A look at cataracts
As we grow older, we are more likely to develop cataracts. A cataract is a clouding that appears on the lens of the eye, leading to a loss in vision. Cataracts can vary in size and thus in the effect they have on vision. They can occur at any age, although they most commonly affect vision in people over the age of 60.
No one is sure the exact cause of cataracts. What is known is that they result from a changing chemical balance in the lens of the eye – the part of the eye that sends light to the retina at the back of the eye. When the lens becomes cloudy, it becomes difficult to see properly. Advancing age, eye injuries, some diseases (e.g., diabetes), certain medications, smoking, and a family history of cataracts are all believed to play a role in the development of this condition.
Cataracts do not spread from one eye to the other – a cataract in one eye will not cause a cataract in the other. Unfortunately, though, cataracts often develop in both eyes at the same time – although they may progress at different rates.
If you have cataracts, it may take years before they significantly impede your vision. Until then, your eye specialist will likely continue to change the prescription of your eyewear to help you maximize your vision. At a certain stage, though, further treatment will be needed. The only effective option at that point is to have surgery to remove the cloudy lens and have a new artificial one implanted.
Cataract surgery is done on an outpatient basis (i.e., no stay in the hospital) and eye surgeons consider it a fairly straightforward procedure. During surgery, local anesthetic is used so you will be awake for procedure, although you won't feel any pain. Afterwards, over-the-counter pain relievers and prescription eye drops are usually enough to help you through the recovery period.
As with any operation, cataract surgery carries some risk - but the good news is that the success rate is high: 95% of people enjoy improved vision afterwards. Often, you may still need glasses to read or see objects up close, but your distance vision may be much better on its own. About 4 weeks after surgery, your eye specialist will examine your eyes and give you a new prescription for new glasses - and a new lease on sight!
Keeping an eye on macular degeneration
Macular degeneration is the leading cause of vision loss in North America for those over the age of 50. While this disease can develop at any age, it is a common part of the aging process, where it is referred to as "age-related macular degeneration," or AMD.
Macular degeneration occurs as the macula deteriorates. The macula is near the centre of the retina (the tissue at the back of the eye that is sensitive to light) and is what allows us to distinguish colour and make out fine detail. As the macula degenerates, a small spot or blurriness appears in the middle of the field of vision, which makes it difficult to see clearly. Over time, this obstruction may increase in size, effectively blocking the view of objects directly in front of the person. While the peripheral vision (the vision off to the side) usually remains intact, some activities that may have been once taken for granted, such as reading, hobbies, sports, or even recognizing the face of a loved one, may no longer be possible.
AMD takes 2 forms, referred to as "dry" and "wet." The dry form accounts for about 90% of cases; it progresses at a gradual pace as the tissue of the retina slowly becomes damaged. The wet form is more severe and involves leakage from blood vessels into the retina, leading to damage and, in turn, rapid loss of vision.
If you have a family history of AMD, speak to your ophthalmologist about your chances of having inherited this condition. Additional risk factors include smoking, damage from ultraviolet light (e.g., the sun's rays), eye injuries or infections, high blood pressure, diabetes, and hardening of the arteries in the eye.
There is no "wonder cure" for AMD. As with many diseases, early detection plays a key role in the success of treatment – so be sure to have regular eye examinations with your eye care professional. While certain vitamin combinations, such as those containing beta-carotene, vitamins C and E, zinc, leutine, zeaxanthin, and omega-3 fatty acids, are known to delay the progression of dry AMD, they cannot stop it completely nor reverse any damage already done. Wet AMD can often be treated through a procedure called photodynamic therapy, which involves injecting a dye and shining an infrared light on the macula to help stop the blood vessels from leaking fluids. This can help restore some vision. Laser surgery is another option. Researchers working on new medications hope that one day these can counter this degenerative disease.
To learn about coping with loss of vision and maximizing the use of remaining peripheral vision, contact the Canadian National Institute for the Blind (CNIB). Or ask your eye care professional to refer you to special resources in your area. While vision loss can lead to feelings of isolation, keep in mind that macular degeneration is a common condition and plenty of help and support is available.
The laser's edge
For more than 2 decades, laser eye surgery has offered many Canadians a chance to walk away from their glasses and contact lenses. Is it right for you?
Laser eye surgery can correct common vision problems such as nearsightedness (myopia), farsightedness (hyperopia), and astigmatism (where an irregular shape of the cornea [the front surface of the eye] makes it difficult for the eye to focus). It is now also being used to help with presbyopia, the inability to focus on objects that are nearby, which a part of aging and is normally corrected with reading glasses.
Canadians can now choose between 4 types of laser eye surgery to correct their vision:
- Photo-refractive keratectomy (PRK) involves using a laser to burn away small amounts of tissue under the surface of the cornea in order to change the shape of the cornea (the front surface of the eye). This change in shape helps you to see better.
- Laser-assisted in situ keratomileusis (LASIK) involves making a small incision (cut) through the surface of the cornea (creating a "flap") so that the surgeons can reach tissues below it. Small amounts of tissue are removed using a laser to burn away the tissue. The flap is placed back over the cornea, and the cornea heals readily afterwards.
- Laser epithelial keratomileusis (LASEK) is a variation of PRK and LASIK that involves making cuts to the outer layer of the cornea so that a laser can burn away small amounts of tissue under the surface of the cornea.
- Epi-LASIK is modified version of LASEK that uses a mechanical device to remove the outer layer of the cornea.
While surgery to the eye sounds painful and may make you feel squeamish, it is in fact a fairly painless operation, and does not require a trip to the hospital. It is performed in special clinics by trained specialists, and the eyes heal quickly afterwards, although you may experience some initial blurry vision (particularly after the PRK and LASEK procedures). The LASEK procedure shares some of the concerns associated with both PRK and LASIK. The risk of infection is low.
While many people find that laser eye surgery corrects their vision to their satisfaction, sometimes it's necessary to return for a follow-up procedure to further correct your vision. This is more common after the PRK and LASEK surgery than after LASIK. And it's possible that you may still need to wear glasses or contacts. This is more likely if your eyes didn't respond well to the surgery (i.e., they reverted to their original condition). It may also be the result of inevitable factors such as vision changes due to aging.
If you're interested in laser eye surgery, make an appointment with an ophthalmologist (medical doctor who specializes in eye and vision care). Based on your individual case, they can recommend whether or not your vision problems could be corrected by laser eye surgery. As with any operation, there are always risks involved (the risk of serious complications is higher with LASIK surgery, as it involves cutting into the cornea), so make sure you ask your doctor any questions you have. And keep in mind that your health benefit plan may not cover this procedure, so there may be financial considerations as well.
Many Canadians opt to wear contact lenses instead of glasses. Contacts offer many benefits: they don't slide down your nose or fog up in winter, they don't bounce up and down while you play sports, and they're less obvious than glasses. Just remember to remove your contacts and wear glasses if you suffer from any eye irritations or suspected infections. While your eye specialist can best recommend which types are suitable for you, here's a look at what's available, and what you should keep in mind.
Soft contact lenses: These are the choice of most contact lens wearers. Soft contacts are made of a type of plastic that contains a high amount of water, which allows oxygen to pass through to the eye. However, as they are so porous, these lenses are also more prone to infection than hard lenses. Soft contact lenses need to be taken out at night and disinfected.
Hard contact lenses: These are made of a more rigid type of plastic than soft lenses, and therefore many people find them less comfortable. Nevertheless, due to their "hard" nature, they are not as fragile as soft lenses and are easier to keep clean. Hard lenses reduce the amount of oxygen that would otherwise reach your eyes, and so they must be taken out at night (and cleaned) to keep your eyes happy and healthy.
Rigid gas-permeable lenses: This is a type of hard contact lens that allows more oxygen to the eye than regular hard lenses. If you have astigmatism (a condition where the front surface of the eye [cornea] is irregularly shaped, making it difficult to focus), your eye specialist may recommend this option.
Extended-wear lenses: These are special lenses (either soft or rigid gas permeable) that have been designed to be worn for many consecutive days without having to take them out at night. Do not attempt to wear your regular contact lenses in this fashion. While these extended-wear lenses offer certain conveniences (e.g., less cleaning), they have been associated with an increase in eye problems such as infections of the cornea, so be sure to discuss the benefits and risks with your eye doctor.
Disposable lenses: Disposable lenses are lenses that are designed to be thrown away after a certain amount of wear. This might be on a daily, weekly, or monthly basis, depending on the type your eye doctor recommends for you. These lenses are made of a thinner material than regular soft contact lenses and have a higher water content. Because they are thrown away and replaced regularly, they offer a lower risk of eye problems that can otherwise develop from a build-up of protein and lipid deposits on lenses. Unless you use the daily disposable lenses, these contacts still need to be taken out at night and cleaned.
Cosmetic lenses: Also known as "tinted" lenses, these contact lenses alter the appearance of the eye colour. These can look very natural and can make light-coloured eyes look darker or dark-coloured eyes look lighter. Several other interesting effects are also available. If you buy lenses that are made purely for cosmetic reasons and do not correct your vision, you do not need a prescription to purchase them in Canada. Prescription contact lenses with tints are also available. Consult your local optical store for more details.