Diabetic Retinopathy Flashcards
Incidence of DR
after 10 years is 50%, and after 30 years 90%
Risk factors for DR
Duration, Poor control, Sudden improvement in control, Pregnancy, Hypertension, Nephropathy, hyperlipidaemia, smoking, cataract surgery, obesity and anaemia
The most important risk factor
Duration
Diabetic macular oedema in pregnancy
usually resolves spontaneously after pregnancy and need not be treated if it develops in later pregnancy
Background diabetic retinopathy
microaneurysms, dot and blot haemorrhages and exudates
Preproliferative diabetic retinopathy
cotton wool spots, venous changes, intraretinal microvascular anomalies (IRMA) and often deep retinal haemorrhages
PDR
neovascularization on or within one disc diameter of the disc (NVD) and/or new vessels elsewhere (NVE) in the fundus
Microaneurysms - where in retina
in the inner capillary plexus (inner nuclear layer)
Very mild NPDR
Microaneurysms only
Mild NPDR
Any or all of: microaneurysms, retinal haemorrhages, exudates, cotton wool spots, up to the level of moderate NPDR
Moderate NPDR
Severe retinal haemorrhages (more than ETDRS standard photograph 2A: about 20 medium–large per quadrant) in 1–3 quadrants or mild IRMA • Significant venous beading can be present in no more than 1 quadrant
Severe NPDR
The 4–2–1 rule; one or more of: • Severe haemorrhages in all 4 quadrants • Significant venous beading in 2 or more quadrants • Moderate IRMA in 1 or more quadrants
Very severe NPDR
Two or more of the criteria for severe NPDR
Mild–moderate PDR
New vessels on the disc (NVD) or new vessels elsewhere (NVE)
High-risk PDR
• New vessels on the disc (NVD) greater than ETDRS standard photograph 10A (about 1/3 disc area) • Any NVD with vitreous haemorrhage NVE greater than 1/2 disc area with vitreous haemorrhage
Exudates - where in the retina
outer plexiform layer
DME - which layers
between the outer plexiform and inner nuclear layers; later it may also involve the inner plexiform and nerve fibre layers
Focal maculopathy
well-circumscribed retinal thickening associated with complete or incomplete rings of exudates. FA shows late, focal hyperfluorescence due to leakage, usually with good macular perfusion
Diffuse maculopathy
diffuse retinal thickening, which may be associated with cystoid changes; FA shows mid- and late-phase diffuse hyperfluorescence
Ischaemic maculopathy
FA shows capillary non-perfusion at the fovea (an enlarged FAZ) and frequently other areas of capillary non-perfusion at the posterior pole and periphery
Clinically significant macular oedema
• Retinal thickening within 500 μm of the centre of the macula • Exudates within 500 μm of the centre of the macula, if associated with retinal thickening; the thickening itself may be outside the 500 μm • Retinal thickening one disc area (1500 μm) or larger, any part of which is within one disc diameter of the centre of the macula
Cotton wool spots - where in the retina
within the nerve fibre layer. They are clinically evident only in the post-equatorial retina
Intraretinal microvascular abnormalities (IRMA)
arteriolar–venular shunts that run from retinal arterioles to venules, thus bypassing the capillary bed and are therefore often seen adjacent to areas of marked capillary hypoperfusion
Intraretinal microvascular abnormalities (IRMA) - FA
focal hyperfluorescence associated with adjacent areas of capillary closure (‘dropout’) but without leakage
