Retinal Vascular Disease Flashcards
What complications can arise from diabetes mellitus in the eye?
The most common is diabetic retinopathy, but it can also cause cataracts, extraocular muscle palsy, stroke, and retinal vascular occlusions.
What is the proposed pathophysiology of how diabetes causes diabetic retinopathy?
Hyperglycemia is believed to be the primary cause of the microvascular complications of diabetes.
Glycosylation of tissue proteins may play a role.
Small vessel occlusions and increased permeability (loss of blood-retinal barrier) are the consequences of diabetes.
Increased red cell and platelet stickiness allow for ischemia and a higher risk of clots to occur.
The proliferation of new vessels (neovascularization) occurs in response to vasogenic factors released by ischemic retina.
What is the clinical presentation of diabetic retinopathy?
Visual loss is usually caused by maculopathy or vitreous hemorrhage.
Visual loss in maculopathy may be small at first but is progressive, while vitreous hemorrhage causes a sudden severe visual loss.
Vitreous hemorrhage occurs because due to diabetes the eye forms new blood vessels and these are often weaker and more likely to burst.
What are some clinical features of diabetic retinopathy?
microaneurysms (focal capillary dilatations)
dot hemorrhages
blot hemorrhages (darker and larger)
exudates (yellow protein-rich material)
cotton wool spots (indicates significant ischemia)
venous changes (looping and bending)
neovascularization
What is a differential diagnosis for diabetic retinopathy?
retinal vein occlusion
hypertensive retinopathy
What are some differentials for sudden painless loss of vision?
Ischemic/vascular causes - thrombus, embolus, TIA/stroke causing hypoperfusion, giant cell arteritis, temporal arteritis
occlusion of central retinal vein
occlusion of central retinal artery
vitreous hemorrhage
retinal detachment
retinal migraine
What are the symptoms and clinical features seen in retinal vein occlusion?
sudden painless loss of vision, decrease in visual acuity,
RAPD sometimes
on fundoscopy - cotton wool spots, blot/dot/flame hemmorhages, swollen optic disc and macular edema.
What are some complications of retinal vein occlusion?
iris neovascularization which can cause a severe painful glaucoma which is difficult to control.
What is retinopathy of prematurity?
occurs in babies often born prematurely or low birth weight babies.
Its development is associated with high inhaled oxygen concentrations during the neonatal period.
Other risk factros include maternal smoking, neonatal sepsis and blood transfusion.
This is because normal neonatal vascularisation is not complete until full-term gestation.
Vessels can then grown normally afterward and resolve or grow abnormally and grow into the vitreous cavity.
Vessels can bleed and the fibrous component can contract causing detached retina.
