AMD glossary for health practitioners and patients

Dry AMD (non-exudative / early AMD)

This is the more common type of AMD. It develops when waste products build up under the macula, and the cells that support central vision (the retinal pigment epithelium, or RPE) gradually get weaker. Vision loss is usually slow and mild at first, with most people initially having near-normal sight or only slight changes. It’s a steadily progressive condition, and over 5 years, 20% of patients with dry AMD develop wet AMD.

Wet AMD (neovascular / exudative / nAMD)

This type of the disease is less common but more serious. Abnormal, fragile blood vessels grow under the macula (choroidal neovascularisation), which can leak fluid or blood. This can lead to macular scarring and subsequent central vision loss. The treatment is focused on stopping choroidal neovascularisation to prevent permanent damage to the eye and putting the condition back to its dry form which would still progressing in the background and needing monitoring.

Choroidal neovascularisation (CNV)

This is the process of abnormal blood vessels growth under the retina in Wet AMD. These vessels are fragile and can leak fluid or bleed, which blurs or distorts central vision.

Retinal scarring

If wet AMD isn’t treated, the abnormal blood vessels can leave scar tissue in the macula. This scarring can cause permanent loss of central vision.

Macula

Macula is the central part of the retina - the light-sensitive layer at the back of the eye. It’s responsible for sharp, detailed central vision, which is essential for reading, recognising faces, driving, or looking at things straight ahead. In AMD, the macula is the area that gets damaged first, which is why people notice changes in their central vision before their side (peripheral) vision is affected.

Fovea

The fovea is a tiny spot in the very centre of the macula. It is responsible for the clearest, most detailed vision, like the focus of a camera lens. Because it’s so critical for high-definition vision, any damage to the fovea from AMD can have a big impact on everyday activities that require sharp central sight. AMD treatment is focused on protecting or stabilising the fovea so that central vision is preserved for as long as possible.

Fundus

The fundus of the eye  refers to the back of the eye, including the retina and blood vessels. During an eye exam, the fundus is checked for signs of AMD, such as drusen or pigment changes.

Retinal pigment epithelium (RPE)

The RPE is a layer of cells that works like a maintenance team for the retina, keeping it healthy and nourished. In AMD, these cells start to wear down, which can affect central vision.

Drusen

Drusen are tiny yellow or white waste product deposits which develop in the layers of the outer part of the retina. Drusen trap moisture thus affecting the normal nourishment and health of the retinal pigment epithelium. Finding drusen is one of the earliest signs of AMD.

VEGF (Vascular Endothelial Growth Factor)

VEGF is a natural protein that helps blood vessels grow. In wet AMD there’s too much VEGF, which causes abnormal blood vessels to form. Treatments aim to balance VEGF -enough for healthy eye function but not so much that it damages vision.

Anti-VEGF treatments

These medications are injected directly into the eye to block excess VEGF. They stop abnormal blood vessels from growing and leaking, helping to preserve central vision. Patients usually receive a series of injections over time.

Photodynamic therapy (PDT)

PTD is a treatment used for some types of wet age-related macular degeneration (AMD), often in combination with the anti-VEGF injections. PDT involves getting a light-sensitive drug into the patient’s bloodstream and activating it by a low-energy laser to close leaking blood vessels in the retina, slowing vision loss.

Treat & extend protocol

This is a way of scheduling anti-VEGF injections. At first, injections are given regularly to control the disease. If the treated eyes remain stable, the time between injections is gradually extended to reduce patient visits while keeping the vision safe.