Ophthalmology Flashcards
(80 cards)
What are the causes of Red Eye ??
Acute Angle closure Glaucoma
Anterior Uveitis
Scleritis
Conjunctivitis (Viral: Clear discharge, Bacterial: Purulent discharge
Subconjunctival Haemorrhage (H/o trauma or Coughing bouts)
Endophthalmitis (Pain+ Vision loss following Intraocular Sx.)
Causes of Sudden Vision loss ??
Transient Monocular Vision Loss (TMVL) is a sudden, transient loss of vision lasting < 24hrs
- Ischaemic/ Vascular: Thrombosis, Embolism, Temporal arteritis; CRVO, CRAO
- Vitreous Haemorrhage
- Retinal detachment
- Retinal Migraine
What is Amaurosis fugax ??
Ischaemic/ Vascular diseases cause TMVL, ‘Curtain coming down’
- Large artery disease (Athero-thrombosis, Embolus, Dissection)
- Small artery occlusive disease (AION ,vasculitis-eg. Temporal Arteritis), Venous disease & Hypoperfusion
- May represent a form of TIA, therefore Rx.- Aspirin 300mg
What causes Ischaemic Optic Neuropathy ??
Occlusion of Short Posterior Ciliary Arteries => damages Optic nerve
Causes of Tunnel Vision ??
Concentric diminution of Visual field
- Papilloedema
- Glaucoma
- Retinitis pigmentosa
- Choroidoretinitis
- Optic atrophy secondary to Tabes dorsalis
- Hysteria
Causes of Mydriasis ??
- 3 rd nerve palsy
- Holmes-Adie Pupil
- Traumatic Iridoplegia
- Phaeochromocytoma
- Congenital
Drugs causing Mydriasis ??
- Tropicamide, Atropine
- Sympathomimetics: Amphetamines, Cocaine
- Anticholinergica: TCAs
Anisocoria can occur in apparent mydriasis, due to the difference with other pupil
What is CRAO ??
Due to Thromboembolism (from atherosclerosis) or Arteritis
- Sudden, Painless U/L vision loss
- Relative Afferent Pupil Defect
- ‘CHERRY Red’ spot on Macula
Rx. of CRAO ??
- Treat the underlying cause (eg. IV Steroids for Temporal Arteritis)
- Acute presentation: Intra-arterial Thrombolysis
- Generally Poor prognosis
RF & Features of CRVO ??
- Increasing age, HTN, CVS diseases
- Glaucoma, Polycythaemia
C/F- - Sudden, Painless reduction or loss of visual acuity, usually U/L
- Severe Retinal Hemorrhage: ‘Stormy sunset’
Rx. of CRVO ??
Conservative Rx.
Rx. indication: Macular edema:- Intra-vitreal anti- VEGF agents
Retinal Neovascularization: Laser Photocoagulation
What is BRVO ??
Occurs when a vein in the Distal Retinal Venous System is occluded
- Due to blockage of Retinal veins at AV crossings
- LIMITED area of fundus is affected
What is the MCC of blindness in adults aged 35 to 65 yrs old ??
Diabetic Retinopathy
- Hyperglycaemia => increase Retinal blood flow & Abnormal metabolism in Retinal Vessel wall => ppt. damage to Endothelial cells & Pericytes
- Endothelial dysfunction => increase vascular permeability => EXUDATE
- Pericyte dysfunc. => Microaneurysm formation
- Retinal ischaemia => GFs production => NEOVASCULARIZATION
Diabetic Retinopathy Classification ??
NON-PROLIFERATIVE D R
PROLIFERATIVE D R
- Retinal Neovascularisation- can cause Vitrous Haemorrhage
- Fibrous tissue forming Anterior to Retinal disc
- More common in Type 1 DM; 50% blind in 5 yrs.
MACULOPATHY
- Hard exudates & other ‘background’ changes on Macula
Which type of D Retinopathy is common in the following-
- Type 1 DM ??
- Type 2 DM ??
- Proliferative D R
- Maculopathy
How is Non-Proliferative D R classified ??
Mild NPDR
- >= 1 Microaneurysm
Moderate NPDR
- Microaneurysm
- Blot Haemorrhages
- Hard exudates
- Cotton Wool spots (Soft Exudates- represents the area of retinal infarction)
- Venous beading/ looping & Intraretinal Microvascular abnormalities (IRMA) less severe than in severe NPDR
SEVERE NPDR
- Blot haemorrhages & Microaneurysms in 4 quadrants
- Venous beading in at least 2 quad.
- IRMA in at least 1 quadrant
Rx. of Diabetic Retinopathy ??
Maculopathy: Intra-vitreal VEGF inhibitor
Proliferative D R:
- Panretinal Laser Photocoagulation
- Intra-vitreal VEGF inhibitors (eg. Ranibizumab
- Both can Slow down progression of PDR & improve visual acuity
NPDR
- Regular observation
- Severe/ Very Severe: Panretinal Laser Photocoagulation
Keith Wagener Classification of HTN Retinopathy ??
Stage 1:
- Arteriolar Narrowing & Tortuosity
- Silver wiring (Increased light reflex)
Stage 2: AV Nipping
Stage 3:
- Cotton-wool exudates
- Flame & Blot haemorrhages (These can collect around Fovea => ‘Macular Star’
Stage 4: Papilloedema
What is Retinitis pigmentosa ??
Primarily affects the PERIPHERAL Retina resulting in Tunnel vision
- 1st sign: Night blindness
- Tunnel/ Funnel vision
Fundoscopy: Black bone spicule- shaped pigmentation in the peripheral retina; Mottling of Retinal pigment epithelium
What is Refsum disease ??
Cerebellar ataxia + Peripheral Neuropathy + Deafness + Ichthyosis
What is Angioid Retinal Streaks ??
Irregular dark red streaks radiating from the optic nerve head
- due to Degeneration, Calcification & Breaks in BRUCH’s Memb.
Causes of Retinal Angioid Streaks ??
- pseudoxanthoma elasticum
- Ehler-Danlos syndrome
- Paget’s disease
- Sickle cell anaemia
- Acromegaly
What is the MCC of blindness in the UK ??
Age-Related Macular Degeneration
- usually B/L condition
- Retinal Photoreceptors degeneration => Drusen formation
- MC in Increasing age (3x increase in >=75yrs) & in FEMALES
- Smoking (2x common)
- FAMILY Hx. (if 1st degree relative => 4x more common)
- IHD : HTN, Dyslipidaemia, DM
Presentation of ARMD ??
Subacute onset of Visual loss (typical)
- Reduced Visual Acuity (particularly: NEAR field objects)
- Dark adaptation difficulty + overall deterioration in vision at night
- Fluctuations in Visual fields (on a day to day basis)
- Photopsia: Flickering & Flashing light
- Glare around the objects