Eye diseases are relatively rare, although they become more common as we get older. All eye diseases should be regarded as serious - even diseases that appear mild have the potential to cause serious damage if not treated appropriately.
Many serious eye diseases do not have dramatic symptoms. Some people with serious eye diseases don't realise there is a problem until they've suffered irreversible damage.
Everyone should have a checkup from an optometrist or ophthalmologist every two years.
Your optometrist will look for any signs of eye disease and may recommend more frequent checks if you're at higher risk.
Five eye diseases are responsible for most of the blindness or poor vision that occurs in the western world:
1: Age-related macular degeneration
Age-related macular degeneration (AMD) is damage to the macula. The macula is the part of the retina responsible for sharp central vision. Over time the blood supply to this area can become compromised and the receptors begin to fail. This affects the quality of information being sent to the brain for processing.
There are two types of AMD, Dry and Wet.
Dry AMD is the most common, accounting for approximately 90% of all cases, and results in a slow deterioration in central vision. Dry AMD cannot yet be cured but can be treated with dietary supplements and lifestyle changes.
Wet AMD is caused by fluid leaking under the macula and can result in a dramatic loss in central vision over a short period of time. Treatment often consists of injections directly into the eye.
Early detection and treatment can lead to very good visual outcomes.
2: Diabetic Retinopathy
For those with diabetes changes may occur and damage the retina at the back of the eye. The risk of developing retinopathy increases with the length of time you have had diabetes and with the quality of control of the condition. Diabetes causes blood vessels to become leaky and as a consequence blood may not get to the target tissue.
In the eye, this might lead to swelling of the macula, cell death, haemorrhaging and scarring leading to retinal detachment.
Diabetics should have their eye health screened on an annual basis, preferably including digital retinal photography so that any changes can be monitored and treatment advised.
Cataracts are cloudy areas that form in the clear lens inside the eye. This cloudiness results in poor vision in the same way that a dirty window scatters light and degrades the image. Cataracts result from aging of the lens and most people will develop some degree of cataract through their life.
If the vision is poor enough the lens can be removed from the eye and replaced with an artificial lens. This is called cataract surgery and nowadays it has an over 95% success rate.
Most people will still need some form of glasses after surgery, however the corrected vision will be far clearer than previous.
Glaucoma is a condition in which the nerve cells which transmit information from the eye to the brain become damaged and prevents visual information from getting from the retina in the eye to the brain. Untreated Glaucoma can lead to ‘tunnel’ vision, whereby peripheral awareness becomes diminished. The damage occurs very slowly and most people who are diagnosed with glaucoma are unaware they have the disease
It is treatable with medication or surgery. Ongoing assessment and timely referral for treatment are necessary.
5: Retinal Detachment
A retinal detachment occurs when the film at the back of the eye breaks away from the underlying tissue. These generally begin as small holes in the periphery and progress towards the centre of our vision.
If untreated they can rapidly result in significant vision loss or complete blindness. Retinal detachments normally presents as the sudden appearance of floaters and/or flashes. These symptoms are often associated with a Posterior Vitreous Detachment (PVD), which is a less serious and much more common occurrence.
If you notice these symptoms you should contact your optometrist’s office immediately. It is likely that they will arrange for you to attend their clinic for a dilated retinal examination to determine the exact nature of the problem.
Other Common Eye Disorders
A pterygium (pronounced ter-idge-ee-um) is a triangular-shaped lump of tissue with blood vessels that grows from the conjunctiva on to the cornea. They are often associated with exposure to dust, wind and glare. They can cause discomfort and also distort vision if they grow far enough onto the cornea.
Wearing sunglasses and using ocular lubricants is indicated for those who have pterygium developing. They can be surgically removed if necessary.
These are small white or yellowish lumps that grow on the conjunctiva. They are probably related to exposure and irritation and are benign. They rarely require treatment, although the lump can disrupt a normal tear film and cause symptoms related to dry-eye.
Dry eye symptoms are one of the most common reasons that people seek to see their optometrist.
Symptoms range from dry, gritty, scratchy eyes to stinging, itching, blurred and watering eyes. The aqueous tear layer is very important to the health of the outer eye and the clarity of our vision. It is made up of a homogenous mixture of many components, and a deficiency in this mix can lead to the symptoms associated with Ocular Surface Disorder (OSD) or ‘dry eye’.
Dry eye can be due to damage to the glands that secrete our tears, associated with disorders such as Sjogren’s syndrome, Acne Rosacea and Blepharitis, or related to environmental factors such as wind, cold air and air-conditioning.
The most common cause of dry eye is Evaporative Dry eye, where there is sufficient tear supply but the layer that slows the evaporation of the tears breaks down. This means the tear film is less stable and dry spots form on the cornea due to environmental stress and/or the decreased blink rate associated with concentrated vision tasks such as reading, sitting at the computer or driving. This can lead to discomfort, red eyes and fluctuating vision.
The part that is difficult to understand is that it can also increase reflex tearing – the eye waters more! However, this tends to be a watery, somewhat salty tear which can actually make the problem worse! This is where ocular lubricants can be beneficial in stabilizing the tear and reducing evaporation. They can also be useful if not enough tear is being produced or if there are irritants causing minor allergic responses or inflammation.
Eyes can also water if there are blockages in the tear drainage channels. Probing and syringing of the ducts can help although sometimes an operation is required to rectify the problem. Our Optometrist can conduct tests to determine the cause of your dry eye and advise you on the best course of action to treat the problem.
Conjunctivitis is an inflammation of the clear covering of the eye. It is sometimes associated with bacterial infection in which case there may be copious discharge and the condition will usually affect both eyes. Often conjunctivitis is associated with viral infection or sometimes with allergy.
The treatment varies with each condition and you should see an Optometrist to have the disease assessed. Jason has training in Ocular Therapeutics and can diagnose the condition and arrange treatment as necessary.
Blepharitis is a relatively common inflammation of the lid margins. The edges of the lids will appear red and there may be deposits about the lids, particularly in the morning.
The condition can affect tear performance and lead to irritation and further inflammation of the conjunctiva and cornea.
Blepharitis can be treated by improving lid hygiene, although sometimes more intensive treatment is required initially.
Our Optometrists can assess the problem and advise you regarding the appropriate treatment. If you have any concerns regarding your eyesight or eye health contact our reception staff to arrange an appointment to see one of our Optometrists.