Although researchers are learning more about cataracts, no one knows for sure what causes them to occur early in some people. Scientists think there may be several causes, including smoking, diabetes, and excessive exposure to sunlight.


MESSAGE FROM THE GUYANA ASSOCIATION OF OPTOMETRISTS

World Sight Day (WSD) is an international day of awareness, held annually on the second Thursday of October to focus attention on the global issue of avoidable blindness and visual impairment. 2010 marks a mid-point in the 20-year initiative, and the theme of World Sight Day 2010 (WSD10) is Countdown to 2020:  The Public Health Importance of Eye and Vision Care. Thursday 14th October, 2010.

Some of the main objectives of the Guyana Association of Optometrists are as follows:-
1)      To unite all registered optometrists and to foster and maintain close professional relationships.
2)      To ensure that the public is given the highest standard of professional care in the conservation and improvement of vision.
3)      To develop, improve and maintain effective optometric public relations programmes in order to keep the public informed of the current developments and further advancements available and the value of professional eyecare.

World Sight Day was created in 1998 by the Lions to highlight the importance of eradicating preventable blindness and improving sight.  The theme of “Blindness and Childhood” was approved for World Sight Day 2007 on October 11. It incorporates the World Health Organization (WHO) /Pan- American Health organization (PAHO)’s Vision 2020 and Right to Sight Plan to eliminate avoidable blindness by the year 2020.

670 million people around the world are blind or vision impaired, simply because they do not have access to an eye examination and a pair of glasses. Why not? Because in a number of countries there are not enough trained eyecare personnel and there is no infrastructure to support these desperately needed eyecare services.

The link between blindness and poverty is clear. 75% of the world’s blindness is avoidable – either treatable or preventable – and 90% of avoidable blindness occurs in the developing world. People in developing countries are ten times more likely to become blind or visually impaired than those in the developed world.

The World Health Organisation (WHO) recognizes that blindness prevention and vision correction rank, along with immunizations, among the most cost-effective and efficient of all health interventions. In May 2006, the World Health Assembly, the governing body of the WHO, passed a resolution giving priority to prevention of blindness and visual impairment. This is the first time the WHO has made prevention of blindness a global priority, encouraging governments to take action and commit resources to the many simple and
cost-effective interventions that can save sight and give a better quality of life to millions.”

The most recent global figures indicate that
•    37 MILLION PEOPLE ARE BLIND

•    75% OF BLINDNESS IS AVOIDABLE – either by prevention or treatment.

•    90% OF BLIND PEOPLE LIVE IN DEVELOPING COUNTRIES

•    More than 82% of all blind people are at least 50 years old.

•    1.4 million children under the age of 15 are blind.

•    EVERY 5 SECONDS a person in our world goes blind and a child goes blind every minute.

•    MILLIONS HAVE UNCORRECTED REFRACTIVE ERROR – adults and children are functionally blind, simply because they do not have the spectacles they need.

•    Without optical care, millions of children are excluded from normal education and adults from productive working lives.

•    Treatment for the prevention and cure of blindness are among the most cost-effective and successful of all health interventions.

For more information on World Sight Day please visit www.v2020.org or www.givingsight.org, or contact the members of the Guyana Association of Optometrists: Dr. Johan DaSilva, Dr. Jose DaSilva, Dr Dionne Fries, Dr. Michele Ming and Dr. Karen Persram.

Eyes: ‘the window to your soul’
Caroline Gammell
The eye really is the “window to your soul”, according to research that suggests it is possible to predict what people are thinking by tracking their gaze.
A flickering glance left or right, up or down can indicate what processes are going on in the mind.
In the study, carried out by the University of Melbourne, volunteers were asked to think of a series of numbers between one and 30 and call them out at random.
The scientists mapped out their eye movements and said they were able to predict what number each person would utter with “reliable confidence”.
The findings suggest that the art of “mind reading” could be founded upon the study of unconscious facial expressions. They could also offer a useful insight for negotiators trying to second guess their counterparts.
Dr Michael Nicholls, a neuroscientist and co-author of the study, said: “Clearly, the eyes not only allow us to see the world around us but they also present a window to the working of our mind.”
The findings, published in the journal Current Biology, were based on the testing of 12 right-handed men who were placed in a darkened room.
Each individual was asked to list every number between one and 40 in as random a fashion as possible.
Each eye was mapped in detail and each tiny movement recorded and measured.
If the eye moved a fraction to the left and slightly down, the next number they picked was likely to be smaller, whereas if it moved to the right and up, the number would be higher.
The scientists were able to make their predictions correctly 60 per cent of the time, according to the research.
Dr Tobias Loetscher, fellow author of the study, said people imagined numbers in a sequential line.
“When we think of numbers we automatically code them in space, with smaller number falling to the left, and larger numbers to the right,” he said.
“That is, we think of them along a left-to-right oriented mental number line – often without even noticing this number-space association ourselves.”
The report concluded: “Apart from supporting the old wisdom that it is often the eyes that betray the mind, the findings highlight the intricate links between supposedly abstract thought processes, the body’s actions and the world around us.
“Our study is also noteworthy because it demonstrates that simply thinking of random numbers is accompanied by systematic changes in eye position.”
Lateral eye movements have previously been linked to mental arithmetic and recalling past memories.
Professor Richard Wiseman, psychiatrist at the University of Hertfordshire, said that the brain ultimately controls both movement and thought.
“The question is what comes first, the movement or the thought. This would suggest it is the movement that precedes the thought. It is an interesting issue.”
Professor Wiseman said that the study was reminiscent of work done by American psychiatrist Edmund Jacobson in the 1950s, where participants were asked to think of the Eiffel Tower and their eyes rose up.
“The brain is hearing a request before it tells you that you have heard that request and so that is why there is an action.”
(Source: UK telegraph)

What is Glaucoma?
Glaucoma is a disease characterized by damage of the optic nerve.  Glaucoma is a very slow, progressive, disease, but once the optic nerve is damaged and vision is lost, the loss is permanent and cannot be regained. It is felt that one of the factors contributing to the damage of the optic nerve is a buildup of pressure within the eye, either from overproduction, or a problem with drainage, leading to a subsequent loss of vision. Another contributing factor is ischaemia, or decreasing oxygenation, of the optic nerve.  Glaucoma often produces no symptoms until it is too late and vision loss has begun. Glaucoma can be hereditary and run in the family. Some specific things can also cause it, like diabetes, previous eye injury or surgery. It can affect people of all ages.
Testing for Glaucoma
There are 3 main testing procedures used in the diagnosis of glaucoma.  They are ophthalmoscopy, tonometry, and perimetry.
Opthalmoscopy: T
his test is where the doctor uses an instrument called the ophthalmoscope to look into the back of your eye and see your optic nerve. The optic nerve should have a small central “cup” where the vessels emerge.  If this cup is enlarged, or irregularly shaped, this is an indication of glaucoma.

Progressive glaucomatous cupping of the optic nerve. The central white cup of the optic nerve becomes enlarged as the rim of the nerve becomes progressively thinner.
(Black Arrow)

Tonometry:
This test involves the use of an instrument called a tonometer which measures the pressure of the intraocular fluid within the eye.  If the pressure is above the “normal” range, this may indicate glaucoma.  The doctor may take several measurements at different times of the day to make this determination.

Perimetry (Visual field test) :
This is a test that checks the function of the optic nerve , especially your peripheral vision.  In glaucoma, it is the peripheral vision that goes before the central vision.  It also helps to monitor progression of the disease.  This is a simple computerized test where you look into a machine and press a button when you see a light.   A computer then assesses your responses and gives a printout.

Gonioscopy:
This is when the doctor uses a special lenses on the eye that allows him to look into the part of the eye involved in  drainage of the fluid called the trabecular meshwork.  This area, where the iris and cornea meet, is narrower than it should be in patients with glaucoma, and this can lead to an increase in pressure.

Types of Glaucoma
Open angle glaucoma:
This glaucoma is the most common type and comprises about 90% of all cases of glaucoma. Unfortunately, there are no symptoms for this type of glaucoma, so you will really not know you have it, sometimes until it is too late and there has been a lot of damage to the vision.  Most of this type of glaucoma is picked up by optometrists during a regular eye exam, which is why you should get your eyes tested every couple of years. If you do have it then your vision will slowly start becoming like you are looking through a tunnel and if it is not diagnosed early and treatment started,  it will eventually lead to blindness.

Normal Vision          Effects of Glaucoma on your vision
Angle closure glaucoma:
This can also be called acute or narrow angle glaucoma. This means that the angle of the drainage canal is blocked and the fluid cannot be adequately drained and this leads to a buildup of pressure. This kind of glaucoma can only be treated with surgery, usually by laser.
Congenital glaucoma:
This type you are born with and this type  usually has symptoms, which include cloudy corneas , excessive tearing, and sensitivity to light.
Pigmentary:
This occurs when pigment from the iris ( the colored part of the eye)  flakes off and blocks the drainage canal.
There is also Secondary glaucoma, which can develop only from really specific things like a tumor, diabetes, as a result of injury or trauma, and other specific conditions.
Unfortunately, most people assume that glaucome will affect their vision and they will see blurry or distorted.  This is why so many people lose their sight from glaucoma.  Glaucoma damages the visual field.  Glaucoma DOES NOT AFFECT sharpness or clarity of vision.  Thus, you can have 20/20 vision, and still have late stage glaucoma.  Because the time from onset of glaucoma to blindness is a long one, the most important thing to realize is that early detection and treatment is critical.  If you are diagnosed in the early stages of glaucoma, you need never go blind with appropriate treatment and monitoring. However, if you are diagnosed when the glaucoma is far advanced, or your treatment is not sufficient, the potential for low vision or blindness exists, and the vision loss is permanent
WHAT IS DIABETIC RETINOPATHY?

Our bodies use glucose (sugar) as fuel for energy.  Glucose is derived from most of the foods that we eat.  The body uses a hormone called insulin to move the glucose into the cells so that it can be utilized. Diabetes is a disease where the body either does not produce enough insulin, or the insulin doesn’t work adequately and this leads to a  buildup of glucose in the blood.
The eye is like a camera.  It uses the cornea and lens to focus light on the retina at the back of the eye.  The retina is made up of cells called rods and cones, which transmit images to the part of the brain responsible for vision.

Diabetic retinopathy is a condition affecting the retina of the eye which occurs when you have had poor control of the blood sugar levels, especially in the early days.  The small blood vessels in the eye get weak, and their walls swell, then they bleed/leak, and then cause scarring. As the vessels leak fluid, this fluid can build up in the retina leading to a condition called macular edema.  This process can lead to the formation of new, immature blood vessels in the retina that can also bleed and leak and create further problems.  This is a gradual process..it does not happen suddenly but over the course of several years.  However, once the vessels are damaged, you cannot make them better, so prevention is the clue to preventing loss of sight.

You may even develop a bleed within the eye.. retinal haemorrhage which  can cause a sudden severe decrease in vision.

If you are diabetic, you should be checking your eyes yearly.  The optometrist or ophthalmologist will examine the retina with an in instrument called an ophthalmoscope.  This allows the examiner to see the blood vessels and check if they are swollen or leaking If the vessels are leaking, you may be referred for laser treatment.  Laser only stops the areas where there is current bleeding and this hopefully prevents further damage to the retina.  The vision will not necessarily improve.  And, in months or years later, another part of the retina may bleed, and you will need laser again.

If you are diagnosed with diabetes, your doctor will use different therapies to reduce the blood sugar: if you are overweight, you will be advised to lose weight,  you will be given advice on your diet, you will be told to exercise, and if these don’t work, your doctor will prescribe medicines. If you are a smoker, your doctors
will advise you to stop smoking as soon as possible.   If you do not keep your blood sugar levels under control, over time, this leads to problems with kidneys, heart, and the eyes.

WHAT IS A CATARACT?

In our eye we have a lens, and when we are young, the lens is clear, like clear glass.  But as we get older, the lens can get cloudy. This is a natural part of ageing.
This cloudiness affects the light passing through the eye to the retina and that can cause vision problems. The image that now hits the retina is not clear and crisp as before, its blurry or even distorted.  Colours seem dimmer and faded almost.   Most people aged 65 and older have a cataract, although in some it may be tiny and in others it may be fairly advanced.  Surgeons usually wait until the vision is severely affected before operating…sometimes here in Guyana people say they have to wait till the cataract gets “ripe”, but what is really meant is that the cloudiness has progressed enough to affect vision.
Rarely, children can be born with cataract and this is termed congenital cataract.

The lens is made mostly of water and protein. The protein is arranged in a particular structure to let light pass through and focus on the retina.  As we age, sometimes some of the protein clumps together. This can start to cloud small areas of the lens, blocking some light from reaching the retina and interfering with vision. This is a cataract.  Most people believe a cataract is a film that grows across the eye, but this is not the case.  Its actually part of the clear lens becoming cloudy.   Because this is a natural part of ageing, no drops can prevent or slow down cataract development. A cataract won’t spread from one eye to the other, although many people develop cataracts in both eyes.

In its early stages, a cataract may not cause a problem. The cloudiness may affect only a small part of the lens. However, over time, the cataract may grow larger and cloud more of the lens, making it harder to see.  You may need to change your spectacle prescription more frequently than before.  Because less light reaches the retina, your vision may become dull and blurry.  Night vision may become worse.  Some patients find colours get duller and not as distinct as before, especially blues.
In the early stages, stronger lighting and eyeglasses may lessen vision problems caused by cataracts. At a certain point, however, surgery will be needed to improve vision. Today, cataract surgery is safe and very successful.  It is considered the most successful elective surgery. During a cataract operation, the ophthalmologist removes the cloudy lens, and replaces it with an artificial one, called an intraocular lens implant ( IOL).  Previously, the surgeon just removed the cloudy lens.  This caused a big drop in focusing power and the patient needed thick “cataract glasses” to then see clearly.  Using an IOL allows the patient to wear normal thickness spectacles.

Although researchers are learning more about cataracts, no one knows for sure what causes them to occur early in some people.. Scientists think there may be several causes, including smoking, diabetes, and excessive exposure to sunlight.

WHY SHOULD CHILDREN GET THEIR EYES CHECKED?

Studies have found that nearly 25% of school-age children have vision problems and neither they nor their parents are aware of them.   This usually occurs because children don’t know what is clear or blurry because they only know that this is how they’ve seen as long as they remember.  Many children have not had an eye examination before entering school and so often it is teachers that pick up that a child is not seeing as well as they should.  But because children in the early classes ( preschool & nursery) don’t really look at small objects or images, it may not be picked up early enoughIn children with visual disorders,  the earlier it is diagnosed and treated, the better it is for the development of their vision.  A recent study found that 11.5% of teenagers have untreated vision problems.  Over 80% of what children learn is processed through the eyes.  The main test used is visual acuity and this is done using a standardized eye chart.  If the child is too young to know the alphabet, there is a chart with pictures available.

The first chart is the standard eye chart.  The second has pictures that the child can describe.  The third shows the letter E in various positions and the child simply points in the direction the E is pointing.

However, the chart only checks visual acuity.  It doesn’t check other visual requirements that a child needs.  For example, it does not check the near vision.  A child maybe farsighted.. see clearly at distance, but blurry at near.  As well, it doesn’t tell if the eyes are straight, whether there is an eye turn ( strabismus).

WHAT VISION IS NEEDED FOR SCHOOL?
The basic vision skills needed for school use are:
•    Near vision. The ability to see clearly at desk level.
•    Distance vision. The ability to see the board clearly.
•    Binocular coordination. The ability to use both eyes together. This lets them write between the lines clearly.
•    Eye movement skills. The ability to aim and focus the eyes accurately, and shift them quickly from one object to another., ie from the blackboard and then down to the desk.
•    Eye/hand coordination. The ability to use the eyes and hands together.
WHAT HAPPENS IF THEY DON’T HAVE ONE/MORE OF THESE?
If any of these skills are not functioning properly, your child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. As a parent, look out for symptoms that may indicate your child has a vision problem. Be sure to tell your optometrist if your child frequently:
•    Loses their place while reading;
•    Avoids close work;
•    Holds reading material closer than normal;
•    Tends to rub their eyes;
•    Has headaches;
•    Turns or tilts head to use one eye only

A good education for your child means good schools, good teachers and good vision. Your child’s eyes are constantly in use in the classroom and at play. If they are not seeing well, learning and participation in recreational activities will suffer. Since vision changes can occur without you or your child noticing them, your child should visit the optometrist at least every year, or more frequently, if specific problems exist. If needed, the doctor can prescribe treatment including eyeglasses, contact lenses or vision therapy.
Guyana offers free eyecare at Port Mourant facility
Eyecare in Guyana has been taken to another level with the opening of the $140M National Ophthalmology Centre at Port Mourant, Berbice, which is offering a wide range of eyecare services.
Specialized staff from Cuba, who arrived to initially man the centre, have assisted with the installation of the high-tech equipment.
Minister of Health Dr. Leslie Ramsammy said that the National Ophthalmology Centre has lifted the eyecare programme in Guyana and that the Ministry of Health intends to make eyecare a primary aspect of Government’s healthcare thrust.  Patients suffering from corrective refractive error, cataract, glaucoma, retinopathy, retina detachment, and certain eye defects are being treated at the Ophthalmology Centre, which is the first of its kind to be built in the Caribbean. One of the Government’s long-term plans is to have eye transplants done. Patients come from as far as Suriname and even from the Guyanese Diaspora to access the free services offered at the Centre,
Minister Ramsammy noted that, previously, eyecare was being dealt with at the tertiary level where services were only available at the Georgetown Public Hospital Corporation and the New Amsterdam Hospital as a regional facility.
“Eye-care was never present in the family healthcare system,” said the Minister, “but we have developed continuity of services; from the health post to the National Referral Hospital in Georgetown and now to the National Ophthalmology Centre at Port Mourant. People are now able to access eye-care at all levels of the healthcare system,” the Health Minister said.
Teachers are continually trained in the use of optical charts, which are used as screening tools to help identify children who may be suffering from impaired vision and may need glasses or contact lenses.
Health personnel at health posts and health centres are also trained to assist persons to get treated early before complete loss of vision occurs.
“Additionally, there are people who may develop diseases of the eye that are far more serious and cannot be corrected by merely wearing glasses. They may sometimes need surgery, for example, for cataract, glaucoma or retina detachment. Treatment for all these complications is available in Guyana but people will have to go to the specialized centres such as the National Ophthalmology Centre, the New Amsterdam Hospital or the GPHC,” the Minister added.
Minister Ramsammy noted that Government is continuously seeking ways to better deliver services to maximize benefits to Guyanese.
“Formerly, whereas people were being treated and had to spend a week in the hospital, now they will be able to go home the same day. We can do surgery where there are micro incisions so that they heal faster,” the Health Minister stated.
The Ophthalmology Centre, which was built under a Guyana/Cuba health sector agreement, sealed in early 2006, also provide services to patients of neighbouring countries.