Dr. Tammy Labreche on macular degeneration
What is macular degeneration?
Macular degeneration is a common eye disease that affects the retina – the light-sensitive area at the back of the eye. More specifically, it affects the macula, the central part of the retina. This is the part that is responsible for seeing what our vision is focused on, providing us with detailed vision.
By far most macular degeneration occurs in older people – in fact, the full name for the condition is age-related macular degeneration, or AMD. Juvenile macular degeneration, also called juvenile macular dystrophy, is far rarer and mainly affects teenagers. It has different hereditary causes that result in different patterns of disease. This article focuses on AMD.
There are two types of macular degeneration: dry and wet. In the dry form, there are deposits underneath the retina, called drusen, that cause blurry patches and distortions and can lead to blind spots in the vision. This form typically progresses at a slow rate; however, it can lead to wet macular degeneration, which can progress much faster.
Wet macular degeneration occurs when new blood vessels form underneath the retina. These new blood vessels can leak fluid or blood, leading to sudden vision changes such as blind spots appearing in your central vision.
Age-related macular degeneration is the leading cause of vision loss in older Canadians, affecting some 2.5 million Canadians, according to Fighting Blindness Canada.
Macular degeneration is caused by damage to the macular region of the retina. Ultimately, aging is the main cause of macular degeneration. Lifestyle choices and genetics influence how fast the disease develops and progresses.
Risk factors include cardiovascular disease, smoking and a family history of AMD. The condition also tends to affect women more than men and those with lighter colouring (pale skin, blue eyes) more often as well.
Macular degeneration doesn’t cause any symptoms in the early stages even though damage to the macula is already occurring. That’s why it’s so important to have regular eye exams.
As the disease progresses, symptoms might include:
- Blurry patches in your vision
- Overall blurriness in vision
- Distortions in lines that should be straight
- Alterations in colour perception
- Glare frequently bothers you
In late stages of macular degeneration, symptoms may include blind spots, dark spots or severe blurriness in central vision. While late-stage macular degeneration can cause vision loss that significantly affects patients’ ability to perform activities such as reading, driving or recognizing faces, it leaves peripheral vision intact and therefore doesn’t cause complete blindness.
Since there are usually no symptoms early in the progression of macular degeneration, regular eye exams are crucial to allow optometrists to catch AMD early and start treatment before the disease causes vision loss.
At these exams, your optometrist will dilate the pupil of your eye with eye drops, then look at the back of your eye to identify if there are waste deposits, called drusen, forming there. They may do imaging using optical coherence tomography (OCT) to get detailed images of the retina. This will help determine the stage of the disease and ultimately the treatment.
Leading a healthy lifestyle can slow down the progression of the dry form of macular degeneration. Treatment may therefore include:
- Vitamins and minerals – particularly vitamin C, vitamin E, lutein, zeaxanthin, zinc, copper and omega 3 fatty acids
- Maintaining a healthy diet rich in leafy greens, fruit and fish
- Quitting smoking
- Exercise to improve cardiovascular health
You will be asked to regularly self-monitor your vision by looking at an Amsler grid. If you notice any blurring, distortion or dark spots in the lines, see your optometrist immediately. The onset of symptoms such as these may indicate leaking fluid or blood in the retina.
As of recently, there are injections available to treat patients with advanced dry macular degeneration. For patients with the wet form of macular degeneration, injections have been available for longer. These injections, of drugs called anti-vascular endothelial growth factor (anti-VEGF), are aimed at preventing the overgrowth and leakage of blood vessels in the retina and can slow or stop vision loss. Injections for both the dry and wet forms have to be given regularly.
There is no way to reverse vision loss that has already occurred. However, there are ways to help patients cope with vision loss so they can lead full lives.
Low vision rehabilitation offers a holistic approach to addressing the areas in which vision loss has interfered with patients’ lives. Interventions might include:
- Environmental modifications such as changing lighting or layout in the home
- Assistive technology such as video magnifiers for reading or bioptic telescopes for driving (for eligible patients)
- Workplace assessments to help patients continue to succeed in their careers
- Counselling to help patients adjust to vision loss
- Referrals to community resources such as mobility assistance or support groups
Waterloo Eye Institute patients
If you’re over 65, OHIP will cover one major eye exam every 18 months and two follow-up assessments if you haven’t been diagnosed with any eligible eye conditions. If you’re under 65 and don’t have an eligible eye condition, a full eye exam costs $120 – note that all fees listed are as of February 2024 and are subject to change. There may be additional fees for some tests. For example, OCT imaging costs $75.
If you have been diagnosed with macular degeneration, OHIP covers one full eye exam a year and two follow-up visits regardless of age. However, your optometrist may recommend more frequent visits and perhaps additional imaging.
If you have the dry form, your optometrist may recommend dietary supplements at your own cost. Other lifestyle interventions, such as exercise and quitting smoking, may also require some investment.
If eye injections are needed, these are performed by ophthalmologists in Ontario, so we will refer you to an appropriate professional and coordinate your care with them. The visits and most injections are covered under OHIP.
If you have vision loss, the Low Vision Clinic at the George & Judy Woo Centre for Sight Enhancement will evaluate your remaining vision and recommend ways to help you maximize it. Because it’s an interdisciplinary clinic, you may see different professionals, such as a low vision optometrist, a counsellor, a high-tech assessor and a therapist who can help you learn to use assistive devices. One fee of $240 covers seeing all these different professionals.
If you need assistive devices, there may be different options to borrow (short term), lease or buy them. Our staff can help you apply to the provincial Assistive Devices Program for funding to buy devices, if applicable.
If you’re experiencing financial challenges, speak to our staff. You may be eligible for support under our Optometric Charitable Care Fund. For some people, public benefits (such as ODSP and OW) or private insurance programs may cover part or all the fees necessary for your care.
The University of Waterloo School of Optometry and Vision Science is ranked fifth worldwide in research output for schools of optometry. We have contributed to better understanding, diagnosing and treating macular degeneration in a variety of ways.
For example, our researchers have found non-invasive brain stimulation can help macular degeneration patients with vision loss read better using their peripheral vision. Research in this area is ongoing and, as of February 2024, we are recruiting patients with macular degeneration to participate in a study (at the link, scroll down for relevant content).
Our researchers are also working with colleagues at the Institute for Quantum Computing and the Hong Kong-based Centre for Eye and Vision Research on new, award-winning technology that uses quantum light beams to help diagnose macular degeneration at the earliest stages. A company to commercialize that technology, Incoherent Vision Inc., has been launched.
Other researchers at the School are working or have worked in areas related to macular degeneration, such as better understanding the cellular aging process in the eye and advancing ocular imaging.
Interested in participating in research? Check out our current studies recruiting participants.