Ophthalmology Flashcards
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
Ix. of ARMD ??
Slit-lamp Microscopy
- Initial IoC
- Accompanied by Colour Fundus Photography to provide a baseline against which changes over time is identified
Fluorescein Angiography
- used if Neovascular ARMD doubted as this can guide intervention with anti-VEGF therapy
Ocular Coherence Tomography
- 3D visualisation of Retina
- Reveals the areas of disease which aren’t visible to microscopy alone
Important Signs of ARMD ??
- Amsler grid testing: Line perception distorted
- Fundoscopy: Drusen, yellow areas of pigment deposition in Macular area => later confluences to form a Macular Scar
- Wet ARMD: Well demarcated red patches may be seen which represent Intra-retinal or Sub-retinal fluid leakage or haemorrhage
ARMD classification ??
Dry Macular Degeneration
- 90% cases (MC)
- aka Atrophic
- Drusen (+)ve: Yellow round spots in Bruch’s membrane
WET Macular Degeneration
- 10% cases
- aka Exudative or Neovascular M D
- ‘CHOROIDAL Neovascularization’
- Leakage of Serous fluid & Blood can result in rapid vision loss
EARLY ARMD
- Non-exudative, age-related maculopathy
- Drusen & alteration to Retinal Pigment Epithelium
LATE ARMD
- Neovascularization, Exudative
Which ARMD can worsen after Laser Photocoagulation ??
Sub- Foveal ARMD (causes Acute Vision Loss)
Rx. of ARMD ??
Anti-VEGF therapy
- Limits progression of Wet ARMD; should be given in 1st 2 months of Dx.
- Ranibizumag, Bevalizumab, Pegaptanib
Laser Photocoagulation
- Slows progression
- Risk of Acute Vision Loss after Rx. which is particularly increased in pts. with Sub-Foveal ARMD
Combination of Zinc + Anti-oxidant Vit. A, C & E reduces progression in 1/3rd pts.
What is Optic Atrophy ??
Pale, well demarcated disc on Fundoscopy; usually B/L
- Causes GRADUAL Vision loss
- It is a descriptive term, it is Optic Neuropathy that results in Vision loss
Causes if Optic Atrophy ??
Acquired
- Multiple Sclerosis
- Papilloedema (Long standing)
- Raised IOP (Glaucoma, Tumour)
- Retinal damage (Choroiditis, Retinitis pigmentosa) & ISCHAEMIA
- Toxins: Tobacco, Quinine, Methanol, Arsenic, Lead
- Vit. B1, B2, B6 & B12 deficiency
CONGENITAL Causes
- Friedreich’s Ataxia
- Mitochondrial disorder (Leber’s OA)
- Wolfram’s synd. (DI DM OA D)
Features of Optic Neuritis ??
- Multiple Sclerosis (commonest association)
- Diabetes. - Syphilis
Features - U/L decrease in Visual acuity over hours to days
- Pain worse on eye movement
- Red Desaturation (Poor discrimination of colours)
- RAPD & Central Scotoma
Rx. & Prognosis of Optic Neuritis ??
High-dose STEROIDS
Recovery takes 4- 6 wks
Prognosis
- MRI: if > 3 white-matter lesions, 5-year risk of developing MS is 50%
What is Papilloedema ??
Optic Disc Swelling caused by increased ICP. Almost always B/L
Features-
- 1st sign: Venous Engorgement
- Loss of Venous Pulsation (many normal pts. do not have this)
- Optic Disc margin Blurring
- Elevation of optic disc
- Loss of Optic Cup
- PATON’s Line: Concentric/ Radial Retinal lines cascading from optic disc
Causes of Papilloedema ??
- Space-occupying lesion: Neoplastic, Vascular
- Malignant HTN
- Idiopathic ICH
- Hydrocephalus
- Hypercapnia
Rare causes: Hypoparathyroidism, Hypocalcaemia, Vit.-A toxicity
What is Posterior Vitreous Detachment ??
Separation of Vitreous memb. from Retina which can rarely lead to tears & detachment of Retina
- Most pts. are > 65 yrs old
- FEMALE preponderance
RF for Posterior Vitreous Detachment ??
As we age, the vitreous fluid in the eye becomes less viscous & thus does not hold its shape as well
- High myopia (myopic eye has a longer axial length than normal)
C/F of Posterior Vitreous Detachment ??
- Sudden Appearance of Floaters (a ring of floaters TEMPORAL to Central vision)
- Flashes of light (Peripheral vision field) & Blurred vision
- Cobweb across vision
- Dark curtain descending down in vision (means there is Retinal detachment)
WEISS Ring on Ophthalmoscopy (detached vitreous memb. around the Optic N form a ring-shaped floater
Ix. & Rx. of Posterior Vitreous Detachment ??
Suspected pts. Examined by an ophthalmologist in < 24hrs to rule out Retinal tear/ detachment
Rx.-
- Will not cause permanent vision loss
- No Rx.- as symptoms gradually improve over 6 months
- a/w Retinal Tear: Sx. is required
Retinal Detachment features ??
- Dense shadow that starts Peripherally progresses to the Central vision
- Veil of Curtain over Vision Field
- Distortion of Straight lines
- Central Vision Loss
Vitreous Haemorrhage Features ??
Large Bleed => Sudden Vision loss
Moderate Bleed => Numerous dark spots
Small Bleed => Floaters
What is Holmes-Adie Pupil ??
Benign condition; MC seen in FEMALES.
- U/L in 80% cases
- Dilated pupils
- Once the pupil is constricted, it remains as such for a long time
- Light reflex: Absent
- Accommodation: Slowly reactive
What is Holmes-Adie Syndrome ??
Holmes-Adie Pupil + Absent Ankle/ Knee reflex
What are the features of Horner’s Syndrome ??
- Miosis + Ptosis + Anhidrosis
- Enophthalmos (due to Narrow Palpebral aperture rather than True Enophthalmos)
How to differentiate b/w Congenital & Acquired Horner’s Syndrome ??
Congenital= Horner’s + Heterochromia
What is Apraclonidine test ??
Alpha-adrenergic AGONIST is used
- Horner’s eye = causes MYDRIASIS (due to denervation supersensitivity)
- Normal eye = Mild MIOSIS (by down-regulating the NE release at Synaptic cleft)
What is Argyll Robertson Pupils ??
“ARP” : Accommodation Reflex PRESENT
PRA- Pupillary Reflex Absent
- Small Irregular pupils
- No light response
Causes: DM, Neurosyphilis
What is Marcus Gunn pupil ??
RAPD is identified by ‘Swinging Light Test’
- Site of Lesion: Anterior to Optic Chiasm (O N or Retina)
Affected eye & Normal eye DILATE when light is shone on the Affected eye
Causes
- Retina: Detachment
- Optic N : Optic Neuritis (eg. MS)
Elaborate the Pathway of Pupillary light reflex
Afferent: Retina => O N => Lateral Geniculate body => Midbrain
Efferent: Edinger-Westphal N (mid brain) => Oculomotor N
What are the Ocular manifestations of Rheumatoid Arthritis ??
Seen in 25% of pts. with RA
- Keratoconjunctivitis Sicca (MC)
- Episcleritis (Erythema)
- Scleritis (Erythema + Pain)
- Corneal ulceration
- Keratitis
Iatrogenic Cause:
- Steroid induced Cataract
- Chloroquine Retinopathy
What is Anterior Uveitis ??
aka IRITIS a/w HLA-B27
- Inflammation of Anterior portion of Uvea: IRIS + CILIARY Body
Associated Conditions:
- Ank. Spon.
- Reactive Arthritis
- IBD (UC & CD)
- Behcet’s disease
- Sarcoidosis: B/L may be seen
Features & of Anterior Uveitis ??
- Acute onset Red eye
- Ocular discomfort & Pain
- PHOTOPHOBIA, Lacrimation
- Blurred vision
- Ciliary Flush: ring of red spreading outwards
- Hypopyon: pus & inflam. cells in the anterior chamber
- Visual acuity initially normal => Impaired
Rx. of Anterior Uveitis ??
Urgent Ophthalmology referral
- Cycloplegics (DILATES pupil => relieves pain & photophobia): Atropine, Cyclopentolate
- Steroids eye drops
Features of Blepharitis ??
Meibomian gland secretes oil which prevents rapid evaporation of tears
- B/L symptoms
- Grittiness & Discomfort, particularly around lid margin
- Sticky eyes in the morning
- Staph. Infection: Red Eyelid margins & Swollen eyelids
- STYES & CHALAZIONS are common
What is Blepharitis ??
Inflammation of Eyelid MARGINS
- Meibomian gland dysfunc. (common POSTERIOR blepharitis) or
- Seborrhoeic Dermatitis or
- Staph. infection (less common; ANTERIOR blepharitis)
More common in pts. with Rosacea
Rx. of Blepharitis ??
Hot Compresses 2x a day (to Soften the lid margins)
Lid Hygiene- mechanical removal of debris
- Cotton wool buds dipped in a mixture of cooled boiled H2O + Baby shampoo (OR)
- NaHCO3 + Cooled, boiled H2O
Artificial Tears
What is Herpes Zoster Ophthalmicus ??
Reactivation of Varicella Zoster virus in the area supplied by Trigeminal V1
- Vesicular rash around the eye (may or may not involve the eye itself)
- Hutchinson’s sign: Rash on the tip of the nose; indicates nasociliary involvement & is a strong indicator of ocular involvement
Rx. of Herpes Zoster Ophthalmicus ??
Oral Antivirals for 7 to 10 days
- Ideally started within 72 hrs
- IV Antivirals (Very Severe infection)
Topical Corticosteroids (used to treat any secondary inflammation of eye)
Ocular involvement (Ophthalmology review)
Complications: Ptosis, Post Herpatic Neuralgia, Keratitis, Conjunctivitis, Episcleritis, Anterior uveitis
What is Keratitis ??
Inflammation of CORNEA. (Microbial Keratitis is sight threatening)
Causes
- Bacterial, Fungal, Amoebic, Parasitic
- Herpes Simplex Keratitis
- Environmental
C/F of Keratitis ??
Red eye: Pain & Erythema
Photophobia
Foreign body, Gritty sensation
Hypopyon
Name the causes for the following regarding Keratitis-
- Bacterial
- Amoebic
- Parasitic
- Environmental
- Stap. aureus (typical) & P aeruginosa (in Contact lens wearers)
Acanthamoebic keratitis - 5% of all cases
- Eye exposure to soil & contaminated H2O
- Pain out of proportion to findings
River blindness- Onchocercal Keratitis
Environmental - Photokeratitis: Welder’s arc eye
- Exposure keratitis
- Contact Lens Acute Red Eyes- CLARE
Rx. of Keratitis ??
Topical Abx.- QUINOLONES (1st line)
Pain: Cycloplegics (eg. Cyclopentolate
Contact lens wearers
- Same day referral to an Eye Specialist for Slit-Lamp Examination to rule out Microbial cause
What is Herpes Simplex Keratitis ??
Most commonly presents with a DENDRITIC Corneal Ulcer
- Red, Painful eye, Epiphora, Visual Acuity (Decreased)
- Fluorescein stain: EPITHELIAL Ulcer
Rx.-
- Immediate referral to Opthalmology
- Topical ACICLOVIR
What is Dacryocystitis ??
Infection of Lacrimal Sac
- Epiphora + Swelling & Erythema at the inner canthus of eye
Rx.-
- Systemic Abx.
- IV Abx. if a/w Periorbital Cellulitis
What is Orbital Cellulitis ??
Infection of Fat & Muscle ‘Posterior to the Orbital Septum’ within the orbit but NOT involving the globe
- Caused by URTI from the Sinuses & carries High Mortality
Risk Factors for Orbital Cellulitis ??
Childhood (7 to 12 years)
Previous Sinus Infection
Lack of HiB vaccination
Recent eyelid infection/ Insect bite on eyelid (Periorbital Cellulitis)
Ear/ Facial Infection
Difference b/w Orbital Cellulitis & Periorbital (Preseptal) Cellulitis ??
It is a less serious superficial infection Anterior to the Orbital septum (due to superficial tissue injury)
- It can progress to O Cellulitis
Reduced visual acuity, Proptosis, Ophthalmoplegia/ Pain with eye movt are NOT consistent with Preseptal C
Presentation of Orbital Cellulitis ??
Redness & Swelling around the Eye
Severe Ocular pain
Visual disturbance
Proptosis
Ophthalmoplegia/ Pain on Eye movt.
Eyelid edema & Ptosis
Drowsiness +/- N & V (Meningeal involvement)
Ix. & Rx. of Orbital Cellulitis ??
CT with Contrast
Blood culture & Swab
- MC bacterial cause: Strept., Staph. aureus, HiB
Complete Oph. Assessment
Rx: Admit + IV Antibiotics
What is Glaucoma ??
Optic neuropathies a/w raised IOP. This can be classified based on whether the peripheral iris i covering the trabecular meshwork (as drainage of aq. humour occurs through this from anterior chamber of eye)
What is Primary Open Angle Glaucoma ??
The Iris is clear of the meshwork; the trabecular network functionally offers an increased resistance to aqueous outflow => increased IOP
- Increases with age
- 1st degree relative have a 16% chance of developing disease
Features of POAG ??
Slow rise in IOP => Symptomless for a long period
- Typically presents after an IOP measurement during a routine test.
Raised IOP > 24 mmHg (Goldmann type Applanation Tonometry)
Visual field defect
Pathological ‘Cupping’ of optic disc
Ix. done for POAG ??
- Automated Perimetry: To assess visual field
- Slit-lamp examination
- Applanation Tonometry
- Central Corneal Thickness
(CCT) measurement - Gonioscopy: Assesses Peripheral Anterior chamber configuration & depth
Rx. of POAG ??
Eye drops: To lower IOP
- 1st line: PGs analogue
- 2nd line: Beta-blockers, Carbonic anhydrase inhibitor or Sympathomimetic drops
- More advanced: Sx or Laser Rx
What is Acute Angle Closure Glaucoma ??
Increased IOP secondary to IMPAIRED Aqueous humour outflow
MC among
- Hypermetropia
- Pupillary Dilatation
- Lens growth a/w age
Features of AACG ??
- Severe pain: Ocular or Head
- Decreased Visual acuity
- C/F worse on Mydriasis (Watching TV in a dark room)
- Hard, Red eyes
- Halos around light
- SEMI-DILATED Non-reactive pupil
- Corneal oedema => dull/ hazy cornea
- N & V; even Abd. pain
Rx. of AACG ??
Emergency; so urgent referral to ophthalmologist
- Direct Parasympathomimetics (eg.- Pilocarpine => causes contraction of ciliary muscles => Trabecular meshwork opens up => Increased outflow
- Beta- blocker: (eg. Timolol => decreased Aq. h production)
- Alpha-2 agonist: Apraclonidine => Dual mechanism => decreases Aq. H synthesis & increases Uveoscleral outflow
IV Acetazolamide (reduces aq. secretion)
Definitive Rx. of AACG ??
Laser Peripheral Iridotomy
- Tiny hole peripheral iris => Aq. H flowing to the ang;e
