Treatment of AMD Flashcards
what has been proven about the modification of the AREDS 2 formula
did not further reduce risk (adding lutein, zeaxanthin, DHA or EPA)
what is the risk of High dose Vit A
may increase risk of lung cancer in smokers/ex-smokers
what is the risk of High dose Vit E
name 3
may be associated with increased mortality rate, heart failure and prostate cancer
what is the risk of High dose zinc
name 2
may be associated with neurotoxicity and prostate cancer
name an anti VEGF that is not licensed for the use of AMD tx and give a trade name example
Bevacizumab - avastin
e.g. Pegabtanib
give a trade name of Ranibizumab
Lucentis
give a trade name of Aflibercept
Eyelea
what was the first ever agent to tx wet AMD called and what problems did it cause, what was this then replaced by
Macugen
intraocular inflammation
replaced by Ranibizumab
what type of structure does Eylea have
what size is it
what 3 things does it target
what is the systemic half life
what is the intravitreal half life
Recombinant fusion protein
115 KDa
VEGF- A, VEGF- B and PIGF
systemic: 5-6 days
intravitreal: 4 days (rabbit)
what type of structure does Avastin have
what size is it
what does it target
what is the systemic half life
what is the intravitreal half life
Recombinant humanized monoclonal antibody
48 KDa
VEGF
systemic: 19 days
intravitreal: 4 days (rabbit) 5 days (human)
what type of structure does Lucentis have
what size is it
what does it target
what is the systemic half life
what is the intravitreal half life
Antibody fragment
150 KDa
VEGF-A
systemic: 2 hours
intravitreal: 3 days (rabbit) 9 days (human)
how is the agent Ranibizumab initially given for tx and how is it given thereafter
0.5mg given monthly until maximum gain achieved (loading)
Treat as deemed necessary thereafter
- Monthly monitoring
- T+E (treat and extend): increase intervals by maximum of 2 weeks
how is the agent Aflibercept initially given to tx AMD and how is it given thereafter
3 monthly doses = 1x a month (loading), then bimonthly up until end of first year
Can extend by 2- to 4- weeks depending on response, but not more frequent than bi-monthly during first year
No monitoring between injections necessary
what is necessary when treating a px with Ranibizumab compared to treating with Aflibercept
monitoring between injections not necessary with Aflibercept/Eylea
name and explain 2 different types of regime for treating AMD with anti VEGF
PRN
– 3 consecutive monthly injections (loading)
– As needed when there’s signs of deterioration
T&E
– Consecutive monthly injections until maximal improvement
– Increase interval between injections if no progression
which tx regime works out better when treating wet AMD with anti VEGF and why
Treat and Extend
PRN not always treated in a timely manner, therefore potentially worse long-term outcomes
what did studies prove about the T&E programme compared to monthly injections
T&E gained comparable vision with fewer injections needed
what did a RCT study about Ranibizumab vs Aflibercept in the 1st year show
Ranibizumab outperformed by gaining more letters with the same amount of injections
what did a RCT study show about Ranibizumab vs Aflibercept after 3 years of T&E regime
both drug effects end up being similar hence no advantage in using one drug over the other
list the 9 steps of the Intravitreal injection procedure in order
Identify correct patient and eye
Consent
Anaesthetise eye topically
Povidone-Iodine - to prevent post op endopthalmitis
Prepare injection
Speculum/Invitria
Inject
Irrigate
?Post-injection antibiotic (stat) - limited evidence not necessary
what is the risk of getting Endophthalmitis post anti VEGF in %
list 4 ways to prevent this
list 2 things that are not necessary to prevent Endophthalmitis
0.019-1.6%
Treat eyelid conditions e.g. blepharitis, ectropian
5% Povidone-Iodine in fornices (min 30s) prior to injection
Sterile equipment to be used
Face mask to reduce air-droplet contamination
Topical antibiotics not required pre- or post- injection
Theatre not necessary (air-flow)
what is the risk of getting inflammation post anti VEGF tx
name to signs that differentiates inflammation to endopthalmitis
1.4-2.9%
Inflammation
Onset of symptoms
<24 hours
A/C activity
Mild-moderate
Endophthalmitis
Onset of symptoms
>24 hours
A/C activity
At least one of:
KPs, hypopyon, fibrin, anterior synechiae
what is the risk of getting a RRD in % post anti VEGF tx and how can it be caused and how can this be prevented
0-0.67%
Usually associated by induction of PVD or incorrect injection technique
Use small needle, tunnelled insertion, 3.5-4mm posterior to limbus
how is IOP elevation a risk factor post anti VEGF injection
Usually temporary
Pre-existing glaucoma risk factor
?low grade trabeculitis, blockage of TM by agent e.g. larger molecule such as avastin
?IOP spike after injection - repeatedly if a person has multiple injections longterm these people have ^ IOPs
what 3 types of Haemorrhage can you risk getting after anti VEGF tx and what is not necessary if this occurs
Subconjunctival ~10%
Subretinal
Choroidal
No need to stop anti-coagulant therapy
list the 5 post tx risk factors after anti VEGF injection
Endophthalmitis Inflammation RRD IOP elevation Haemorrhage
which anti VEGF drug has no systemic adverse effects attributable to VEGF inhibition
Macugen
what 4 types of systemic risks is associated with Avastin
Increased risk of non-ocular haemorrhages
CVA, MI in 0.5%
Death in 0.4%
what systemic risk is associated with Lucentis
and what is not a risk which is with Avastin
increased risk of non-ocular haemorrhages; echhymosis, GI, etc
No increased risk of death, MI, CVA
Improve chances of stabilising/improving
_ injections needed to gain __ letters
_ injections required to maintain
8 injections needed to gain 15 letters
5 injections required to maintain
