How does age-related macular degeneration (ARMD) develop?
- The retina is a thin tissue that lines the inside of our eyes and creates the images that we see. The macula is a special part of the retina that creates the central vision (what we see when we look directly at something). The retina is supplied with nutrients and oxygen by blood vessels which act as a transport system between the eye and the rest of the body. These blood vessels are also responsible for getting rid of the waste that builds up in the retina. Sometimes this waste material can get caught between the cells (building blocks) of the retina and the blood vessels. When this happens the cells of the macula can become starved of nutrients, unable to breath and unable to get rid of their waste. This is essentially the way dry macular degeneration develops.
- The cells of the retina may start an emergency procedure to help with the lack of oxygen. They release factors to begin building new blood vessels. Unfortunately these blood vessels are not constructed very well and leak blood into the eye. This bleeding can get out of control and cause significant damage inside the eye. This is the way wet macular degeneration develops.
What are the types of macular degeneration?
- Dry ARMD – slower progressing form of the disease, can cause distortion of vision and potentially severe vision loss, gradually over many years. May also progress to wet ARMD in some cases.
- Wet ARMD – faster progressing form of the disease, similar symptoms as dry ARMD but can progress much more quickly to vision loss (sometimes over a period of days). This needs to be managed by an ophthalmologist but can be very treatable if diagnosed and sent to an ophthalmologist in time.
What are the symptoms?
- In the early stages can cause no noticeable symptoms at all
- distortion of vision (a telephone pole will look wavy instead of straight)
- loss of vision
Factors that put you are risk for macular degeneration:
- family history
- older age
- white skin colour
- lighter coloured irides (blue eyes)
- history of vascular disease
What can be done to manage ARMD?
- there is no cure for either form of the disease
- those that are not diagnosed with ARMD but have risk factors need to be monitored on a regular basis to ensure they don’t develop signs of the disease (everyone can benefit from regular eye exams, even those without risk factors!)
- those diagnosed with dry ARMD can be treated with specific lifestyle changes and medications to reduce the risk of progression to vision loss
- those diagnosed with wet ARMD need to be monitored by an ophthalmologist in conjunction with an optometrist and may require injection of medication into the eye (which is surprisingly easy and comfortable)
- OCT is a hugely beneficial and easy way of imaging the macula and central retina for the diagnosing and monitoring of ARMD. Pierce Family vision offers OCT service, ask your optometrist if you can benefit from this test at your next eye appointment
Dr. Tristan Faria