What causes macular degeneration
Quick answer: Macular degeneration is usually caused by a mix of ageing changes in the retina (macula) plus risk factors like family history, smoking, high blood pressure, and long term oxidative stress. You cannot control age or genetics, but you can reduce risk by not smoking, managing heart health, eating a nutrient dense diet, protecting your eyes from UV, and getting regular eye checks.
Key takeaways
- Most cases are age related and develop slowly over years.
- Genes matter, but lifestyle factors can shift your risk up or down.
- Smoking is one of the strongest modifiable risk factors.
- Early detection matters, especially if you notice distortion or a new blurry patch in central vision.
If you are exploring nutrition for eye health, our Eyes collection and Top Vision Support collection can help you compare options. Supplements are not a cure, so we recommend using them as part of a broader plan with your optometrist or GP.
What macular degeneration is
Macular degeneration, often called age related macular degeneration (AMD), affects the macula, the central part of the retina that helps you see fine detail. It can make reading, driving, and recognising faces harder, while side vision often stays clearer.
There are two main types:
- Dry AMD (more common): gradual thinning and build up of deposits called drusen.
- Wet AMD (less common): abnormal blood vessels grow and leak, which can damage central vision faster.
Main causes and risk factors
Ageing changes in the retina
The most common driver is ageing. Over time, the retina can become less efficient at clearing waste products, and the protective layer under the retina (retinal pigment epithelium) can weaken. Drusen can accumulate and the macula can thin, which contributes to dry AMD.
Family history and genetics
Macular degeneration often runs in families. Certain gene variants are linked with higher risk, especially genes involved in inflammation and how the body handles oxidative stress. If a parent or sibling has AMD, your risk is higher, so regular eye checks become even more important.
Smoking
Smoking increases oxidative stress and reduces blood flow to the retina. It is consistently linked with higher risk of developing AMD and faster progression. If there is one change we prioritise, it is quitting smoking or getting support to quit.
Cardiovascular health
High blood pressure, high cholesterol, diabetes, and a history of cardiovascular disease can increase AMD risk. The retina is very sensitive to changes in blood supply. Managing these conditions with your healthcare team supports both eye health and overall wellbeing.
Diet patterns and nutrient intake
Diets low in colourful vegetables, omega 3 rich foods, and antioxidant nutrients may be associated with higher risk. Nutrients often discussed for macular support include lutein, zeaxanthin, vitamin C, vitamin E, zinc, and copper. For people with intermediate AMD, some clinicians recommend an AREDS2 style supplement based on clinical trial evidence. It is not usually recommended as a preventive supplement for everyone.
Body weight and physical activity
Carrying excess weight and being inactive can worsen cardiovascular risk factors that influence retinal health. Even modest increases in activity can be a helpful part of a prevention plan.
Light exposure and eye protection
UV exposure can contribute to cumulative eye damage. Wearing sunglasses that block UV and a brimmed hat in strong sun is a simple habit, especially in New Zealand where UV levels can be high.
Other factors your optometrist may consider
- Previous eye conditions and inflammation
- Ethnicity and iris colour (risk patterns vary)
- Certain medications and overall health history
What to do next if you are worried
If you are coordinating care for a parent or family member, focus on three practical steps: identify symptoms early, book an eye assessment, and reduce risk factors that are changeable.
- Know the symptoms: learn common signs in our guide to macular degeneration symptoms.
- Book an eye check: an optometrist can examine the retina and may do retinal imaging or OCT scans.
- Ask about stage and options: treatment differs for dry vs wet, and supplements are most relevant for specific stages.
Can supplements help
Supplements cannot reverse macular degeneration, but some evidence supports specific formulas for slowing progression in people with intermediate AMD or advanced AMD in one eye. The best known is the AREDS2 formula. Because needs vary, we recommend discussing supplements with an eye care professional, especially if the person takes blood thinners, has kidney issues, or is on multiple medicines.
To compare common options, see our article on best supplements for macular degeneration.
FAQs
What are the early signs of macular degeneration?
Early signs can be subtle. People may notice straight lines looking wavy, difficulty reading small print, needing brighter light, colours looking dull, or a blurry or blank spot in central vision.
What causes macular degeneration?
It is usually caused by ageing changes in the retina plus a mix of risk factors such as family history, smoking, cardiovascular health, and long term oxidative stress. Wet AMD is caused by abnormal blood vessels growing under the retina and leaking.
How is macular degeneration diagnosed?
An optometrist or ophthalmologist can diagnose AMD with an eye exam, retinal photos, and often optical coherence tomography (OCT). They may also use an Amsler grid to check for distortion and may refer urgently if wet AMD is suspected.
Can macular degeneration be treated or slowed down?
Wet AMD is often treated with prescription eye injections that target abnormal blood vessels. Dry AMD is managed with monitoring, risk reduction, and in some cases an AREDS2 style supplement for appropriate stages. Your clinician will advise what fits the person’s stage and health profile.
When should you see an optometrist or GP for macular degeneration?
Book an eye check if you have risk factors or any new change in central vision. Seek urgent assessment if straight lines suddenly look wavy, a dark patch appears in the centre, or vision worsens quickly, as these can be signs of wet AMD.
Next steps
- Macular degeneration NZ guide
- Macular Degeneration Symptoms: Early Signs and When to Get Help in NZ
- Dry vs wet macular degeneration: key differences
- Macular degeneration treatment options: what to know
- Best Supplements for Macular Degeneration (NZ Guide)
