My eye doctor can detect which disease? - High blood pressure

There is a lot of confusion about what optometrists really do. We are so stereotypically associated with asking people "Which is better, 1 or 2?" and correcting vision problems that people are sometimes surprised to hear that we do a lot more! To help with the confusion I decided to start this new blog series "My eye doctor can detect which disease?". Some might surprise you, some might not. In today's blog I want to go over one that you might not expect: High blood pressure.

High blood pressure is extremely common. Approximately 20% of adults have high blood pressure with another 20% having high normal blood pressure (which puts them at higher risk of developing high blood pressure later on). Of these people another 20% are unaware that they have high blood pressure at all! This is important because as you may have heard high blood pressure is a silent killer. It has no symptoms so people are often not aware there is a problem until something serious happens like a heart attack or a stroke.

So how can your optometrist help? When we look inside of your eyes during a routine eye exam we aren't just looking for things like cataracts, macular degeneration and glaucoma. We're also looking for signs of systemic (or full body) problems like high blood pressure. The eyes are the only place in the body where we can directly look at your blood vessels without having to cut you open. This means that we can look and see exactly what is happening. In high blood pressure there a few key things that we are looking for.

In this picture you can see the silvering of some blood vessels and also see how some blood vessels are 'nicking' or pinching the ones underneath. This is typically what I see in the average person with uncontrolled, untreated high blood pressure.

  • Silvering of blood vessels - normally your blood vessels are a nice red colour but when someone has high blood pressure the blood vessel walls thicken. Over time this means that the blood vessels reflect more light and look more silver.
  • Wavy blood vessels - normal blood vessels in the eye follow a nice smooth path. If blood vessels are really curvy that can be an indication of high blood pressure.
  • Pressure on the blood vessels - as high blood pressure worsens the blood vessels may actually start to push down on other blood vessels restricting how much blood flows either in or out of your eye.
  • Bleeds - As those blood vessels crush each other blood can back up and eventually burst the blood vessel causing bleeds in your eye. You can also end up with white areas on your retina that aren't getting enough blood. Imagine it like squeezing a hose: no water comes out one end and water starts backing up on the other side of the blockage.
  • So much more - we can have things like leaking from blood vessels, swelling of the optic nerve and other signs.

This is high blood pressure gone seriously wrong. Uncontrolled high (very high) blood pressure over long periods of time can lead to a very unhealthy retina.

As you can see, there's no shortage of things that can go wrong in the eye with uncontrolled high blood pressure. Some of the more severe problems (Bleeding, leakage, swollen optic nerve etc) are fairly rare and only occur in very extreme untreated cases of high blood pressure. What I frequently see in my clinic are some of the early signs (the silvering, wavy blood vessels or pressure on blood vessels) and that let's me have a conversation about high blood pressure with you. In some cases your family doctor may already be aware and is either monitoring or already treating the issue. Sometimes though people have no idea and are shocked that they have high blood pressure and that it was found during a routine eye exam! It's important to keep blood pressure controlled to reduce your risk of so many very severe problems and early intervention and treatment is always better than trying to recover from something like a heart attack or stroke.

If you have any concerns that you might have high blood pressure I would urge you to book an appointment with your family doctor. While optometrists can detect high blood pressure it isn't our area of expertise to treat and manage high blood pressure effectively. If we detect it in office we always will send you back to your family doctor to both confirm the diagnosis and if needed start treatment. What's most important is remembering to have regular health checks with both your family doctor and your local doctor of optometry!

If you have any questions about this or anything else feel free to contact us on Twitter, Facebook, Google +, via our website or phone us at (403) 474-6744.

Amblyopia - How do we treat it?

My last blog about amblyopia discussed what amblyopia is and why it happens. It’s been a while so if you forget what amblyopia was or missed that blog follow the link back and find  out more before reading about how we treat amblyopia.

So what do we do about amblyopia? It’s actually not all that difficult! If there is a large amount of farsightedness or astigmatism our first step is to correct the prescription. A lot of parents get lost about now. We’ve just spent the last several minutes explaining to them that their child can’t see properly even with glasses and now we’re saying that they need glasses to fix the problem. This is especially tricky if there is no change in how well the kid sees without glasses or with!  It’s totally fair to question what we’re doing and why. The idea is to provide the eye (or eyes) with a nice sharp image. It may not make any difference in how well they see at first but over time as the eyes receive a nice sharp image they will learn more and more how to see better. If we go back to our earlier analogy with the flowers it’s sort of like watering the poor neglected flower. Just because you watered it doesn’t mean it instantly comes back to health and looks amazing. It takes care and time to nurse that flower back into full bloom.

If the amblyopia is only in one eye or is strabismic (eye turn) patching an eye is often required. The reason we have to patch in cases where only one eye is affected is  because if we don’t the better eye will just take over and keep doing all the work. This prevents the weaker eye from doing any work and slows or eliminates how well it will improve. The good news is that research has found that patching is NOT required all day every day! In fact it is only required for a few hours each night though we do recommend that the patient does some visually stimulating activities like reading, colouring or even video games.

There are certainly some cases that are more complicated and require more intervention and far more intensive vision therapy. Some patients may eventually require an eye surgery if they have an eye turn but the majority of patients with amblyopia can be easily treated so long as it is detected early. The older we are the harder it is to treat amblyopia as our brains are more set in their ways. So book your kids in for an eye exam today! You may think they see just fine, they may seem to see well but remember amblyopia may only affect one eye and young kids often don’t realize what they aren’t seeing!

If you want to read more feel free to check out the following links or as always you can contact us on Twitter, Facebook, Google +, via our website or phone us at (403) 474-6744.

Doctors of Optometry Canada - Amblyopia

Mayo Clinic - Amblyopia

 

Amblyopia - An introduction to a common and confusing problem

Let me introduce you to one of the  most commonly misunderstood eye disorders that occurs in children and can continue into adulthood: amblyopia. Why is amblyopia so confusing? The biggest problem is that it’s hard to explain in a way that makes sense to everyone. So let’s hunker down and understand what amblyopia is.

Amblyopia is often also called lazy eye. This is horribly confusing because strabismus (where the eye turns in, out, up or down all or most of the time) is also commonly called a lazy eye. While an eye turn can lead to amblyopia, it doesn’t always and many people have amblyopia without an eye turn. Confused yet? What is amblyopia then? Officially it is decreased vision, even with glasses on, without any other disease or health problem being present. To really understand amblyopia though we need to know where it comes from. Remember that when we are born we don’t see perfectly well! In fact our eyes develop and learn how to see from the time we’re born until we are about eight years old.

There are two types of amblyopia. One type is called refractive  (meaning related to the prescription) the other type is called strabismic (meaning that there is an eye turn). The prescription related type of amblyopia is almost always caused by either very high amounts of farsightedness or very high amounts of astigmatism that have not been corrected with glasses. Sometimes this will happen in only one eye but it will often happen in both. The problem is that if you have a very large amount of farsightedness or astigmatism it’s not possible to see well at any distance.  Strabismic amblyopia occurs when an eye is always turned out or turned in. Since that eye is always off to the side our brain edits out any images from it and it doesn’t get used. This is a great example of use it or lose it! Remember that when we are young our eyes are still learning how to see. If during that time, when we are learning how to see, our eyes never have a clear image (or just isn't used!) we never develop the ability to see as well as we should. To put it another way imagine you had two potted flowers. One flower you diligently watered and fertilized every day but the other flower you more or less ignored. Even if they started out with the same potential the flower that got taken care of would thrive while the other would wither away. Eyes are obviously not exactly the same but an eye that gets daily stimulation with sharp clear images will learn and develop much better than an eye that doesn’t.

So what do we do about it? I'll cover how we treat amblyopia in my next blog! Until then if you want to read more feel free to check out the following links or as always contact us on Twitter, Facebook, Google + or via our website or phone us at (403) 474-6744.

Doctors of Optometry Canada - Amblyopia

Mayo Clinic - Amblyopia

Cataracts: They're not what you might think they are!

Often when I talk with my patients about cataracts they’re very unclear about what a cataract really is! Lots of people seem to think it’s something affecting the front of the eye and can be peeled off. Others think it can just be lasered off. Others think cataracts only happen in older people. None of these things are strictly true. Cataracts are one of the most common eye disorders in the world and so of course lots of myths have sprung up around them. Let’s figure out what cataracts are, who they affect and what you can do to prevent or treat them.

To fully understand cataracts you need to know a very little bit about the anatomy of the eye. The biggest thing to absorb here is that the pupil, the dark central part of your eye, is not an actual thing. The pupil is actually nothing! It’s just a hole. Behind that hole though is a very cool structure called the crystalline lens. The lens in your eye not only provides some of the focusing ability of your eye so you can see far away it also flexes and changes shape to allow you to see clearly when you look at things that are close to you as well. Overtime that lens can become cloudy. This prevents as much light from getting to your retina and also causes light to scatter. This leads to a combination of blurred vision and night glare. This is a cataract.

This is an example of an extremely dense cataract. They almost never get this bad in Canada as people usually seek treatment before their vision is this bad.

So now that we know what a cataract is, what causes it? There are actually a lot of different causes so today I’ll go over just a few. One of the most important causes of cataracts is exposure to UV light. Over the long term UV light causes the lens inside of our eye to cloud up. Your best protection against this is to wear sunglasses as much as possible when outside, even on cloudy days or as the sun is going up or down. Many people think there is a much lower risk of UV exposure when it’s cloudy or during sunrise or sunset but while the UV exposure is somewhat reduced UV is still getting through to your eyes and skin.

An impact or other types of injury (such as electric shock) can also cause cataracts in otherwise young and healthy people. The trauma to the eye and to the lens can cause the lens itself to rupture or crack. These cracks allow fluid to enter into the rigidly organized lens and allows a cataract to form. The most obvious way to prevent this is to protect yourself against injury! Wear safety glasses if you’re doing work where something might hit you in the eye and definitely while participating in sports like squash that carry a high risk of getting hit in the eye.

The last type of cataract I’ll go over today is congenital. Congenital is fancy word for ‘you’re born with it’. Roughly ⅓ of congenital cataracts are genetic, ⅓  are caused by a disorder or disease and ⅓ are idiopathic… another fancy word that means we don’t really know where they come from. Hospitals do typically check newborns to make sure they don’t have an obvious or significant congenital cataract that requires treatment . That said I have a lot of patients that have minor congenital cataracts that aren’t really an issue but they had no idea were there.

So cataracts are inside the eye and are the clouding of the lens behind our pupil. They can affect anyone from newborns to seniors depending on a lot of different factors. These facts probably fly in the face of what you thought cataracts really were! The good news is that cataracts can be easily removed with a relatively quick and easy surgery. That’s a topic for another blog though! For now, if you have any questions you can always contact us on Twitter, Facebook, Google + or via our website. For more information check out the following links.

Doctors of Optometry Canada - Cataracts

CNIB - Cataracts

Psychedelic, surreal, multi-coloured shapes in my vision!

Alberta is a land of ups and downs when it comes to weather (you may have noticed this recently with our ‘spring’ weather). +20C in December? -10C in July? -40C on Tuesday and +20C on Wednesday? These are just normal weather patterns here and as anyone who gets migraines can tell you it’s not fun. The wild temperature swings wreak havoc on our systems and can cause some funny things to happen.

You’re busy doing your thing when suddenly your vision goes a little funny. You may notice shapes or colours or motion in your vision, not right in the middle but just off to the side. The effect may get larger or smaller. It may move faster or slower or not at all. Sections of your vision may simply vanish and go dark or you may still be able to ‘see’ but things you know should be there just aren’t visible to you anymore (like whatever is supposed to be there pulled a chameleon on you and has become invisible). You may have never had this happen but if these symptoms sound familiar you’re not alone. If you had this happen and didn’t panic at least a little I’m impressed. I’m an optometrist and when this happened to me even though I fully recognized my symptoms and knew what was happening my heart rate bumped up a few notches. This event is known as an ocular migraine.

I know what you're thinking... what the heck did I eat? No, you aren't having a psychedelic trip, this is an example of an ocular migraine. Everyone experiences them differently though so if yours doesn't look exactly like this don't panic.

The term ocular migraine implies that you should get a headache afterwards. That’s not always the case. Some people do have migraine headaches after seeing these images in their vision but not everyone. You may have heard of people getting an aura that tells them they’re about to get a migraine. That’s essentially what this is. Auras or 'ocular migraines' usually last about 20 minutes and are followed by a return to normal vision and depending on the person a headache, a migraine, or absolutely no pain.

So, what the heck is going on? It’s not certain but what is believed to happen is that for some reason the blood vessels in the visual cortex (the very back of your brain… about as far from your eyes as you can get and still be in your head) shrink way down and not as much blood is getting through as before. This lack of blood flow means your brain can’t function the way it would like and you start to experience really bizarre things in your vision. It takes your brain, usually, about 20 minutes to figure out this isn’t normal at which point the blood vessels do one of two things. They either return to their normal size, blood flow returns to normal levels and you stop feeling like you ate a brownie you shouldn’t have OR the blood vessels expand to their maximum size stretching themselves to be as big as they can. It’s that extreme stretch that causes the horrible pain people experience with migraines. In some cases the vision changes can last longer than 20 minutes. This usually occurs if someone completely panics causing an adrenaline surge. The resulting stress levels can cause the visual changes to linger for about an hour.

Here’s the real kicker. There’s not much you can do about this. We think that all those blood vessel antics are caused by the same things that cause migraines… so, almost anything (certain smells or foods, weather patterns, stress, lack of sleep. The list goes on and on). Migraine medication can be helpful if a person is getting ocular migraines all the time and it’s seriously interfering with their life but otherwise we just recommend that a person sit back and enjoy the show for 20 minutes.  If you’re driving it is strongly recommended to pull over and wait it out. These vision changes are temporary and do not cause any damage to your eyes or your brain.

So rest assured that if you have been properly diagnosed with an ocular migraine your eyes are safe and sound. I would love to leave it at that but there is one more thing. Not all flashes in your eyes are harmless. Retinal holes, tears and detachments can cause symptoms including flashing lights in your vision, floaters and a curtain moving in and out of your vision. These flashes do not go away in 20 minutes and generally are noticed at the very edge of your vision. Retinal detachments are extremely serious and cause permanent loss of vision. If you experience flashing lights in your vision of any kind it is best to have it properly checked by an optometrist.  These visits are considered medically necessary and are fully covered by Alberta Health Care. I would advise against taking a risk. If you see flashing let an optometrist have a look at your retina to confirm everything is normal.

For more information feel free to contact us on Twitter, Facebook, Google +, via our website, phone us at (403) 474-6744 or come in anytime. You can also read more at the links below.

All About Vision - Ocular Migraine

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