1.2.3: Discuss px importance systemic disease Flashcards
(APR – screen sharing record with assessor px taking meds for systemic disease) Indicators: Takes a thorough history from the px to include meds, control & disease duration Demonstrates a thorough understanding of the disease process for diabetes, inflammatory disease etc Provides a layman’s explanation of the disease Patient encounter: Patient taking medication for systemic disease e.g. cardiovascular disease, diabetes.
What needs to be recorded with DM:
• Record: type/duration/control
- Control - compliant with meds, up to date with GP
- Poor control = fluctuating refraction
- Lens hydration impacts Rx, lens may swell and bulge, causing myopic shift
- Proliferative = hyperopic shift
• If no med name (if the px does not know- assessor will ask for examples
Describe diabetic screening:
• All diabetic px over 12 invited annually (T1 & T2)
• Offered because DR doesn’t tend to cause symptoms in early stages
• Screening based primarily on digital fundus images (nurses, technicians)
• Images graded, 3 levels of grading
- Stage 1 - background
- Stage 2 - pre proliferative
- Stage 3 - proliferative
• Any images with signs of retinopathy will be sent to level 2 and 3 grading Images that may require referral will be graded by at least two graders
• Referred from DRS to HES if proliferative and/or severe maculopathy
Diabetic screening: Frequency
• If your last 2 screening results showed any signs of retinopathy - recall 12/12
• If your last 2 screening tests found no retinopathy - recall 24/12
• If you’ve only been screened once before, you’ll be screened every year. You’ll usually be moved over to 2-yearly screening if you receive 2 screening results where no retinopathy is found.
Where is diabetic screening done:
• Diabetic screening depends on area
• Can be done in high street practices with DRS contract
• Pxs may go to HES if higher risk category i.e poor compliance
• Glasgow - remote screening teams in health centres etc
• Number on NHS inform site
Explaining diabetes:
This is a conditions where the amount of sugar (glucose) in the blood is too high because the body can’t use it properly. This is usually caused by your body not having enough insulin or having poor insulin which does not work properly. Insulin is the chemical that helps your body absorb sugar.
Ocular impact of DM
• Diabetic retinopathy
• Corneal neuropathy
• Delayed healing of corneal epithelium
• Cataract
Types of diabetic retinopathy:
• Background: microaneurysms, dot/blot haems, exudates >2DD from fovea
• Pre-proliferative: cotton wool spots, venous beading, deep retinal haemorrhages, exudates <2DD from fovea
• Proliferative: pre-retinal haemorrhages, exudates <1DD from fovea, disc & retinal neovascularisation - NVD or NVE
• Advanced: traction/fluid RD, vitreous haemorrhage, neovascular glaucoma
Pathogenesis of diabetic retinopathy
• DR is predominantly a microangiopathy in which small BVs (capillaries) are particularly vulnerable to damage from high glucose levels
• Affects both type 182, more prevalent among T1
• High blood sugar promotes oxidative stress as there is an imbalance between free radicals and antioxidants in the body; the excessive amounts of oxygen-derived free radicals damage blood vessels
• In the early stages, weaker areas in the small blood vessels form microaneurysms which can result in intraretinal leakages i.e. haemorrhages and exudates
• Main concern at this point is a large number of leakages or leakage near the macula
• Capillaries can also become blocked and the bloody/oxygen supply compromised causing hypoxia
• VEGF is stimulated in response to this oxygen deprivation resulting in the formation of new leaky blood vessels eventually resulting in more bleeding and scaring
• For a hypoxic retina, treatment options include
Treatment options for DR hypoxia:
For a hypoxic retina, treatment options include
• Anti VEGF injections - intravitreal ranibizumab/lucentis
• Diuretics - acetazolamide
• PRP (lessens the amount of retina that needs oxygen by killing off peripheral cells in order to reduce VEGF), 2000-4000 laser burns
Explaining diabetic retinopathy:
• (DR prevalence Scotland: 5.9%)
DR is a complication of diabetes caused by high blood sugar levels damaging the retina The retina is the light sensitive layer at the back of the eye that coverts light into electrical signals. These signals are then sent to the brain which allows us to see. The retina needs a constant blood supply in order to do so. Overtime, it is these blood vessels that can become damaged if blood sugar levels are persistently too high. DR can lead to blindness if it is left undiagnosed and untreated. However, it usually takes several years for diabetic retinopathy to reach a stage where it threatens your sight. To minimise risk, people with diabetes should ensure they control their blood sugar, BP and cholesterol as well as attending their regular diabetic screenings. Would also advise px to contact practice immediately is the experience gradual worsening of vision, sudden vision loss, shapes floating in vision, blurred or patchy vision, eye pain or redness. Px should not wait till screening/routine test.
Diabetes: Corneal neuropathy:
• Reduction in corneal nerve density causing corneal desensitization
• Starts with DED symptoms, progresses to breakdown of epithelium, corneal oedema & ulcers
Diabetes: Delayed healing of corneal epithelium:
• Increased risk of infection & persistent defects
• Recurrent corneal erosions
Diabetic cataract:
• Age related cataracts (NS/CO/PSC) occur earlier/may progress quicker
• Young diabetics may develop ‘diabetic cataract = snowflake opacities
Diabetic medication and side effects:
• Insulin - may cause hypoglycaemia which causes dizzy spells; in rare cases may cause presbyopia when first starting treatment due to shifting fluids which affect the lens; generally stabilises
- Novorapid - ingredient insulin aspart, fast-acting and works rapidly to normalise blood sugar levels, begins working after 10-20mins, lasts 3-5 hours
- Levemir - ingredient insulin detemir long acting, subcutaneous injection only, up to 24-hour duration of action
• Metformin (biguanide) (2) - dry eye and increase risk of angle closure
• Gliclazide - lens changes, refractive error shifts
High blood pressure: Pathogenesis and ocular presentation
• Hypertension is a medical condition where the pressure inside the arteries is persistently elevated
• The initial response of retinal arterioles to systemic hypertension is vasoconstriction
• Prolonged HBP can lead to hardening of vessel walls, AV nipping and eventually increased vascular permeability
• Side effects of HBP on the eye can include a blockage in the blood vessels of the retina (CRAO or CRVO), loss of vision due to a loss of blood supply to the optic nerve (NAAION), loss of peripheral vision due to stroke, or a transient loss of vision that comes & goes (amaurosis fugax)
• May also cause cotton wool spots, retinal haemorrhages, retinal ischaemia and neovascularisation
