|GLAUCOMA – SNEAK THIEF OF SIGHT|
World Glaucoma Week, 8th to 14th March, is a joint initiative between the World Glaucoma Association and the World Glaucoma Patient Association to raise awareness of this silent robber of vision. Glaucoma is a group of eye diseases that cause progressive damage of the optic nerve at the point where it leaves the eye to carry visual information to the brain. If left untreated, most types of glaucoma progress without warning nor obvious symptoms towards gradually worsening visual damage and may eventually lead to blindness. Glaucoma is the second most common cause of blindness worldwide. Once incurred, visual damage is generally irreversible, which has led to glaucoma being described as the “silent blinding disease” or the “sneak thief of sight”.
TYPES OF GLAUCOMA
There are several types of glaucoma, the two main kinds being open-angle glaucoma and angle-closure glaucoma. Secondary glaucoma may occur as a complication of other visual disorders, such as cataracts or diabetes, but the vast majority is primary. Less common types of glaucoma include normal-tension glaucoma and pigmentary glaucoma. Some forms of glaucoma may occur in infancy or childhood, and although rare, it can be present at birth. In all types of glaucoma, the optic nerve is gradually damaged.
CAUSES OF GLAUCOMA
Aqueous humor is a clear fluid which circulates in the inner eye, keeping it firm and nourishing it. It usually flows out of the eye through a channel, but if for any reason drainage is blocked, pressure builds within the eye, gradually damaging the optic nerve. It was thought that the cause of most or all glaucomas was high pressure within the eye, but it has been found that even people without abnormally high intraocular pressure may suffer from glaucoma.
RISK FACTORS FOR GLAUCOMA
Glaucoma typically affects adults over the age of 40, although it can occur in younger adults, children and even infants. The earlier the onset of the condition, the more aggressive it tends to be. Family history and ethnicity have a role to play. Other risk factors include a high degree of shortsightedness or farsightedness, diabetes, trauma to the eye and certain medications, particularly corticosteroids.
SYMPTOMS OF GLAUCOMA
In the early stages most people with chronic glaucoma are unaware that they have the condition which develops slowly and without symptoms. The main sign is usually a decrease in peripheral or side vision, but by the time this is noticed some irreversible vision loss and damage to the nerve has already occurred. Acute or angle-closure glaucoma occurs more rapidly with more obvious and severe symptoms and damage, as the intraocular pressure rises quickly. Symptoms experienced may include sudden severe pain in one eye, nausea, partial loss of vision, blurred vision and halos around lights. In such cases, medical intervention should be sought immediately.
DIAGNOSIS OF GLAUCOMA
Glaucoma can be detected as part of a routine eye examination. Tonometry assesses eye pressure, and a visual field test may be performed to measure the loss of peripheral vision. The pupils may be dilated to give the optometrist a clear view of the retina and the ability to evaluate optic nerve damage. Photographs may be taken so that changes can be monitored from visit to visit. Rather than waiting for symptoms by which time there may be a loss of vision, visit your optometrist regularly for an eye examination. Early detection leads to early management and a better prognosis!
TREATMENT OF GLAUCOMA
There is no cure for glaucoma as yet, and vision loss is irreversible. However, treatment can slow down or even stop the progression of the disease. Eye drops, oral medication, laser surgery or microsurgery are treatment options to lower eye pressure. Discuss these with your optometrist who will guide you with regard to the most appropriate treatment for you and refer you to an ophthalmologist if necessary.
PREVENTION OF GLAUCOMA
While glaucoma cannot be prevented, a healthy lifestyle and maintenance of physical as well as eye health may minimise the risk and help protect vision. Cutting back, or preferably, giving up smoking reduces the risk of chronic disease, including eye disease. Exercise facilitates blood circulation throughout the body, including the eyes. Know and inform your optometrist about your family history, particularly as it relates to eye conditions. Protect your eyes from the harmful effects of the sun.
Following a balanced diet is simple common sense, and some research points to specific foods that should be avoided and those that should be included in the diet if one has glaucoma. Avoid foods linked with high cholesterol levels and blood vessel damage which can occur anywhere in the body including the tiny blood vessels in the eyes. Cut back on caffeine and substitute coffee with antioxidant-rich green tea. Keep salt consumption to a minimum.
Foods rich in omega 3 fatty acids are recommended for eye health. Include sea food, leafy green vegetables, eggplant, goji berries, blackcurrants and oranges in your diet. Cocoa, red wine and green tea contain flavonoids which have powerful antioxidant and neuroprotective properties.
A glaucoma diagnosis is often daunting and difficult to accept, and it may come as a shock when there were no warning signs or indications to alert the person to its existence. It is a life-long condition, but it can be effectively managed. Understanding it and taking responsibility for being part of the treatment process, having regular eye examinations and discussing concerns with your optometrist play a role in helping to protect the eyes against further damage.
|WHEN GLASSES AREN’T ENOUGH|
“When my son’s eyes were examined the optometrist found that he had 20/20 vision, but he is still struggling in the classroom.”
“My child was found to be shortsighted. Glasses helped her to see more clearly but her teacher reports that her reading is not what it should be
The majority of people are born with the potential for good eyesight, but the ability to interpret and understand what is seen is a learned skill which begins to develop from birth. Visual skills include being able to focus, fixate and use both eyes together in order to be able to process visual information. As well as this, there needs to be coordination between the eyes, the other senses and the brain. Problems in any of these areas may manifest as learning problems. Being able to read letters on an eye chart may not guarantee that a child has adequate skills for reading and learning. While glasses may be beneficial for a child with acuity problems, vision therapy may be necessary to address the issue of visual perceptual problems.
Vision therapy is an individualised supervised treatment programme designed to correct visual perceptual deficiencies. The goal of vision therapy is to train the child’s brain to use the eyes to receive information effectively, comprehend it quickly and react appropriately. Vision therapy can play an important role in the overall treatment of a child’s learning problem. As well as eyestrain, headaches and double vision, children with learning difficulties often experience feelings of frustration, lack of confidence and low self-esteem. Although many children with learning problems have average to above average intelligence, they feel that they are not as smart as other children, and this may impact on their behaviour, motivation and social interaction. Correcting the vision problems can have a positive impact in all areas of the child’s functioning and help him to reach his potential.
Following a comprehensive assessment, a therapy plan is created to address the child’s specific areas of difficulty. Vision therapy programmes are individually designed for each child based on the severity of the conditions being treated and the child’s motivation and level of readiness.
Vision therapy sessions include procedures designed to develop and enhance the following skills:
Visual attention and figure-ground perception – the ability to focus on important visual information while filtering out irrelevant background information, for example identifying the first letter of a word or finding a particular word in a list of words;
Tracking – the ability to follow a line of text or a moving object smoothly and accurately with both eyes, for example a ball in the air or the words in a sentence;
Fixation – the ability to use both eyes at once to quickly and accurately locate a series of stationary objects, such as words on a page while reading;
Focusing – the ability to look quickly from something close by to something further away and vice versa while maintaining clear vision, for example from the teacher to a book or a book to a computer screen;
Peripheral vision – the ability to monitor and interpret what is happening around one and gather visual information from a wide area while focusing on something specific;
Depth Perception – the ability to judge the relative distance of objects, and to see and move accurately in three-dimensional space, such as when hitting a ball or being aware of the position of words and letters on a page and in relation to each other;
Binocularity or eye teaming – the ability to smoothly, equally, simultaneously and accurately use both eyes together;
Visual discrimination – the ability to visually recognise differences and similarities, for example between numbers or letters;
Visualisation – the ability to form mental images in the mind’s eye, to retain and store information for future recall, and to create new ideas.
As well as working on these specific skills, vision therapy helps children to maintain their attention on a task without being distracted.
Vision therapy utilises procedures, programmes and activities designed to enhance and improve specific visual perceptual skills. Optical devices such as therapeutic lenses, prisms or tinted filters may be used. Computers have produced major advancements in the administration of vision therapy. State-of-the-art technology and software allow vision therapists to offer their clients challenging programmes for the enhancement of their visual skills.
Visual therapy sessions usually take place in the therapist’s rooms, but eye exercises may be given for the child to do at home under parental supervision, to reinforce what has been achieved during the therapy session. Emphasis is placed on integrating the visual skills with the other perceptual skills that are essential to the learning process. Generalising the newly acquired visual abilities to the activities of daily life allows these new visual skills to become self-reinforcing and efficient vision becomes a habit.
Vision therapy has proven to be effective in helping children with learning-related visual problems. As with most problems, the earlier visual perceptual deficits are detected and treated, the better the prognosis for future schooling. Enhancing the skills of the young child who is struggling to learn to read will make it easier for him to read to learn later in his school career.
Not only are the eyes the windows to the soul, they also offer a glimpse into the mind and the internal state of the body. The pupils, the black circles in the centre of the eyes, respond to light entering the eyes. In low light they dilate or widen to collect more light, while in bright light they constrict or become smaller. Pupil size is also modulated for reasons other than light, for example thoughts, emotions or mental effort.
Certain prescription medications can cause the pupils to become dilated by interfering with the chemicals that transmit messages from the brain to the eyes, and recreational drugs, such as hallucinogens and stimulants have a similar effect. Neurological conditions of the nerves which go to the eye can interfere with constriction and dilation of the pupils and are often accompanied by other vision symptoms. Injury to the eye may damage the nerves controlling the pupils or the iris, disrupting normal pupillary response. Brain injury as a result of trauma, a stroke or a tumour can cause increased intracranial pressure which can affect the eyes and the reaction of the pupils. Whether it’s caused by external or internal factors, pupil dilation is an involuntary nervous system response. In other words, we can’t control it.
The visual cortex processes and interprets the images transmitted by the eyes to the brain. A different part of the nervous system, the autonomic nervous system, controls the involuntary functioning of the body, functions over which we have no control, such as heart rate, perspiration and pupil dilation. Stimulation of the autonomic nervous system’s sympathetic branch, known for triggering “fight or flight” responses when the body is under stress, induces pupil dilation, whereas stimulation of the parasympathetic system, known for “rest and digest” functions, causes constriction. The size of the pupils at any given time reflects the balance of these forces acting simultaneously.
For over a century, scientists have reported that the pupils dilate for reasons unrelated to the levels of light in the environment, betraying mental and emotional states within the body. Pupillometry is a valuable tool for psychological research because the eyes are easy to observe and provide a sensitive indicator of cognitive, emotional and sensory response. It has been used to assess everything from sleepiness, introversion and sexual interest to race bias, moral judgement and depression. Pupil dilation can indicate attraction or surprise, as well as feelings of anger and fear. One researcher has reported that the pupils are able to reflect mental effort very precisely, while another has shown that pupil size increases in proportion to the difficulty of a task. Pupillometry became popular in the advertising industry during the 1970s as a way to test consumers’ responses to television commercials.
Sounds can evoke pupil dilations, depending on their emotional content. Highly arousing sounds, such as loud voices arguing lead to larger pupil dilations than neutral sounds such as background office noise. When people are listening to music, their emotional reactions to the music are reflected in their pupil size. New research has introduced an innovative hearing test that may help people who are unable to respond directly, due to a physical disability for example. The test relies on measurements of pupil dilation rather than a response such as pressing a button.
Pupil dilation may be performed by optometrists during a comprehensive eye examination to purposely increase the size of the pupil and force it to remain open and not constrict in response to light. Special drops are inserted into the eyes to dilate the pupils, allowing the optometrist a closer look at the retina, the blood vessels and the optic nerve at the back of the eye. As well as giving information about the health of the eyes, this examination may reveal the early stages of conditions such as diabetes before symptoms are apparent. While your eyes are dilated, your vision will be blurry, you will have trouble focusing on close objects and you will be extra sensitive to bright light. Sunglasses will help with the glare and light sensitivity which usually lasts 4 to 6 hours.
|HOW DOES ARTHRITIS AFFECT THE EYES?|
Arthritis is most commonly thought of as inflammation causing swelling and pain in the joints. But the condition can cause problems in other, more unexpected areas of the body, including the eyes. Arthritis is a chronic disease which can affect people of any age, race or gender. Women experience more arthritis-related eye problems than men do.
TYPES OF ARTHRITIS
There are about 100 different forms of arthritis and related diseases, including rheumatoid arthritis, osteoarthritis, psoriatic arthritis, fibromyalgia and gout. The most common types linked with eye problems are rheumatoid and psoriatic arthritis. Rheumatoid arthritis is an autoimmune disease which attacks the connective tissue lining the joints. This connective tissue is made up mostly of collagen, which is the primary substance of the sclera and cornea of the eye. Psoriatic arthritis is an inflammatory condition which can affect connective tissue.
Juvenile or childhood arthritis, as the name suggests, is an umbrella term to describe the many autoimmune and inflammatory conditions that can occur in children aged 16 or younger. The exact cause is unknown, but it is believed to be related to genetics, certain infections and environmental factors. Although the various types of juvenile arthritis share common characteristics, each type is distinct and has its own special concerns and symptoms. Juvenile arthritis, also called juvenile rheumatoid arthritis or childhood arthritis, can affect many parts of the body, including the eyes. The problems may be caused by the disease itself or by medications the child takes to manage the disease. Children with juvenile arthritis should have regular eye examinations as symptoms of visual problems may not be apparent until they are advanced. Early detection is the key to the best possible outcome.
EYE PROBLEMS LINKED WITH ARTHRITIS
The hallmark of arthritis is inflammation which can lead to various eye conditions:
Dry Eye Syndrome
Many people who have arthritis also suffer from dry eye, a condition characterised by reduced tear production and/or poor tear quality. Women are more likely than men to have dry eye syndrome with arthritis. Symptoms may include a sensation of something in the eye, blurred vision, increased sensitivity to light and watering of the eyes. If left untreated, dry eye is not only uncomfortable but can lead to infections and corneal scarring. People with dry eye may need to use an ointment, artificial tears, or eye drop medication to help keep their eyes moist. Tiny plugs, called punctal plugs, are sometimes inserted in the tear ducts to help keep tears on the eye surface.
Some people with arthritis, particularly older people, may develop scleritis, inflammation of the sclera, the white part of the eye. The inflammation thins the sclera and can become dangerous. Scleritis symptoms can appear as continuously red eyes despite using eye drops, deep eye pain and light sensitivity. It is often an indication that the inflammation in the body is out of control, requiring adjustment to the arthritis medication to reduce the inflammation.
Uveitis is inflammation of the uvea, the vascular layer of the eye found between the retina and the sclera and including the iris, the coloured part of the eye. Eye pain, light sensitivity, blurred vision and redness are symptoms of uveitis. There is a risk of permanent vision loss, particularly in children with psoriatic arthritis, who should be screened regularly for uveitis as symptoms may not be present until there is vision damage. Steroid treatment may help control scleritis and uveitis inflammation. However, it is important to note that one of the side effects of steroid use can be other eye problems.
A cataract is the clouding of the eye’s naturally clear lens, resulting in cloudy or blurred vision, poor night vision and the perception that colours seem faded. Long term use of steroid medication to treat arthritis can increase the risk of developing cataracts. Surgery is usually performed to remove the cloudy natural lens and replace it with an artificial lens to improve vision.
Glaucoma is damage to the optic nerve that usually occurs due to high pressure inside the eye. When the channels that usually drain fluid from the eye become inflamed due to arthritis, eye pressure builds up, gradually damaging the optic nerve and eventually causing vision loss. Glaucoma can also develop as a side effect of corticosteroid treatment for arthritis. Because glaucoma has no symptoms in its early stages, regular eye examinations are essential to detect the condition and begin treatment early. Later symptoms may include blurred vision, halos around lights and blank spots in the field of vision. Eye drop medication can help reduce eye pressure. Sometimes surgery may be needed to help improve the flow of fluid from the eye.
Arthritis is a risk factor for conjunctivitis, an inflammation or infection of the lining of the eyelids and the white of the eyes. The symptoms include itchy or burning eyes, watery eyes, eye redness and a yellow discharge that crusts around the eyes. It is usually treated with antibiotic eye drops and sometimes steroid drops to reduce inflammation.
Like adults, children with arthritis are at risk of developing these eye conditions, due to the arthritis itself or the ongoing long-term treatment of the disease.
As well as monitoring and managing inflammation throughout the body, people with arthritis should have their eyes checked regularly for early detection of problems and protection of the eyes against further damage.
|STARS IN OUR EYES!|
Not unlike cartoon characters who have stars circling their heads when they are hurt, we “see stars” when we bump our heads, stand up too quickly or rub our eyes too vigorously. What causes this to happen? The retina at the back of the eye converts light entering the eye into electrical signals which are transmitted to the visual area of the brain where they are perceived as images. Normally the cells in the retina respond to light but sometimes an electrical impulse is triggered in the brain in other ways, and the brain interprets this as specks of light. In effect, the brain is tricked into seeing light that is not present. The phenomenon of experiencing light without light actually entering the eye is known as a phosphene and may come from a variety of sources.
Why does it happen when we bump our heads? The human brain is surrounded by cerebrospinal fluid. Because there is some space around the brain, it is able to move within the skull but is cushioned and protected from injury by this fluid. If, however, we bump our heads with force, the brain may hit the area of the skull where the visual cortex, which processes visual information, is situated. This irritation triggers the nerve cells to discharge electrical impulses which are perceived as spots of light or “stars”.
Seeing stars when standing up too quickly is a response which occurs from inside the eye itself rather than from an external source, like a bump on the head which stimulates the visual cortex directly. When we change positions quickly, we may have a postural drop in blood pressure, causing a brief delay in blood being pumped back towards the heart from the legs. There is a momentary reduction of blood flowing to the retina, slightly reducing its supply of oxygen. Abnormal signals are transmitted to the brain which perceives light although there is no external light source. This response is sometimes accompanied by buzzing in the ears. Both the stars and the buzzing usually disappear on their own after a few seconds or if the head is lowered.
The most common phosphenes are pressure phosphenes which are caused by mechanical stimulation. Rubbing the eyes briefly interrupts normal blood flow to the retina and applies abnormal pressure on the optic nerve which sends false signals to the visual cortex for processing. The “stars” we see are essentially the random firing of electrical impulses to the brain. These images can persist for a while when the rubbing stops and the eyes are opened, but once the tissues return to normal, the stars fade with no lasting effects. Other mechanical causes of phosphenes sometimes include sneezing, laughing, coughing and blowing the nose.
Phosphenes have been reported by astronauts exposed to radiation in space, as well as by people who have not been exposed to light or have been deprived of visual stimulation for long periods of time, for example prisoners in isolation. They may also be one of the side effects of certain medications. Some migraine sufferers experience “seeing stars” before the onset of the headache.
While phosphenes are generally no cause for concern, seeing sudden or frequent flashes of light in one or both eyes for no apparent reason could indicate a potentially dangerous eye condition, particularly if they are accompanied by pain or vision disturbances. These would be regarded as a medical emergency requiring immediate medical intervention.
|TAKE A LEAP|
So, the shortest month of the year will be 24 hours longer. That’s all it means… right?
Leap years get us all superstitious. We attach strange meanings to things. We think an extra day makes the year magical. But actually, it all comes down to science.
Yip, it’s all thanks to the solar year being 365.2422 days. Not 365. It takes 365.2422 days for the earth to revolve around the sun. That 0.2422 doesn’t sound like much, but it adds up if no one does something about it. Over centuries, the seasons will eventually get messed up and everything will move out of alignment. Basically, the world will get even more crazy-mixed-up than it already is.
So, adding an extra day every four years keeps everything in perfect balance. Well, it sorts out the earth’s problem of 0.2422. Everything that happens on earth is still crazy-mixed-up – load-shedding, SAA, global politics – but the cosmos can only do so much.
And… end science lesson. Begin history lesson.
The Ancient Greeks decided to have their Olympics on the first day of spring. And because they were jumping events, this day was called Leap Day. And because they were from Athens, legend has it they were called athletes. And because this information comes from the Internet, it must be true?!
Then they decided the Olympics should only happen every four years. Some history books say it’s because people needed time to travel to Athens to participate. (Four years, though? Really?!) Other theories suggest the delay was due to battles over broadcasting rights to show the Olympic Games on TV. (Not really…)
So, what does all this mean for us? For those of us interested in seeing the world, and helping others to see it too? Well, a leap year is an opportunity to turn things upside down and see things a different way. It’s an opportunity for us to put on our glasses backwards. No, not literally… but an opportunity to see things through new eyes. It’s like Opposite Day, and a chance for new perspectives.
It’s also a day for us to step out of ourselves and be bold. So that pair of sunglasses you’ve been too scared to wear? February 29 is your chance to put them on and step out into the world.
Or it’s just a day. A day that means nothing more than a mathematical remedy to the problem of 0.2422.
So, which is it? Well, that all depends on how you see it.