Image supplied by Gemma Corkery-McClean, Specsavers Whangarei, NZ
In the photograph shown, the appearance of larger / confluent drusen is present, as is a central area of atrophy, classified as late stage age-related macular degeneration (AMD).
AMD is the most common cause of blindness in Australia and New Zealand.
The risk of developing AMD increases with age. Family history and smoking are also major risk factors.
Signs may include one or more of the following:
- Difficulty with central vision tasks, including reading and driving
- The need for increased lighting / illumination to perform visual tasks, increased glare sensitivity, changes in colour perception or difficulty with night vision
- Distortions in vision; wavy appearance of straight lines
- Darker or ‘missing’ patches in vision.
On examining the retina, early changes to the macula include the appearance of drusen (which can progress) and both hyper- and hypo-pigmentary changes. Late stage disease can be in the form of geographic atrophy and/or macular exudate and bleeding.
Historically, an inconsistent approach to classifying or diagnosing AMD included terms such as: early AMD, late AMD, intermediate AMD, dry or wet AMD, neovascular AMD, end-stage AMD, and AMD with geographical atrophy. This led to confusion for clinicians attempting to explain the condition as well as for patients attempting to understand the severity of their condition and the risk to their functional vision loss.
More recently, the Beckman classification, which is drawn from AREDS (the Age-Related Eye Disease Study), recommends that the single diagnosis of AMD should be used, then classified into: normal ageing, early AMD, intermediate AMD, and late AMD (geographical atrophy and/or neovascular lesions).1,2
Progression & Prognosis
Identification of early symptoms, signs and risk factors for progression form part of a standard clinical diagnosis and management. For example, AREDS reports a 25% risk of developing advanced AMD for a patient with large drusen and pigmentary changes in both eyes.3
Patients at risk of development or progression of AMD should be counselled appropriately. Certain steps may be taken to reduce risk of progression. These include:
- Regular and timely review by an optometrist and/or ophthalmologist to monitor the condition
- Regular self-monitoring and screening changes to vision with an Amsler grid
- Changes to lifestyle, including the increase of green / leafy vegetables or foods high in antioxidants in diet, and cessation of smoking
- Intravitreal injections of anti-VEGF treatment by an ophthalmologist.
Further guidance on AMD referral and management can be found on the RANZCO website.
1. Ophthalmology. 2013 Apr;120(4):844-51. doi: 10.1016/j.ophtha.2012.10.036. Epub 2013 Jan 16. Clinical classification of age-related macular degeneration. Ferris FL 3rd1, Wilkinson CP, Bird A, Chakravarthy U, Chew E, Csaky K, Sadda SR; Beckman Initiative for Macular Research Classification Committee.
2. Am J Ophthalmol. 2001 Nov;132(5):668-81. The Age-Related Eye Disease Study system for classifying age-related macular degeneration from stereoscopic color fundus photographs: the Age-Related Eye Disease Study Report Number 6. Age-Related Eye Disease Study Research Group.
3. Arch Ophthalmol. 2005 Nov;123(11):1570-4. A simplified severity scale for age-related macular degeneration: AREDS Report No. 18. Ferris FL1, Davis MD, Clemons TE, Lee LY, Chew EY, Lindblad AS, Milton RC, Bressler SB, Klein R; Age-Related Eye Disease Study (AREDS) Research Group.