Wednesday, November 24, 2010

Stye In My Eye

What is a Stye?
A stye is basically a blocked gland in the eyelid which becomes infected. Kind of like getting a pimple on the eyelid. Bacteria, skin cells, and oil can cause the blockage.

The medical term for a stye is Hordeolum. They tend to be painful and they can be either internal or external.

How are styes treated?
Simple therapy involves applying heat the affected area to express the gland and release the blocked material.
In more difficult cases, doctors may prescribe ointment and/or oral meds.
And in the some cases, minor surgery may be require to remove the stye.

How do you prevent styes?
Lid hygeine. Simple things such as warm compresses and gentle lid scrubs can help keep the eyelids clean and healthy.

To do this you simply warm up a cloth or towel with warm water and apply the heat to closed eyelids for 5 minutes. At the end of the 5 minutes use the warm towel to gently massage your eyelids and then lightly scrub at the eyelid margin to wipe away any debris.

Doing this on a daily basis will help prevent blockage and inflammation of the eyelid glands.

For patient who have Blepharitis (eyelid inflammation), it is important to do these warm compresses twice daily. Click here for more info on Blepharitis.
 
Thanks for reading. Please feel free to pass this information on to anyone who may find it useful.



Wednesday, November 10, 2010

Contact Lenses

They come in a variety of shapes, sizes, and colours...

Soft contact lenses (SCL):These are the most common and they are disposable.
  • This means that after wearing the lenses for a period of time, they are disposed of and a new, fresh pair is used
  • Lenses can be monthly (ex. Air Optix, Frequency 55, Proclear, Biofinity, etc), two week (Acuvue Oasys), and daily disposable (CIBA Dailies, Acuvue 1-day, etc)
  • Also available for astigmatism and patients over 40 who need reading glasses (more information in my post All Kinds of Blurry)
Daily disposable lenses are the healthier option for your eyes for the simple reason that a fresh, sterile lens is being used every single time. Most infections are a result of poor storage or lens care. A lot of these problems can be avoided with daily lenses.

Rigid Gas Permeable (RGP):AKA Hard lenses. Considered older technology but actually provide better optics, better oxygen flow, and less infections. Less popular simply because they are uncomfortable to begin with. But patients who get used to them, stick to them.

Hybrid Lenses:Combination of a hard lens with a soft "skirt". Supposed to provide superior vision of RGPs without being as uncomfortable. But, they haven't been as successful as expected.

Orthokeratology (Ortho-K):Contact lenses that are worn while you sleep. Over night, they flatten the cornea and temporarily correct near-sightedness. Also mentioned in my post Laser Eye Surgery.

Important things to REMEMBER:No matter how good a contact lens claims to be at allowing oxygen pass, or keeping your eyes hydrated, or preventing bacteria from sticking to it, at the end of the day it is still a piece of plastic in your eye.

Contact lenses are considered to be medical devices and, as such, should be looked at by a doctor before they are dispensed and any time the patient experiences any problems.

Three big NOs:
  • No sleeping
  • No swimming
  • No tap water
These are the quickest ways to cause infections which can be potentially vision threatening (see picture below).

Other uses:Contact lenses are not only used to improve vision. Here are a couple of other interesting uses:
  • Diabetic patients
    • Lens changes colour when sugar levels in tears increase
  • Bandage
    • Used to cover scratched corneas or after LASIK surgery
  • Administer drugs over long periods of time
  • Tracking eye movements in ocular studies
FAQ:
Q: Can I get coloured contact lenses even if I have no prescription?
A: Yes. But FYI, these lenses tend to be the least healthy for your eyes.

Q: How often should I replace my contact lens case?
A: Usually every 3 months or when your solution runs out. Whichever comes first.

Q: If I wear contact lenses, do I still need a pair of glasses?
A: Yes, you should always have a good pair of glasses to give your eyes a break and just in case something happens to the contacts.

Q: What if I'm on vacation and I forgot my contact lens solution and my contacts are bothering me and there isn't a pharmacy close by and my cousin says its no big deal, can I just store my contacts in tap water?
A: No. No tap water. Ever. I hope that is clear enough :)

Healthy Cornea

Acanthamoeba infection (from tap water)

Corneal Ulcer due to overwear

Tuesday, November 2, 2010

Lazy Eye

"Contrary to what some believe, a lazy eye is not one that doesn't like to wake up and go to work in the morning."
- Anonymous Eye Doctor with a sense of humour

The medical term for Lazy Eye is Amblyopia

So why do eyes become lazy?
  • The brain is very picky! When it is not receiving a clear image or if it is receiving double images, it begins to shut off connections to the eye that is causing it the most grief
  • This process usually happens during childhood and if it is caught before the age of 7, it can be reversed depending on how bad the situation is and how cooperative the patient is
There are two main situations in which this happens:
  • Eye turn
    • In this case, the patient probably has double vision so the brain will stop communicating with the eye that is turned in/out, which will stop the double vision
    • Sometimes surgery is needed to straighten the turned eye, other times simple wearing a patch over the good eye will help force the turned eye back
  • Difference in prescription
    • If there is a large difference and one eye is very blurry, the brain will again shut it off because it doesn't like dealing with two eyes producing different images
    • Glasses are the obvious answer. Sometimes a patch over the good eye will help force the blurry eye to work harder
As you can see a Lazy Eye problem actually becomes more of a Picky Brain problem.

And as the saying goes, "you can't teach an old dog new tricks".

So, once the brain has made all the connections it wants to make, it is very difficult to make it go back. This is why it is important to catch it early! (Before age 7 or 8)

After this cutoff, even providing a patient their full prescription may not improve their vision because no matter how clear the image is, it is not being sent to the brain.


FAQ:
Q: Can a person have 2 lazy eyes?
A: That is a fantastic question! And, yes. I recently blogged about a patient I had seen who had high astigmatism in both eyes. So the connections for both eyes were not fully formed during childhood due to blurry vision and at this point in her life, glasses did not help very much.

Q: What is astigmatism?
A: The answer to this can be found in am earlier post called "All Kinds of Blurry" along with info on other causes of blurry vision

Q: How early should kids have their eyes checked?
A: Both the Canadian and American Association of Optometrists recommend that children have their first eye exam at 6-12 months and again at age 3.

Thanks for reading. I hope this information was helpful. Please feel free to send me any questions or comments. And also pass this on to anyone who may find it useful.