Week 17 - DM Flashcards
Types of Diabetes Mellitus
- Insulin Dependent (IDDM)
- Non-Insulin Dependent (NIDDM)
- Pre-Diabetes
- Gestational
Diabetic eye disease types:
Anterior Segment
- Dry Eye
- Diabetic Keratopathy
- Uveitis
- Cataract
Posterior Segment
- Vitreous Haemorrhages
- Diabetic Retinopathy (DR)
Examples of Anterior Segment Complications of Diabetes
Aqueous Deficient Dry eye
Diabetic neurotrophic keratopathy
Epithelial fragility
Delayed epithelial healing
Superficial punctate keratopathy
Persistent epithelial defects
Recurrent corneal erosions
Neurotrophic corneal ulceration
Filamentary keratitis
Descemet‘s folds
Diabetic Keratopathy
70% of diabetic patients suffer from corneal complications
Cornea experiences 4-fold higher glucose level in diabetics
Examples:
- Superficial punctate keratitis
- Recurrent corneal erosion
- Persistent epithelial defect (corneal)
- Diabetic neurotrophic keratopathy
Diabetic Neurotrophic Keratopathy
Occurs in up to 64% of diabetic patients
Involves reduction of corneal nerve density
May lead to permanent vision loss
Characterised by structural and functional changes of cornea
Signs/Symptoms:
Impaired corneal sensitivity
Epithelial defects (loss of protective function)
Impaired healing
Corneal ulceration
Loss of vision
Three stages
Corneal Sensitivity in Diabetes
Up to 55 % of diabetic patients have reduced corneal sensitivity
Corneal sensitivity still difficult to measure and quantify
Anterior Uveitis in Diabetes
Presenting features
Poor glycaemic control
Type 1
Advanced Type 2 (Neuropathy etc.)
Acute
Anterior
Diabetes and Cataract
Cortical
Nuclear
Snowflake
Main Risk Factors: Who is likely to have DR?
Hyperglycaemia
Hypertension
Diabetes duration
Ethnicity (African, Hispanic, South Asian)
Puberty and pregnancy (DM type 1)
Signs of DR
Microaneurisms
Retinal haemorrhages
Hard exudates
Cotton-wool spots
Venous tortuosity and beading
Neovascularisation
Tractional retinal detachment
Macular oedema
Scottish diabetic retinopathy grading:
When assessing the fundus, you are grading 2 things:
General and Peripheral Retina
Macula
and note any other findings
What are the DR Grades?
R0
• No diabetic retinopathy anywhere Rescreen 12 months
R1
• Background diabetic retinopathy BDR - mild
• The presence of at least one of any of the following features
anywhere
- dot haemorrhages
- microaneurysms
- hard exudates
- cotton wool spots
- blot haemorrhages
- superficial/ flame shaped haemorrhages
R2
• Background diabetic retinopathy BDR - observable
• Four or more blot haemorrhages (ie >AH) in one hemi-field only (Inferior and superior hemi-fields delineated by a line passing through the centre of the fovea and optic disc)
R3
• Background diabetic retinopathy BDR – referable
• Any of the following features:
- Four or more blot haemorrhages (ie >AH) in both inferior and superior hemi-fields
- Venous beading (>AH)
- IRMA (>AH)
R4
• Background diabetic retinopathy BDR – referable
• Any of the following features:
- Four or more blot haemorrhages (ie >AH) in both inferior and superior hemi-fields
- Venous beading
- IRMA (>AH)
What are the DM Maculopathy Grades?
M0
• No features 2 disc diameters from the centre of the fovea sufficient to qualify for M1 or M2 as defined below.
M1
• Lesions as specified below within a radius of > 1 but 2 disc diameters the centre of the fovea
- Any hard exudates
M2
• Lesions as specified below within a radius of 1 disc diameter of the centre of the fovea
• Any blot haemorrhages
• Any hard exudates
How do Optometrists Contribute to DR?
Screening and early detection of diabetic eye problems
Monitoring and patient advice
Treatment of anterior segment disease
Referral for further investigation and/or treatment
How may DR present during H+S?
Vision:
Px may tell you that their vision fluctuates throughout the day – may be worse when they are hungry or after exercise.
General Health:
Px may tell you they are being investigated for diabetes
They may be diet controlled (no meds)
Family History:
Who (immediate family) had DM? TYPE? Age of Onset? Any effect on this family members eyes?
H+S - Monitoring already diagnosed?
General Health:
If Px is already diagnosed, you need to ask:
- Type
- Duration
- Medications
- Stability with meds/lifestyle
- Who monitors it?
- When was the last check-up with GP?
Are they attending DRS
- If yes – when was it? Were they advised of any changes in the back of their eye?
- If no – any reason why not? Consider putting them on annual recall and monitoring them within your practice
During Refraction:
Biggest indication: Fluctuating visual acuity throughout refraction
You should consider DM as part of your differential diagnosis whilst refracting if this is the case, especially if there are other risk factors.
What needs to be checked during Anterior Eye Health
Quantitative and qualitative evaluation of tear film
Measurement of corneal sensitivity
Treat any dry eye and monitor corneal defects
Look for inflammation in the anterior chamber
Look for any structural changes in the lens
Refer if persistent visual impairment
What needs to be checked during Posterior Eye Health
Fundoscopy Assessment
Consider dilation if:
Small pupils (<2mm)
>1 year since Px attended DRS
Poor blood glucose level control (H+S, Refraction)
First eye exam since diagnosis (yet to attend DRS)
Assessment can be aided with fundus photography
The best way to detect retinopathy early—when still treatable and before vision is irreversibly lost
Management: Shared Care and Recall
Monitor:
Every 2 years if Px is under a DRS scheme and seen annually
Annually, if Px does not under a DRS scheme and seen annually
(This can vary depending on health board)
Letter to GP:
To reassess blood glucose level and/or medication if clinically indicated
Referral:
GP – If first presentation at eye exam, for assessment and diagnosis
Ophthalmology - If clinically indicated
How does GP: Investigation and (Confirmation of) Diagnosis
Assessment of Blood Glucose Level
Blood Test
Urine Test
Once diagnosed, Px name goes on diabetes list
All diabetic patients are invited to attend annual retinal screening
How does GP: Management
Management of underlying IDDM or NIDDM
Monitor Px frequently to check general health
- Glycated haemoglobin (HbA1c) blood test (IDDM)
Referral to community optometry
Referral into local diabetic retinal screening scheme (DRS)
NHS Diabetic Retinal Screening Service
Nation-wide service
All diabetic patients over 12 years of age will be invited annually
Screening based primarily on digital fundus images
Non-mydriatic fundus photo (technicians, nurses)
Dilation if required (approx 25% of patients)
All images will be graded by an Optometrist
Optometrists’ role at the Diabetic Retinal Screening Service
Medical Retina Specialisation
Advanced grading of digital fundus images
Run slit-lamp clinics
Clinical decision-making/referrals
Diabetic retinal screening service: Management
Any images that may require referral will be graded at least by two graders
Referral from DRS directly to ophthalmology outpatient clinic
Screening result letter will be sent to patient and GP
If image quality at screening appointment inadequate: patient to be booked for appointment at slit-lamp clinic
NHS Diabetic Retinal Screening Service
Format of screening can vary based on health board:
Glasgow: Patients attend hospital-based screening clinics, also mobile clinics (van-based)
Lothian: Patients attend hospital or GP practice-based screening clinic, or are seen annually by their community optometrist
Ayrshire: Patients are see locally by an accredited community optometrist
DRS Referral Criteria
Can be considered appropriate for community optometry
Retinopathy and maculopathy are graded separately
Refer to Ophthalmology only if graded as:
R3 (advanced background retinopathy)
R4 (proliferative retinopathy)
M2 (severe maculopathy)
Ophthalmologist: Treatment
• Pan-retinal Photocoagulation (PRP)
• Anti-Vascular Endothelial Growth Factor Treatments
- Anti-VEGF agents can arrest, or even reverse, proliferative retinopathy and macular oedema
- E.g., intravitreal ranibizumab (LUCENTIS®)
- Less destructive than laser
• Intravitreal Corticosteroids
- Intraocular corticosteroids widely used to treat macular oedema
- Modest improvement of VA possible
- Long-acting steroid implants may be used
• Vitrectomy
- May be useful in advanced diabetic retinopathy
Example: vitreous haemorrhage
- May develop in proliferative DR, when new fragile vessels burst
Key Role of Optometrists
Optometrists are primarily involved in the diagnosis and monitoring of diabetic eye disease
Referral urgency depends on severity of retinopathy and maculopathy
Refer to HES when (Scottish DRS Grading):
R3 (advanced background retinopathy)
R4 (proliferative retinopathy)
M2 (severe maculopathy)
Optometrists goal:
Optometrists goal: is to identify anyone with pre-proliferative diabetic eye disease
With early diagnosis and laser photocoagulation, vision loss may be prevented/reduced
In case of vision loss, some sight may be regained by with anti-vascular endothelial growth factors or vitrectomy
DRS Criteria and Recall
Diabetic Retinal Screening
Optometrist (with medical retina specialisation certificate)
Perform (dilated) fundus photography in these patients annually and report any changes to GP/Ophthalmologist.
Routine Eye Examination
Annual recall for these patients IF they are not seen annually. If under DRS annually already – you see these Px’s every 2 years.
