Ophthalmology Flashcards
Give 3 common differentials for a red eye.
Common and treatable in primary care: blepharitis conjunctivitis, dry eye, episcleritis, styes, chalazion
Give 3 differentials for a red unilateral painful eye.
These are all red flags.
Iritis, corneal ulcers and foreign bodies, scleritis, acute angle glaucoma. Unilateral - tumour
What is blepharitis and how does it present?
Blepharitis = inflammation of the eyelid margin
Sx: sore, gritty, itchy eyes, hard to open in morning, bilateral, intermittent. May have lumps - chalazia, styes
May have dry eye syndrome: watery eyes, blurred vision, dry eyes and intolerance of contact lenses.
Associated seborrheic dermatitis: dandruff, oily skin, facial rashes.
Associated rosacea: facial flushing, redness or telangiectasia.
How would you diagnose blepharitis?
Hx - exclude tumour, red flags are unilateral, painful. Localised lash loss could be sebacious gland carcinoma - ask if unsure.
Ex: mild conjunctival redness, loss of eyelashes, in-growing eyelashes (scraping eyelid),
seborrheic –> lashes stuck together, greasy appearance of anterior lid margin
staphylococcal –> collarettes (crusting on base of eyelashes), hard scales
Posterior –> meibomian gland orifices covered with small oil globules/foam. lid lumps (chalazia and styes)
How is blepharitis managed?
Not curable but manageable. Lid hygiene - clean using sterilised water and cotton wool
Warm compress
Lubricating eye drops eg polyvinyl alcohol
Give 3 differential diagnosis for acute visual loss.
Think inflammation, vascular occlusion, haemorrhage.
retinal artery and vein occlusions, giant cell arteritis, optic neuritis, retinal detachment, vitreous haemorrhage, visual field loss due to stroke and intracranial tumours
Give 3 differentials for gradual visual loss.
Think degenerative, neuropathy, vasculopathy.
refractive error, cataract, macular degeneration, open angle glaucoma
What is a cataract?
Cataracts are where the lens in the eye becomes cloudy and opaque. This reduces visual acuity by reducing the light that enters the eye
How does central retinal artery occlusion present? What would you see on fundoscopy?
Sudden painless loss of vision like a curtain coming down.
Relative afferent pupillary defect
Fundoscopy will show a pale retina (due to lack of perfusion) with cherry-red spot (macula)
How is central retinal artery occlusion managed?
Refer to ophthal
If GCA is the cause treat that - ESR, temporal artery biopsy, prednisolone 60mg.
No evidence for intervention as artery is too small - vision will be lost.
Manage risk factors for atherosclerosis
Can try ocular massage, inhaling carbogen to dilate the artery, or sublingual isosorbide dinitrate
How does central retinal vein occlusion present? What would you see on fundoscopy?
Sudden painless loss of vision.
Pooling of blood –> macular and optic disc oedema, retinal flame and blot haemorrhages, VEGF and neovascularisation.
How is central retinal vein occlusion managed?
Refer to ophthal for treatment of macular oedema, prevent neovascularisation and glaucoma. This is done with laser photocoagulation, intravitreal steroids, and/or anti-VEGF eg ranibizumab.
Manage risk factors for atherosclerosis, check for associated conditions - ESR (SLE), FBC (leukaemia), BP (htn), glucose (diabetes)
How does diabetic retinopathy present and what would you see on fundoscopy?
Asymptomatic (found on screening), can cause haemorrhage.
Fundoscopy:
Cotton wool spots = nerve fibre damage
Microaneurysms = bulges in blood vessel walls
Hard exudates = lipid deposits
Blot haemorrhages
Neovascularisation
IntraRetinal Microvascular Abnormalities - dilated tortuous retinal capillaries/AV fistula
How would an optic melanoma present and what would you see on fundoscopy?
Asymptomatic. no pain or field defect.
Large grey raised blotch on fundoscopy.
Mx - often not treated if not causing problems.
How does retinitis pigmentosa present? What would you see on fundoscopy?
Night blindness, starting in childhood (hereditary), loss of peripheral vision before central vision (may have good acuity).
Fundoscopy shows ‘bone-spicule’ pigmentation around the mid-peripheral area, pale optic disc.
What is the pathophysiology of retinitis pigmentosa?
Congenital inherited condition involving degeneration of the rods and cones in the retina. More degeneration of rods than cones –> night blindness.
Asso syndromes eg:
Usher’s syndrome (+hearing loss),
Bassen-Kornzweig syndrome (+neurological symptoms)
Refsum’s disease (+neuro + hearing + skin problems)
What is glaucoma?
Optic nerve damage caused by significant rise in intraocular pressure, caused by blockage in aqueous humour.
Open angle = gradual increase in resistance through the trabecular meshwork, so aqueous humour cannot exit the eye.
How does glaucoma present?
Asymptomatic - found on routine eye check
Peripheral visual loss (tunnel vision)
Pain, headache, blurred vision, halos around lights
How is glaucoma diagnosed?
Visual fields
Tonometry:
Non-contact - puff of air. Less accurate
Goldmann applanation tonometry = gold standard, actually makes contact with cornea, accurate IOP
Fundoscopy - cupping of optic disc >0.5 cup:disc ratio
Give 3 risk factors for glaucoma other than older age.
FHx
Black ethnicity
Shortsightedness (myopia)
What is the management of open-angle glaucoma?
Reduce IOP
Treat if IOP >24mmHg, follow up
First line: Prostaglandin analogue eye drops eg latanoprost. These increase uveoscleral outflow. SEs - eyelash growth, eyelid pigmentation and iris pigmentation.
Beta blocker eg timolol - reduce production of aquous humour
Carbonic anhydrase inhibitors eg acetazolamide - reduce production of aquous humour
Sympathomimetics eg brimonidine - reduce production of aqueous fluid and increase uveoscleral outflow.
Trabeculectomy
What is acute angle closure glaucoma?
Iris bulges forward and seals off trabecular meshwork from the anterior chamber, preventing aqeuous humour from being able to drain away. Optic nerve damage, ophthalmology emergency - sight threatening.
Give 4 risk factors for acute angle closure glaucoma.
Increasing age
FHx
Females are affected around 4 times more often than males
Chinese and East Asian ethnic origin. Unlike open-angle glaucoma, it is rare in people of black ethnic origin.
Shallow anterior chamber
Give 3 medications that can precipitate acute angle-closure glaucoma.
Adrenergic medications such as noradrenalin
Anticholinergic medications such as oxybutynin and solifenacin
Tricyclic antidepressants such as amitriptyline, which have anticholinergic effects
How does acute angle closure glaucoma present?
Unwell, acute onset Severely painful red eye Blurred vision Halos around lights Associated headache, nausea and vomiting Red, teary eye Unilateral fixed dilated pupil Firm eyeball Hazy cornea Reduced visual acuity
What is the management of acute angle closure glaucome?
Same day referral to ophthalmology for laser iridotomy.
While waiting:
Lie on back without a PILOw
PILOcarpine eye drops (2% blue, 4% brown). This is a muscarinic agonist –> miotic =constricts pupil, and causes ciliary muscle contraction.
Acetazolamide 500mg PO (carbonic anhydrase inhibitor)
Analgesia, antiemetic if required
Hyperosmotic agents eg mannitol
Timolol to reduce aquous humour
Sympathomimetic eg Brimonidine
What is ARMD? What are the types?
Age related macular degeneration: most common cause of blindness in UK.
10% wet, worse prognosis, treatable
90% dry, untreatable
What are drusen?
Yellow deposits of proteins and lipids between the retinal pigment epithelium and Bruch’s membrane in the macula.
Can be normal, but larger and more drusen indicated MD (wet and dry)
Give 3 similarities and 3 differences between wet and dry AMD.
Both: Worsening central visual field loss, reduced visual acuity, crooked or wavy lines. Drusen, atrophy of retinal pigment epithelium, degeneration of the photoreceptors.
Wet: VEGF –> Neovascularisation from choroid layer of the macula into the retina, causing oedema and more rapid visual loss, may have bilateral disease, can treat with anti-VEGF eg ranibizumab
Dry: Gradual, no treatment - control RFs
Give 4 RFs for ARMD.
Age, smoking, white or Chinese ethnic origin, FHx, CVD
How is ARMD diagnosed?
Reduced acuity using a Snellen chart
Scotoma (a central patch of vision loss)
Amsler grid test can be used to assess the distortion of straight lines
Fundoscopy. Drusen are the key finding.Slit-lamp biomicroscopic fundus examination by a specialist can be used to diagnose AMD.
Optical coherence tomography is a technique used to gain a cross-sectional view of the layers of the retina. It can be used to diagnose wet AMD.
Fluorescein angiography involves giving a fluorescein contrast and photographing the retina to look in detail at the blood supply to the retina. It is useful to show up any oedema and neovascularisation. It is used second line to diagnose wet AMD if optical coherence tomography does not exclude wet AMD.
