What is glaucoma?

Glaucoma, a second leading cause of blindness, is a group of eye disorders often associated with a dangerous build-up of internal eye pressure (intraocular pressure or IOP) which can damage the eye’s optic nerve that transmits visual information to the brain. As these changes are permanent, visual loss from glaucoma is irreversible.

What are the different types of glaucoma?

Glaucoma can be classified either based on their “angle” or causes. “Angle” refers to the internal structure of the eye drainage system that controls the outflow of fluid (or aqueous) from the eye. The “angle” can be viewed using special diagnostic contact lenses or gonioscopy.

  • Primary open-angle glaucoma (POAG) – commonest form of glaucoma
  • Acute closed-angle glaucoma (AACG)
  • Chronic closed-angle glaucoma
  • Normal-tension glaucoma
  • Secondary glaucoma
  • Congenital glaucoma

What symptoms will I experience if I have glaucoma?

Glaucoma often is called the “silent thief of sight” because most types typically cause no pain and produce no symptoms till the disease has progressed to a late stage. This is because only the peripheral or side vision is affected during the early stages. Central vision is only affected very late.

However, acute closed-angle glaucoma (AACG) can cause sudden onset of intense eye pain, nausea, vomiting, headache, blurred vision and seeing halos around light due to a sudden increase in IOP. AACG accounts for about 10% of all glaucoma cases in Singapore and is an ophthalmic emergency requiring urgent medical attention by an eye surgeon.

What should I do if I am worried about having glaucoma?

As most people with glaucoma have no symptoms, glaucoma eye screening is the only way of detecting the disease. At Nobel Eye & Vision Centre, we have the latest diagnostic and imaging tools (such as visual field assessment, optical coherence topography) to detect glaucoma, even when it is at an early stage. As glaucoma is irreversible, early detection and early initiation of treatment offers the best visual outcome for the patient.

Who should go for glaucoma screening?

Glaucoma is an age-related eye disease. Therefore, anyone above the age of 45-years-old should go for screening once in 2 to 3 years. Annual screening is recommended for those above 65-years-old. Those with strong family history of glaucoma, high myopia, diabetes mellitus and previous eye injury or eye inflammation should also be screened regularly.

What are the various treatment modalities for glaucoma?

There is no cure for glaucoma but we can lower the IOP, prevent progression of the disease and preserve patient’s vision. There are 3 main treatment modalities:

1) Medications
Medications in the form of eye drops or tablets can help to reduce IOP by either reducing the production of fluid within the eye or increasing its outflow from the eye.

2) Laser surgery
When the IOP is not adequately control with medications, laser surgery can be performed to help the outflow of fluid. Laser iridotomy and laser trabeculoplasty are the 2 main types of laser surgery.

3) Glaucoma drainage surgery

Surgery (trabeculectomy) may be needed in advanced cases not controlled with medications or laser treatment.

The choice of treatment modalities will depend on the severity of the disease. Medications are usually tried first. Laser or glaucoma drainage surgery may be needed if there is evidence of disease progression despite medications.

As glaucoma is not a curable disease, patient will require lifelong monitoring and treatment. Regular reviews can help to detect progression and the treatment regime can be changed accordingly.