A retinal migraine (also known as an ophthalmic migraine, visual migraine or ocular migraine) can be distinguished by the appearance of a noticeable disturbance that leads to a temporary loss of vision. This is unlike the visual ‘aura’ that common migraine sufferers sometimes experience.
A retinal migraine often comes on suddenly. It can either be on its own (i.e. no ‘headache’) or accompanied by a ‘common migraine’, complete with throbbing, head pain and nausea. Although the cause is still unknown, some researchers believe that a retinal migraine is caused by a vascular spasm in or behind an eye.
Retinal migraines are apparent in 1 in 200 migraine sufferers.
If you are a migraine sufferer, there are several indications that you may be experiencing a retinal migraine.
The International Headache Society has produced a definition of the symptoms that relate to a retinal migraine. The most common symptom is short-term loss of vision in one eye only. Others include:
A headache that lasts from 4 -72 hours. The symptoms can:
Approximately 20% of common migraine sufferers experience what is known as ‘an aura’, which can include flashing lights and visual blind spots. An aura usually appears in both eyes.
Retinal migraines involve episodes of temporary vision loss, or blindness in one eye only.
Most people quite rightly have difficulty identifying the difference between the two. After all, visual changes can be part of an ‘aura’ as well as a retinal migraine.
Because retinal migraine symptoms appear in one eye only, one method of ascertaining this is to cover one eye, then the other. Still, this technique is far from fool proof.
If you suspect you may be suffering from retinal migraines, you’ll need a full medical examination in order to diagnose it correctly. It will often be a case of ruling out other disorders including a blood clot, stroke, pituitary tumour, detached retina, or drug abuse.
As with common migraines, the best form of treatment is prevention.
Preventative treatment can depend on trying to find the triggers that might cause you to suffer a retinal migraine – they may include stress, fatigue or food sensitivities. You may also be prescribed a prophylactic medicine such as aspirin, betablockers, antidepressants or ‘common’ migraine preventative drugs such as sumatriptan.
Research into migraine prevention is an ongoing process and there are currently no conclusive cures.
A retinal migraine is a term that applies to a migraine that affects the sight. The problem is that it is difficult to diagnose, is often confused with a common migraine and there is no specialised ‘cure’ – prevention is often the best form of treatment.
Humour, or Humor (depending on which side of the world you live) is a traditional Latin word. It is used to describe some bodily secretions that are considered to affect a person’s health.
Your eye is divided into 3 chambers – the anterior chamber, the posterior chamber and the vitreous chamber. The vitreous chamber is the large chamber at the back of your eye, the anterior chamber is the space between your cornea and iris, while the posterior chamber is the space between your iris and the lens of your eye.
Both the anterior and posterior chamber is filled with aqueous humour.
The aqueous humour is a thin, transparent fluid similar to plasma. It’s made up of 99.9% water – the other 0.1% consists of sugars, vitamins, proteins and other nutrients. This fluid nourishes the cornea and the lens, as well as giving the eye its shape.
The aqueous humour plays an essential role in the health of your eye. As well as nourishing the cornea and the lens by supplying nutrition such as amino acids and glucose, the aqueous humour will:
Without becoming too technical, the aqueous humour is continuously produced by the ciliary processes (located in the anterior chamber near the lens of the eye). To work as it should, the production must be balanced by drainage at an equal rate.
Even small variations in the production or outflow of the aqueous humour are significant, because they will have a large influence on your intraocular pressure.
When the intraocular pressure is increased, it can lead to glaucoma, a major cause of vision loss.
The aqueous humour fills the anterior and posterior chambers of the eye. It is one of the fundamental components in ensuring that the optical physics and health of your eye are properly maintained. Continuous production of aqueous humour is critical to the shape, size and quality of image your eye can provide.
In the most basic of anatomical terms, the eye is divided into three sections: the anterior chamber, the vitreous chamber and the posterior chamber.
The vitreous chamber is positioned at the back of the eyeball. It is the largest of the chambers and takes up around 80% of the eye.
The vitreous humour (also known simply as the vitreous) is a clear, colourless fluid that fills the space between the lens and the retina of your eye. 99% of it consists of water and the rest is a mixture of collagen, proteins, salts and sugars. Despite the water-to-collagen ratio, the vitreous has a firm jelly-like consistency.
The vitreous performs a vital role in protecting your eye. Most importantly, it helps it to hold its ‘spherical’ shape.
The vitreous also comes in contact with the retina (the light-sensitive surface at the back of the eye that acts like the film of a camera). The pressure of the vitreous humour helps to keep the retina in place.
As you age, the vitreous liquefies and shrinks, much like a bowl of gelatin shrinks with time. Portions of the mixture of collagen and proteins also become ‘stringy’, like the white of an egg does as it ages. These stringy entities float around the rest of the vitreous, casting a shadow on the retina. These are called ‘floaters’ – you may notice them as specks, or strings or other shapes that you see just out of the corner of your eye.
The vitreous itself does not adhere to the retina. However, on the surface of your retina there are literally millions of fine fibres. Because the vitreous shrinks as you age, these fibres can ‘tug’ on the retinal surface. If this shrinkage causes a section of the fibres to pull away all at once, it is called a vitreous detachment. These are common in people over the age of 65 and extremely common in people over 85.
A vitreous detachment is more likely to happen if you have suffered from myopia (near-sighted), have had an eye injury or if you have experienced an eye inflammation (uveitis).
In itself, a vitreous detachment should cause no problems with your vision other than an increase in ‘floaters’. While this can be annoying, you should find that they don’t affect your day-to-day life. The only risk factor you would face is the slightly increased chance of a retinal tear or the more serious, retinal detachment.
If you notice a reddish tint to your vision and your vision is blurred, you may be suffering from a vitreous haemorrhage.
Although there are no blood vessels located in the vitreous there are vessels in the surrounding retina– a vitreous haemorrhage can occur when one of these ruptures. Other symptoms of a vitreous haemorrhage include an increase in floaters and sensitivity to light.
Occasionally, a vitreous detachment will cause a ‘clump’ of the fibres on the surface of the retina to create a tear in the sensitive retinal tissue. Even the smallest of tears in your retina will need to be treated, because it will increase the risk of a retinal detachment. Retinal tears can be sealed with lasers or cryotherapy.
The most serious disorder involving the vitreous humour, a retinal detachment is a medical emergency. It happens when liquid (vitreous) seeps through a retinal tear, causing the retina to ‘peel’ away from the supporting layers (much like wallpaper peels away from the wall when it’s damp). Click here for more information.
There are a number of issues related to the vitreous humour that can lead to you requiring a procedure called a ‘vitrectomy’. If you suffer from a retinal detachment that threatens the macula, a tear or tears in your retina, a vitreous haemorrhage or another problem that affects the retina, you may require this surgical procedure.
Your retinal specialist will remove the vitreous and then replace it with silicone gas or oil. This will restore normal pressure in your eye. Click here for more information on this and other retinal treatments.
The vitreous chamber is the largest cavity in the eye, which makes the vitreous humour the most prominent liquid in the eye. Present at birth, it changes little until we enter our fifth decade when it begins to shrink, which can lead to disorders ranging from harmless floaters to a vision-impairing retinal detachment.
Retinitis pigmentosa (RP) is in fact the collective name for a range of genetic diseases that damage the retinal rod and/or cone cells (the photoreceptors), causing vision loss. It affects the retina, the thin layer of light-sensitive cells at the back of the eye.
In most cases, retinitis pigmentosa is an inherited eye condition affected by at least one defective gene. The gene(s) cause the formation of an incorrect type of protein in the retina. This seemingly minor flaw actually results in the rods and/or cones in the retina losing their effectiveness.
Retinitis pigmentosa isn’t a common condition, but it is estimated that approximately one in around 3000 Australians is affected by RP. There is no such thing as typical retinitis pigmentosa. The speed of progression, severity and the age of onset vary considerably – it can start as early as 10. Symptoms usually begin in adolescence and progress over time.
The retina acts like the ‘film’ of a camera, sending information about shapes, colours, patterns and movement via the optic nerve to the brain, where the information is processed. If the retina is damaged in any way, this will cause visual disturbances or loss of vision.
The retina is made up of millions of cells known as rods and cones (so named because of their physical resemblance to rods and cones).
Rods are found in much greater numbers than cones and are located across the entire retinal surface. The highest concentration of the rods is located around the edges of the retina. These allow you to see what is above, below and to the side of the object you are looking at. The rods are sensitive in low lighting conditions, and provide your night vision.
The cones are located mainly in the centre of the retina. Their primary function is to help distinguish colours and fine detail. They perform poorly in low lighting conditions, which is why it is difficult to see detail in the dark.
Retinitis pigmentosa is a progressive condition, so the symptoms become worse with time. Although RP can happen even if your family has no history of the disorder, it is especially important to watch for symptoms if you have a genetic disposition for the disease.
Symptoms of retinitis pigmentosa may include:
Commonly, the light sensitive rod cells in the peripheral retina are first affected, which will progressively cause vision to worsen over time as more cells die, leaving just the very centre of vision remaining. This is known as tunnel vision.
Therefore, to see anything in their peripheral vision, the affected person will have to move their eyes to see what is above, below or to the side of the focused object. In other cases, central vision can also be affected, so reading and detecting colours and visual details become difficult.
The development of cataracts (which causes the lens of the eye to become cloudy or opaque) is a common complication of retinitis pigmentosa. However, removing the cataract doesn’t necessarily improve vision significantly if the person already has RP.
Unfortunately, there is currently no known treatment that will slow, or prevent retinitis pigmentosa. A great deal of development and research is being undertaken throughout the world to find ways to control the condition. This has included research into vitamin therapy and gene therapy, but to date results are inconclusive.
Another alternative development that is being explored is an implantable light-sensitive electrode (retinal prosthesis). This “bionic retina” has been under trial, but has yet to produce significantly improved vision for blind patients.
Finally, there are experiments underway with transplanting healthy retinal cells into damaged retinas, but it is too early in the process to know how successful this direction may prove to be.
Your eye specialist will be able to give you advice on what to expect and how to manage the progression of RP. Other management strategies include:
Retinitis pigmentosa is rare and indiscriminate – it’s important to understand that no one is at fault, as people who have no genetic disposition to it can acquire RP. It is also difficult to predict the progress of any retinitis pigmentosa because any sufferer could experience a different rate of decline in vision.
On the positive side, it should be noted that many people with retinitis pigmentosa live busy, active lives, making adjustments to adapt to their vision loss.
High blood pressure will put you at risk of developing a number of health disorders, including those that affect the heart, brain, kidneys, arteries – and the eyes.
Hypertensive retinopathy is the name given to damage to the retina, as a result of high blood pressure. The retina is the layer of tissue at the back of the eye that works like ‘film’ in a camera. It plays such an important part in a person’s vision that any damage to it is considered serious.
If you have high blood pressure, this can lead to the narrowing of the tiny, delicate vessels that supply blood to the retina. This damage can lead to the loss of clarity in your vision. The higher your blood pressure and the longer it has been elevated, the more damage you risk.
Other factors can also contribute to hypertensive retinopathy including diabetes, high cholesterol and smoking. All of these issues can increase the risk of damage and, potentially, cause vision loss.
The only way to treat hypertensive retinopathy is to control your blood pressure and ensure that it doesn’t become too high.
Unfortunately, if you are suffering hypertensive retinopathy you may not realise it, as the symptoms aren’t always obvious. However, there are a few signals that may indicate you are suffering from the condition:
All these signs must be dealt with immediately.
Your eye specialist will use an instrument known as an ophthalmoscope to check for any sign that the blood vessels in the eye have narrowed, or whether there are signs of fluid leaking from the blood vessels. Then, he will assess the degree of damage. The severity of hypertensive retinopathy varies. Diagnosis is provided in ‘stages’:
Grade 1. At the minimum level, there may be no obvious symptoms and the narrowing of your arteries can be barely detectable.
Grade 2. The narrowing of your arteries is detectable. You may also be experiencing visual irregularities.
Grade 3. There may be a number of changes in the blood vessels, leakage from the blood vessels and swelling elsewhere in the retina.
Grade 4. At this level, the hypertensive retinopathy may include swelling of the optic nerve and the centre of the retina – the macula. This can cause vision loss.
Your ophthalmologist may use a fluorescent dye and a specialised camera (a fluorescein angiography) to examine the condition of the blood vessels.
The retina will usually recover if the blood pressure can be controlled, but a grade 4 level of retinopathy is likely to involve permanent damage to the optic nerve, or macula.
Severe (grade 4) sufferers of retinopathy may also have other health issues such as heart and kidney problems, and are at a greater risk of having a stroke.
If you suffer from high blood pressure and notice any signs of vision loss or headaches, urgent medical attention is required.
If you suffer from high blood pressure, this can be a chronic medical condition. See your GP, who will help you to take steps to control your blood pressure – this will include following a healthy diet and exercise. If you suffer from high blood pressure and have any symptoms that could indicate it is affecting your eyesight, see an eye specialist immediately.
Today, when people think about laser eye surgery, they think LASIK (Laser-Assisted in Situ Keratomileusis). While LASIK is right for the majority of patients under the age of 50, there are some people who do not qualify for the procedure, especially if they have thin or irregularly shaped corneas.
As long as your eye is otherwise healthy and your prescription isn’t unusually high, you will most likely qualify for another form of laser eye surgery – ASLA (Advanced Surface Laser).
If ASLA laser eye surgery has been recommended for you, you can rest assured that the actual visual outcome is the same for both LASIK and ASLA procedures. However, there are a few factors that you should be aware of.
Because ASLA is a surface laser eye surgery procedure (that is, no flap is created), it requires a longer period to recover. Your surgeon will recommend you take about 5 days off work, so you’ll naturally need to fit that into your schedule.
You will also find that your eyesight fluctuates over the first few weeks – in particular, your near vision may vary. This is completely normal; in fact, you should expect this to happen for up to 6 weeks after your ASLA laser eye surgery procedure. The fluctuations will lessen within a week, and you’ll be able to go about your day-to-day business.
With time, it will settle down.
During your ASLA procedure, you will feel some sensations but no pain (click here to read more).
However, during recovery from ASLA laser eye surgery, some discomfort is normal – your surgeon will provide you with medication and drops to take home with you after your procedure.
If you are worried about pain levels, you can ask your doctor for more medication during the post-operative consultation.
Although this varies, day two post-procedure will be the most uncomfortable day for most people. As your epithelium (surface) cells are beginning to regenerate, pain will come and go. Some patients will be worried: again, this is completely normal and will pass.
During the first 2-3 days post ASLA laser eye surgery, watching television, reading or looking at a computer may be uncomfortable. We recommend that, before your procedure, you consider the following:
Around Day Four you can begin to engage in normal activities.
Expect to experience discomfort from the condition known as Dry Eye during the first 2-3 weeks. This is because surgery has temporarily reduced corneal nerve sensitivity, and your eye does not sense the need for lubrication, resulting in reduced tear production.
It sometimes presents itself as a feeling that you have ‘something in your eye’. It’s especially noticeable upon wakening. You will be given lubricating drops – use them and appreciate that this phase will pass.
You can be confident that your discomfort will subside, the pain will be short-lived and your eyesight will settle – around 98% of ASLA laser eye surgery patients will experience 20/20 vision or better. So, while the first few days can be a little challenging, the good news is that afterwards you can enjoy the freedom of living without glasses or contact lenses.
Rather than brush the facts under the carpet, we feel that as long as you understand that what is happening to you is part of the healing process, you can prepare wisely – and look forward to the final results.
Eye twitching is something that happens to everyone now and then. A twitching eye doesn’t hurt, but it can certainly be very annoying. When your eye twitches, it usually indicates a muscle spasm.
It can be very difficult to pinpoint what the specific cause might be, although if you’re a regular ‘eye twitcher’ you may be able to identify a trigger, such as stress or lack of sleep.
Causes of eyelid spasms include:
Occasionally, eye twitching can be indicative of something more serious and should be further investigated.
Sustained, chronic movement of both eyes is known as ‘benign essential blepharospasm’. This indicates a neurological condition that can result from a range of disorders such as the following:
Although very rare, eye twitching may be a side effect of a brain or nerve disorder. They include:
Occasionally, a twitching eye can be a side effect of taking a certain medication, which may include drugs used for the treatment of psychosis and epilepsy.
A twitching eye is quite harmless. The majority of times, it should stop naturally after a period of time. However, there are certain cases when you should seek advice from a specialist:
Your doctor will test for common signs that might indicate a brain or nerve disorder. In which case, you are likely to be referred to a neurologist or other specialist.
In the majority of cases, a minor eye twitch will just disappear naturally after you have a good night’s sleep, although it will help if you also reduce your intake of alcohol, caffeine and nicotine. If stress appears to be a trigger, long-term prevention should include finding ways to reduce your stress levels.
In the case of dry eye, it may be worth trying ‘artificial tears’, available from your pharmacy, first. However, a specialist should be consulted if these don’t appear to help.
For benign cases of ‘essential blepharospasm’, there is no successful cure, but there are some treatments that can reduce the severity of the condition. The most commonly recommended treatment is botulinum toxin (also known as Botox), which can help relieve spasms for a few months before its effect minimises.
Generally, these have been found to provide short-term relief only and proven to be effective for a mere 15% of cases . You may find that other treatments such as biofeedback, acupuncture or hypnosis are effective,
That twitching eye of yours is most likely a harmless muscle spasm and is probably the result of triggers such as stress or fatigue. However, if the ‘twitch’ persists, see your optometrist or GP, who will refer you to an ophthalmologist if need be.
The iris is the thin, coloured ring-like structure in the eye.
What is commonly known as your eye colour actually refers to the colour of your iris. Iris colour can be blue, green, brown or less common colours, such as grey, hazel (a combination of light brown, green and gold), violet and pink.
The large, round opening in the centre is the pupil. Light rays that enter the pupil are absorbed, giving the pupil the appearance of being black.
They work as a team –together, the iris and the pupil control the amount of light that enters the eye.
The iris ‘sphincter’ muscle is about 1mm wide and circles the pupil. It is responsible for constricting the pupil, while the aptly named ‘dilator’ muscle is responsible for enlarging the pupil.
Your pupil constricts (narrows) when a large amount of light enters your eye, as when you move from indoors to outdoors, while it will dilate (enlarge) thus allowing more light to enter the eye when you, say turn off a light, or go indoors. Changing your focus from distance to near objects, or taking certain drugs, can also cause the pupil to constrict.
Emotion can also cause your pupil to dilate. For example, if you are in a ‘fight or flight’ situation, a rush of adrenaline will open the pupil to allow it to better assess the situation. For the same reason, the pupil also dilates if you are attracted to someone – the more light that enters the eye, the easier it is to observe the person.
Equally, an emotion can constrict your pupil – for example, if you are shown a picture that is frightening or unpleasant, your pupil will automatically constrict in order to let less light into the eye.
There is a study devoted to pupil size as an indicator of emotion, known as pupillometrics.
In more general terms, the iris sits between the cornea and the lens of the eye. The actual iris is flat and acts as a ‘divider’, separating the front of the eye (the anterior chamber) from the back of the eye (the posterior chamber).
The colour, structure, pattern and texture of your iris are as unique as your fingerprint. In alternative medicine, ‘iridology’ is based on the theory that the characteristics of your iris can indicate any health issues elsewhere in your body.
Iris recognition (as opposed to retina scanning) is being used more, around the world, as a method of identification, Mexico being the first country to use iris scanning on ID cards (in 2011)
The iris is a complex and very essential, hard-working component of the eye – far more than just a pretty colour, even though that is what most of us pay attention to. Together with the pupil, it plays an essential role in vision and an increasingly important role in today’s identification technology.
One of the questions we are often asked is what a person will experience during laser eye surgery.
As with many events in life, the answer varies – but it is unusual for a person to feel any pain whatsoever during either LASIK laser eye surgery or ASL laser eye surgery procedures. In fact, the most common reaction from most patients immediately after the procedure is finished is – “is that it?” For most patients, it seems to be over in next to no time.
If you are considering laser eye surgery but are hesitating because of the unknown, here is an outline of what you can expect.
As well as being offered a sedative, you will be given anaesthetic eye drops before laser eye surgery. Once you have been given time for your sedative to work, you will be taken into the procedure room and lie down on a surgical bed.
Obviously, there will be some sensations during your procedure, however it depends on whether you are having LASIK or ASLA laser eye surgery. It’s worth noteing that the final results of both types of laser eye surgery are exactly the same.
LASIK is a laser eye surgery procedure that involves the use of two lasers. The first (called a femtosecond laser) is used to create a perfect incision that allows the surgeon to gently fold back the ‘flap’. During this stage, a gentle ‘clamp’ will be placed on your eye (so you can ‘blink’ without actually closing your eyes) and then the surgeon will ‘dock’ what feels like a suction cup over your eye – this positions the laser exactly where it needs to be. You will obviously feel both the clamp and the docked cup, but no pain or discomfort is involved (although some people say that the sensation of pressure from the suction is the most memorable of all during the procedure).
The surgeon will then use the laser to perform the first part of the procedure – you may feel a bit of pressure, but no pain, and your vision will be blurry. The surgeon will control things at this stage and there is no need to look at a fixation light This will last around 60 seconds before moving onto the next eye.
Advanced laser technology will allow the laser to compensate for even the smallest of movements.
Your surgeon will then move the flap. You will most likely not feel anything except for the sensation of a surgeon’s hands near your eye.
The second step involves the use of what is called an excimer laser. This laser will gently reshape the corneal bed (the stroma). You will be asked to look at a fixation light. Some people feel a slight sensation during this step, but again no pain. This lasts no more than 60 seconds per eye.
Now, the surgeon will reposition the ‘flap’ – you may feel a slight brushing but it is neither painful nor uncomfortable.
Then, you’re done. You go home and rest your eyes for the remainder of the day.
If your cornea is deemed to be too thin or irregular in any way, ASLA (Advanced Surface Laser) may be recommended.
This particular laser eye surgery procedure uses only one laser, the excimer laser.
Once you have had a sedative and anaesthetic drops are applied, you will be taken into the procedure room and lie down on the surgical bed. A plastic clamp is then placed on your eye, so you can ‘blink’ without actually closing the eye. This isn’t painful or uncomfortable.
Your surgeon will place a few drops of a solution on the surface of the cornea. This solution will soften the cells and then the surgeon will gently remove them in order to have access to the layer of cells that need to be reshaped.
This part of the procedure isn’t painful. In fact, you may feel nothing at all, although the sensation of hands so close to your eyes may, at first, feel daunting.
Next, the excimer laser will be used to reshape your cornea. You will need to look at fixation light (again, this is not the laser, simply a spot which will allow you to focus). Many people do not feel anything during this part.
Finally, a ‘bandage’ contact lens will be placed on your eye. You will need to keep them in place for around four to five days – this allows time for your epithelial cells to regenerate and grow back.
Recovery time from ASLA is longer than LASIK. While there is no pain during the procedure, it’s normal to feel some discomfort in the following three days post-procedure. Your surgeon will prescribe you painkillers and drops, which you’ll take home with you after the procedure.
For more information about laser eye surgery, click here.
Before having laser eye surgery, people have many questions. One of the most frequently asked questions is ‘will I go blind?’.
Millions of people worldwide have had laser eye surgery since its introduction in 1989. Today, it is accepted that 90% of patients worldwide who have had laser eye surgery will have perfect results – up to 98% of patients are able to drive legally without glasses or contact lenses after their procedures.
The aim of laser eye surgery is to correct a person’s vision – whether they are nearsighted or farsighted – by reshaping the cornea. It is extremely rare that a post-operative complication cannot be corrected.
In some cases (1% – 5%), a patient may be under corrected or over corrected. This will be apparent in the first few months and can usually be fixed by a second surgical procedure (at no extra cost to the patient).
Other possible complications include:
The vast majority (up to 99%) of people who have had a laser eye surgery procedure are extremely happy with their outcome. 98% of people can drive legally without the use of glasses or contact lenses following laser eye surgery.
As laser eye surgery advances and surgeons perform more of these procedures, the risks decrease. Certainly, this is why many it’s recommended that people seek out the most experienced eye surgeons who work with the most up-to-date technology.