Macular Degeneration: Early Signs and What OCT Can Detect

Macular degeneration affects central vision, which is the vision you use for faces, reading, screens and driving. Peripheral vision is generally spared, so people rarely go completely blind, but the vision that is lost is the vision most people would least choose to lose.

It is age related, it is common beyond fifty, and its early stages are usually silent.

Dry and wet, and why the distinction matters

Dry macular degeneration accounts for the large majority of cases. Deposits called drusen accumulate under the retina and the tissue gradually thins. It progresses slowly, often over many years, and many people retain useful vision throughout.

Wet macular degeneration is far less common but far more aggressive. Abnormal blood vessels grow beneath the retina and leak, and vision can deteriorate over weeks rather than years.

That difference drives everything else. Dry disease is monitored. Wet disease is a matter of urgency, because injection treatments work considerably better before extensive damage has occurred.

What to watch for

The early stages usually produce nothing noticeable, which is why detection tends to happen at a routine examination.

Once symptoms do appear, the ones that matter are distortion and central disturbance. Straight lines that appear bent or wavy, a doorframe that kinks, a patch near the centre of vision that seems missing or smudged, difficulty recognising faces, or needing progressively more light to read.

Sudden distortion, or a sudden change in central vision, should be treated as urgent rather than monitored. That pattern is more typical of the wet form, and the treatment window is measured in weeks.

How it is detected and monitored

Examining the retina shows drusen and pigment changes. What examination alone cannot show is what is happening within the layers of the retina.

OCT imaging produces a cross sectional view of the macula at a resolution measured in microns, which reveals fluid, thickening and structural change well before they become visible any other way. It also produces a measurable baseline, so subsequent scans can be compared rather than judged by impression.

This is the single most useful tool in distinguishing stable dry disease from something beginning to convert, and that distinction determines whether you are reviewed in a year or referred this week.

On supplements, accurately

The AREDS 2 trial examined a specific combination of vitamins and minerals in people who already had intermediate or advanced macular degeneration in at least one eye.

Two things are commonly misstated about it. It did not show benefit for people with early or no macular degeneration, so it is not a preventive supplement for the general population. And it does not reverse existing damage. What it showed was a reduction in the risk of progression to advanced disease in a specific group.

One detail is worth knowing. The original AREDS formula contained beta carotene, which was associated with increased lung cancer risk in smokers and former smokers. AREDS 2 replaced it with lutein and zeaxanthin for that reason. If you smoke or have smoked, the formulation matters.

Whether a supplement is appropriate depends on which stage you are at, which is a question for your examination rather than the pharmacy shelf.

What else genuinely helps

Not smoking is the most powerful modifiable factor by a considerable margin.

Beyond that, the evidence supports sun protection, blood pressure control, and a diet weighted toward leafy greens and oily fish. None of these are dramatic individually, and all of them are worth doing.

Where to from here

Macular degeneration rewards early detection more than almost any other eye condition, because the treatments that exist work best before substantial damage.

At Noranda Optometrist we image the macula with OCT as part of examining adults, and we can tell you which stage you are at and what monitoring interval is appropriate. If you are over fifty, or have noticed any distortion in your central vision, that is worth having looked at.