6.1.9 Manages patients presenting with macular degeneration.

Question 1

Distinguising between Wet & Dry AMD

Dry vs wet: Symptoms

Answer 1

DRY:

Initially asymptomatic, then…
Gradual reduction in VA
Metamorphopsia
Central scotoma (when advanced)

WET:

Sudden reduction in VA (<6/12)
Metamorphopsia
Central scotoma

Question 2

Dry vs wet: Signs

Answer 2

DRY:

Drusen
Focal hyper/hypopigmentation
Geographic atrophy

WET:

Drusen & pigment abnormalities
Haemorrhage
Hard exudates
Retinal elevation
Pigment epithelial detachment (PED) leads to disciform scarring

Question 3

Complications of AMD

Answer 3

• Serous fluid leaks from the choriocapillaris passing through Bruch’s membrane, leading to an RPE detachment.
• Must understand difference between Occult & Classic & Combination!
  
  • Occult happens below RPE
  • Classic happens above RPE after getting through chroid so worse prognosis!
  • Both generally have a green-greyish lesion on the macula and generally haemorrhaging. Occult will look less distinct but classic is more well defined and delineated

Question 4

Establishes Patient Needs & Visual Function with AMD

Answer 4

• Ask about hobbies especially relating to near tasks like reading
• Must do amsler or the assessor will not accept the record
  
  • Looks at central 20 degrees of fixation
  • When held at 1/3 of a metre, each square subtends 1 degree
  • Multiple charts available. Found in page 5 of Kanski or pg 56 of Visit 2 AOP student zone
• Thinking of LVAs!
• REVIEW TYPES OF AMSLERS

Question 5

Risk factors

Answer 5

• Age ^
• Race - late AMD more common in Caucasians
• Gender – females > males
  o Greater risk possibly due to longevity
• Heredity – risk of AMD is up to 3 times as high if first-degree relative has the disease
• Smoking - doubles risk (2-3x) of AMD
  o Tar of cigarettes = hydroquinine = oxidative stress = DRY
  o Nicotine = induces capillary formation = WET
• Hypertension & other cardio-vascular risk factors (vascular disease > ischaemia/accumulation of waste products > degeneration of RPE)
• Dietary factors
  o Low in omega 3 & 6, vitamins, carotenoids, and minerals
  o High fat intake, obesity, excessive alcohol consumption
  o BMI of 30 = higher risk
• Aspirin – evidence is limited
• Females – greater risk possibly due to longevity
• Cataract surgery – can speed up progression from dry to wet
• No evidence for increased risk of AMD due to light exposure

Question 6

Stages of Dry AMD and their defininition

Answer 6

No apparent ageing changes: No drusen, No AMD, pigmernaty changces
Normal ageing chancges: only druplets, no AMD pigmentory changes
Ealry AMD: Medium drusen (63um-125um), no amd pig changes
Intermediate AMD: Large drusen 125> um
Late AMD : Neovasc or geographic atrophy

Question 7

Stages of wet AMD

Answer 7

 Late AMD (wet active)
o CNV
o Ocular (fibrovascular PED / serous PED with neovascularisation
o Mixed predominantly or minimally classic CNV with occult CNV)
o Retinal angiomatous proliferation (RAP)
o Polypoidal choroidal vasculopathy (PCV); macular neovasc, occurs more in African Americans & Asians

 Late AMD (wet inactive)
o Fibrous scar
o Sub-fovea; atrophy or fibrosis secondary to an RPE tear
o Atrophy
o Cystic degeneration
o Eyes still may develop of have recurrence of late wet active AMD

Question 8

Management: Dry

Answer 8

 No treatment available - prophylaxis only
 Address risk factors – first you would advise to modify = smoking
 Other risk factors to address dietary/alcohol
o Encourage diet rich in leafy greens / omega 3 & omega 6/fatty acids
o Diet rich in vitamin C and E
Antioxidants are also availble!

Question 9

Antioxidants

Answer 9

 Antioxidants to reduce free radical damage by giving an electron to a free radical to prevent the chain reaction and stop them from causing damage
 Lutein, zeaxanthin and meso-zeaxanthin and xanthophylls – 3 main macular pigments = act as antioxidants
 Carotenoids = antioxidant
 Macushield - contains 3 carotenoids including zeaxanthin
 Optihealth - contains lutein and zeaxanthin; vitamin A; manganese also helps protect against free radicals
o Some evidence that Vitamin A supplements should not be given to smokers as it may increase the risk of lung cancer

 Amsler to monitor progression from dry to wet
 Low vision aids if necessary
 Glasgow and great Clyde guidance
o AMD/VA/amsler stable no referral
o Reduced VA/amsler distortion – routine

Question 10

Wet referral?

Answer 10

 Wet AMD fast-track referral on SCI gateway (1-2 weeks)
Anti-VEGF
 Most used treatment
 Criteria – 6/12 or worse
 Avoids the proliferation of new & unhealthy blood vessels
 Visual prognosis
o 25% cases VA improves
o 90% VA remains stable
 Ranibizumab (lucentis) – approved by NHS Scotland & NICE - £742
o Initial loading dose – 3 injections, every 4 weeks
o Maintenance injections usually 1-3 months, for as long as necessary
o Effective for all lesion types
 New drug – Brolucizumab (Beovu) – now approved by NHS Scotland & NCE, can increase time between appointments to 12 weeks – minimize treatment burden for patients

Question 11

Other historical treatments

Answer 11

 Laser photocoagulation – few cases suitable, not usually justified
o Laser destroys new choroidal vessels at the cost of destroying nearby retinal cells – does not prevent recurrences
o Immediate reduction in VA, but better VA in long term
o Benefit only significant after 6 months of treatment
o Still approved but basically been abandoned for anti-VEGF
o
 Photodynamic treatment to occlude new blood vessels in CNV
o Uses verteporfin – highly-reactive oxygen molecules damage the choroidal neovascular endothelium = thrombosis of subretinal choroidal network
o Reduces chance of significant visual loss – no improvement in VA
o Cost-Ineffective