AMD -testing patients and management Flashcards
What is important in history when detecting AMD or recognising if px is at risk?
Diet, systemic conditions like diabetes, htn, high cholesterol, overweight px, smoker, FH of AMD, previous cataract sx
What symptoms should you look out for?
Reduced vision, distortion, gradual or sudden onset, 1 eye or both, difficulty performing tasks like reading, cooking, any dietary supplements?
How can questions about vision onset help with management?
Only those with recent onset wet AMD are suitable for medical intervention.
How can questions about daily tasks help with management?
May indicate that they need extra help around the house i.e. consider referral for low vision rehabilitation and/or to social care.
Which chart is it better to measure VA with and why?
EDTRS logMAR
because there are far more letters in the 6/24 – 6/60 range, where many patients with AMD will see. This enables more precise measurement of visual acuity in these people.
It is also encouraging for someone with 6/60 vision to be able to read 5 letters on the logMAR chart rather than just 1 letter on a Snellen chart.
How does VA play a role in management of AMD patients?
Treatment decisions for intravitreal injections are also made on the basis of the number of letters read on a logMAR chart in most hospitals.
NICE guidelines recommend Lucentis treatment only for those with VA between 6/12 and 6/96, so VA testing is important to determine whether they are eligible for treatment.
Also, in patients not suitable for medical intervention, VA helps to guide on referral for registration as SI or SSI.
What other tests should be done to give important info about their VA?
Amsler
Contrast sensitivity
Colour vision
Microperimetry
What is the purpose of an amsler test?
The amsler chart is a test of the central visual field.
The purpose is to plot areas of distortion and scotomas, which may indicate the presence of underlying neovascular changes.
How can you use an amsler to monitor a patient?
Monitoring scotomatous areas is also useful in patients with established AMD and vision loss, as it helps the practitioner to give guidance on maximising the use of residual vision, for example using an eccentric viewing strategy.
(used to monitor pxs at risk of developing into wet amd)
How is an amsler done?
Instructed to look at the chart daily to check for the distortions which may indicate the onset of wet AMD.
33cm, monocularly with reading spex
1. Do any of the lines in the grid appear wavy, blurred or distorted?
2. Do all the boxes in the grid look square and the same size?
3. Are there any “holes” (missing areas) or dark areas in the grid?
4. Can you see all corners and sides of the grid (while keeping your eye on the central dot)?
(30cm)
•
What do you do if a patient stuggles with amsler instructions?
If a px struggles with procedure, you may suggest something simpler, like looking at some blinds, or a particular window frame each day.
How can colour vision tests help?
Measurements of RedGreen and YellowBlue colour thresholds can provide a sensitive measure of functional change in AMD.
What colour vision test can you use for AMD px?
Blue-yellow defects are commonly seen in early AMD, so Ishihara is not an appropriate test to use for assessing this condition.
Recent tests, such as the colour assessment and diagnosis (CAD) test, allow a more precise assessment of chromatic thresholds, which has been shown to be sensitive to early AMD.
What can central visual fields detect?
In patients with central visual loss due to AMD, microperimetry can be useful to plot scotomas, monitor disease progression, and assess fixation stability.
How can the info from central visual field tests help you manage px?
Training patients with central visual loss to use a non-foveal location to fixate (so-called ‘eccentric viewing’).
Why is a dilated fundus exam important and using volk after?
In elderly patients with small pupils and media opacities, examination through the dilated pupil facilitates a thorough stereoscopic examination of the macular region.
A stereoscopic view (for example, using volk) will help substantially with the identification of elevations of the retina caused by subretinal or intraretinal fluid and fibrovascular membranes.
What is the gold standard for identifying AMD at the hospital?
Fluorescein Angiography – gold standard for identifying wet AMD in hospital eye clinic.
Fundus autofluorescence – useful for evaluating geographic atrophy (usually in hospitals)
Does px need to tell DVLA if they have AMD?
Px must inform DVLA if:
AMD in one eye (bus, coach, lorry drivers)
AMD in both eyes (car drivers)
(Bus, coach and lorry drivers need to inform the DVLA if they have AMD in one eye only)
How do you as an optician manage dry AMD?
DON’T REFER asymptomatic early AMD OR late dry AMD
▪ No treatment for dry AMD
Reassurance as atm dry AMD doesn’t have any proven treatment so nothing we can do to reverse the changes of the drusen
Low vision aids
NB High adds
Prevention advice: quit smoking, diet of fruit and veg, AREDS supplement
When do you refer DRY AMD?
Only refer LATE dry AMD to HES for certification of SI or to access low vision services OR if new symptoms develop suggesting wet AMD
What is AREDS?
AREDS trial looked at the ability of antioxidants + zinc to prevent progression in people who already had AMD.
Found a significant reduction in the Odds ratio in people who took the anti-oxidants plus zinc. Zinc is concentrated in the retina and is required for the functioning of many enzymes, including ones with antioxidant functions.
Reduction in risk only applied to those with intermediate AMD, or advanced AMD in the fellow eye.
In other words, advising patients with untreatable advanced AMD in one eye to take the AREDS formulation of nutritional supplements, is supported by the literature as a way of potentially slowing progression in the fellow eye.
No evidence that it prevents AMD in people who don’t have it to start with.
ALWAYS TELL PX TO FIRST CHECK WITH GP BEFORE TAKING SUPPLEMENTS
How would you tell patient they have AMD?
AMD is an eye condition which affects the central part of your retina which is called the
macula. It causes changes to your central vision.
Talk about what problems they may face, treatment, prevention, progression, give amsler
How do you as an optician manage Wet AMD?
Urgent referral is warranted if there is a marked distortion, blurring or scotoma seen on Amsler, which is of RECENT onset, if there is a recent onset reduction in VA (whilst treatment will only be given to those in the range 6/12-6/96, newly developed CNV should still be referred urgently if the VA is outside of this range), or if a hyperopic shift in Rx has occurred.
WHEN do you refer Wet AMD?
VA 6/12-6/96
No permanent structural damage to fovea
Lesion size < 12 disc areas
Evidence of disease progression.
Blood < 50% lesion area
Longstanding wet AMD with scar tissue formation, and nAMD with VA worse than 6/96 is not suitable for medical treatment, however best to refer all newly diagnosed wet AMD for ophthalmological opinion.
What are the currently used treatments for Wet AMD?
Anti-VEGF antibody binds to & inhibits all forms VEGF-A:
Ranibizumab (Lucentis)
Bevacizumab (Avastin) and Pegaptanib (Macugen) are all anti-VEGF intravitreal injections used in treatment of wet AMD
How does anti-vegf help wet amd?
In wet AMD, vascular endothelial growth factor molecules bind to VEGF receptors. This starts a cascade of chemical reactions, which leads to proliferation of vascular endothelial cells, and increased permeability and migration of vessels, all of which results in angiogenesis (the development of new vessels). Anti VEGF therapy attempts to disrupt this cycle, thereby providing a way of treating all types of neovascular AMD.
Which anti-VEF is the treatment of choice
Ranibizumab
Why is ranibizumab better than the other 2?
Pegaptanib less effective than Ranibizumab
Bevacizumab Not licensed for intraocular use, therefore not recommended by NICE
What is Aflibercept (Eylea)?
Not an antibody, but a fusion protein made of two parts of VEGF-receptor molecule
How does eyelea work and how often is it needed?
Blocks VEGF-A and B & Placental Growth Factor
3 x 4-weekly loading dose. 8-weekly maintenance dosing.
What is NICE’s opinion on eylea?
2013: NICE approved for use in same patients eligible for Ranibizumab.
Effectiveness very similar.
What is another treatment that’s rarely used for Wet AMD?
Photodynamic Therapy (PDT)
What is PDT?
Intravenous injection of a photosensitizer, verteporfin- binds to low density lipoproteins in the blood, taken up by cells in new blood vessels. A low powered laser is directed onto the area of CNV to activate the photosensitizer.
What is the disadvantage of PDT?
It leaves a scotoma as the choroid and retina in this region are also destroyed.
Retreatment required
When might ophthalmologist decide to stop treating a WET AMD px?
Criteria for discontinuation: persistent deterioration VA; identification of anatomical changes in retina indicating inadequate response to therapy.
3 signs of early AMD?
Soft Drusen
Focal Hyperpigmentation
2 symptoms of early AMD?
Slight distortion on Amsler grid, corresponding to location of drusen
Gradual reduction in VA
Management of early AMD?
Monitor, advise on lifestyle changes (e.g. stopping smoking and nutritional supplements) and provide Amsler grid for self-assessment.
5 signs of WET amd?
Haemorrhage
Exudates
Visible retinal elevation
Sub-retinal fluid or pigment epithelial detachment
Sub-retinal neovascular membrane may be seen as greenish grey lesion
3 symptoms of early AMD?
Presence of markedly distorted, blurred, or absent lines on Amsler grid
Recent onset marked reduction in VA (6/12 to 6/96)
Hyperopic shift in Rx
Management of WET AMD?
REFER URGENTLY
via rapid access referral route if available locally
5 signs of advanced AMD (Not suitable for treatment)
Geographic atrophy
Disciform scar
Extensive exudates,
haemorrhage, fibrosis, macular elevation
2 symptoms advanced AMD
Central scotoma on Amsler chart
VA reduced to below 6/96
Management of advanced AMD
Refer non-urgently to assess fellow eye, and consider LVA assessment and training, visual impairment counselling and registration.
Refer urgently if in any doubt Re. treatment suitability.
What should always be given with verbal info to the px
WRITTEN INFO
Can also tell them about macular society or other helpful online sources of info
