain, halos around lights, sudden blurry vision, nausea and vomiting. If you have these symptoms, make sure you see an eye care practitioner at once so that measures can be taken to prevent permanent vision loss.
Congenital glaucoma: This is seen in infants, signs of this type of glaucoma include profuse tearing, corneal edema, photophobia, corneal enlargement etc.
Pigmentary glaucoma: The drainage angle gets blocked by pigments from the iris and gives rise to this type of glaucoma.
Secondary glaucoma: In this type of glaucoma, the rise in intraocular pressure is associated with some primary ocular or systemic disease.
Normal-tension glaucoma: The etiology of this type of glaucoma is unclear. It is characterized by glaucomatous pressure measurements consistently lower than 21mmhg. Normal tension glaucoma is believed however to result from chronic reduced vascular perfusion, which makes the optic nerve head susceptible to normal intraocular pressure.
Diagnosis of glaucoma can be made after series of tests which include:
Opthlmascopy: The optic disc is carefully observed for changes. The examiner looks out for large-cupped disc as well as asymmetry of the cups of both eyes, pallor areas on the disc etc.
Tonometry: This is used to measure the intraocular pressure. An abnormally high intraocular pressure reading indicates a problem with amount of fluid (aqueous humour) in the eye normal intraocular pressure should be below 21mmHg.
Perimetry: This is a visual field test used to determine if you are experiencing vision loss from glaucoma.
Gonioscopy: This enables the examiner to see the drainage angle which controls the outflow of aqueous and thereby affect intraocular pressure.
There are several glaucoma predisposing factors such as:
Family history: A family history of glaucoma positions you at greater risk of developing the disease. This means that if you are related to persons with glaucoma, you may be more prone to developing the condition yourself.
Anatomical factors: Hypermetropic eyes, shallow anterior chamber, eyes with narrow angle of anterior chamber etc.
Existing medications: Glaucoma has been linked to long term use of corticosteroid, especially for long term allergy sufferers.
Age: Although advanced age puts you at an increased risk of developing glaucoma. Glaucoma can be seen in all age groups. Therefore, yearly eye check is recommended for everyone no matter the age.
In conclusion, eye checks can save your sight because glaucoma can be identified in the early stage. If glaucoma is detected early, treatment can prevent further loss of vision.