What is the link between diabetes and the eye?
The current number of patients in Canada living with Diabetes is 3.3 million. The most common form of diabetes currently is Type II, accounting for about 90% of the cases in Canada. As many as 1 million people are living with undiagnosed diabetes and people often think that diabetes is only detected by a physician, however, a comprehensive eye examination by your eye doctor can also detect early signs of diabetes. According to the National Eye Institute, diabetic retinopathy is the leading cause of blindness in American adults.
How can diabetes affect my eyes?
- Diabetes and complications of diabetes, including uncontrolled blood sugars can affect many parts of the eyes.
- Diabetes can cause changes of fluctuations in vision and your glasses prescription, premature presbyopia (reduced ability to focus on near objects), early cataracts, glaucoma, nerve paralysis that innervate different muscles of the eye and much more
- The most serious of all the diabetic changes within the eye is diabetic retinopathy
What visual symptoms can I get from my diabetes?
- Fluctuating and blurred vision
- Double vision
- Visual field loss
- Flashes and floaters
What is diabetic retinopathy?
- According to the Canadian Diabetes Association, 23% of Insulin-dependent (Type I) diabetics are affected by diabetic retinopathy, and 14% of Type II diabetics are affected.
- The retina is one of the layers at the back of the eye and over time diabetes can change the vasculature of the retina.
- Diabetic retinopathy occurs when there is a weakening of the tiny blood vessels that supply the retina which ultimately can cause leakage of the blood from these vessels (little hemorrhages), the growth of new blood vessels, swelling of the layers within the retina as well other changes.
- Retinopathy can be detected early, however, if goes undetected the circulation within these vessels begins to decrease, depriving the retina of oxygen and parts of the retina can die. If diabetic retinopathy continues without being untreated it can lead to blindness.
Can Diabetic Vision Loss be prevented?
Yes, if you are a diabetic it is important to have a dilated eye examination at least once a year to allow your optometrist to do a thorough investigation of the health and integrity of your eyes
It is, however, important to know that once damage has occurred the effects on your vision are usually more permanent and as such it is important to control your sugars which will minimize your risk of developing diabetic retinopathy.
What is the treatment of Diabetic Retinopathy?
If detected early, diabetic retinopathy is monitored on a shorter review schedule which is determined by your optometrist, however, if necessary there are further treatments including anti-VEGF (intraocular injections), which will slow down the production of new vessels within the retina. Laser therapy may also be used, which consists of a small beam of light focused to the retina which burns and seals off the leaking vessels. Some other cases may require retinal surgery. Overall, early detection is the key to early management.
What can I do to prevent diabetic eye disease?
- Monitor and maintain control of your own diabetes
- See and listen to your family doctor on a regular and consistent schedule
- See your eye doctor for a thorough eye examination when first diagnosed and then at least on a yearly basis, however, it may be recommended to be seen on a shorter review schedule based on any pathology detected.
Information source
Challenges that children with vision problems face
Studies show that approximately 80% of what a child learns is information that is presented visually. If a child’s vision, eye health and binocular vision (how the eyes and eye muscles work together) status are not in top form then their ability to retain, learn, perform basic tasks and remain attentive will be compromised.
While vision-based skills are most commonly detected when children are at school, it is important to have your child’s first exam prior to commencing school to set them up for success with learning. Some other activities that can show clues of visual problems may include:
- Sports – depth perception (catching a ball, kicking a ball), wide field of vision (being able to detect a ball coming from the side) and hand-eye coordination delays can show signs of visual troubles. Watch for overly clumsy children, delayed swing at a baseball consistently, inability to catch a large ball consistently, etc.
- Reading – monitor your children for reading ability, teachers are good advocates of what level of reading ability children are typically for the age of your child. Watch for children consistently losing their place, mixing up letter or numbers, letter reversals (b’s are d’s, c’s are o’s, etc.) and using their finger to read.
- Watching TV – sitting really close to the TV can indicate that your child’s vision is not as clear as it could be for the distance. Another sign could be that your child always tilts their head or closes one eye to watch TV or look out the window in the car.
It is important to know that children’s vision is not only impacted by being near-sighted (myopic), far-sighted (hyperopic) or astigmatic but also their binocular vision status or the ability for the muscles to communicate accurately without extended effort to maintain clear, single vision.
Binocular vision disorders (BVD) are quite common. The University of Waterloo did a retrospective review of school-aged students who all had an Individual Education Plan specifically for reading and over ¾ of the students had good eye-sight, but importantly over 1/3 of the students scored below the normal for their binocular vision assessment
BVD is often classified by Optometrists under three main categories:
- Accommodation – put simply this is the focusing part of the eye, more specifically focusing at near or changing focus from distance to near and vice versa
- Vergence – eye teaming, this can mean troubles turning the eyes in (convergence), typically when looking up close and divergence (eyes turning outwards). A common binocular vision diagnosis in children is convergence insufficiency, which is quite often recognized as children having difficulties turning their eyes in to read
- Oculomotor – also recognized as eye tracking, children often present with difficulties keeping their place reading and require finger or ruler to keep their spot on the line they are reading.
The good news with children with BVD is it is often treated, although, often requiring referrals to special optometrists and vision therapists, glasses are not often the solution. Optometrists can often provide recommendations for specific tasks including school work and learning.
Common behaviours and symptoms of children with BVD:
- Poor handwriting (spacing, letter sizing)
- Activity avoidance
- Difficulty reading
- Difficulty seeing the board and difficulties copying from the board
- Difficulty identifying shapes, colours and letters in an age-appropriate way
- Frequently bumping into objects
- Stomach aches and headaches when away from home (wanting to come home from school because they are finding it difficult)
- Anxiety in public places
- Closing one eye to look at things
Children in BC are covered by MSP until they are 19 for their eye examinations, which are typically done annually, however, there are certain instances why children may need more frequent eye examinations, see your eye doctor today!
Do I have cataracts?
A cataract is a clouding of the eye’s natural lens, which lies behind the iris and the pupil. The lens works much like a camera lens, focusing light onto the retina at the back of the eye. The lens also adjusts the eye’s focus, letting us see things clearly both up close and far away.
Cataract signs and symptoms
A cataract starts out small, and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass or viewing an impressionist painting. However, as cataracts worsen, you are likely to notice some or all of these problems:
- Blurred vision that cannot be corrected with a change in your glasses prescription.
- Ghost images or double vision in one or both eyes.
- Glare from sunlight and artificial light, including oncoming headlights when driving at night.
- Colors appear faded and less vibrant.
What causes cataracts?
No one knows for sure why the eye’s lens changes as we age, forming cataracts. Researchers are gradually identifying factors that may cause cataracts, and gathering information that may help to prevent them.
Many studies suggest that exposure to ultraviolet light is associated with cataract development, so eye care practitioners recommend wearing sunglasses and a wide-brimmed hat to lessen your exposure. Other types of radiation may also be causes. For example, a study conducted in Iceland suggests that airline pilots have a higher risk of developing a nuclear cataract than non-pilots, and that the cause may be exposure to cosmic radiation. A similar theory suggests that astronauts, too, are at greater risk of cataracts due to their higher exposure to cosmic radiation.
Other studies suggest people with diabetes are at risk for developing a cataract. The same goes for users of steroids, diuretics and major tranquilizers, but more studies are needed to distinguish the effect of the disease from the consequences of the drugs themselves.
Some eyecare practitioners believe that a diet high in antioxidants, such as beta-carotene (vitamin A), selenium and vitamins C and E, may forestall cataract development. Meanwhile, eating a lot of salt may increase your risk.
Other risk factors for cataracts include cigarette smoke, air pollution and heavy alcohol consumption.
Cataract treatment
When symptoms of cataracts begin to appear, you may be able to improve your vision for a while using new glasses, stronger bifocals and greater light when reading. But when these remedies fail to provide enough benefit, it’s time for cataract surgery.
If you need cataracts removed from both eyes, surgery usually will be done on only one eye at a time. An uncomplicated surgical procedure lasts only about 10 minutes. However, you may be in the outpatient facility for 90 minutes or longer because extra time will be needed for preparation and recovery.
Glaucoma, “the silent disease”
Glaucoma, a silent eye disease, is the most common form of irreversible blindness in the world. It is actually a group of diseases that causes progressive damage to the optic nerve.
- Glaucoma is a progressive eye disease that can lead to permanent vision loss if not controlled.
- There is currently no cure for glaucoma, but there are many treatments available for stopping and slowing the progressive damage to the eye. Treatment, however, can’t reverse damage that is already done.
- Glaucoma affects the optic nerve which sends visual information from your eye to your brain.
- Glaucoma is called the “Thief Sneak of Sight” because there are often no symptoms in the early stages such as pain or “pressure sensation” as one may expect, and by the time it is diagnosed there may already be permanent vision loss.
- When vision loss occurs, peripheral vision is typically affected before central vision. As a result, glaucoma is a major public health issue because individuals usually do not notice any problem with vision until end stages of the disease when there is severe and irreversible vision loss.
- Awareness and regular eye exams are key to early detection and preventing vision loss.
What Causes Glaucoma?
Glaucoma is caused by a buildup of natural fluid that doesn’t drain properly from the eye. The buildup of fluid can result in high pressure in the eye which is the most common cause of the condition. There are many types of glaucoma, which include:
Chronic (open angle) glaucoma occurs when pressure builds up over time, usually as a result of aging. This is the most common type of glaucoma.
Acute (angle closure) glaucoma is an acute condition where pressure builds up suddenly and demands immediate medical attention. Symptoms include blurred vision, eye pain, headaches, seeing halos around lights, nausea and vomiting.
Secondary glaucoma results from another eye disease, condition or a trauma to the eye.
Normal tension glaucoma is when there is no build up of pressure but the optic nerve is still damaged. We are still not yet sure what causes this type of glaucoma.
Who is at Risk for Glaucoma?
Everyone is at risk of glaucoma however there are certain factors which increase the likelihood of developing the condition. Vision loss from glaucoma can be greatly reduced when detected and treated early which is why knowing your risk factors can play a tremendous role in prevention.
Age
Age is one of the biggest risk factors, as your chances of developing glaucoma increase significantly after the age of 40. In fact people over 60 years old are six times more likely to get the condition.
Ancestry and Family History
Individuals from African American, Hispanic, Asian and Native American or Aboriginal Canadian descent are at increased risk. Family history is a very strong factor as the condition occurs twice as much in people with close relatives who have had glaucoma.
Previous Eye Injury, Traumas or Surgery
Eye injuries, traumas or surgeries have been known to sometimes cause secondary glaucoma which can happen immediately after the injury or procedure, or even years later. Even childhood injuries can result in secondary glaucoma later in life.
Use of Steroids
Studies show that prolonged steroid use is linked to increased elevated intraocular pressure which increases the risk of open-angle glaucoma.
Certain medical and eye conditions such as diabetes, hypertension and high myopia (nearsightedness) also increase a person’s risk of developing glaucoma.
Glaucoma Treatment
While there is no cure for glaucoma, there are treatments to slow down the progression of the disease including eye drop medications, iridotomies, iridectomies, laser procedures and surgeries.
Glaucoma Prevention
Other than taking care of any underlying conditions that may increase the risk of developing glaucoma, there is little one can do in the way of prevention. You can however reduce your chances of suffering vision loss. The first step is knowing the risk factors and signs of the condition (even though as mentioned most cases have no symptoms in the early stages, until vision is already lost).
The best possible way to prevent vision loss is to have regular comprehensive eye exams to check the health of your eyes and if your eye doctors prescribes medication for glaucoma, make sure to diligently take them as directed. Your eye doctor will be able to conduct certain tests to detect eye diseases such as glaucoma before you even begin to notice symptoms. If you have any of the risk factors above, mention it to your eye doctor, and always be sure to schedule a yearly eye exam, or as often as your eye doctor recommends, to check the health of your eyes and rule out any underlying or developing eye conditions like glaucoma.
Macular degeneration
Macular degeneration (also called AMD, ARMD, or age-related macular degeneration) is an age-related condition in which the most sensitive part of the retina, called the macula, starts to break down and lose its ability to create clear visual images. The macula is responsible for central vision – the part of our sight we use to read, drive and recognize faces. So although a person’s peripheral vision is left unaffected by AMD, the most important aspect of vision is lost.
AMD is the leading cause of vision loss and blindness in Americans of ages 65 and older. And because older people represent an increasingly larger percentage of the general population, vision loss associated with macular degeneration is a growing problem.
It’s estimated that more than 1.75 million U.S. residents currently have significant vision loss from AMD, and that number is expected to grow to almost 3 million by 2020.
The two forms of AMD
The dry form of AMD is more common – about 85% to 90% of all cases of macular degeneration are the dry variety.
Dry macular degeneration. Dry AMD is an early stage of the disease, and may result from the aging and thinning of macular tissues, depositing of pigment in the macula, or a combination of the two processes.
Dry macular degeneration is diagnosed when yellowish spots called drusen begin to accumulate in the macula. Drusen are believed to be deposits or debris from deteriorating macular tissue. Gradual central vision loss may occur with dry AMD. Vision loss from this form of the disease is usually not as severe as that caused by wet AMD.
A major study conducted by the National Eye Institute (NEI) looked into the risk factors for developing macular degeneration and cataracts. The study, called the Age-Related Eye Disease Study (AREDS), showed that high levels of antioxidants and zinc significantly reduce the risk of advanced dry AMD and its associated vision loss.
The AREDS study also indicated that taking high dose formulas containing beta carotene, vitamins C and E and zinc can reduce the risk of early stage AMD progression by 25%.
Wet macular degeneration. Wet AMD is the more advanced and damaging stage of the disease. In about 10% of cases, dry AMD progresses to wet macular degeneration.
With wet AMD, new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive cells in the retina, causing blind spots or a total loss of central vision.
The abnormal blood vessel growth in wet AMD is the body’s misguided attempt to create a new network of blood vessels to supply more nutrients and oxygen to the macula. But the process instead creates scarring and central vision loss.
Macular degeneration signs and symptoms
Macular degeneration usually produces a slow, painless loss of vision. Early signs of vision loss associated with AMD can include seeing shadowy areas in your central vision or experiencing unusually fuzzy or distorted vision. In rare cases, AMD may cause a sudden loss of central vision.
An eyecare practitioner usually can detect early signs of macular degeneration before symptoms occur. Usually this is accomplished through a retinal examination.
What causes macular degeneration?
Many forms of macular degeneration appear be linked to aging and related deterioration of eye tissue crucial for good vision. Research also suggests a gene deficiency may be associated with almost half of all potentially blinding cases of macular degeneration.
Who gets macular degeneration?
Besides affecting older individuals, AMD appears to occur in whites and females in particular. The disease also can result as a side effect of some drugs, and it appears to run in families.
New evidence strongly suggests that smoking is high on the list of risk factors for macular degeneration. Other risk factors for AMD include having a family member with AMD, high blood pressure, lighter eye color and obesity. Some researchers believe that over-exposure to sunlight also may be a contributing factor in development of macular degeneration, and a high-fat diet also may be a risk factor.
How is macular degeneration treated?
There is as yet no outright cure for macular degeneration, but some treatments may delay its progression or even improve vision.
There are no FDA-approved treatments for dry AMD, although nutritional intervention may be valuable in preventing its progression to the more advanced, wet form.
For wet AMD, there are several FDA-approved drugs aimed at stopping abnormal blood vessel growth and vision loss from the disease. In some cases, laser treatment of the retina may be recommended. Ask your eye doctor for details about the latest treatment options for wet AMD.
Testing and low vision devices
Although much progress has been made recently in macular degeneration treatment research, complete recovery of vision lost to AMD probably is unlikely. Your eye doctor may ask you to check your vision regularly with an Amsler grid – a small chart of thin black lines arranged in a grid pattern. AMD causes the line on the grid to appear wavy, distorted or broken. Viewing the Amsler grid separately with each eye helps you monitor your vision loss.
If you have already suffered vision loss from AMD, low vision devices including high magnification reading glasses and hand-held telescopes may help you achieve better vision than regular prescription eyewear.
Flashes & Floaters, what are they?
If you see specks or what appears to be debris, or perhaps pieces of lint floating in your vision, these are “floaters”. They are usually harmless. They would be seen most easily while looking at a plain background, like a white wall or clear sky.
Floaters are in reality clumps of gel-like cells inside the vitreous – the clear, jelly-like fluid that fills the inside of your eye. Floaters look like webs, specks, strands, and other shapes. What you are seeing are in fact the shadows of floaters cast on the retina, the light-sensitive inner lining of the back eye panel.
Symptoms of Spots or Floaters
With a special eye light, your doctor will detect floaters in your eyes even if you don’t notice them yourself. If a shadowy shape or spot passes in your field of vision or near the side, you are seeing a floater. Because they are inside your eye and suspended within the gel-vitreous, they move with your eyes as you scan and try to see them.
What Causes The Spots or Floaters?
Some floaters are present forever as part of the eye’s development. Others can grow over time.
In middle age, the gel-vitreous begins to liquefy and contracts. Some parts of the vitreous form clumps or strands inside the eye. The vitreous pulls away from the back eye-wall causing a posterior vitreous detachment (PVD). PVD is a common cause of floaters.
Floaters are more common:
- With nearsightedness
- After cataract surgery
- After laser surgery of the eye
- During or after inflammation in the eye
Treatment for Spots and Floaters
As mentioned above, most spots and floaters are harmless and only annoy the visual field. Many fade away on their own to become insignificant. Some doctors may perform surgery to remove floaters, but this should be advised only in rare cases.
Flashes of Light
Flashes of light occur often in older people and are usually due to mechanical stimulation of photoreceptors when the gel-like vitreous “pulls” on the light-sensitive retina. They may be an early warning sign predicting a detached retina – a serious problem which could lead to blindness if not treated immediately.
Some experiences of light flashes appear as jagged lines or “wavy heat” in both eyes, lasting 10-20 minutes. These types of flashes are usually caused by a spasm of the blood vessels in the brain, also called a migraine. If a headache follows the flashes, these are known as migraine headaches. Jagged lines or “heat waves” however can and do occur without a headache. These light flashes are called an ophthalmic migraine -a migraine without a headache.
Are Spots Flashes, or Floaters Emergencies?
The sudden appearance of significant numbers of floaters, especially if accompanied by flashes of light or other vision disturbances, could indicate a retinal detachment or other serious problem in the eye. A study reported in the Journal of the American Medical Association in 2009 found that one in seven people with the sudden presence of eye floaters and flashes will have a retinal tear or detachment. If you suddenly see floaters, visit your eye doctor immediately.