The Retina Flashcards
Name the 5 layers of the retina
- optic nerve fibre layer (inner)
- ganglion cell layer
- bipolar cell layer
- photoreceptor layer
- pigmented epithelium (RPE) (outer)
What imaging can be used to assess the layers of the retina & fovea
Optical Coherence Tomography
What are the types of diabetic eye disease
- non-proliferative retinopathy
- proliferative retinopathy
- maculopathy
Diabetic eye disease pathophysiology
→Loss of pericytes
→Protein glycosylation
→Blood vessel leakage
→Increased blood viscosity
→Reduced oxygen transport
→RETINAL ISCHAEMIA
Name the 4 signs of NPDR
- cotton wool spots
- microaneurysms/ dot haemorrhages
- blot haemorrhages
- venous changes (looping/beading)
Is NPDR typically asymptomatic or symptomatic
Asymptomatic
What are dot haemorrhages/ micro-aneurysms
Localised outpouchings of retinal capillaries where pericytes are lost. One of the earliest signs of NPDR
What are cotton wool spots
Ischaemic disruption of the axons in the nerve fibre layer
What are venous changes in NPDR
Generalised dilation and tortuosity plus areas of focal narrowing (beading)
What are blot haemorrhages in NPDR
Intraretinal haemorrhages and infarcts. The more visible, the more ischaemic the retina
What is the 4-2-1 rule
Classification of severe NPDR….
-Blot haemorrhages in 4 quadrants
-Venous beading in 2 quadrants
-IRMA in 1 quadrant
What are IRMA in NPDR
IntraRetinal Microvascular Abnormality - Represent shunts between the arterioles and venules, bypassing the retinal capillary bed. Act to supply areas of non-perfused retina
How is PDR classified
-NVD (disc)
-NVE (elsewhere in retina)
-NVI (iris)
How can PDR cause loss of vision
PDR treatment
Laser PRP (pan-retinal photocoagulation)
Where do you laser in PDR & why
Laser the ischeamic peripheral retina
This reduces VEGF production
This preserves vision
Laser in PDR consequence
Loss of peripheral vision
What are the two main signs of diabetic maculopathy
Exudates & microaneurysms in macula
When would you treat diabetic maculopathy
When it affects the fovea
What is exudates
Lipid deposits from leaking blood vessels
Diabetic maculopathy treatment
Anti-VEGF injections
What are the two types of retinal vein occlusion
Branch RVO (BRVO)
Central RVO (CRVO)
How does retinal vein occlusion present (symptoms)
- Painless vision loss
- RAPD (if significant)
Retinal vein occlusion pathophysiology
- Atherosclerotic plaque travels through artery
- Artery shares sheath with vein
- Artery occlusion causes venous & capillary pressure to rise
- Blood products extravasate veins
- Hypoxic drive occurs & VEGF is production/ released
Retinal vein occlusion signs
Retinal vein occlusion risk factors
Retinal vein occlusion management
Retinal artery occlusion two types
CRAO & BRAO
Retinal artery occlusion symptoms
Retinal artery occlusion pathophysiology
Retinal artery occlusion signs
Retinal artery occlusion management
What are the two types of age related macular degeneration
Dry (most common, 90%)
Wet
Dry ARMD pathophysiology
Deposition of drusden (accumulation of byproducts - proteins, lipids, and inflammatory mediators) in RPE and between RPE and Bruch membrane results in slow progressive atrophy of the local RPE
Wet ARMD pathophysiology
- Neovascularisation in choroid, mediated by VEGF
- New vessels are small and fragile → more likely to haemorrhage so more likely to result in visual loss
Wet ARMD treatment
Anti-VEGF
Dry ARMD treatment
None
- monitoring & e.g. supplements
Wet vs ARMD clinical presentation
What can help you differentiate ARMD & diabetic eye disease
Age (ARMD = older) &
Distribution (ARMD = macular distribution)
What is retina detachment
Detachment of Neurosensory retina from RPE
What are the three types of retinal detachment
- Rhegmatogenous
- Tractional
- Executive
Rhegmatogenous vs Non-Rhegmatogenous
Rhegmatogenous retinal detachment risk factors
- Posterior vitreous detachment
- Pathological myopia
- Previous intraocular e.g. cataract surgery
- Trauma
Rhegmatogenous Retinal Detchment (RRD) classic triad of symptoms
-Floaters: pigment cells in vitreous
-Flashes of light: mobile retina
-Shadow in vision: detached film of camera
Retinal detachment treatment
Vitrectomy
