OnExam

Performing the Test

  1. Check the patient's visual acuity using a Snellen eye chart
  2. To properly examine the macula and peripheral retina, mydriatic drops should be used; however, in family practice this is often not available
  3. Patients with sight-threatening diabetic retinopathy should be assessed by a general ophthalmologist or retinal specialist
  4. Perform ophthalmoscope examination
  5. Focus on the optic disc and retina for pathologic changes:
    • Nonproliferative retinopathy
      • Microaneurysms - Red round spots at the end of small arteries
      • Dot haemorrhages - Larger red dots with sharp borders
      • Blot haemorrhages - Larger red dots with indistinct borders
      • Hard exudates - Small, white or yellowish deposits with sharp margins that have a waxy or glistening appearance
      • Soft “cotton wool” exudates - White patches with ill defined feathery edges
      • Venous beading - Veins resemble a string of beads
      • Intraretinal microvascular abnormalities(IRMA)
    • Proliferative retinopathy (new vessel formation)
      • Neovascularlization of the disc (NVD) - New small vessels that often resemble a wagon wheel
      • Neovascularization elsewhere (NVE) - New small vessels at least one disc diameter away from the disc
    • Macular edema (may accompany any stage of nonproliferative or proliferative retinopathy)
      • Difficult to visualize, but clues are rings of hard exudates and diminished visual acuity

References

  1. Bickley L, Szilagyi P. BATES’ Guide to Physical Examination and History Taking. 9th edition. Lipincott Williams & Wilkins; 2007.
  2. McGee, S. Evidence Based Physical Diagnosis. St. Louis Missouri. Saunders Elsevier. 2007.
  3. Canadian Diabetes Association Clinical Practice Guidelines Expert Committee. Canadian Diabetes Association 2008 clinical practice guidelines for the prevention and management of diabetes in Canada. Can J Diabetes. 2008; 32(suppl 1): S1-S201.
  4. Gardner D, Shoback D. Greenspan’s Basic & Clinical Endocrinology. 8th Edition. USA. McGraw-Hill. 2007