Conditions in Children
Common eye conditions
During early childhood, each eye must receive a clear and equal image in order for vision to develop. Amblyopia (or “lazy eye”) is reduced vision in one (or sometimes both) eyes that occurs in early childhood due to an interruption of normal visual development. Anything that prevents clear vision in either eye during the critical period (birth to eight years of age) can result in amblyopia. Causes can include:
- A turned eye (strabismus)
- Different focusing ability between the two eyes (long sightedness, short sightedness or astigmatism)
- Physical interruption to clear vision – e.g. droopy eyelid (ptosis), cloudy lens (cataract)
- Damage to the back of the eye (retina)
Early detection and treatment of amblyopia are vital. Amblyopia is most successfully treated before eight years of age.
Treatment varies depending on the cause, but often includes wearing glasses and covering the stronger eye with a patch. These measures stimulate the eye with poorer vision, making it work harder and improve with time.
Strabismus (sometimes called “squint”, “lazy eye” or “turned eye”), is a common condition where the eyes do not line up together. This means that when one eye is looking at something, the other eye may turn inwards toward the nose (esotropia or convergent squint) or outwards toward the ear (exotropia or divergent squint). It can be present all the time or just every now and then. Strabismus usually appears in early childhood and rarely may be present from birth.
What causes strabismus?
Strabismus affects approximately five in every 100 children. It occurs due to a failure of the eyes to maintain good alignment, which can be due to a number of factors. There are six muscles attached to the white outer layer of each eyeball. Contraction and relaxation of these muscles control how the eye moves. Anything that affects the way in which these muscles work together can result in strabismus:
- In most cases, strabismus occurs due to a failure of the visual area of the brain that controls eye alignment.
- Children who have a problem with the focus of their eyes, especially those who are long-sighted, can develop strabismus.
- Less commonly, it may occur due to a condition affecting the eye muscles themselves.
- Strabismus can also appear after head injuries or illnesses that cause weaknesses in the eye muscles.
How is vision affected?
When the eyes are not straight and working together, each one sends a different image to the brain. To stop confusion, the brain will sometimes ignore part of the image from one eye. If one eye then becomes dominant, it can lead to a decrease in vision in the turned eye – this is called amblyopia.
Strabismus may also affect a child’s ability to judge distance and depth, resulting in poor hand-eye coordination or clumsiness.
Signs and symptoms of strabismus
Common signs can including closing one eye, clumsiness, unusual head position or eyes that look misaligned. In some children, strabismus may only be obvious when looking in a particular direction, or when the child is tired or unwell. In other cases, the symptoms aren’t discovered until a child is old enough to describe the problems they are having, such as blurred or double vision, or difficulty reading.
How is strabismus diagnosed?
It is normal for a baby’s eyes to look misaligned for short periods of time up until the age of around four months. Strabismus that is present always, or is becoming increasingly obvious, is not normal. Because strabismus can be a sign of serious eye and health conditions, the child should be seen as early as is practical for assessment, diagnosis and treatment.
Eye professionals, including ophthalmologists, orthoptist and optometrists, use an assortment of tests to see if a child’s eyes are straight and working together. Your child will also require a full examination of the internal eye, which includes the use of drops to dilate the pupils. Sometimes, a prolonged eyepatch test is also needed.
How is strabismus treated?
Treatment aims to improve the alignment of the eyes and to bring back, or protect, normal vision. Treatment does depend on the cause, but in general may include:
- Full time glasses
- Eye patching for some of the time
- Surgery to straighten the eyes
- Surgery to remove the cause of the turn (e.g. cataract removal)
Valley Eye Specialists incorporates the Queensland Paediatric Ophthalmology and Strabismus Surgeons (QPOSS), a group of expert ophthalmologists who are trained in detecting and treating strabismus in children.
Blocked tear duct, or nasolacrimal duct obstruction (NLDO), is a common eye problem amongst newborn babies and infants. It causes constant watery or sticky discharge in one or both eyes from soon after birth. Unlike in conjunctivitis and other eye infections, the “white” of the eyeball itself does not become inflamed and red with a blocked tear duct. However, due to the ongoing watering, the eyelid skin around the affected eye/s may become red and inflamed.
Most commonly, a blocked tear duct will settle with time, or with regular simple massage of the tear duct. In most cases this will occur by 12 months of age, but it may take longer. Early intervention is considered if the blocked tear duct leads to other problems, such as recurrent conjunctivitis or tear duct infections.
When an infection occurs due to a blocked tear duct, the tissues surrounding the eye (eyelids and side of the nose) may become increasingly red, swollen and inflamed. This will need treatment with antibiotics and/or surgery.
Any infant with a watery eye should be assessed by a healthcare professional and/or an ophthalmologist to ensure that it is not being caused by a less common but more serious problem.
At Valley Eye Specialists, our paediatric ophthalmologists offer care and advice for blocked tear ducts, and can also proceed with probing with or without stenting of the tear ducts if this is needed.
Right blocked tear duct before (below) and after (above)
Blepharitis is a chronic inflammatory condition involving the eyelid margins. If can affect both children and adults. Mostly, it responds to simple treatment and is not a vision-threatening problem.
Blepharitis arises from blocked glands (Meibomian glands) and an alteration in the substance that these glands normally make and secrete onto the margin of the eyelid. It is thought that, in some people, blepharitis is caused by a sensitivity to the bacteria which normally live on the skin.
Common symptoms of blepharitis include:
- Red eyelids
- Crusting of the eyelashes
- Red, dry or irritated eyes
The most important treatment for blepharitis is good “eyelid hygeine”, and this should be performed regularly even when eyes seem comfortable and uninflamed. Other treatments may be required if this is not effective on its own, and your ophthalmologist will be able to discuss which treatments will be most likely to help in your particular case.
When untreated or severe, blepharitis may lead to complications such as:
- Chronic conjunctivitis
- Tear film abnormalities like dry eyes
- Marginal keratitis
- Loss of eyelashes
These conditions are best treated by your ophthalmologist, but most of the time prevention is possible through good eyelid hygiene.
A chalazion, or meibomian cyst, is a common eye condition in both children and adults alike. It usually presents as a lump on the eyelid which waxes and wanes with time. These lumps can be single or multiple and may affect one eye or both simultaneously or subsequently. People with conditions such as rosacea, seborrheic dermatitis or blepharitis are more prone to multiple and recurrent chalazia.
Chalazion arises from a blocked gland that is present in the normal eyelid. These blocked glands then become chronically inflamed, and enlarge to form a painless lump at the eyelid margin. These lumps are non-infective and non-contagious, but on occasion secondary infection is possible.
Mostly chalazia respond to simple eyelid hygiene practices involving regular daily warm compresses and massaging the lid margins. If complicated by infection, antibiotics are usually also required. Rarely, chalazia will need to be treated with a simple surgical drainage procedure if they are very large, chronic, infected or do not respond to the simple treatments outlined above.
Keratoconus occurs when the normally round cornea (the clear window at the front of the eye), becomes thin and irregular (cone shaped). This abnormality in the shape of the cornea impairs the ability of the eye to focus light on the retina (the eye’s camera film), resulting in distortion of vision.
In early stages, keratoconus causes slight blurring of vision. These symptoms often present in the late teens or early twenties. Keratoconus usually affects both eyes, but is often asymmetrical in its severity.
As the condition progresses, the cornea thins and vision may become more distorted.
Eyeglasses or soft contact lenses may be used to correct short-sightedness and astigmatism caused by the early stages of keratoconus, whilst rigid gas-permeable lenses are often more suited to correct irregular astigmatism in keratoconic patients.
In selected patients, documented progression can be reduced by using a technique called corneal cross-linking (CXL).
In approximately 10-25% of cases of keratoconus, progression may render vision correction with glasses or contact lenses insufficient. In these cases, patients may require corneal transplantation, where the thinned, irregular corneal tissue is replaced with healthy donor corneal tissue.
Myopia, or short-sightedness, is a common eye problem worldwide and the rate is increasing! 1.5 billion people around the world are myopic to some extent.
Risk factors and complications
We don’t know exactly why myopia occurs but there are some genetic factors (so it can run in families) and there are also some environmental factors involved. Known risk factors include:
- Genetics – especially amongst Asian populations
- Prolonged near work activities
- Reduced outdoor exposure and activities
Myopia has a risk of causing other problems in the eyes, like cataract, glaucoma, retinal tears and detachments, and problems with the macula.
What to expect from a myopia progression clinic appointment
Regular routine reviews are required to demonstrate progression of myopia before commencing treatment. To determine whether progression has occurred, your child’s vision will first be tested. Then the length of the eye will be measured, as well as the overall power of the eye (refractive error). Finally, a dilated examination may be performed to check that the macula and peripheral retina are healthy.
Treatment of myopia
Simple treatment options that might help include:
- Glasses with full correction
- Increasing time spent outdoors
- Specifically compounded weak atropine eye drops
Atropine eye drops require a prescription, and are only available from select compounding pharmacies.
Cataract is a cloudiness or loss of transparency of the lens in the eye. It causes blurring of vision, which in some cases can severely affect vision. About 1 in 2, 500 babies will be born with a cataract which can be in one or both eyes. There are many causes of childhood cataracts, so blood tests are often required to determine the cause if there is no-one else affected in the family.
Because babies have to learn to see, cataracts in this age group often need urgent surgery for removal. This is usually carried out between six to eight weeks of age. The eyes grow during childhood, so placing an artificial lens inside the eye (as in adult cataract surgery) is not the best way to achieve good visual focus throughout childhood. Instead, babies are usually fitted with hard contact lenses after surgery, which can be easily taken out and cleaned weekly.
The results of cataract surgery in babies are very good – if both eyes are affected, there is an 80 % chance the child will grow to have vision good enough to obtain a driver’s licence.
Optic disc drusen is caused by an abnormal deposition of a protein-like material at the point where the optic nerve enters the back of the eye. The number and size of the optic disc drusen tend to increase over time, but they usually do not cause any symptoms.
Although the cause of optic disc drusen is unknown, its occurrence tends to run in families and so it is common for other first-degree family members to be affected. Optic disc drusen is not usually apparent in children younger than four to five years old.
Should I let other physicians who may be caring for me or other family members know about this?
Optic disc drusen may be confused with papilloedema, which is a true swelling of the optic disc due to other medical conditions. For this reason, once a diagnosis of optic disc drusen has been made, it is useful for you to let your optometrist and GP know.
There is no proven treatment for optic disc drusen, and most of the time they do not cause any visual problems. Rarely however, they may cause secondary problems and for this reason periodic eye examination (every year or two) is recommended.
There are a number of reasons your child may require glasses. At your appointment with your ophthalmologist, your child will have eye drops instilled that will temporarily dilate their pupils and paralyse the focusing muscles in the eyes. This allows the ophthalmologist to accurately measure the need for glasses.
Some reasons why glasses may be prescribed for your child include:
1. Long sightedness (hypermetropia):
- Most children are a little long sighted – this is not usually a problem as the eye is able to compensate by changing the shape of the lens to gain clear focus.
- However, a significant amount of long sightedness can lead to blurred vision, particularly for close objects.
2. Short sightedness (myopia):
- A significant amount of short sightedness can lead to blurred vision for objects in the distance
- In most cases, short sightedness stabilises in early adolescence, but sometimes it can continue to progress with age. This is something your child’s ophthalmologist will monitor closely, and if necessary special drops can be prescribed to slow down this progression.
- In an eye with astigmatism, the front of the eye is shaped like that of a rugby ball instead of a soccer ball, meaning that light fails to come to a single point of focus in the eye. This leads to blurred vision at all distances.
4. Glasses for control of an eye turn:
- If your child has been diagnosed with an eye turn (strabismus), this may be secondary to being significantly long sighted.
- By correcting the long sightedness with glasses, the eye muscles can relax and so the eyes straighten.
- In this case therefore, glasses are used to maintain the ability for both eyes to work together and maintain equal vision.
- It may be possible over time for the glasses prescription to be reduced, but this is different for all children and your child’s ophthalmologist will advise you regarding the best treatment plan for your child.
- Sometimes glasses used for this reason aren’t effective, and other treatment options such as surgery will then need to be considered.
You may have some difficulty encouraging your child to wear their new glasses. Your child’s ophthalmologist will be able to discuss strategies to help improve glasses wear.
Placing a patch over your child’s stronger eye is the most common form of treatment for amblyopia.
Your ophthalmologist will advise regarding the amount of patching required – this will depend upon your child’s vision and their age.
Types of eye patches:
1. Orthoptic eye patches:
- These are adhesive eye patches that stick directly onto the skin
- They can be purchased from selected pharmacies or online and come in a variety of sizes, colours and designs.
- Alternatively, you can make your own patches by using materials readily available from most pharmacies.
2. Material patches for glasses:
- These are material patches that fit over one side of the glasses frame and can also be purchased online.
Care must be taken during patching, as your child may not be able to see as well as usual. For example:
- Your child will have difficulty judging depth and distances. Take care on stairs and when running around.
- Your child’s peripheral vision will be reduced on the side that is being patched, and they may have difficulty with tasks they would normally find very easy. Take care when crossing the road or playing outside.
- Your child’s vision will be poorer than usual, as the better eye is the one being patched. Allow your child to sit closer to objects and provide reassurance that this frustrating experience will improve with time.
Tips for encouraging patch wearing
Don’t be discouraged if your child resists patching treatment in the early days – this is extremely common and usually improves with time, especially as their vision improves.
- Try to make the experience positive. Praise and rewards such as sticker charts work to reinforce patch wearing.
- Allow your child to undertake a favourite activity while patching, e.g. colouring in, reading, watching their favourite television show, playing board or iPad games.
- Involve your child in decorating their patch – e.g. placing a sticker on their patch.
- If your child is old enough, explaining why the patching is needed may help. Also explain this to family members, carers and teachers and ask for their assistance as much as possible.
Preventing patch removal
- Patching in the morning may be more successful, as children are usually more tolerant when they are less tired.
- Create a routine for patching. Younger children may be told “wear the patch until nap time” and older children can be shown on a clock what time the patch will be removed.
- Try placing the patch over the eye during sleeping – it may not be noticed upon waking. Note that only waking hours are counted towards patching therapy.
- Mittens may be worn by younger children initially, in order to make it harder for them to remove the patch themselves.
- Patching may be divided into sessions are carried out to fit around playtime and school, e.g. two hours before school and two hours after school.