Diabetic Retinopathy Flashcards
what is the cause of diabetic retinopathy?
diabetes
what are the risk factors to developing diabetic retinopathy?
duration of diabetes, poor blood sugar control, hypertension, hypercholesterolaemia, pregnancy, smoking, dramatically improved diabetic control leads to short term worsening
what are the two components of diabetic retinopathy?
macular oedema
retinal neovascularisation
what is the overarching mechanism of diabetic retinopathy?
Vascular Dysfunction and Permeability
what are the types of diabetic retinopathy?
No retinopathy Background retinopathy Maculopathy Pre-proliferative retinopathy Proliferative Advanced retinopathy
what is the definition of no retinopathy?
There are no abnormal signs present on the retina. Vision normal.
what is the definition of background retinopathy?
Signs of microvascular leakage (microaneurysms, haemorrhage, exudates) away from the macula. Vision normal.
what is the definition of maculopathy?
Exudates and haemorrhages within the macular region and/or evidence of retinal oedema, and/or evidence of retinal ischaemia within the macular. Vision is reduced; sight threatening
what is the definition of pre-proliferative retinopathy?
Evidence of arteriolar occlusions (IRMA, cotton wool spots). The veins become irregular and may show loops. Vision normal.
what is the definition of proliferative retinopathy?
The occlusive changes have led to the release of a vasoproliferative substance from the retina, resulting in the growth of new vessels either on the disc (NVD) or elsewhere on the retina (NVE). Vision norml; sight threatening
what is the definition of advanced retinopathy?
Proliferative changes result in bleeding into the vitreous or between the vitreous and the retina. Neuroretina may be pulled from its overlying pigment epithelium by a fibrous proliferation associated with the growth of the new vessels. Vision is reduced, often acutely, with vitreous haemorrhage; sight threatening.
what is the pathophysiology of diabetic retinopathy?
- Chronic hyperglycaemia
- Glycosylation of protein/basement membrane (of retina vasculature)
- Loss of pericytes (capillaries become leaky)
- Reduced O2 transport – tissue hypoxia
- Vasoformative factors are produced – neovascularisation
- vessels are of poor - haemorrhage and scarring
what are flame haemorrhages of the eyes?
rupture of vessels microaneurysms at the nerve fibre level
what are blot haemorrhages?
deep haemorrhages
what are the different stages of diabetic retinopathy?
Mild NPDR Moderate NPDR Severe NPDR Proliferative Macular Oedema
what is the definition of mild NPDR?
1 or more microaneurysm
what is the definition of moderate NPDR?
o microaneurysms
o blot haemorrhages
o hard exudates
o cotton wool spots, venous beading/looping and intraretinal microvascular abnormalities (IRMA) less severe than in severe NPDR
what is the definition of severe NPDR?
o blot haemorrhages and microaneurysms in 4 quadrants
o venous beading in at least 2 quadrants
o IRMA in at least 1 quadrant
what is the definition of proliferative NPDR?
Characterised by neovascularisation
o New vessels on posterior vitreous - lacy new vessels and cotton wool spots
o Grow on disc, periphery and iris
o Posterior vitreal detachment
what is the definition of macular oedema?
o Leading cause of blindness is diabetes
o Can present at any stage
o As oedema, patient will notice blurry central visiom
o Seen as hard exeudates
o Fluid build up under RPE layer – seen on OCT
what is the management of retinopathy (DR)?
o No proliferative – observe/rescreen
o Proliferative – laser – abolish peripheral to preserve central
Surgery? – virectomy
What is the management of maculopathy (DR)?
o Reduced vision only
o Anti-VEGF
o Occasional “focal” laser
what is the pathophysiology of hypertension retinopathy?
- Hypertension results in diffuse constriction of retinal vessels
- Can become persistent, leading to thickening with focal constriction
- Breaking tight junctions leads to microaneurysms, macroaneurysms
what are the fundoscopic features of hypertension retinopathy?
- Attenuated blood vessels – copper or sliver wiring
- Cotton wool spots
- Ard exudates
- Retinal haemorrhage
- Optic disc oedema
what is the management of hypertension retinopathy?
optimise management, usually improve once BP is under control
