What is glaucoma?
Glaucoma is a group of eye conditions which causes progressive damage the optic nerve. The optic nerve transmits all the light information to the brain, so we can interpret what we see. Therefore, damage to this nerve causes an irreversible loss of vision and visual field.
It can occur at any age, but is most common in adults.
Glaucoma is a leading cause of blindness in people over age 60, and roughly 1 in 8 Australians will have it by age 80.
Vision loss due to glaucoma cannot be recovered. As a result, regular eye testing is critical to identify and address it before it causes lasting damage. Coastal Eye Surgeons provides a range of conservative, laser and surgical treatment options for glaucoma.
Different types of glaucoma
There are many types of glaucoma, all of these can be classified into one of the following:
Open-angle glaucoma
Open-angle glaucoma is the most common form of glaucoma and generally progresses slowly. It occurs when the drainage of fluid from the front of the eye occurs too slowly. This causes an increase in eye's pressure which can damage the optic nerve.
Symptoms of open-angle glaucoma may include:
40% of vision can be lost without people knowing. As damage to the optic nerve progresses they may notice:
- Loss of peripheral vision
- "Foggy" vision
- Tunnel visionÂ
Healthy vision versus glaucoma-affected vision.
Angle-closure / Narrow Angle Glaucoma
Angle-closure glaucoma is less common and usually more severe than open-angle glaucoma.
It occurs when the angle between the iris and the cornea is narrower than normal, or in fact closed, which decreases the drainage of fluid in the front of the eye. This leads to a dangerous build up of pressure in the eye, which then "squashes"/damages the nerve at the back of the eye. Â
Symptoms of angle-closure glaucoma may include:
- Painful red eye
- Severe headache
- Nausea and vomiting
- Blurred vision and halos around lights
Acute angle-closure glaucoma is a sight-threatening medical emergency and needs to be addressed as soon as possible to avoid permanent vision loss.
If these symptoms onset suddenly, see your local emergency department or ophthalmologist’s office as soon as possible.
How is glaucoma diagnosed?
Glaucoma is known as ‘the silent thief of sight’ because it often occurs and progresses without any noticeable symptoms, until vision loss has started.
It is usually picked up in routine eye exams, which is why it’s important to have your eyes tested regularly. Most people by the age of 40 will need glasses, so the Optometrist should be able to pick up signs of glaucoma and refer you to a specialist if necessary.
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Glaucoma can be detected through a comprehensive eye exam, that will include the following:
- Visual acuity - measure distance & reading vision
- Visual Field testing – this measures central and peripheral vision
- Macular and optic nerve scans – these are pictures obtained with ultrasound technology to measure the thickness of the nerve and macula
- Tonometry – measures your intraocular pressure (pressure in your eye)
- Pachymetry - measure the thickness of your cornea
- Gonioscopy - grades the degree of "openness" of your angle
Glaucoma: Treatment options
Accurate assessment and diagnosis of a person's glaucoma is important, so as to ensure that treatment is tailored specifically for that person. Â
Treatment is targeted towards decreasing the pressure in the eye. The aim being to achieve a pressure that doesn't damage the optic nerve. Therefore treatment is focused towards decreasing the "tap" of the eye and increasing the "outflow" of aqueous from the eye, thereby decreasing the pressure in the eye and therefore on the optic nerve at the back of the eye.
Coastal Eye Surgeons can suggest and provide a range of topical drops, laser and surgical treatments that can decrease eye pressure.
Medical Treatments
Topical drops to decrease eye pressure.
There are a number of different drops that work on the eye to decrease the pressure.
Often one drop is started and the effect of this is ascertained and additional drops may be commenced until the desired intra ocular pressure is reached.
Laser Treatments
Selective laser trabeculoplasty (SLT)
SLT can be used for all types of open angle glaucoma and ocular hypertension.
SLT uses laser light that stimulates the body's own healing response that targets the "cleaning" of the drainage area of the eye, which increases the outflow of fluid and thereby decreases the intra ocular pressure. Â
Studies show that SLT decreases the intra ocular pressure by 20% in 80% of people who have it. It also shows that 2 years after the treatment, 50% of those still have an effect at 2 years.
Coastal Eye Surgeons can perform this laser treatment in rooms by using a laser machine, which is similar to the one that is used to look at your eye. You need only 1 anaesthetic drop prior, and the laser takes approximately 5 to 10 minutes to perform.
Your eye pressure will be checked one week after the procedure, but the full effect of the laser won't be known until six weeks after, which will be your second post laser check. Â
Peripheral Iridotomy (PI)
PI is used for treatment of narrow or closed angle glaucoma.
The laser places a small channel in the iris which allows for the pressure behind the iris to be released, thereby generally opening the angle and preventing a blinding attack of glaucoma.Â
Coastal Eye Surgeons can perform this laser in it's Hope Island Market Place rooms. The laser is a piece of equipment similar to what is used to examine the eye on your routine visit. Numbing drops are placed in your eye and the procedure takes approximately five to ten minutes. Â
The effect of the laser should be immediate. You will be given anti inflammatory drops after the laser for a week and will be reviewed two weeks after the laser
Cyclodiode laser treatment
Cyclodiode laser treatment destroys part of the ciliary body, the structure in the eye which makes aqueous fluid, using a laser. This reduces intraocular pressure long-term by reducing fluid production, which means less fluid has to drain consistently.
MicroPulse laser
At Coastal Eye Surgeons, we employ a MicroPulse laser in some of our eye procedures. This laser uses a stream of short, repetitive, low-energy pulses to cut, rather than a continued beam of energy. The breaks between pulses allow eye tissue to cool, reducing damage to the eye.
Surgical treatments
Trabeculectomy
Trabeculectomy is a surgical procedure which creates a new drainage system for the fluid of the eye to flow and be absorbed.  This procedure is often used for young patients who have not been able to achieve a low enough intra ocular pressure with drops and or laser treatment.
There is no implant placed in the eye, instead, the structures of the eye are used to fashion this new drainage system. Â
Kahook Dual Blade
Coastal Eye Surgeons are certified to provide the Kahook Dual Blade® procedure. This single-use tool is designed to remove a section of the trabecular mesh while causing minimal disruption to the surrounding tissues. It is engineered to fit in Schlemm’s canal, helping to maintain natural overflow pathways.
Trabeculotomy
Trabeculotomy is very similar to trabeculectomy. Rather than removing the trabecular mesh and creating a new drainage route, it involves opening the natural drainage system and allowing the aqueous fluid to drain properly. Trabeculotomy is usually performed in children.
GATT
A gonioscopy-assisted transluminal trabeculotomy (GATT) is used for the treatment of open angle glaucoma when drops and or laser hasn't managed to lower the intra ocular pressure to a acceptable point.
The operation involves removing the superficial drainage system, or "plug holes" of the eye., thereby allowing the fluid to drain straight into the "plumbing of the eye. GATT is sometimes combined with cataract surgery.
Glaucoma Drainage Devices
Glaucoma drainage devices are used when a person's intra ocular pressure is not adequately controlled with drops and or laser.  This device, essentially creates a new plumbing system for the eye.
Coastal Eye Surgeons will tailor and choose the most appropriate type of drainage device according to the individual patient's glaucoma.Â
These include the Amhed glaucoma valve, Baerveldt glaucoma implant, iStent and Hydrus device.