Near-sighted cell discovered in retina

Researchers have discovered a cell in the retina which may control the growth of the eyeball and the cause of myopia.   It also seems that indoor light might stimulate this cell to increase the amount of nearsightedness one develops.  This contributes to the observation that kids that spend more time outdoors tend to be less nearsighted.

Read more here.

Dr Michael D. Nelson, OD

 

How Do I Prevent Nearsightedness?

There is a nearsighted epidemic going on in the world.  In the 1970’s about 20% of NorthAmerican and Asian 20 year olds were nearsighted.  Now it is about 40% of North American and 96% of Asian 20 year olds.

While we don’t fully understand why or how, studies seem to indicate that more time spent outdoors seems to protect against becoming nearsighted.  Studies show that about 90-120 minutes outdoors in the sun can reduce nearsightedness.  What we do know is that it is not related to amounts of upclose work, as the studies have corrected for that.  In fact, there are some schools in Taiwan that have ‘bright-light’ classrooms where the walls and ceilings are made of see through plastic and these students seem to be less nearsighted than in other schools.

So get outside!!!

Cure to Asia’s Nearsighted Epidemic

eyetrain sports vision training

Tetris training for Amblyopia

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The age old question – Are video games bad for my eyes?  Well one recent study says no, at least if used under specific conditions.

A recent study published in Current Biology showed that amblyopia can be reduced in adults using training with the video game Tetris.  Amblyopia affects up to 5% of the population and occurs when the connections from the eye to the brain do not develop as well in one eye.

Traditionally, patching the good eye and viewing images monocularly has been the treatment for amblyopia in children.  This treatment is effective in children but does not seem to be as effective in adults.  This recent study shows that when Tetris was played with diochoptically (one eye viewing the stationary objects and the other viewing the moving objects) 3D vision and vision in the weaker eye improved, compared to just playing the game monocularly.

Michael Nelson, OD  Waverley Eye Care Centre

Word of the day: Emmetropization

Word of the Day:  Emmetropization

Five points to you if you can fit this one into your everyday conversation.

If you have brought your toddler in for an eye exam you may have been told by your Optometrist that they are farsighted, or hyperopic.  What may have been puzzling is that your eye doctor may not have been concerned about this and in fact they may have told you that your toddler didn’t need glasses.  This may seem contradictory – why wouldn’t I get glasses for my toddler so they can see perfectly?  The answer is emmetropization.  Emmetropization is the natural process in humans and animals that causes the eye to grow in such a way so that it will have no refractive error.  When we are born, we are naturally born farsighted, or hyperopic.  This means that rather than the image being focused on the retina, it is focused behind the retina.  The body can recognize this and it will cause the eye, lens and cornea to grow in such a way that will try correct the farsightedness.  This process goes on during the first 5-7 years of life.  So babies are naturally born farsighted and then at about age of six they often have no prescription.    What it is important for your optometrist during the eye exam is to see just how farsighted your toddler is – if they are farsighted by too much or too little it may be important to get glasses to develop normal eyesight.  For information on when is the ideal time for your first eye exam check here.

Michael D. Nelson, Optometrist

“I am worried that my child has ‘pink eye’, is this ‘pink eye’?”

If you get a blank stare from your eye doctor to this question, it is because technically there is no condition known as ‘pinkeye’ – in fact, to an eye doctor a pink eye means nothing more than an eye that is red.

There are lots of causes for a red eye ranging from bacterial infection, viral infection, allergies, abrasions, dryness or contact lens wearers.  The medical term for a red, inflamed eye is conjunctivitis.  So you can have bacterial conjunctivitis, allergic conjunctivitis, viral conjunctivitis, etc.  For the most part most children’s red eyes will be due to a virus, bacteria or an allergy.  The good news is that it is rare for any of these to result in vision loss.  The key is to get an eye exam to determine the proper diagnosis so you can start the appropriate treatment.

If it is allergic, the key to treatment is to remove the source of the allergy, consider anti-allergy medications and use cool compresses.

If it is a bacterial conjunctivitis, the body is good at fighting this off in less than a week but there are excellent antibiotic eye drops that can clear this up much faster.  Bacterial conjunctivitis can be contagious so you want to make sure you wash hands often and don’t share towels.

For viral conjunctivitis, much like the common cold, there are no treatments available – you just have to let your body’s immune system fight it off.  Like bacterial infections these can be contagious so you want to wash hands often and not share towels.  Certain viral infections can be very contagious and some have potential to affect vision and for this reason, it is sometimes advised that children stay home from school until the conjunctivitis has resolved.  Sometimes viral infections are the ones referred to as ‘pinkeye’, however this term is used so loosely and often incorrectly that it often confuses the issue.

The key in to conjunctivitis is to get an eye exam so you can get a proper diagnosis and treatment.

Michael D. Nelson, Optometrist

When should a child’s first eye exam be?

If there is a family history of eye problems, other than the need for glasses, or if you suspect an eye problem, children should have their first eye examination at 6 months of age.  Signs of vision problems include:  a turned or crossed eye, a whitish area within the pupil of the eye or if your child is unable to follow movements by 6 months of age.

If there are signs of problems and no family history then 3 years old is a great age for a first eye checkup.  Don’t worry if you child is shy or doesn’t know their alphabet yet as a child’s eye exam is often much different than an adults…we have pictures and can collect a lot of information even if they don’t say a word.

Michael D Nelson, Optometrist

Children Should Get Eye Exam Before Using 3D Games

PRESS RELEASE

CHILDREN SHOULD GET EYE EXAM BEFORE USING 3D GAMES

WINNIPEG, MB, MARCH 28, 2011: With the release of the Nintendo 3DS yesterday, the issue of eye safety in children under 6 has come into question. 1 in 20 children under the age of 6 suffer from amblyopia (lazyeye) and usually have no symptoms. Amblyopia(Lazyeye) occurs when a child does not develop normal vision in one eye. This impairs the ability to see 3D images or have normal depth perception. Amblyopia can only be treated if detected and diagnosed, therefore and eye exam with an Optometrist is critical for children under 6.

The Nintendo 3DS uses a new innovative design which shows a slightly different image to each eye. The result is the ability to see 3D images without the need for 3D glasses. Nintendo has officially warned that this technology should not be used by children under the age of 6 because it may harm their immature vision. Eye doctors, on the contrary, have said this or other 3D technology may not directly harm a young child’s vision. In children with amblyopia, it could result in eyestrain and headaches.

According to available reports less than 15% of children under 6 years old have had an eye exam. This means preventable vision loss has gone undiagnosed and untreated. Some parents wait for kindergarten vision screenings. These screenings come too late for treating amblyopia. An eye exam with their Optometrist starting at age 3 ensures the normal development of 3D vision in children.

eye exam

Amblyopia

Amblyopia is a disorder of the visual system that is characterized by poor or indistinct vision in one or both eyes that is otherwise physically normal. The brain and the eye work together to produced vision: Light enters the eye and is focused on the retina. The retina changes light into nerve signals that travel along the optic nerve to the brain (visual cortex). The medical term for the connections between the eye and the brain not working properly is amblyopia. The eye itself looks normal, but the brain does not interpret normal vision. Putting on glasses (without treatment) will not produce 20/20 vision.

How common is amblyopia?

Amblyopia is the most common cause of visual impairment in childhood. It affects about 5% of the population. Unless it is successfully treated in early childhood, amblyopia persists into adulthood, and is the most common cause of monocular (one eye) visual impairment.

What causes amblyopia?

Amblyopia may be caused by any condition that affects normal visual development or use of the eyes. Amblyopia can be caused by:

  • Strabismus, an imbalance in the positioning of the two eyes
  • Excessive farsightedness or astigmatism
  • Unequal prescription between the two eyes
  • Opacities such as cataracts

 

How is amblyopia treated in children?

Treating amblyopia involves making the child’s brain use the eye(s) with the reduced vision. The best outcome is achieved if treatment is started before the age of five. Currently, there are two ways used to do this:

  • Glasses (correcting the optical defect)

This is treatment of hyperopia, myopia, and/or astigmatism through the use of full-time glasses. This stimulates vision development in the brain.

  • Occulusion (patching)

An opaque patch is worn over the stronger eye for months to a year, forcing the brain to use the amblyopic eye. Patching forces the brain to use the visual cortex designated to the weaker eye to develop normal vision.

More than you ever wanted to know about Amblyopia:

Physiology:

Amblyopia is a developmental problem in the brain; the part of the brain corresponding to the visual system from the affected eye is not stimulated properly, and develops abnormally. This has been confirmed via direct brain examination. David H. Hubal and Torsten Wiesel won the Nobel Prize in Physiology or Medicine in 1981 for their work demonstrating the irreversible damage to ocular dominance columns produced in kittens by sufficient visual deprivation during the so-called “critical period”. The maximum critical period in humans is from birth to two years old. The problem is caused by either no transmission or poor transmission of the visual image to the brain for a sustained period of dysfunction during early childhood. Amblyopia often affects one eye, but it is possible to be amblyopic in both eyes if both are similarly deprived of a good, clear visual image. Detecting the condition in early childhood increases the chance of successful treatment.

Symptoms:

Many people with amblyopia, especially those who are only mildly so, are not even aware they have the condition until tested at older ages. Amblyopes even after being treated to 20/20 may suffer from poor spatial acuity, low sensitivity to contrast and some “higher level” deficits to vision such as reduced sensitivity to motion. These deficits are usually specific to the amblyopic eye, not the unaffected “fellow” eye. Amblyopes also suffer from problems of binocular vision such as limited stereoscopic depth perception and usually have difficulty seeing the three-dimensional images in hidden stereoscopic displays such as autostereograms. However, perception of depth form the monocular cues such as size, perspective and motion parallax is normal.

My Story: (since many patients ask)

At 5 months of age, my mother noticed occasionally that one of my eyes was slow to follow. The first 4 doctors told her she was an uptight first time mother. The fifth doctor said, yes one eye was more farsighted and had astigmatism. My mother often questioned the eye doctor, since I was reading at age 3, why I needed to come back every 3 months to monitor the vision. Since I had to wear the heavy glass lenses in the 1970’s, I now hold back and prescribe glasses reluctantly. Still today, both my parents, my younger sisters, and all 3 kids see better than 20/20 without glasses. My oldest daughter slipped from 1 line better than 20/20 down to 20/20 so we did glasses at age 4; one hour a day for one month and she returned to 20/15.

National Eye Institute-Supported Research

A Randomized Trial Comparing Part-Time (6 hours a day) Versus Minimal-time Patching (2 hours a day) for Moderate Amblyopia was conducted to determine whether the visual acuity improvement obtaining with part-time patching is equivalent to the visual acuity improvement obtained with minimal patching for moderate amblyopia. Recend findings show that patching the unaffected eye of children with moderate amblyopia for two hours daily works as well as patching the eye for six hours when combined with a minimum of 30 minutes of near work. Shorter patching time should lead to better compliance with treatment and improved quality of life for children with amblyopia. Watching TV, playing video games, or using the computer did not enhance visual development but worked well as rewards to wearing a patch. Thirty minutes of near work can include reading books, puzzles, colouring, crafts, mazes.

dr selena friesenDr. Selena Friesen, Optometrist

Waverley Eye Care

Winnipeg, Manitoba

Common Eye Conditions

0-6 years:

Common Eye Conditions that may be noted in 6 year olds and under include the following: Myopia(nearsightedness), Hyperopia (farsightedness), Astigmatism, Amblyopia(Lazy Eye), Strabismus (turned eye) and Eye Infections.

In my opinion the most important of these is Amblyopia, which affects 5% of children and responds well to treatment under the age of 6. Unfortunately it only affects one eye so most children will often have no symptoms or complaints. Worse yet, any reduced vision that is still present after the age of 7 is usually permanent. Amblyopia is an important reason to ensure annual eye exams starting at 3 years old.

6-20 years:

Common Eye Conditions that may be noted in 6 year olds to early 20’s include the following: Myopia(nearsightedness), Hyperopia (farsightedness), Astigmatism, Amblyopia(Lazy Eye), Eye Infections, Eye Trauma and Contact Lens related problems.

The most common vision problem in this age group is refractive in nature, meaning a need for glasses. I recommend annual eye exams for this age group because I think it is important to detect any vision problems early so that blurred vision does not cause a problem in school. In Manitoba at least a portion, if not all, of the eye exam fee is paid for by Manitoba Health for those 18 and under.

 

Michael Nelson, OD