Week 18 - AMD Flashcards
Key features of the Macula
- Densely packed cone photoreceptors
- An absence of rods at the fovea
- Fovea is avascular and in this area the retina is supplied with oxygen which diffuses from the choroid to the foveal retina
- Fovea 1.5mm across
- Foveola 0.15mm diameter – cones most densely packed in this area
- Avascular zone 0.5mm diameter
- Half of the retinal nerves in the optic nerve serve the fovea
Describe AMD
- AMD: long-term degenerative condition
- Leading cause of visual impairment in the UK
~600,000 people diagnosed (UK) - AMD is relevant to optometrists as loss of sight can have impact on quality of life and emotional health
Statistics
Prevalence estimates for UK by age groups (all types of AMD):
50+ y: 2.4 %
65+ y: 4.8 %
80+ y: 12.2 %
Number of people with AMD predicted to rise
26,000 new cases each year (NICE estimate)
Key reasons: aging population, increase in life expectancy
Workload implications for HES
AMD and visual impairment
- Visual impairment (6/18 or worse) from AMD affects
4% of UK population > 75 years
14% of UK population > 90 years
1.6% have VA < 6/60 in population > 75 years
AMD Risk Factors - Nice Guidance
- Diet low in omega 3 and 6 and cartenoids and minerals is a risk of AMD
- Lack of exercise
- Smoking
- Older age
- Hypertension
- Family history of AMD
- BMI of 30 kg/m2 or higher
- Presence of AMD in the other eye
- High fat diet
Dry AMD
- More common
- Slowly progressing
- No sudden loss of vision
- Managed by Optometrists in most cases
Dry AMD - NICE classification
Normal eyes
- No signs of AMD.
- Small (hard) drusen (<63 micrometres) only.
Early AMD
- Low risk of progression:
- Medium drusen (≥63 but <125 micrometres), or
- Pigmentary abnormalities.
Medium risk of progression:
- Large drusen (≥125 micrometres), or
- Reticular drusen, or
- Medium drusen with pigmentary abnormalities.
High risk of progression:
- Large drusen (≥125 micrometres) with pigmentary abnormalities, or
- Reticular drusen with pigmentary abnormalities, or
- Vitelliform lesion without significant visual loss (best-corrected acuity better than 6/18), or
- Atrophy <175 micrometres and not involving the fovea.
Late AMD (dry)
- Geographic atrophy (in the absence of neovascular AMD).
- Significant visual loss (6/18 or worse) associated with:
Dense or confluent drusen, or
Advanced pigmentary changes and/or atrophy, or
Vitelliform lesion.
Define Reticular Drusen
• Drusen: sub retinal pigment epithelium deposits
• extracellular debris composed of lipids and proteins which sit just below the RPE, or between the RPE and bruchs membrane
• Reticular drusen are also known as pseudo-drusen or subretinal drusenoid deposits.
• Contrary to the drusen which lie below the retinal pigment epithelium (RPE), reticular drusen are located superficial to the RPE.
• They are yellowish subretinal lesions arranged in a network and indicate a greater risk of AMD progression
Vitelliform lesion
• Accumulation of lipofuscin within the subretinal space
• Lipfuscin and extracellular deposit accumulation in drusen is below the RPE.
• Lipofuscin is is a heterogeneous material composed of a mixture of lipids, proteins, and different fluorescent compounds, the main fluorophore of which has recently been identified as a derivative of vitamin A
Dry AMD – the Role of the Optometrist
- Make the diagnosis
- Give relevant advice (including advice on driving and smoking cessation)
- Counselling – diagnosis is often a shock
- Provide Information – needs to be accessible (e.g. large print)
- Monitor – disease progression
Referral
Low Vision Services
For SI or SSI Registration (Ophthalmology)
To Social Services
Management of Dry ARMD
No treatment available
Advise on lifestyle modifications
Advise patients on nutritional supplements
Educate about symptoms of progression and self-monitoring
Aim: to slow down the progression
Management of dry ARMD: Emerging treatments in the US
• Complement Factor inhibitors
- FDA approved
- Intravitreal injections
- Monthly or bimonthly
- Utility has been shown in patients with severe dry AMD ( Geographic atrophy )
Nutritional Supplements – AREDS
- (Age-related eye disease study)
- Large scale, randomized, double-masked, placebo- controlled clinical trial (RCT)
- Looked at effectivity of supplements in delaying preventing onset progression of AMD
- antioxidant supplements reduced the risk of AMD progression in those with moderate/ high risk of progression
- But, a systematic review showed that supplements had no effect in the prevention of AMD
- Omega-3 fatty acids may help prevent AMD
Smoking cessation
- Smoking increases oxidative stress
- Second most important risk factor (after age)
- Most important modifiable risk factor
- Smoking:
Slows down choroidal blood flow
Promotes ischemia
Reduces macular pigment
Other lifestyle modifications
Increased physical activity > No direct evidence
Reduced alcohol consumption > Unclear whether moderate consumption is a risk
Reduction of waist-hip ratio > Especially in obese – unclear?
Diet rich in omega-3 polyunsaturated fatty acids > Evidence for decreased risk
Education / Self-monitoring
Amsler
Report changes to optometrist
Ensure deterioration is investigated for progression to neovascular (wet) AMD
Dry AMD - Management NICE Guidance
- Generally Dry AMD managed by community optometry
- Refer people with late AMD (dry) to hospital eye services only: for certification of sight impairment or
• if this is how people access low-vision services in the local pathwayor
• if they develop new visual symptoms that may suggest late AMD (wet active)or
• if it would help them to participate in research into new treatments for late AMD (dry).
The Royal College of Ophthalmologists
Key point:
“Treatment for non-neovascular AMD is limited and consists mainly of counselling, smoking cessation, visual rehabilitation and prescription of AREDS style vitamins to reduce risk of progression in those expected to benefit. Clinical trials of novel therapies are now taking place but are not currently available in clinical practice.”
Referral for Registration can get the px what benefits:
- Benefits of registration
- National Entitlement Card (NEC)
- Scottish National Blind Persons Scheme
- Disabled Persons Railcard
- TV Licence discount
- Blue Badge
Referral – Low Vision Services
Local Hospital
Resource Centre
LVA Qualified Optometrist
Rehabilitation
- Rehabilitation based on adaptation to vision loss
- Advise on low vision services
- Support patients in dealing with visual impairment
- Direct to suitable information, e.g. Macular Society
Referral to Social Services
- RNIB
- Eye Care Liaison Officer
- Virtual or in person
- Discuss diagnosis and assess needs
- Macular Society
AMD and Depression?
- Sight loss linked to depression
- The prevalence rates of depression in elderly populations with sight loss are between 25 per cent and 45 per cent.
- The relative risk of depression is estimated to be around 3.5 times higher for those with sight loss compared to those fully sighted.
It is estimated that up to 30 per cent of those living with age related macular degeneration experience moderate to severe depressive symptoms due to vision loss.
AMD and Falls?
- Falls are a major cause of disability
- 1.7x higher in people with sight loss
- 47% of falls in low vision patients are due to their sight loss
- The cost to NHS of falls associated with sight loss in Scotland is at least £1million per annum.
Wet AMD
Less common
Rapid onset
Sudden loss of vision
Referral to Ophthalmology usually required
Wet AMD - NICE classification
Late AMD (wet active)
- Classic choroidal neovascularisation (CNV).
- Occult (fibrovascular PED and serous PED with neovascularisation).
- Mixed (predominantly or minimally classic CNV with occult CNV).
- Retinal angiomatous proliferation (RAP).
- Polypoidal choroidal vasculopathy (PCV).
Late AMD (wet inactive)
- Fibrous scar.
- Sub-foveal atrophy or fibrosis secondary to an RPE tear.
- Atrophy (absence or thinning of RPE and/or retina).
- Cystic degeneration (persistent intraretinal fluid or tubulations unresponsive to treatment).
Wet AMD referral
Urgent referral
NICE guidance:
Make an urgent referral for people with suspected late AMD (wet active) to a macula service, whether or not they report any visual impairment. The referral should normally be made within 1working day but does not need emergency referral.
Electronic (via SCI Gateway)
Via Macular Pathway
Not usually ‘letter in hand’ same day referral
Patient needs to be seen at Macular Clinic (where OCT and Fluorescein Angiography are available)
Wet AMD: Treatment
- Treatment usually with anti-VEGF injections
- Course of 3 injections
- Review/ monitoring period
- May require further courses of injections
Patients may be discharged back to community Optometry , Optometrist to monitor for progression/ new fluid. OCT is required
- Re-referral to HES
- Involvement in anti-VEGF treatments
Discharge of AMD patients from hospital
Based on
- how stable the condition is and
- if treatment will bring any further benefits to the patient
Discharged patients should see an optometrist or GP urgently if any new symptoms develop
In particular patients who have been treated for wet AMD in one eye and develop problems in the contralateral eye
Aims of management
- Prevent (further) vision loss
- Halt progression of new vessels
Types of anti-VEGF drugs
Scottish Medicines Consortium has approved ranibizumab and aflibercept for use in NHS Scotland
A note on Late AMD (indeterminate)
Late AMD (indeterminate)
- Retinal pigment epithelial (RPE) degeneration and dysfunction (presence of degenerative AMD changes with subretinal or intraretinal fluid in the absence of neovascularisation).
- Serous pigment epithelial detachment (PED) without neovascularism.
Aflibercept for neovascular age-related macular degeneration (2016)
Review compares aflibercept and ranibizumab for neovascular AMD
Aflibercept’s safety profile similar to ranibizumab
Limited data on adverse events, leading to imprecise estimates
Aflibercept’s eight-week dosing reduces treatment burden
Potential to lower risks associated with frequent injections
Laser treatment of drusen to prevent progression to advanced age-related macular degeneration (2015)
• Trials confirm laser photocoagulation of drusen leads to disappearance
• No reduction in risk of developing CNV with treatment
• Doesn’t limit occurrence of geographic atrophy or visual acuity loss
• Ongoing studies to assess nanosecond laser treatment for drusen regression and neovascular AMD prevention
Omega 3 fatty acids for preventing and slowing the progression of age-related macular degeneration (2015)
Omega 3 LCPUFA supplementation up to five years doesn’t reduce risk of advanced AMD or moderate to severe visual loss.
No published randomized trials on dietary omega 3 for primary AMD prevention.
Current evidence doesn’t support increasing omega 3 intake to prevent or slow AMD progression.
For older adults with age‐related macular degeneration (AMD), what are the effects of lampalizumab or pegcetacoplan administered at different frequencies? (2024)
This review found that 4 to 8 weekly intravitreal injections of pegcetoplan (complement factor inhibitor) showed slowed growth of the area of geographic atrophy in dry AMD patients
The review did not find strong evidence of enhanced low contrast acuity in the treatment groups compared to the placebo groups
