Diabetic Eye Disease 2-Management Part 1 + 2 Flashcards
what are the referral guidelines for all stages of DR/M/ P?
go look at the first diab brainscape
How would we class AND manage this fundus?
Also list characteristics
R1 + M0- annual review
few scattered dot haemorrhages and possible microaneurysms, all well away from the macular area.
how would we class AND manage this fundus?
Also list characteristics
R1 + M1
Management-refer, to be seen soon (within 4 weeks)
Characteristics: a retina with definite intraretinal haemorrhage and exudate changes with a few within a disc diameter of the fovea.
what further tests can be conducted for suspect diab maculopathy?
visual acuities and amsler
How would we class AND manage this fundus?
Also list characteristics?
R2 + M1
Management - refer to be seen soon (within 4 weeks)
Extensive non proliferation changes throughout retina inc within 1 DD of fovea- presence of multiple blot haemorrhages= R2 also significant Cotton wool spots
How could we class AND manage this fundus? Also list characteristics
R3A- refer as emergency - call hospital to arrange this- evident haemorrhages that can lead to tractional ret detachment
How could we class AND manage this fundus? Also list characteristics
R3: Refer urgently to be seen within 1 week
NVD- Can’t see macula in this though so unsure if any M changes
How could we class AND manage this fundus? Also list characteristics
R3A- emergency same day even phone HES to send px
-tractional Retinal Detachment
as well as standard referral pathway, where else should we refer the px?
To the GP especially if undiagnosed- Diabetes mellitus need to be diagnosed, managed and controlled
what are 4 modifiable risk factors in diab retinopathy?
- blood sugar levels
- lipid levels- Research into statins to help DR going on
- blood pressure
- smoking- this isn’t a defined risk factor
what is the ‘legacy effect’?
where good glycaemic control can protect against future DR progression
how does blood pressure control have an influence on DR?
-Potential for reduced microaneurysm, reduced hard exudates and cotton-wool spots and was aasociated with less need for photocoagulation
how does lipid lowering affect DR?
Reduces risk of macular oedema and exudation
what does reducing lipid levels impact in DR progression?
reduces risk or progession of macular oedema and exudation
what type of DM is smoking a risk association with?
T1 DM
What is the main treatment (laser) for DR?
argon laser photocoagulation (focal and scatter)
What treatment is available to treat clinically significant macular oedema?
focal laser therapy (ALSO REDUCES RETINAL THICKENING)
when should scatter laser treatment be considered?
in eyes with severe non proliferative OR early proliferative DR (esp if T2 DM) and all eyes with severe proliferative
how much does early treatment reduce the risk of blindness caused by DR by?
Reduced risk of blindness in 5 years from 50% to 5% in people with proliferative DR.
list three studies done in order to see the effective treatments for DR?
- DCCT study (Investigates T1)
- ETDRS
- UKPDS (Investigates early T2)
does aspirin cause a risk in DR?
No affect on progression of DR
Should we consider a vitrectomy in advanced active DR?
yes
what was the ETDRS ? ( NOT talking about VI test chart)
4- year RCT evaluating argon laser photocoagulation + asprin treatment for non-proliferative & early proliferative DR assessing risk & benefits of this in 1989
what can be defined as ‘clinically significant macular oedema’ (CSMO)
-Retinal thickening at or within 500µm of the centre of the macula
-Hard exudates at or within 500µm of the centre of the macula, if associated with thickening of the adjacent retina
-Retinal thickening of one disc area or larger any part of which is within one disc diameter of the centre of the macula
when do we use early laser treatment ( focal laser photocoagulation )for CSMO?
if bvs are leaking as it seals off the bvs
what laser treatment do we use in the case of diffuse leakage from capillaries in macula (diffuse diabetic macular oedema) ?
laser grid photocoagulation-places numerous coagulations around the fovea in to restore the blood–retinal barrier.
prevents futher deterioration BUT HARDLY ANY IMPACT in restoring VA
Can laser grid photocoagulation have an impact on restoring vA?
No
how can we minimise damage to the fundus with laser?
by using low energy laser burns
what growth factors can laser have an effect on?
laser can
-upregulate biochmeical mediators with antiangiogenic activity eg PEDF (pigment epithelium derived growth factor)
-stimulates increase of angiotensin 2-inhibiting VEGF induced angiogenesis/VEGF
-less VEGF= less vascular permeability
do exudates always get reabsorbed after laser treatment?
not always- gradually absorb but Extensive exudates within fovea causes irreversible damage
can focal laser coagulation improve vision?
yes-can actually improve vision by 2 lines in in 35% of patients at 2 years
what is the growth factor promoting new vesselgrowth?
VEGF
List the 2 Anti-VEGF Injections available for DR treatment
- Ranibizumab (Lucentis)
- Aflibercept (eylea)
What is Ranibizumab?
a monoclonal antibody fragment, which binds to and inactivates all isoforms of VEGF-A.
what is bevacizumab?
not licensed for use in the eye, but cheaper, so used widely globally (rarely prescribed by the NHS).
what is the recommended retinal thickness when treating with Ranibizumab?
400 microns or more
what is the recommended retinal thickness when treating with Ranibizumab?
400 microns or more
At what retinal thickness should we start treating with Ranibizumab?
400 microns or more
what Anti-VEGF treatment is available for CSMO and how does it work?
-aflibercept (EYLEA)
a recombinant fusion protein that acts as a soluble decoy receptor and binds to VEGF-A, VEGF-B and placental growth factor (PlGF)
is the recommended retinal thickness for CSMO using Eylea also 400 microns or above?
Yes (NICE, 2015)
What is a disadvantage of laser photocoagulation?
retinal scarring- can become more of a risk if fovea involved (scotoma risk)
disadvantages of laser therapyfor macular oedema?
-can stabilise but not improve VA
-laser scar expansion an lead to a scotoma
what two treatments can be used in combination for CSMO?
Ranibizumab (Reduces risk of prolif DR developing) and laser treatment
what is another therapy for CSMO which can be used in ‘resistant’ cases when focal laser and anti-VEGF injections not working?
+ give two examples of the medication used
intraviteral steroid therapy:
- Triamcinolone injections
- long-acting fluocinolone acetonide (FA).
state 2 disadvanatges of intravitreal steroid injections when treating CSMO?
- Raised IOPS
- Cataract formation
general referral pathway for R2 pre-prolif diab ret?
- refer to GP for blood tests (HbA1c, blood pressure, lipids.),
- refer to ophthalmologist- can consider prophylactic laser photocoagulation depnding: on severity, risk of progressiona and symptoms
Management for R3 prolif diab ret?
refer to ophthalmologist
Following will be considered:
- Pan retinal photocoagulation (PRP) recommended for patients with active proliferative DR
- Intravitreal anti-VEGF injections to stabilise retinopathy, before cataract or vitrectomy
- Vitrectomy for px with vitreous haemorrhage (especially if non clearing haemorrhage or associated with RD/ ghost cell glau/ tractional RD)
what is pan retinal photocoagulation?
laser burns to peripheral retina
why is pan retinal photocaogulation used in DR and how does it work?
Reduced outer retinal oxygen consumption , so now oxygen from the choroid can reach the inner retina where it doesn’t normally
Reduced hypoxia 🡪 reduced VEGF production 🡪 reduced neovascularisation.
May also work by killing ischaemic retina, so reducing VEGF production
does pan retinal photocoagulation improve vision
NO- just stabilises it - although halves risk of severe visual loss
6 disadvantages of pan retinal photocoagulation?
- collateral damage to retinal tissue
- macular oedema (decrease in VA)
- colour vision defects
- generalised field restriction
- difficulty adjusting to changes in light levels
- can be painful
name an alternative to pan retinal photocoagulation?
cryotherapy
what do we want the fundus to appear as post pan retinal photocaogulation?
we want paler areas not white as white can indicate disruption of neurosensory retina.
Strong white patches indicate full thickness burns and visibility of sclera.
What 4 types of glaucoma are associated with diabetes mellitus?
-neovascular glaucoma (caused by rubeosis iridis)
-Open angle glaucoma (not conclusive association)
-Narrow / Closed angle glaucoma
-Secondary glaucoma
what is neovasc glauc?
growth of vessels on iris/trabec meshwork-ocular emergency
what treatments for diab may make a px predisposed to glaucoma?
- steroid treatment
- panretinal photocoagulation,
- scleral buckling to treat RD
- Silicone oil to treat RD
- intraocular gas to treat RD
how do we treat neovasc glauc?
treated with panretinal photocoagulation (to reduce hypoxia) + medical treatments e.g. atropine to reduce congestion, steroids to reduce inflammation, anti-glaucoma drugs + surgical treatment e.g. trabeculectomy in advanced cases.
how are diab px more at risk of developing cataracts earlier?
- glucose reduces to surbitol (an alcohol) & cannot pass through membranes
- accumulation of this in the lens = osmotic imbalance stress (water draw into lens)
- then lens fibres can rupture + burst = cataract
what is a diabetic cataract?
increaed free radicals float around and less antioxidants, and in the case of diab lenses advanced glycation end products in lens may be linked to diabetic cataracts.
what 2 risk factos can make a px with DM more prone to cataract?
poor blood sugar control, increased duration DM.
what is another word for true diabetic cataract
snowflake cataract
what is true diabetic cataract?
Multiple white anterior and posterior subcapsular and cortical opacities seen. (also vacuoles- this is all why they’ere called SNOWFLAKE)
is true diab cataract uni or bilateral?
bilateral
is true diab cataract rare
yes
what type of DM can be a risk facotr for true diab cataract?
Related to very high serum glucose levels in young type I diabetic Px.
what two types of age related cataract occur in DM px?
- Cortical
- Posterior Subcapsular
how much earlier can age related catarcat occur in Diabetic px than non diabetics?
May appear ~10 years earlier than in non-diabetic Px.
what two optic nerve conditions can be associated with diabetes?
- AION
- diabetic papillopathy (disc oedema, mild visual loss)
What palsies are associated with DM?
3rd, 4th and 6th nerve (we won’t forget this after OSCE)
WHAT IS THE RISK PERCENTAGE OF DIAB PXS GETTING CRANIAL NERVE PALSIES
25-30% in over 45s (acute OM palsy)
Does diab 3rd nerve palsy spare the pupils?
yes
what 4 corneal conditions occur in DM px
- Reduced corneal sensitivity due to corneal neuropathy
- Aqueous tear deficiency (Dry Eye Syndrome)
- Corneal endothelial dysfunction
- diab epitheliopathy
when do we consider diabetes and the cornea
when fitting cls or refractive surgery
what occurs in diabetic epitheliopathy?
- recurrent erosions
- Corneal abrasions
- Persistent epithelial defects
do we dilate all diab pxs?
no, esp if they are on the diab screening programme-You should dilate any patient with DM who has not been screened within the past 12 months.
recall for px on diab screening programme
routine recall-often 2 years
Recall for px NOT on diab screening programme
recall 12 months-encourage px to attnd, and should dilate any px who hasnt been in pastn 12 months
typical H+S for diab px?
- What type of DM?
- What age of onset?
- Ask about risk factors- well controlled diab? Hyperlipidamiea? High cholesterol?? Ht? smoking?
- When were you last seen by the DESP?
- Any problems with vision at distance or near? Any flashers or floaters? Diplopia?
- Plus usual detailed H&S.
Name the sx associated with M1, R3, CAG, fluctuating blood sugar, Cataract and nerve palsy.
(these are all associations of DR)
- M1: reduce VA
- R3: haemorrhage –> sudden vision loss, dark floaters
tractional RD –> sudden loss of vision, flashes, curtain/veil - CAG: haloes, hazy vision, pain, redness
- Fluctuating blood sugar: fluctuating rx + blurred vision
- Cataract: decrease in vision + CS
- Nerve palsy: diplopia
Relevant clinical tests for diab px?
- VAs
- CS
- colour vision
- VFs
- IOPs
- Oculomotor status and pupils
- indirect ophthalmoscopy
- Fundus photography
- OCT
- Anterior eye / anterior chamber / vitreous
- Retinal vasculature (Fluorescein angiography) moreso hes
what Clinical test is commonly used in hes for DR?
Fluorescein angiography-leaky bvs fluoresce
How do microaneurysms appear on fluoroscien angiography?
LITTLE WHITE SPOTS
do leaky bvs appear as hyper or hypo fluorescing on fluoroscien angiography?
hyperfluorescent region
on the other hand, Dark patches (hypofluorescent) where capillaries are non perfused . Pale splotches = laser burns
why is fluorscien angiography a good clinical test to do?
can notice wispy or development of new bvs even with obscuring vit haem on normal fundus photo
how is an OCT used for DM pxs? (3 points)
- management of diabetic maculopathy
- measure thickness + observe oedema thickness
- assess pre-post treatment change
