Glaucoma is a chronic condition characterised by damage to the optic nerve at the back of the eye with a corresponding damage to the visual field. The biggest risk factor for developing glaucoma is raised pressure in your eyes, but the eye pressure doesn’t always need to be raised to develop it. A family history of glaucoma such as having a parent or sibling with glaucoma can raise your risk of developing the condition. If you are over the age of 40 and have a family history of glaucoma you should see an optometrist for a comprehensive eye examination.
Glaucoma is often first detected by optometrists through checking of the eye pressure, optic nerve and field of vision. Glaucoma does NOT have symptoms in its early stages making it important to have regular eye tests.
An optometrist who suspects glaucoma will often refer to an Ophthalmologist to confirm the diagnosis and begin treatment.
At Your First Visit
A member of the clinical team will perform some very important tests which are essential to the doctor seeing you later. These include measurement of your visual acuity, eye pressure, thickness of your cornea (which influences the eye pressure reading), noting of your spectacle prescription, refractive error and colour vision.
They will then perform two specialised glaucoma tests: a visual field assessment and an OCT scan of your optic disc. These reveal critical information about the how healthy your optic nerve is and how well it is functioning.
Your doctor will conduct a thorough history and examination of your eyes paying particular attention to glaucoma risk factors. Family history is important and it is a good idea to ask parents or siblings if they have been diagnosed with glaucoma before your appointment as this is relevant to your risk having the condition.
Your general medical history is also important as there are associations between raised eye pressure and general medical issues such as high blood pressure and diabetes. Certain medications such as a prolonged course of cortisone can raise your risk of developing glaucoma.
When examining your eyes your doctor will be paying particular attention to the front of your eyes by performing a test called gonioscopy. This involves applying a contact lens on the surface of the eye after local anaesthetic drops have been applied. This test is performed mainly to exclude a condition called primary angle closure which is where the front of the eye is shallow or narrow raising your risk of developing glaucoma. This may warrant a preventative laser procedure called a YAG Laser iridotomy.
Your pupils will then be dilated in order to get the best possible view of the back of your eyes paying particular attention to your optic nerves as this is the structure which is damaged in glaucoma. The optic nerve appearance is then correlated with the specialised tests you will have had performed at your first visit prior to seeing the doctor.
The diagnosis of glaucoma is usually fairly straightforward to make however sometimes a patient needs to be observed over a few visits before committing them to a potentially life changing diagnosis.
You and your doctor will mutually agree on a treatment plan which may involve:
- Selective laser Trabeculoplasty (SLT) – this is a very commonly performed outpatient laser procedure to lower your eye pressure
- Use of eye drops to put in your eyes on a daily basis
- Observation as there is not enough evidence to begin treatment yet
- YAG Laser Iridotomy – performed if you have met the threshold to be diagnosed with primary angle closure
After beginning treatment with either drops or laser you will be followed up in 2-4 weeks to check if the eye pressure has reduced and you are tolerating the treatment well. Glaucoma is a chronic condition and requires periodic follow up usually on a six-month basis along with the specialised testing to ensure the structure and function of your optic nerve is being maintained. Certain lower risk patients may be under a shared care arrangement between your doctor at Derwent eye specialists and your optometrist under close liaison.
Glaucoma Australia: www.glaucoma.org.au
Calculate your glaucoma risk: www.calculator.glaucoma.org.au
Glaucoma Research Foundation: www.glaucoma.org