Astigmatism

What is astigmatism?

Astigmatism is a common and treatable eye condition. It occurs when the surface of the cornea or crystalline lens is not spherical, giving an astigmatic eye more than one point of focus. This means that light from an object does not focus exactly on the retina, but at two separate points.

With curves that are steeper in one direction than the other, an eye with an astigmatism could have a cornea that is not spherical – shaped more like a rugby ball than football.

What are the symptoms?

Many people have a small degree of astigmatism and their sight remains unaffected

In more severe cases, near or distant objects may appear blurred. You may also suffer from tired eyes or headaches while trying to focus.

What are the causes?

People can be born with astigmatism, or it can occur later in life. Although it can develop after an eye injury, an eye disease or eye surgery, the exact cause is usually unknown, although genetics can play a part. What is certain is that astigmatism is not caused by using a computer, watching too much television or reading in bad light.

How is it treated?

There are two types of astigmatism, regular and irregular. Irregular astigmatism is often caused by a corneal scar or ‘scattering’ in the eye’s crystalline lens. While this type of astigmatism can’t be corrected by standard prescription lenses, it may be corrected by contact lenses or, in minor cases, by laser eye surgery. Regular astigmatism, arising from either the cornea or crystalline lens, can be corrected by a toric lens.

Presbyopia

What is presbyopia?

Presbyopia is a condition associated with the ageing of the eye which makes it harder to focus clearly on close objects. Flexibility of the natural lens diminishes with age, and by their mid-forties, even people who have never needed spectacles start to need reading glasses.

If you already wear glasses for seeing at a distance, and are now experiencing the symptoms of presbyopia, varifocal lenses may be the solution, as they combine two prescriptions in one lens.

Advances in contact lens technology also mean that presbyopia can be easily corrected with multifocal lenses, which enable you to see clearly at all distances.

What are the symptoms?

The first symptoms most people notice are difficulty reading fine print or books, unless they are held at arm's length.

Those with the condition may also experience eyestrain when reading for long periods, particularly in low light conditions. Blurring of near objects or temporarily blurred vision when changing the viewing distance are also common symptoms.

The symptoms of presbyopia become less noticeable in bright sunlight, when the pupil becomes smaller.

Flashes and floaters

What are flashes and floaters?

Floaters are an extremely common and harmless occurrence, observed particularly against a bright background, as little black specs or spots that seem to float around within your visual field.

Flashes refer to the occasional flashes of light observed in the far periphery or corner of your vision, most often on extreme gaze.

Neither are of any great significance unless they occur in very large and increased numbers. If this is the case, they could be the sign of a retinal detachment, and you are advised to seek urgent advice.

What are the symptoms?

Floaters have the following features:

• They can be of varying shapes and sizes and look like black dots, shadows, hairs or cobwebs.
• They’re more prominent against pale and light backgrounds, especially in sun light.
• They can move when your eye moves and dart away when you look at them.

Flashes have the following features:

• They can look like small sparkles, lightning, fireworks or streaks of light.
• Tend to be in the extreme corners of the eye.
• Last for undefined amounts of time and can randomly come and go.
• Always check one eye at a time, with the other eye covered.

What are the causes?

Flashes and floaters are common among people over the age of 65 and those who are short sighted.

As we get older the ball of jelly inside our eyes (the vitreous humour) changes - it shrinks and pulls away from the retina, creating small gaps which cast shadows onto the retina manifesting themselves as floaters. Sometimes the vitreous humour can pull on the retina itself, physically stimulating the retina, usually leading to flashes.

Sometimes this pulling process can cause the retina to rip or tear. This is what causes the vast increase in floaters and sometimes flashes and can be the start of a retinal detachment and needs urgent attention.

Flashes and floaters can sometimes be caused by other eye diseases.

How is it treated?

Flashes and floaters are harmless and, while irritating, no treatment is usually needed. They should always be monitored, mentioned and discussed with an Optometrist during an eye examination. In many cases they will get less noticeable on their own as the brain adjusts to the changes in the eyes.

However, you should consult your Optometrist immediately if you experience:

• A sudden increase in the number of floaters or if they start to look different - especially if associated with increases in flashing lights.
• See more noticeable floaters or they appear in the second eye too.
• A change in vision or floaters that make day-to-day activity difficult, such as driving or reading.
• Grey areas, shadows or a curtain effect appearing in your vision.

The above could be signs of a more serious issue such as a retinal detachment or a retinal tear and medical assistance should be sought immediately.

What can I expect to happen?

If you notice flashes or floaters you should discuss it with your Optometrist, who will check the back of your eye, the vitreous humour and your peripheral fields of vision. They may need to use dilating eye drops to get a better view of the retina. If they suspect that there may be a more serious cause then they will refer you to the hospital.

We recommend you have an eye test at least every two years, regardless of symptoms and/or conditions.

Dry Eye

What is dry eye?

Tears within the “tear film” are a complex combination of varying layers of water, oils and lipids, helping to lubricate the eye, wash away debris, stabilise vision and protect against infection.

When the volume of tears on the surface of the eye and beneath the lids is not enough, the eye can feel dry, irritated and inflamed.

What are the symptoms?

There are a number of symptoms which can include:

• The feeling of burning, grittiness, sore or itching eyes.
• Brief or intermittent blurring of vision.
• Discomfort in bright light.
• Red eyes.
• Watering eyes - excessive watery tears lacking crucial lubricant properties.

Contact lens wearers may find that their lenses become increasingly less comfortable to wear.

What are the causes?

The causes of dry eye are varying and can be caused by several factors:?

• Reduced blink rates associated with visual tasks – eg computer use.
• Side effects from taking certain medication - such as antihistamines or beta blockers.
• Pre-existing medical conditions – including rheumatoid arthritis or Sjorgen syndrome.
• Pre-existing eye conditions such as blepharitis or eyelid conditions.
• Hormonal changes - typically associated with being female, middle age or pregnancy.
• Problems with drainage via the tear ducts.

There are also a number of non-medical and lifestyle conditions that can cause dry eyes such as:

• Hot or windy climates.
• Contact lens wear.
• Smoking.
• Air-conditioning units.

How is it treated?

There are no real cures for dry eyes, however symptoms can be managed in the following ways:

• Increasing your blink rate.
• Modifying environmental factors, such as more frequent breaks from computers.
• Using dry eye drops, gels or ointments.
• Wearing glasses/sunglasses for protection.
• Treating any underlying cause, such as improving eyelid hygiene.
• Nutrition and hydration, including Omega-3 supplements.

What can I expect to happen?

Optometrists have a number of tests available to detect and monitor dry eyes and will offer a personalised management plan. Extreme cases may be referred to a hospital Ophthalmologist for further testing.

We recommend you have an eye test at least every two years regardless of symptoms and/or conditions.

Conjunctivitis

What is conjunctivitis?

Conjunctivitis is an inflammation of the conjunctiva, which is the thin layer which covers the white of the eye and the inside of the eyelids. It can affect one or both eyes, causing discomfort. The conditions is sometimes known as pinkeye.

What are the symptoms?

The symptoms of conjunctivitis can differ, based on the primary cause. However, pink, bloodshot or puffy eyes are a common indication you may have the condition. Other indicators can include itching, a burning feeling in the eye or sticky eyelashes, particularly when you wake in the morning.

What are the causes?

In addition to infection from bacteria, viruses or other organisms, conjunctivitis can be caused by an inflammation or allergy.

Usually lasting for between two and three weeks, viral conjunctivitis tends to cause a watery red eye. In the majority of cases, it will not affect your vision. However, you may experience blurred vision or glare when looking at lights.

Bacterial conjunctivitis is more likely to cause a redness of the eye, accompanied by a sticky yellow discharge.

How is it treated?

The symptoms of most forms of conjunctivitis will normally clear on their own after a few weeks, so treatment isn’t always needed.

As it is not caused by bacteria, viral conjunctivitis does not respond to antibiotic drops. Of course, antibiotic drops can be helpful in cases of bacterial conjunctivitis, and are often prescribed for a one or two-week course.

Treatment of viral conjunctivitis often involves the use of artificial tears and over-the-counter painkillers, along with cold compresses and regular cleaning of the eyelids. Much like a cold or the flu, viral conjunctivitis will disappear when your body fights off the germs and becomes immune to the virus.

For severe cases of viral conjunctivitis, or when the cornea is affected, steroid drops can be are given. If you have any type of conjunctivitis, you should not wear contact lenses.

How can it be prevented?

Conjunctivitis can be easily spread through contact with infected items, such as pillowcases, tissues, towels and flannels, as well as through water droplets from coughing or sneezing.

As it is so contagious, thorough and frequent hand washing is absolutely essential if you are to avoid passing on the condition. You should also carefully dispose of tissues after use and avoid sharing flannels and towels.

Blepharitis

What is blepharitis?

Blepharitis is inflammation of the eyelash follicles, causing the eyelid margins, or rims, to become red and swollen. It is a common condition which can develop at any age, but is more common in young children and people over 50.

Most people experience repeated episodes followed by periods with no symptoms. It is not possible to catch blepharitis from someone else who has it.

What are the symptoms?

Symptoms of blepharitis include:

• Eyelids that are red, inflamed or puffy.
• Eyes that feel itchy, dry, sore or gritty.
• Frothy or oily deposits in your tears.
• Sticky eyelids; especially first thing on waking.
• Increased sensitivity to bright light.
• Dandruff-like crusts appearing on the eyelashes.

Who is at risk?

Blepharitis is more common in people aged over 50, but can develop at any age. As we get older, the small glands at the lid margins can become blocked more easily. The tears then contain less lubricants, making the eyes feel gritty.

What are the causes?

Blepharitis can be caused by a number of factors, such as:

• Bacterial infections.
• Dysfunctional glands in the eyelids.
• Localised complications from skin conditions, such as dermatitis.
• Exposure to chemicals, fumes, smoke or other pollutants/irritants.
• Poor hygiene when using cosmetic beauty products.

Blepharitis is usually a low-level but chronic inflammation. Many people experience periods of time with no symptoms, however it does usually come back.

How is it treated?

Your Optometrist can usually spot the signs of blepharitis by looking closely at the front surface of your eyes, especially at the eyelids and surrounding area. The first-line treatment in managing blepharitis is a dedicated lid hygiene regime.

Symptoms can be reduced by:

• Using blepharitis eyelid cleaning solutions, gels or wipes as advised by your Optometrist.
• Warm compresses, eye masks or eye bags placed against the eyelids can help loosen crusts and soften the waxy build up from within the glands.
• Avoiding using eye make-up (particularly mascara and eyeliner) until symptoms have cleared.
• Make-up will need replacing as it is likely to have become contaminated.
• Severe cases may need antibiotics or tear supplements.

What can I expect to happen?

A good eyelid hygiene regime will reduce the symptoms and help prevent them. Your Optometrist can give you further advice on treating blepharitis. However, it is a condition that can recur after treatment.

We recommend you have an eye test at least every two years regardless of symptoms and/or conditions.

Cataracts

What are Cataracts?

Cataracts are formed when the clear lens inside the eye starts to become cloudy, thereby reducing the quality and clarity of the image formed on the retina.

Once the reduction in vision starts to impact on the quality of life (while driving, for instance), referral for cataract surgery is required. Cataract surgery today is usually an out-patient procedure carried out under local anaesthesia. Although cataracts are known to form at any age, they are more typically age-related, found mostly in people over the age of 65.

What are the symptoms?

Cataracts typically develop slowly over a long period of time and are not painful, however in some instances they can develop more suddenly. The main symptoms of cataracts are:

• Misty or blurry vision
• Difficulty in reading or seeing details at a distance
• Experiencing double vision
• Being dazzled in bright lights - particularly driving at night
• Changes to colour vision, including colours seeming faded or washed out

What are the causes?

Cataracts are the result of a loss of transparency of the crystalline lens. This naturally occurs as we get older. However, a number of other factors can contribute to the development of cataracts, such as:

• Overexposure to UV sources, including excessive sunlight
• Taking steroids for long periods of time
• Injuries to the eye or following eye surgery
• Contact with toxic materials and radiation

Cataracts can form at any age. There are cases where babies are born with them, and these are known as congenital cataracts. In younger people they can result from conditions such as diabetes, certain medications and other eye problems.

How is it treated?

Treatment is only usually started once the cataract begins to affect vision and interrupt daily routine tasks.

This is usually done by a short and simple eye operation, involving a procedure under local anaesthetic in which the old lens in the eye is replaced with a clear plastic implant.

What can I expect to happen?

Cataracts can be spotted during a routine eye examination. Your Optometrist will refer you to a hospital Ophthalmologist once your vision becomes affected. They will then discuss surgery in more detail, if it’s an option for you. The Ophthalmologist will discuss the potential visual expectations following surgery.

Vision is normally instantly improved once surgery is completed. Once fully recovered many patients find they have good clear distance vision. However, new glasses are frequently needed, especially for reading, as the prescription often changes following the cataract operation.

We recommend you have an eye test at least every two years regardless of symptoms and/or conditions.

Diabetes

What is diabetic retinopathy?

Diabetic retinopathy is a closing of the blood vessels in the retina, resulting in the retina being starved of blood. This leads to fragile and abnormal blood vessels growing on the surface of the retina, which can lead to permanent loss of vision – either from bleeding into the eye, detachment of the retina or retinal scarring.

What are the causes?

Diabetic retinopathy affects up to 80% of all patients who have had diabetes for 10 years or more.

The condition particularly affects those with poor diabetic control, resulting in blood sugar levels which are too high over long periods of time.

How is it treated?

Research indicates that at least 90% of new cases could be prevented if proper treatment and monitoring of the eyes is carried out on a regular basis.

Regular eye tests can help to spot the early signs of this condition and enable you to take action to control diabetes before it damages your body and your eyes. People with diabetes are entitled to free annual eye tests from the NHS.

It’s also important to have regular health checks, as there are often no early warning signs for diabetic retinopathy. The same applies to other diabetes-related conditions, such as diabetic macular oedema. A person with macular oedema is likely to have blurred vision, making it hard to do things like read or drive. In some cases, the vision will get better or worse during the day.

Macular Degeneration

What is macular degeneration?

While age-related macular degeneration (AMD) is the most common, occurring in those aged 65 or over, there are other, less common types that can affect people of any age.

There are two principle types: wet AMD and dry AMD. Wet AMD tends to be more sudden in onset and thus more serious, occurring at any age, while dry AMD is typically associated with age and is slower in onset.

In both types the macular (the central part of the eye) deteriorates, resulting in a loss of central vision.

What are the symptoms?

Most people do not experience any symptoms in the early stages, especially if dry degeneration is present in only one eye. As the macular cells deteriorate, people may notice the following visual changes:

• Straight lines, such as lamp-posts or door frames, appearing distorted or bent.
• Vision becoming blurry or developing gaps.
• Objects changing shape, size or colour.
• Dark spots like a smudge on a glass appearing in the centre of your vision.
• Difficulty in adapting from dark to bright lighting.
• Discomfort or a glaring sensation in bright light.
• Words disappearing when reading.

Macular degeneration is a painless condition. However, the sudden onset of symptoms should be reported to your Optometrist.

What are the causes?

The cause of macular degeneration is unknown, however there are certain factors that are believed to heighten the risk of developing the condition. These include:

• Age - macular degeneration is most prominent in over 65s.
• A family history of the condition.
• Smoking.
• Poor diet - especially one which lacks antioxidants or is high in saturated fat.
• High blood pressure.
• Overexposure to UV light.
• Gender - more women are diagnosed than men.

How is it treated?

Wet AMD requires referral to an Ophthalmologist, who will discuss the options available.

There is no known effective treatment for dry macular degeneration, although lifestyle choices and nutrition may play a role in minimising further progression.

Evidence shows that increasing the intake of antioxidants and improvements to the diet, including foods rich in certain nutrients, such as lutein and zeaxanthin, can help reduce the risk of macular degeneration. These are found in spinach, broccoli and sprouts, as well as in specific AMD nutritional supplements. For further advice on supplements speak to your Optometrist.

Those with AMD often find increased lighting or contrast helpful. The use of electronic devices, such as tablets, can prove very useful, as they can be adjusted for illumination and contrast.

What can I expect to happen?

Optometrists have a number of ways to test for macular degeneration and early signs can be spotted during a routine eye test. If macular degeneration is suspected, you may be referred to a hospital Ophthalmologist for a full diagnosis.

Glaucoma

What is glaucoma?

In some instances, glaucoma may be linked to increased pressure of the fluid inside the eye pressing on the nerve, while in others it is thought to be due to reduced blood flow.

In all cases however, the impact is a gradual impairment in the sensitivity of parts of the retina, increasingly causing areas of loss of vision and the ‘visual field’. Often, patients do not have any symptoms in the early stages of glaucoma, so regular eye screening is essential to detect this condition.

What are the symptoms?

There are two main types of glaucoma; chronic (developing slowly) and acute (which involves a sudden onset). In the early stages of chronic glaucoma, there are few if no symptoms - as the condition progresses the extent of the peripheral vision reduces.

In acute glaucoma the following symptoms may be experienced:

• Short bursts of pain, discomfort and in extreme cases nausea.
• A brow ache that comes and goes.
• Seeing coloured rings around bright lights.
• Hazy or misty vision.

What are the causes?

The eye needs a certain amount of pressure to keep its shape and to function correctly. The balance of pressure is maintained by the aqueous humour, the eye’s internal watery liquid.

In some cases of glaucoma, optic nerve damage is caused because there is more fluid being produced than draining away, leading to the build-up of pressure. Glaucoma can also be caused by a weakness in the optic nerve.

Certain groups of people are more at risk of glaucoma, especially those who are:

• Aged over 40.
• Very short sighted.
• Of African, Caribbean, East Asian or South Asian origin.
• Closely related to someone with chronic glaucoma.
• Already have raised tension within the eye.

What can I expect to happen?

During an eye test an Optometrist will carry out several tests that can detect any signs of glaucoma by:

• Measuring your eye pressure – usually using the “puff of air” test or sometimes with yellow drops and a blue light.
• Examining your optical nerve using an optical microscope, looking for signs of pressure build up.
• Assessing the peripheral extent of your field of vision.

If glaucoma is detected then your Optometrist will refer you to the hospital for further diagnosis and treatment, usually involving eye drops to reduce the pressure. Although damage caused by glaucoma can’t be cured, early diagnosis, constant monitoring and treatment can help minimise the rate of progression.

If you drive and have been diagnosed with glaucoma, you must inform the DVLA.

We recommend you have an eye test at least every two years regardless of symptoms and/or conditions. If you are over 40 and have a family history of glaucoma then we recommend you have an eye test every 12 months.

More information can be found on the following sites at www.nhs.uk or www.glaucoma-association.com You can also call the information, support and advice service, Sightline, on 01233 64 81 70.

Retinoblastoma

What is retinoblastoma?

In the UK, around 40 to 50 new cases of retinoblastoma are diagnosed each year, making it one of the rarest forms of childhood cancer.

In about two-thirds of cases, only one eye is affected, while in the remaining third tumours develop in both eyes. The number and size of tumours on each eye may vary.

What are the symptoms?

If your child is showing one or more of the signs below, take them to have their eyes examined at the earliest possible opportunity.

A white pupil or reflection

A white reflection or pupil may be seen in a photograph where a flash has been used. Often, one eye will have the normal ‘red eye’, but the other may look white, yellow or orange. This may be seen in just one or many photographs of the child.

No 'red eye' in flash photograph

In a photograph where one eye has 'red eye', which is normal, the other eye may look black or just look 'wrong'. This can also be a sign that something is not right.

A squint

Although a squint can be nothing more than just a squint, it can also be a sign of retinoblastoma. So it’s always worth having it checked out quickly, just to make sure.

A red, sore or swollen eye without infection

A child's eye may become very red and enflamed for no reason. This symptom is usually accompanied by one or more of the other signs outlined here.

A change in colour to the iris

The iris, the coloured part of the eye, can sometimes change colour in one eye, sometimes only in one area.

Deterioration in vision

A child’s vision may deteriorate over time or they may have had poor vision from birth. You may notice that your child does not focus or ‘fix and follow’ as well as other children or babies of the same age.

Many of the signs mentioned above may also be signs of less severe condition, so if you notice any of the signs above, get your child checked quickly, if only to rule out retinoblastoma and give you peace of mind.

Treatment

Retinoblastoma has one of the best cure rates of all the childhood cancers. In the UK, around 98 per cent of children will survive, but early diagnosis really is important.

The priority of retinoblastoma treatment is to safeguard the life of the child, then to preserve vision and minimise any side effects or complications.

The exact course of treatment will depend on the individual case and will be decided by the Ophthalmologist, often in consultation with a paediatric Oncologist. Treatment options include cryotherapy, laser therapy, chemotherapy and enucleation, which is removal of the eye.

For further information about Retinoblastoma visit www.chect.org.uk.