Diabetic Retinopathy Flashcards
Risk factor for DR
- African and Hispanic ethnicity
- T1DM (have diabetes for longer period, more time to develop DR complications)
- Duration of diabetes - >10 years
- High HbA1c - >8.0%.
Work up for DR
- Visual acuity (best corrected – distance and near, monocularly)
- Pupil reactions (direct/consensual and near pupil responses)
- Motility and cover test (correct any diplopia with prism)
- Visual field screening (minimum confrontation fields)
- Refraction (diabetes can lead to lens swelling and dioptric changes)
- Slit lamp Biomicroscopy (with dilation)
a. Identify any NVC, cataracts, corneal changes. - IOP (pre & post dilation)
- Stereoscopic fundus exam (using 0.5 or 1.0% tropicamide)
- Dilated retinal photography.
- Gonioscopy (assess glaucoma risk, narrow angle/NVC)
Signs for DR
decrease VA, decreased contrast sensitivity, increased central/paracentral retinal thickness, presence of intraretinal cysts.
Qs for DR classification and management
- How severe is the DR?
- Is there macula oedema?
- Is it clinically significant?
What is CSME
a. Macula thickening ≤500um (1/3 DD) from fovea
b. Hard exudate ≤500um from fovea with adjacent retinal thickening
c. Retina thickening ≥1 disc area in size, any portion of which is ≤1500um (1DD) from fovea.
Clinical findings for Mild NPDR
MA + retinal hb / CWS/ Hex
Clinical findings for Moderate NPDR
Hb/MA > photo 2A + CWS or venous beading + IRMA in 1/4
Clinical findings for Severe NPDR
One or more (4/2/1):
- Hb/MA Hb/MA > photo 2A in 4/4
- Venous beading in 2/4
- IRMA >Photo 8A in ¼
Clinical findings for Mild PDR?
NVD or NVE or Fibrous proliferation
Clinical findings for Moderate PDR?
NVD <Photo 10A (1/4 – 1/3 DA) or Vhb/PRhb and NVE <1/2 DA and NVD absent
Clinical findings for Severe PDR?
One or more (4/2/1):
- NVD>1/4 – 1/3 DA (Photo 10A)
- NVD and Vhb /PR hb
- NVE >1/2 DA and V hb /PR hb
Read follow up and referral timelines for DR
Read follow up and referral timelines for DR
Management for DR
Management:
1. Optimize cardiovascular risk factors.
a. Report to GP for intensive glycaemic control (recommended by DCCT) – aiming for <6.0%
b. Recommend intensive blood pressure control (UKPDS) - <130mmHg systolic target.
c. Recommend weight loss – 5 -10% reduction.
d. If px has high cholesterol recommend change from levato to fenofibrate (reduce DR risk)
2. Recommend regular aerobic training (30min 4x a week)
a. Exercise that make you puff
3. Referral to ophthalmologist for
a. Anti VEGF – Aflibercepts better for VA 6/15 or worse or PDR (DA VINCI + VISTA + VIVI DME study) May use Ranibizumab or Bevacizumab if needed.
b. Steroids: Dexamethasone (implant) may be used in alone or in combination with PRP. Triamcinolone 1mg or 4mg (worse VA than PRP, risk of endophthalmitis, retinal tear/detachment, elevated IOP, cataract). Fluocinolone Acetonide (surgical implant) – use alone or with PRP. Risk of elevate IOP and cataracts.
c. Panretinal Photocoagulation (PRP) – decrease demand for blood supply → decrease in new vessels. RISK of severe vision loss and progression of DR
d. Pars Plana Vitrectomy: beneficial for non-clearing vitreous hb and traction RD. Minimal functional improvements.
New emerging tx in DR
- Neuroprotective agent: doxycycline (50mg) or glycosaminoglycan. Prevent DR progression. Doxycycline has not significant functional/anatomical improvement.
- Angiopoietin 2 – antagonist of the tunica internal endothelial cell kinase (TIE2) receptor →increased vascular permeability and angiogenesis. Intravitreal injection TID for 4 weeks – multiple dosages available)
- Encapsulated cell technology (ECT) – allow a genetically modified group of cells lines expressing the gene of interest to encapsulate in synthetic semi-permeable capsules, allow diffusions of nutrients to these cells while protecting them from the hosts defence mechanism.
