Glaucoma is a sight-threatening eye condition that affects the optic nerve, the nerve located at the back of the eye that sends the message from the eye to the brain. The mechanisms that cause glaucoma are not completely understood and are still the subject of a vast amount of research but we do know that increased pressure inside the eye leads to glaucoma.

The eye is like a soccer ball/football; pressure is required to keep it the right shape (round) so that the optics (lenses of the eye) can focus images on the retina (the tissue at the back of the eye that detects light). The images produced on the retina are sent to the brain by the optic nerve. (The brain processes the information and produces what we see.) Fluid is constantly produced by the eye and drained away from it, producing the pressure inside the eye (called the intra-ocular pressure (IOP)).

Once the pressure inside the eye gets too high, it starts to kill the nerve fibres that make up the optic nerve. This gradually causes vision loss since the brain is no longer receiving the message from the eye. Vision loss in glaucoma is usually very slow and gradual with the peripheral vision generally lost first, resulting in tunnel vision, followed by loss of the central vision, resulting in complete blindness. Think of it like the wires that make up the cable that gives your television its picture being cut very slowly and gradually and as the wires are cut, parts of the picture are lost until the whole cable is cut and there is no picture at all.

The pressure inside the eye tends to increase as we age, so glaucoma is a disease of increasing age. Glaucoma is very common, affecting about 1 in 10 people over age 60. However, anyone at any age can develop glaucoma. There are several challenges in detecting glaucoma as generally there are no symptoms in the early stages of the condition, and the eyes do not become sore or red. In fact, almost half of your vision would have to be lost before you notice it when you have glaucoma. Unfortunately, glaucoma is currently detected in only half of the people that actually have it, i.e. the condition is never detected in about half the people that have it.

Glaucoma is thus called the silent thief of sight and is one of the eye diseases of highest importance for the clinical team at Mortimer Hirst to detect and treat, due to it being so difficult to detect. Every patient that consults one of our optometrists undergoes a series of tests to determine whether they have glaucoma or are at risk of developing glaucoma.

Detecting glaucoma as early as possible is of immeasurable importance as once vision is lost as glaucoma continues to progress, it cannot be recovered. However, if treatment is initiated early enough vision loss can be prevented and you can continue living life as normal and doing the things you enjoy. The primary treatments for glaucoma are aimed at reducing the pressure inside the eye in an attempt to prevent further vision loss. These pressure lowering treatments include pressure lowering eye drops, usually the first line of treatment, and surgical options, usually reserved for more severe cases.

The clinical team at Mortimer Hirst is at the forefront of optometric glaucoma management and have undergone specialist training to allow them to prescribe the eye pressure lowering eye drops. If your optometrist at Mortimer Hirst suspects that you have glaucoma after conducting all of the detection tests, a referral will be made to an ophthalmologist specialising in glaucoma to make a definitive diagnosis. Once diagnosed, the ophthalmologist will discuss the treatment options including pressure lowering eye drops and surgery. The optometric glaucoma specialists at Mortimer Hirst work closely with ophthalmologists specialising in glaucoma in both the public and private health sector. Thus, if eye drops are considered to be the best option, glaucoma can be co-managed and monitored by both our glaucoma specialists at Mortimer Hirst and the diagnosing ophthalmologist.

Since glaucoma can affect anyone at any age, has no symptoms and can only be detected using specialised tests designed to detect the condition, we recommend that everyone has regular eye examinations and visual health checks with our optometric glaucoma specialists at Mortimer Hirst.

Written by Dr Aki Gokul and the clinical team at Mortimer Hirst. www.akigokul.co.nz

Mortimer Hirst, 42-44 Hurstmere Road, Takapuna

www.mortimerhirst.co.nz