Showing posts with label Retina. Show all posts
Showing posts with label Retina. Show all posts

Thursday, January 29, 2015

The eye examination photo series - Part 1

We are always looking for new ways to share what we do at Ocean through our social media.  To kick off 2015 with a blend of style and information, one of our optometrists and owners, Dr. John Wilson, decided to create a series of Instagram images showing the eye examination in 10 steps.

We've already talked about what a comprehensive eye examination involves (see blog here), bringing it to life with pictures is lets us share it in a whole new fashion!  Great thinking, John.

Let's take a look at the pictures and give a little more detail as to what is going on.  This first series of pictures involves the steps that go together for our preliminary assessments.

Auto-refractor/keratometer
This machine may appear a little scary, however, there's really nothing to it.  We get you all lined up, one eye at a time, so that you see a picture.  The picture helps the eye to focus into the far distance, so usually they have images with items on the horizon, like hot air balloons or houses.  Once it is completely aligned you may see the image go in and out of focus as the instrument goes through a series of steps to gain a complete reading.

The information the instrument provides is an estimate of the focus of the eye and a measurement of the curvature of the front surface of the cornea.

The next instrument, the tonometer, is perhaps the one most people have concern over.  The tonometer measures the pressure of the fluid in the eye using a gentle puff of air.  It is definitely not sore or uncomfortable, however, our natural reflexes make the air-puff seem like quite the surprise.

Non-contact tonometer

It is important for us to measure the pressure of the eyes as part of providing a comprehensive assessment of the overall eye health.  For those that are really squeamish, however, we do have another technique for assessing eye pressure - just let us know.

The last of the trio of instruments used in our preliminary assessments is the digital fundus camera.

Digital Fundus Camera

This last step is very straightforward, just keep looking straight at the flashing light, keep your eyes nice and wide open and we'll take photographs of your retinas.  These pictures provide a great way to both initially  view the retina and also to monitor the health of the retina over time.

At each eye examination we can compare the newest retinal photographs with previous ones on file, either side-by-side or even overlaying them one on top of the other.  We also have filters and effects which can be used to enhance the images to assist with interpretation.

One last great feature of taking retinal images, that we love, is that it gives our optometrists the ability to show you exactly what they are looking at when they are examining the back of your eyes.

If you have any questions about any of these steps during the eye examination, do not hesitate to ask.  Both Dr. John Wilson and Dr. Euan McGinty are very keen to make sure that you have an excellent experience when you come in to Ocean Optometry.  Taking time during their eye examinations is definitely something that they will do.

If you are reading our blog and thinking, "Hey, I need an eye exam." then we would be honoured to take good care of your eyes.  You can call us directly on (902) 446-4470 or use this link.

To check out our Instagram feed, just click on the logo!

 @OceanOptometry Instagram
Ocean's Instagram

Thursday, December 18, 2014

'Tis the season!

Seasonally named eye conditions!

We're sure that you've come to recognise our optometrists, Dr. Euan McGinty and Dr. John Wilson, are eye geeks through and through.  So for this holiday season, our eye guys thought they'd share some seasonal naming quirks for eye conditions!

All of these are real eye conditions ... well ... almost all, for a bit of Christmas fun we're throwing in a fake one - let's see if you can pick out the fake one.

1- Christmas Tree Cataract

Usually cataracts are a haziness or discolouration of the natural lens inside the eye, which sits just
Christmas Tree Cataract - (image Medscape)
behind the iris.  They can look foggy or smokey to look at and can cause a similar effect on our vision.  Christmas Tree Cataracts are slightly different, this cataract tends to form highly reflective particles in the eye, which significantly bend the light or refract it.  These refractive and reflective properties give the cataract a highly coloured, iridescent and sparkly appearance which is where it gets its name from.

Similar to other cataracts, we would monitor this for its affect on your vision and look for associations with medical conditions.  While it is very pretty to look at, its affect on your vision would depend upon how significant it was in size and its location in the lens.

2 - Frosted Angiitis

This uncommon condition gives an distinct appearance to the blood vessels at the back of the eye and can unfortunately lead to significant degradation in the quality of vision.  Perhaps due to its rareness, the cause can sometimes be a mystery (idiopathic); however it is thought to be associated with an immune response from the body.

Frosted blood vessel appearance

3 - Rudolph Vasculature

A normal and healthy eye, which has a slightly unusual presentation in the blood vessels entering and
Classic Rudolph Vasculature presentation
leaving the optic disc at the back of the eye.  The optic disc is the natural blind spot at the back of the eye, where there are no light receptor cells.  At this point the optic nerve leaves the eye to carry the nerve pulse signals to the brain and where the blood vessels enter and leave the eye.

In Rudolph Vasculature the blood vessels all leave going upwards, giving the appearance likened to the antlers of a reindeer, and due to the twisting of the blood vessels there appears to be a "red nose" in the center of the optic nerve.  No known side effects are associated with this condition.

4 - Snowball Vitreous Floaters

Snowball floaters (bottom-left) - (image Optos.com)
Floaters are not an uncommon finding and often we can be aware of them in particular lighting conditions or against blank backgrounds - a white wall or a blue sky.  As floaters can also be a sign of activity in the eye, they definitely should not be ignored and if you experience new floaters always arrange an appointment for assessment without delay.

Snowball floaters are usually inflammatory cells, which are white in appearance, and occur in a condition called Pars Planitis.  The presence of floaters may actually be the only symptom of this condition, which is generally benign and may only cause a small effect on vision, if at all.

5 - Macular Star

Macular Star (yellow star to the right) - (photo EyeWiki)
The macula is the central part of the retina, which is the most sensitive area responsible for fine detail and colour vision.  When we talk about seeing 20/20 vision, it is this part of the retina which is working for us.

A Macular Star forms due to leakage of lipid rich fluid leaking from the blood vessels into the tissues of the retina, often forming a classic star pattern around the macula. 

If seen, it is important to try to identify the cause, although sometimes the cause is unknown.  It can be related to hypertension or to nerve inflammation.  The nerve inflammation, when caused by infection, is most commonly related to cat-scratch disease.

Thankfully, for most of these conditions, they are quite rare to see!
This will be our last blog until 2015, we do hope you are enjoying them.

Many thanks to all our friends, followers, supporters, customers, patients who have made 2014 such a fantastic year for Ocean Optometry - we can't wait for 2015!

Happy Holidays from all at Ocean!



Wednesday, January 15, 2014

The eye examination ... what do you see back there?

One of the greatest privileges of being an optometrist is to be able to look at our patient's eyes in great detail, including right through the pupil to the back of the eye.  The eye is an amazing organ with many intricate details which we routinely examine as part of our eye examinations and so often we take our sight for granted, but many may wonder what are we actually looking at back there when we examine the eyes.

Examining the eyes isn't as scary as some may think, especially given the popular myth in the late 19th and early 20th centuries that the eyes somehow recorded what we saw and that if you photographed the eyes of a dead person you could see the last thing they saw (http://en.wikipedia.org/wiki/Optography and http://www.college-optometrists.org/en/college/museyeum/online_exhibitions/eye/optography.cfm).  This popular concept was used as a plot device in some fiction of the time and was even employed as an investigative technique for some actual forensic investigations.

Our digital retinal camera
At Ocean Optometry we are pleased to include retinal photography as part of our standard comprehensive
eye examination* and we use a Nikon DSLR camera back mounted on a digital retinal camera to capture the images even before you see Dr McGinty or Dr Wilson.  These images are seamlessly integrated into your electronic health record at Ocean and will be reviewed with you by our doctors as part of your eye examination.

Here is an example of one of our digital images:

Digital Retinal Image - Right Eye

You can clearly see some very important structures in the eye, although on first glance it may resemble more the appearance of Mars or the Sun towards sunset.  The salmon pink colour of this photograph shows a nice healthy retina, with the blood vessels overlying the retina.  The lighter/thinner blood vessels are the arteries, which supply oxygenated and nutrient rich blood to the tissues.  The darker/thicker vessels are the veins which take the blood back to the heart.  The vessels branch out from a single point, with smaller and smaller branches, nicely resembling a tree in appearance.

In the lighter pink areas, almost yellow, the retina is light enough that the underlying blood vessel structure is visible.  This is from the white of the eye, right round at the back of the eye!

The point where the blood vessels enter and leave is also the point where the optic nerve leaves the eye to take the information to the brain about what we are seeing.  This is the optic nerve head or the optic disc and creates the natural blind spot in the eye which we all have.  Careful examination of the optic nerve head is very important to help to assess for the presence of glaucoma.  Using digital photographs as part of our eye examination allows for careful comparison in appearance of the optic nerve head between visits to help detect change over time.

Central in the picture is a darker area, called the macula.  The macula is the area of greatest sensitivity of the retina, it has the highest density of light receptive cone cells present, the highest density of pigment underlying the macula and has a very rich supply of nutrients provided through the underlying vessel structure.  Unfortunately, if this area is damaged the impact on our quality of vision can be significant and this is why regular assessment to look for signs of diseases such as Macular Degeneration is important.

One final feature we often get asked about when we are discussing the retinal images is "what is that bump/lump in the top right corner?".  This is a historical feature in retinal photographs and is always in the top right corner as a way of saying "This way up!".  Prior to digital photography, retinal photographs relied upon either 35mm slide film of polaroid film to capture the images, once printed a photograph could be rotated and with slide, flipped even, which could lead to confusion over the area of the eye you were looking at or if you were looking at a right or a left eye.  So don't worry about the bump, we want it to be there!

* There is a $25 co-pay for digital retinal photography for MSI paid eye examinations.
Quality ensured using our Nikon camera