Hypertensive Retinopathy Flashcards
Explain the term hypertension
This is where the bp has been over 140/90 on more than 2 occasions
Explain the prevalence of hyp retinop
32% men 30% women
What are the risk factors of hbp
Smoking, obesity, race, age
Explain the arteriolar response in hypertension and av ratio changes?
Vasoconstriction and the av ratio reduces (normal-2/3)
Explain atherosclerosis
This is where there is a decline of muscular and elasticity in the arteriolar wall which leads to a hardening and thickening of the walls and hence thy ant respond as well to hbp
What happens to the light reflex with arteriosclerosis?
As the walls harden with plaque the light reflex loses its brightness and becomes broader and diffused
Explain copper wiring
This is where atherosclerosis had built up so much that there’s only a narrow space for blood to travel in the artery. The brightness is more and more diffused but then during fundoscopy the light reflects off the artery and you see a diffused red/brown light
Explain silver wiring
The arteriolar wall is completely opaque and you get a bright reflex reflecting off
What does hypertension damage more and which signs are shown?
Hypertension breaks the blood retinal barrier by compromising the tight junctions and increasing permeability which allow harmful things to get in which lead to blood, plasma and lipids coming in.
This leads to haemorrhages, oedema and exudates
What are the sx of hyp ret
It’s a symptomatic but extreme cases leads to blur due to swelling at ONH and macula oedema
How do the signs of hypertensive ret appear?
As bilateral and symmetrical.
What is the first sign of hypertension ret
Narrowing. Normal av ratios are 2/3 but the arteriolar walls narrow which narrows them to 1/2
Explain tortuousity
This is where there are changes in the structure of vessel walls. This is a sign of changes but shouldn’t be used in isolation to diagnose someone with hypertension ret
What’s nipping (gunna sign)
Thinner Walled venules compressed by arterioles
What’s salus sign?
Deflection and tapering (changing direction and thinning)
What are myelinated fibres?
Blood vessels sit underneath the nerve fibre layer. Nerve fibre layers are transparent but when they’re opaque they are myelinated
Where’s the hidden layer of blood vessels?
Between the inner nuclear and outer plexiform
Where do flame haemorrhages occur?
Blood vessels leaking in NFL and the shape is an arcuate design because it follows the NFL shape. Follows the shape of diverging path or ganglion cell axons
Where are dot and blot? and explain their characteristics
They are leaking within the inner nuclear and outer plexiform and because the blood is squashed in the middle the shape doesn’t change from a dot
What leads to oedema?
Leaking of vessels into the tissue, causes oedema which causes thickening and elevation of retinal surface which causes a swelled appearance
explain the characteristics of hard exudates?
Well defined, yellow/white, develops around vesssels, clustered together, form in the outer plexiform and because of exudates from everything (blood, plasma and lipid), take time to develop and less likely to resolve after exudation stops
Explain soft exudates:
White, fluffy, NFL, hide vessel that are under and show places where there isn’t enough blood because of blocked arterioles which is due to damage because of hbp
When there’s an increase of axoplasmic material with soft exudates, what happens?
Swelling of neural tissue in NFL leading to cell death but cotton wool spots disappear but damage is already done and visual field won’t disappear
Explain how you find optic disc swelling?
Edges blur, vessels travel in and sticking out of the ONH. REFER
What is the differential diagnosis of hyp ret?
Diabetic retinopathy which is more educative and with more haemorrhaging and oedema.
Also retinal vein occlusion which is unilateral
What is the management of hyp ret?
Refer to gp for management for their diet and lifestyle and also to check for other diseases. Medication such as calcium channel blockers and ace inhibitors (ramipril and amplodipine).
- moderate: ring and see if urgent
- moderate/severe: refer urgent. (Associated with risk of stroke and heart disease)
Explain hyp ret classification
- none: no signs
- mild: narrowing, nipping, copper wiring
- moderate: flame, dot/blot, cotton wool, hard exudates
- severe: all including disc swelling
