Contents
Introduction
With an increase in the ageing population globally, we will be seeing more diseases that typically affect elderly patients. One such condition is age-related macular degeneration (ARMD). AMRD is an acquired degeneration of the retina, specifically the macula, that usually affects the central vision initially. Classically people in their 50s-60s are first affected, and vision may become progressively worse if not treated properly. ARMD is a leading cause of blindness worldwide. Although the exact cause is not known, the main factors for the development of ARMD include increasing age, smoking, positive family history and cardiovascular risk factors.
Types of ARMD
ARMD can be divided into two different types: dry/non-neovascular or wet/ neovascular ARMD. Dry ARMD accounts for the majority of cases (approximately 90%), but it can progress to wet ARMD. The table below briefly describes the differences between the two forms of ARMD:
Different Aspects of ARMD
| Dry/non-neovascular ARMD | Wet/neovascular ARMD | |
| Clinical Features | – Drusens (hard or soft) – Retinal pigment epithelium (RPE) changes (such as hyperpigmentation or atrophy) – Vitelliform lesion – Reduced visual acuity – Scotomas (a partial loss of vision) – Metamorphopsia (distortion of vision) | – Reduced visual acuity – Scotomas (a partial loss of vision) – Metamorphopsia (distortion of vision) – Choroidal neovascularisation – Retinal angiomatous proliferation (RAP) – Retinal haemorrhage – Exudation – Retinal or pigment epithelial detachment |
| Investigation | – Optical coherence tomography (OCT) – Fundus autofluorescence | – OCT – Fluorescein angiography (FFA) |
| Management | – Regular use of Amsler grid – Supportive treatment and counselling – Smoking cessation – Vitamin supplementation – Increase intake of green vegetables such as, cabbage, spinach and broccoli | – Anti-vascular endothelial growth factor (VEG) therapies – Supportive treatment and counselling – Regular use of Amsler grid – Lifestyle changes as for dry ARMD – Registration for visual impairment (if required) |
Classification of dry ARMD
AREDS stands for Age-Related Eye Disease Study, which was first launched by the National Eye Institute in 1992. They have devised a classification system for the staging of dry AMD as detailed below (a simplified version):
| Classification | Clinical Findings |
| No ARMD | None or a few small drusen |
| Early ARMD | Any or all of the following: · Multiple small drusens · Few intermediate drusens · RPE abnormalities |
| Intermediate ARMD | Any or all of the following: · Extensive intermediate drusen · At least one large drusen · Geographic atrophy NOT involving the centre of the fovea |
| Advanced ARMD | Geographic atrophy involving the fovea and/or any of the features of neovascular ARMD |
Complications of ARMD
Certain complications have been associated with ARMD, such as visual impairment, blindness, depression, Charles Bonnet Syndrome, falls and fractures. The above is by all means a non-exhaustive list.
Other complications have been associated with the treatment of ARMD such as endophthalmitis after anti-VEGF treatment.
Summary
ARMD is a chronic, progressive condition that affects many people around the world. It is important for healthcare professionals to pick up on the subtle signs of this disease early so that we can encourage patients to change modifiable risk factors as soon as possible. It is strongly recommended to advise patients to attend a routine optometrist review, in order to better detect the initial signs of ARMD, and especially to spot the development of wet ARMD from dry ARMD promptly.
Further Reading
- Eyewiki is a fantastic resource to learn about various ophthalmic conditions and usually sets out the information under different subsections which makes it easier to understand.
- NICE CKS – AMD
- Oxford Handbook of Ophthalmology – Age-related macular degeneration
Written by Dr Sammie Mak (Ophthalmology Clinical Fellow) & reviewed by Mr Mohamed Hassan Mansour Hegab (ST3)
