Opthalmology Flashcards
Painless Vision loss is usually secondary to what events ?
Vascular events: - vitreous haemorrhage - central retinal artery occlusion - optic neuropathy - ARMD
Painful vision loss is usually secondary to what events ?
Inflammatory events: - Uveitis - Acute angle closure glaucoma - keratitis - optic neuritis
Sudden visual loss is usually due to:
- vascular events (most are sudden) - Retinal detachment - Acute angle closure glaucoma
Chronic visual loss is usually due to:
- Cataracts - ARMD - Uveitis - Keratitis
What are the ophthalmic manifestations of a stroke?
- CN palsies - VF loss
Ophthalmic manifestations of MS?
- Optic neuritis - Nystagmus
Ophthalmic manifestation of IBD?
Uveitis
Ophthalmic manifestation rheumatoid arthritis?
Scleritis
How might contact lenses cause involution ptosis?
May cause levator aponeurosis to detach from tarsal plate
what is entropion?
Lid inturning: typically due to degeneration of lower (rarely upper) lid fascuak attachments and their muscles - Usually >40 yrs - inturned lashes irritate cornea
Management of entropion?
- Tape lower lid to cheek - Botulinum toxin injection - Surgery for long lasting relief
What is Ectropion?
Lower lid eversion: causes eye irritation, watering +/- ketaitis
what is blepharitis?
- Lid inflammation - due to staphs, seborrhoeic dermatitis - causes burning, itching , red margins with crusting on lashes
what are dendritic ulcers of the eye ? treatment?
- Corneal ulcer due to HSV infection - treat with steroid eye drops and aciclovir
signs of nasolacrimal duct non-canalization?
- child with persistent watery eyes - prone to attacks of conjunctivitis
what Ig is prevalent in tears ?
IgA
Causes of dry eye syndrome (Keratoconjunctivitis sicca)
- decreased tear production with age - Sjogren’s - mumps - sarcoidosis - amyloid - lymphoma, leukaemia - mucin deficiency in tears (e.g. Stevens-Johnson syndrome, pemphigoid etc)
causes of excess lacrimation
- emotion - corneal abrasions - foreign body - entropion - conjunctivitis - acute glaucoma
What is considered to be the cause of a painful Horner’s syndrome until proven otherwise ?
Internal Carotid artery dissection - pain in the neck and side of head + Miosis
Causes of Horner’s syndrome?
- PICA or basilar artery occlusion - Pancoasts tumour - MS - Cavernous sinus thrombosis - Klumpke’s palsy
What is Horner’s syndrome?
Disruption of the sympathetic fibres, so the pupil is miotic (smaller) and there is partial ptosis - the pupil does not dilate in the dark
Signs of third nerve palsy ?
- Ptosis - Exopthalmos (as recti tone decreased) - Fixed pupil dilation - eye = down + out
Who is acute angle glaucoma most likely to affect ?
- most common 60-70 (>40) - South Asians, Chinese - Females (4:1)
Presentation of acute angle glaucoma
- Severe, rapid, progressive pain spreading around orbit + frontal headache - Blurred vision (Rapidly progressing to vision loss) + coloured haloes around light - Usually Unilateral - Nausea + vomiting, systemic malaise (may be presenting complaint in elderly)
Who is at greater risk of close angle glaucoma; long or short sighted people?
Long sighted (hypermetropes)
Precipitants of acute angle closure glaucoma attack:
times of mid-dilated pupil: - moments of stress/excitement - watching TV in dim lighting - topical mydriatics - systemic anticholinergics
Findings o/e in AAGC?
- generally unwell - Red eye (Ciliary flush-redness around periphery of cornea) - Hazy cornea + non-reactive, mid-dilated pupils - Globe hard on palpation - IOP raised (norm = 10-21mmHg)
Diagnostic criteria for Acute Angle Closure?
Ocular pain, Nausea/Vomiting + History of intermittent blurring of vision with Haloes AND 3 of: - ICO >21 - Conjunctival infection - Corneal Epithelial oedema - Mid-dilated, fixed pupils - Shallow chamber
Differential Diagnoses of severe ocular pain with visual loss?
- AACG - Anterior Uveitis - Scleritis - Optic Neuritis
Treatment of AACG?
- Topical: B-blockers, steroids - Pilocarpine (miosis to open blockage) - IV carbonic anhydrase inhibitors e.g. Acetazolamide (decreases formation of aqueous) - Systemic analgesics +/- antiemetics - Peripheral Iridectomy - once IOP decreased: small pice of iris removed I nboth eyes to allow free circulation of aqeous
Pathogenesis of AACG?
Blocked drainage of aqeous from the anterior chamber via the canal of schlemm. - pupil dilatation worsens the blockage - IOP rises > 60 (norm = 10-21)
Complications of AACG
- Permanent vision loss - Recurrent attacks - Attack in other eye - Central retinal artery/vein occlusion
What is primary open-angle glaucoma characterised by ?
- Adult onset - IOP >21 - Open Iriocorneal angle - Glaucomatous optic neuropathy - Visual field loss (compatible with nerve fibre damage) - Absence of an underlying cause
Pathogenesis of open angle glaucoma?
- Increased resistant to aqueous outflow within the trabecular meshwork -> causing IOP to rise -> damage to the optic nerve - raised IOP influences retinal ganglion apoptosis (mechanical compression of optic nerve head + compromise of local vasculature)
Which is the most common form of glaucoma ?
Primary open angle glaucoma (1-2% > 40)
Risk factors for primary open angle glaucoma?
- Increasing age - Family history - Afrocarribean (presents earlier + more severe) - Ocular hypertension - Myopia (short sighted) - retinal disease - Diabetes and systemic hypertension
Presentation of primary open angle glaucoma?
- usually don’t notice anything - by the time symptomatic 90% optic fibres irreversibly damaged - Abnormalities with IOPs + visual fields noticed incidentally at routine optician apt.
What is Gonioscopy ?
Measurement of the angle between the cornea and the iris to assess whether the glaucoma is open or closed angle. (Initial assessment only)
What is Tonometry
Objective measurement of IOP
Investigations in glaucoma?
- Gonioscopy - Corneal thickness (affects IOP reading) - Tonometry - Optic disc:cup ratio (progression of disease) - Visual fields
Which drugs are used to control IOP ?
- topical B-blockers - Prostaglandin analogues - Carbonic anhydrase inhibitors - Miotics - Sympathomimetics
What is the action of Carbonic Anhydrase Inhibitors?
reduce aqueous secretion by ciliary body. Weak diuresis in systemic use.
Contraindications of Carbonic Anhydrase Inhibitors?
- renal impairment - metabolite imbalance - severe hepatic impairment - sulfonamide sensitivity (acetazolamide) - breast-feeding.
what structures are included in the uvea?
Pigmented part of the eye, including: iris, ciliary body (ant.) and choroid
Systemic diseases causing Uveitis?
- ankylosing spondylitis - sarcoidosis - IBD - psoriasis - Behcets - Juvenile idiopathic arthritis
Presentation of Uveitis?
- Acute, unilateral pain - photophobia - blurred vision (aqueous precipitates) - Lacrimation - circumcorneal redness (ciliary congestion) - Initial small pupil -> irregular or dilate irregularly due to adhesions
what is Talbot’s test ?
test for Uveitis: - pain worsens on convergence (accommodation)
Age group most commonly affected by Uveitis ?
20-50 (working age)
Characteristic sign if anterior uveitis on slit lamp exam?
presence of cells in aqueous humour - appears like bits of dust floating in the dark - cloudy - anterior chamber flare
Which infections are associated with anterior uveitis?
Herpes simplex Herpes Zoster - due to immune reaction to organism
What infections is granulomatous uveitis associated with?
- Toxoplasmosis - CMV - TB - Syphilis - AIDS (CMV, HSV, Cryptococcus, candiasis)
Management of uveitis
- Corticosteroids (reduce inflam. and prevents adhesions) - Cycloplegic-mydriatic drug (e.g. cyclopentolate) - paralyse ciliary body (relieves pain + prevents adhesions) - Abx if infectious
complications of uveitis
Vision loss due to: - crystalloid macular oedema - secondary cataracts raised IOP (with or without glaucoma) - retinal detachment - neovascularsation
Red flag considerations in a red eye
- Acuity affected ? - painful globe ? (foreign body?) - Pupil respond to light ? - Cornea damaged? (use fluorescin eyedrops)
What is Keratitis?
Inflammation of cornea - white are on cornea representing collection of white cells
what organisms may be causative for infective corneal ulcers?
- pseudomonas (progress srapidly) - HSV - Fungal: candida/aspergillus -Protozoal: acanthamoeba
Presentation of corneal ulcers
- Pain - Photophobia - reduced visual acuity - red eye - systemic e.g. Headache, nauseated, generally unwell/run down
what is chloramphenicol?
topical treatment for bacterial eye infections
presentation of episcleritis
- acute mild pain/gritty discomfort - localised or diffuse red eye - unilat or bilat - no associated ocular symptoms other than watering