The World Glaucoma Association is this week marking World Glaucoma Week, in a bid to raise awareness on the need to tackle the ever-increasing challenge posed by glaucoma.

Glaucoma is a common eye condition. According to the WHO World Report on Vision 2019, there are around 80 million people with glaucoma and it is the fourth leading cause of preventable loss of vision. The prevalence of glaucoma is expected to increase significantly in the future, mostly due to an ageing population.

A survey by Cachia J. et al. (1989) had found that around three per cent of those older than 40 years in Malta had glaucoma. An ongoing study will shed light on the current disease burden locally.  

From personal experience, the word ‘glaucoma’ evokes various misconceptions. It is frequently wrongly linked with eye pain or headache and is equated with high pressure in the eye. General understanding about the condition is low and increased public awareness would help bring people forward to undergo regular eye testing. 

So, what exactly is glaucoma? Defining this disease is challenging and ‘glaucoma’ is a label given to many different conditions which, ultimately, result in permanent damage to the nerve that conveys visual information from the eye to the brain, the optic nerve. High pressure in the eye is a major risk factor for glaucoma but glaucoma may occur and worsen despite normal eye pressure and one may have elevated eye pressure without ever developing glaucoma.

Other risk factors include family history, poor blood circulation, other eye conditions and any type of steroid use in susceptible individuals. However, predicting one’s risk is difficult and anyone may be affected by glaucoma. 

The loss of vision in glaucoma is usually very slow. The deficit is initially mostly confined to the field of vision (how much one can see to the side/up/down while looking straight ahead) and is commonly not felt by the individual. Having a defect in your visual field is like having missing pieces of a puzzle. This means that an individual may have a significant number of missing pieces and still feel that the vision is normal and have no symptoms at all.

An ongoing study will shed light on the current disease burden locally

Glaucoma becomes significant if it worsens quickly enough and affects the centre of the field of vision. However, glaucoma is usually stable and not associated with loss of vision if managed adequately. 

Loss of vision from glaucoma can have significant implications, such as inability to drive, work limitations and depression. While driving, glaucoma may lead to an increased risk of not seeing a person crossing the road or miss road signs, with possible disastrous consequences.

While most cases have no symptoms initially, some can have a combination of eye pain, redness and blurred vision, sometimes accompanied by severe nausea and vomiting. These cases need urgent medical attention and commonly need hospital treatment as the eye pressure may be very high.

Rarely, glaucoma can occur at a young age, even in babies. Glaucoma can be found in young patients who undergo an eye check as part of the management of another condition or else there may  be features, such as an abnormal appearance of the eye, which would prompt the parents/guardians to seek medical advice.

The current treatment options focus on slowing (ideally stopping) further loss of vision. Generally, little can be done to recover what has been lost. Therefore, cases need to be detected before significant damage can occur. This can be achieved by screening eye tests, which are done even if there are no problems with vision. The frequency of eye testing depends on the individual situation but once a year is generally adequate.

Testing should start as early as possible. Even very young children benefit from a screening eye test but mostly to detect the presence of a lazy eye rather than glaucoma. Adults should undergo regular testing from at least 40 years of age. Locally, glaucoma screening can be done within some health centres and there is no age restriction. Glaucoma screening commonly includes eye pressure measurement and a special test of the visual field needing specialised equipment and it can be nurse-led. 

When glaucoma is established, treatment mostly focuses on lowering the pressure in the eye with eye drops. Treatment success depends on the resilience of the patient in applying the drops daily for many years. Laser and surgery may also be required.

Glaucoma treatment is personalised and the patient has an important role to play. Treatment choices depend on the benefits and risks of the various options and the specific situation of the individual. Treatment does not always lead to the desired outcome and various approaches may need to be tried. In addition, treatment is also limited by what is locally available. Unfortunately, loss of vision is not always avoided.

There is ongoing research around the world on how to reverse the glaucoma damage and on other therapeutic options but these are mostly at an early stage and not clinically available. Once the optic nerve function is lost, it cannot be replaced or transplanted.

With regards to nutritional supplements, high-quality evidence is limited. However, having a healthy lifestyle can have a positive effect on eye health.

Patients who suffer from glaucoma should encourage their relatives to consider their need for an eye test. The public in general should seek advice from a healthcare professional.

James Vassallo is an ophthalmologist at Mater Dei Hospital.