Unit 6 ocular disease Flashcards
DR risk factors
Type 1 more common (40%), Type 2 (20%)
Duration of Disease
Before 30yrs – 50% risk after 10 years
After 30yrs – 90% risk after 10 years
Poor Metabolic Control
Pregnancy
Hypertension (most will have both conditions)
Obesity
what is hypertension
Hypertension is a medical condition where the pressure inside the arteries is persistently elevated
The initial response of retinal arterioles to systemic hypertension is vasoconstriction
Prolonged HBP can lead to hardening of vessel walls, AV nipping and eventually increased vascular permeability
hypertensive retinopathy grading
Grade 1 – arteriolar narrowing – 2:1 - GP
Grade 2 – arteriolar narrowing / nipping – 1:3 - GP
Grade 3 – narrowing, nipping, haemorrhages, exudates and Cotton wool spots – HES
Grade 4 – narrowing, haems, exudates, Cotton wool spots, disc swelling, macular star - HES
in severe cases swollen disc, macular oedema as well
CRAO
Sudden painless monocular loss in vision
VA < CF, complete loss – generally all areas of the VF (Unless a cilioretinal artery supplying a critical macular area preserves vision)
RAPD
White, oedematous retina; cherry ret spot at fovea; Attenuation of arteries and vein
Referral emergency same day if <24hrs
Urgent if >24hrs
BRAO
Sudden painless altitudinal or sectoral visual field loss; vision may be unaffected
Signs confined to the region of the retina supplied by the affected branch
VA is variable; RAPD often present
Fundus signs may be subtle; whiteish, oedematous SECTOR of the retina (area of ischaemia)
Altitudinal or sectoral VF defect – which may become permanent if left untreated
ischaemic CRVO
- VA poor
- RAPD
- Dilation/tortuosity, flame shaped & dot-blot haem, cotton wool spots
Rubeosis develops in 50% of eyes – 100 day glaucoma, new vessels at disc and elsewhere - poss vitreous haem as complication
Macula may develop atrophic retinal and RPE changes, ERM and chronic CMO
Urgent referral to HES (same day referral to GP for blood workup)
Emergency referral if IOPs > 40mmHg
ACE inhibitors - Lisinopril & ramipril side effect
may cause ciliary body oedema which leads to reduced accommodation and angle closure
hyperthyroidism
Thyroid eye disease / Graves
WET phase (myogenic) - EOMs (recti; IR affected first) swell up to 8-10x normal size (2-3 years)
DRY phase (mechanical) - Fibrosis & secondary muscle contracture
Connective tissue inflammation; redness, discomfort, peri-orbital swelling
Corneal exposure; gritty/redness
Diplopia and proptosis
May cause visual loss due to ONH compression
Marfans syndrome
Autosomal dominant connective tissue disorder
Tall, thin stature with long limbs
Myopia, corneal abnormalities, ectopia lentis – dislocation of lens, retinal detachment
rheumatoid arthritis
Dry eye disease / Sjogrens syndrome
Iritis – 2nd episode; refer for systemic work up
Episcleritis / scleritis – refer for systemic work up at 3rd episode
multiple sclerosis
Demyelinating disease affecting CNS
Optic neuritis; mostly commonly retrobulbar
ocular manifestations of high cholesterol
o Arcus
o Xanthalesma
o Retinal emboli – Hollenhorst plaque
o CRAO
o CRVO
what is the primary response of the retinal arterioles to systemic HBP?
HBP is vasoconstriction
* Arteriolosclerosis refers to hardening and loss of elasticity of small vessel walls
o Manifested most obviously by AV nipping at crossing points
o Mild AV changes may be seen in the absence of HBP
* In sustained HBP the inner blood-retinal barrier is disrupted, increased vascular permeability leading to flame-shaped haemorrhages and oedema
* Increased venular tortuosity can be associated with chronic hypertension and pre-hypertension, though evidence on tortuosity is conflicting
* CRVO
Ankylosing Spondylitis
ocular manifestations
o Acute anterior uveitis, occurs in about 25% of pxs
o Episcleritis
o Scleritis
o Keratitis
o Mechanical ptosis
o Cataract
asthma ocular manifestations
o Dry eye
o Cataract
o Glaucoma
o CSR – due to steroid inhalers
RVO risk factors
o Increasing age (>65)
o HBP
o Hyperlipidaemia
o Diabetes
o Glaucoma
o Oral contraceptive pill
o Smoking
CRAO cause
Central retinal artery occlusion (CRAO) is caused by a blockage in the central retinal artery, usually by a blood clot or cholesterol deposit
what is non ischaemic CRVO
Where the outer retinal layers are still perfused as choroidal circulation remains
intact
* 30% will progress onto ischaemic
Sudden onset, unilateral blurred vision (6/36-6/60). Main concern: conversion to ischaemic
Signs
* Tortuous dilated veins in all 4 quadrants of the retina
* Round/Blot and flame haemorrhages
* Occasional CWS
* Mild Possible macula and disc oedema
* Mild/absent RAPD
residual signs of cRVO
- Disc collaterals
- Epiretinal Gliosis
- Pigmentary changes at the macula
Tx CRVO
Treatment – Laser PRP for neovascularisation, Intravitreal Anti-VEGF and steroids for
neovascularisation and macula oedema
Investigation – Investigate underlying cause and blood work up. Assess whether
ischaemic or non-ischaemic.
risk factors CRAO
Aged 70-80yrs
* Carotid artery occlusive disease
* systemic hypertension
* high cholesterol
* smoking
* diabetes
* history of stroke or TIA
* Amaurosis Fugax attack (sudden blanking of vision lasting a few seconds)
sudden painless loss of vision
later developments of CRAO
- Atrophy of inner retinal layers and optic nerve
- Neovascularisation at the disc and iris
- Vessels remain attenuated and cherry red spot reduces over weeks
management CRAO
- Massage the globe with px laying down
- REBREATHE CO2.
- Nd-YAG laser of embolus if visible
- Acetazolamide (Carbonic Anhydrase inhibitors): Decreases IOP by decreasing
Aqueous Humour production - Sublingual Isosorbide dinitrate: Causes vasodilation, can help move a clot
- Anti-coagulants (e.g. Warfarin) as risk of stroke/ischaemic heart disease is high.
symptoms of TIA
- Weakness
- Numbness down one side of body
- Vertigo
- Diplopia
- Slurred speech and loss of balance/co-ordination
- Transient vision loss (amaurosis fugax):
o Curtain coming down on vision, can be total or sectorial, resolves
completely (centrally first)
o Most common cause: embolism
o High risk of impending CRAO or vision loss through AION.
Urgent referral to GP and Ophthalmology for MRI and bloods.
