Information
Editors
Age-Related Macular Degeneration (AMD)
Essentials
- Age-related macular degeneration (AMD or ARMD ) refers to degeneration of the area of high-acuity vision (macula) in the fundus of the eye, associated with aging.
- AMD is divided into dry and wet forms.
- The dry form progresses slowly over several years.
- The wet form may progress rapidly within days or weeks.
- In AMD, both distance and near vision deteriorate.
- Refer a patient with the suspected wet form of the disease for investigations and treatment by an ophthalmologist within 1-7 days.
Epidemiology
- AMD is the most common cause of visual impairment in patients aged over 65 years in industrialized countries.
- According to an estimate, there were almost 200 million people worldwide with 2020, increasing in 2040 to 288 million people http://pubmed.ncbi.nlm.nih.gov/25104651/.
- In Finland, the number of patients with AMD is estimated to exceed 100 000.
- AMD represents about 40% of all cases of visual impairment entered in The Finnish Register of Visual Impairment.
- In people over 65, AMD accounts for about 60% of all cases of visual impairment, and about half of these are due to the wet form of the disease.
- About 10-20% of patients have the wet form of the disease.
Risk factors
- Age is the most important risk factor.
- AMD has certain risk factors in common with cardiovascular morbidity: hypertension, arteriosclerosis, hypercholesterolaemia, overweight, low level of physical activity, and an unhealthy diet.
- Eating fish, vegetables, berries and fruit is recommended to prevent AMD.
- Smoking is a risk factor for AMD, as well.
- Persons with AMD have been shown to have a genetic predisposition, most strongly associated with genes of the complement system.
Findings
Atrophic or dry form
- In the dry form of the disease, atrophy of the retinal pigment epithelium, pigment dispersion and drusen deposits can be seen.
Exudative or wet form
- The wet form of the disease is often preceded by the dry form.
- Pigment epithelial detachment and damage can be seen in wet AMD.
- Fragile, oozing new blood vessels grow from the choroid under the retina.
- Retinal bleeding and exudates are typical for the wet form of disease.
Symptoms
- Distortion of straight lines (metamorphopsia) or changes in image size (micropsia, macropsia); e.g. during reading, the size of the letters may vary and some letters may disappear.
- The patient may see a grey central patch or a part of the central vision may be lacking (relative or absolute scotoma), which makes it difficult to read or recognise people's faces.
- The patient may experience that her/his colour vision has changed (especially the colours blue and yellow).
- Both near and distance vision progressively deteriorate.
Diagnosis
- The diagnosis is based on patient history, visual acuity, manual ophthalmoscopy or biomicroscopy and optical coherence tomography (OCT) or optical coherence tomography angiography (OCT-A).
- In the case of differential diagnostic problems, fluorescein angiography (FAG) or indocyanine green angiography (ICG) may be used.
- Diseases to be considered in differential diagnosis include myopic retinal degeneration, central serous chorioretinopathy, inflammatory processes, diabetic retinopathy, vascular occlusions and vascular structural changes, tumours and hereditary degenerative diseases.
References
- Bakri SJ, Thorne JE, Ho AC et al. Safety and Efficacy of Anti-Vascular Endothelial Growth Factor Therapies for Neovascular Age-Related Macular Degeneration: A Report by the American Academy of Ophthalmology. Ophthalmology 2019;126(1):55-63. [PubMed]
- Elshout M, Webers CAB, van der Reis MI et al. A systematic review on the quality, validity and usefulness of current cost-effectiveness studies for treatments of neovascular age-related macular degeneration. Acta Ophthalmol 2018;96(8):770-778. [PubMed]
- Solomon SD, Lindsley K, Vedula SS et al. Anti-vascular endothelial growth factor for neovascular age-related macular degeneration. Cochrane Database Syst Rev 2019;3():CD005139. [PubMed]