Glaucoma
Glaucoma is a group of eye conditions in which damage to the optic nerve leads to progressive, irreversible visual loss. It is often called the "silent thief of sight" because the painless loss of vision usually occurs gradually over a long period of time, and is often only recognized when very advanced.
Raised intraocular pressure (IOP) is the main risk factor for developing glaucoma, but it does not have to be present in all cases. Some people with relatively low intraocular pressures may develop glaucoma, whilst others with much higher pressures never develop optic nerve damage.
Glaucoma is typically classified as being "Open Angle" or "Closed Angle".
Open Angle Glaucoma:
Open angle glaucoma is the main type of glaucoma seen in Caucasians and Afro-Carribeans. It typically develops in those above 60 years of age, and usually produces no obvious symptoms until advance stages of the disease.
Closed Angle Glaucoma:
Closed angle glaucoma is the main type of glaucoma seen in Asia. It can appear suddenly and is often painful (known as acute angle closure glaucoma). Visual loss can progress rapidly, but fortunately, the pain usually brings patients to their doctor early in the course of the disease. The chronic type (chronic angle closure glaucoma) presents very much like open angle glaucoma, asymptomatic until late in the course of the disease.
There are also secondary forms of glaucoma, meaning that glaucoma develops as a result of some underlying condition (such as uveitis, steroid use, eye injuries), as well as the congenital/developmental/juvenile forms.
What are the Risk Factors for Developing Glaucoma?
The following groups are at higher risk for developing glaucoma:
• Above 60 years of age
• Family history of glaucoma
• Certain races being predisposed to the different types of glaucoma (mentioned above)
• Previous eye injury (may damage the eye's drainage system, resulting in raised intraocular pressure)
• High myopia and hypermetropia
• Long term topical steroid eye drop use
How is Glaucoma Diagnosed?
Screening for glaucoma is usually part of a standard eye examination by ophthalmologists.
Testing for glaucoma would include:
• Visual acuity testing
• Visual field testing
• Intraocular pressure measurement via tonometry
• Dilated eye examination: eye drops will help dilate the pupils to allow proper examination of the retina and optic disc.
How is Glaucoma Treated?
The goal of glaucoma treatment is to avoid further nerve damage, preserve visual function and total quality of life with minimal side effects and at a sustainable cost. Currently, vision loss due to optic nerve damage from glaucoma cannot be restored, hence the importance of early detection and treatment. Treatment also seeks to preserve residual visual function by preventing further damage to the optic nerve.
Kinds of treatment include:
• Eye drops eg. beta blockers, adrenergic agonists, parasympathetic agonists, prostaglandin analogues
• Laser therapy eg. laser trabeculoplasty
• Surgery eg. trabeculoplasty, glaucoma drainage implant surgery
The article above is meant to provide general information and does not replace a doctor's consultation.
Please see your doctor for professional advice.