What is Macular Degeneration?
Age-related Macular Degeneration (AMD) is the leading cause of blindness in the developed western world. Approximately 1 in 3 people over the age of 75 will suffer from mild AMD. AMD can be split into two main types: dry AMD and wet AMD.
Dry age-related macular degeneration (AMD) involves the slow deterioration of macula – the most sensitive area of the retina at the back of your eye. The macula is responsible for detailed vision, the ability to read, recognise faces and colour vision. As the cells of the macula slowly die off they are not renewed and this leads to slow loss of central vision. Damage to the macula will affect the central vision only, meaning someone with AMD may have perfect peripheral vision, seeing everything well except the very thing they are looking directly at.
The term dry does not suggest the sufferer has dry eyes. Dry eyes is a symptom or disease affecting ones tears. The term dry, in the case of AMD, simply describes macular disease in the absence of fluid. The presence of swelling, fluid or blood in the macula would suggest wet AMD.
The progression of dry AMD varies from person-to-person, but it generally develops slowly over many years. People often carry on as normal for many years despite dry AMD.
What are the symptoms of dry AMD?
The symptoms of dry AMD vary with the severity of the condition and will affect different people in different ways. Common symptoms include:
1. Gaps or dark spots (like a smudge on glasses) may appear in your vision, especially first thing in the morning.
2. Objects in front of you might change shape, size or colour or seem to move or disappear.
3. Colours can fade.
4. You may find bright light glaring and uncomfortable or find it difficult to adapt when moving from dark to light environments.
5. Words might disappear when you are reading.
6. Straight lines such as door frames and lampposts may appear distorted or bent.
Diagnosing dry AMD
We use our Zeiss Clarus 500 ultra-high-definition retinal camera to produce highly detailed true colour retinal images of the macula. Pictures can be compared year on year to look for subtle changes. We also use Optical Coherence Tomography (OCT) scans which create cross-sectional images of the retina and take highly detailed measurements of your macula. These measurements can be compared to what is normal for your age and also compared with previous measurements of your eye to detect even the most minute change in macular health. Fundus autofluorescence and macular pigment density analysis may also be used to complement the normal eye examination.
Treatment for dry AMD
There is currently no medical treatment available for dry AMD so you might not be referred to hospital, unless confirmation of the diagnosis is required or we feel you would benefit from a hospital low vision service. We offer a private low vision service in the practice. If your sight has worsened and you would like to be registered as sight impaired you will need a hospital appointment.
Disease progression of dry AMD
Around 10-15% of people with dry AMD go on to develop wet AMD. If you have dry AMD and notice a sudden change in your vision, it is important that you contact us immediately to be assessed. If we confirm the presence of wet AMD it is imperative that we refer you urgently via the macular fast-track referral service to a specialist macular ophthalmologist for treatment.