eyes eyes eyes Flashcards
What is glaucoma?
Where the intra occular pressure in the eye is raised due to the aqueous humour not being able to leave the eye
What is open angle vs closed angle glaucoma?
In acute angle-closure glaucoma: iris bulges forward and seals off the trabecular meshwork from the anterior chamber preventing aqueous humour from draining –> Raised intraocular pressure –> oedema cornea –> blurred vision –> iris sphincter ischaemic so pupil is fixed and dilated
What are the RF for open angle glaucoma?
Afro carribean
near sighted (myopia)
fhx
age
What are the sx of open angle glaucoma?
Reduction in peripheral visual fields - tunnel vision Halos around light at night Headache fluctuating pain blurred vision
How do you diagnose open angle glaucoma?
Measure the intra occular pressure via Goldmann applanation tonometry
Differentiate between open and closed using Gonioscopy to measure the iridocorneal angle.
Visual field testing
Fundoscopy to look at optic disc for cupping
What is the mx of open angle glaucoma?
In GP give pilocarpine (miotic) and acetazolamide (carbonic anyhydrase inhibitors)
FIRST LINE: Prostaglandins to increase aqueous humor leaving the eye - e.g. latanoprost
Topical beta blockers to decrease aqeous humour production e.g. timolol
What are the RF for closed angle glaucoma?
Asian ethnicity Female Age hypermetropia - long-sighted Drugs: anticholinergics, adrenergics
What is the presentation of closed angle glaucoma?
Sx: V PAINFUL RED EYE!! Reduced acuity Halos at night around lights headache, N+V Worse at night due to pupil dilating, but may resolve when sleep as that causes it to constrict
O/E: Red eye Firm, hardened eye when palpate Hazy cornea fixed and dilated pupil
What is the mx of closed angle glaucoma?
Call 999
Get pt to lie back
Adminster pilocarpine and acetazolamide if have it
Opthamologists have more drugs and can do surgery to relieve the eye pressure - iridectomy
How does pilocarpine work?
Acts on andrenergic receptors and constricts the eye (miosis)
What is age related macular degeneration?
Degeneration of the macular portion of the eye which includes: the choriod (blood supply) and photoreceptors.
Most common cause of blindness in UK
What are the two different types of macular degeneration. Explain difference?
Dry (90%): macular degeration
Wet (10%): Dry + new vessels grow which leak blood + fluid. Worse prognosis. Presents more acutely.
What are the RF for AMD?
Age
Smoking
CVD
Fhx
What is the presentation of AMD?
Sx:
Reduced acuity from the CENTRE of vision
straight lines become wiggly
O/E:
Dresen (lipid deposits) on optic disc with fundoscopy
Scotoma (central visual field loss)
Amsler grid test to see distorted lines
Optical coherence tomography used by specialist
What is the mx of AMD?
Dry: Manage RF
Wet: Can get anti- VEGF injections into eye
What is diabetic retinopathy?
Diabetes causes damage to the walls of blood vessels —> the vessels then leak their contents (e.g. lipids forming hard exudates or haemorraging) or form microaneurysms (bulging)
Neoproliferation occurs as eye releases growth factors to deal with damage
Nerve damage causes cotton wool spots to form
What are the complications of diabetic retinopathy?
Retinal detachment
Cataracts
Vitreous haemorrhage
What is the mx of diabetic retinopathy?
Manage the DM!
Laser photocoagulation
Anti-VEGF injections
Surgery if v bad
Explain the pathophysiology of a cataract
The lens focuses light onto our retina. In a cataract is where the lens becomes cloudy.
What are the RF for a cataract?
Congential (screened for in NIPE) AGE! Diabetes Smoking Steroids
How do cataracts present?
A general decreased visual acuity Asymmetrical Starbursts form around lights at night Colours become brown/ yellow Loss of red reflex
What is the mx of cataracts?
If symptomatic then can operate - break down lens and replace with an artifical one
What is the pupil?
A hole in the iris
How does the pupil constrict vs dilate?
Constrict (miosis): Parasympathetic nerve fibres contstrict which travel along the occulomotor (3rd nerve)
Dilate (mydriosis): Sympathetic innervation
What are the causes of abnormal mydriasis?
3rd nerve palsy Raised ICP Drugs e.g. cocaine Trauma Congenital Anticholinergics
What are the causes of abnormal miosis?
Horner’s syndrome
Cluster headaches
Opioids
What is the pathophysiology of a third nerve palsy?
3rd Nerve supplies:
all eye muscles apart from superior oblique and abductor so is down and out
has parasympathetic nerve fibres so palsy results in mydriasis
supplies levator palpebrae superioris so without there is a ptosis
What is a possible cause of a 3rd nerve palsy?
3rd nerve travels through the carvenous sinus and along posterior communicating artery so an aneurysm/ thrombosis involving these
What is the pathophysiology of Horner’s syndrome?
Sympathetic nerve fibres arise from the spinal cord and travel alongside the carotid artery
Damage to them results in anhidrosis (no sweating), miosis and ptosis
What is a test for Horner’s syndrome?
Cocaine eye drops not dilating pupil as noradrenalin is not being released so cocaine does not have usual effect
What is blepharitis?
Eye lid inflammation
How does blepharitis present?
Gritty, itchy, dry bilateral, red eyelid, may lead to style/ chelazia
Mx of blepharitis?
Clean eyelid using baby shampoo. Can use lubricating eye drops
What is a stye vs a chalazion?
Stye = infection of glands in eye Chalazion = gland blocked so become a cyst
How do styes vs chalazion present?
Stye = Red, inflammed, painful, lump Chalazia = uncomfortable, red, nodule
How are styes and chalazion mx?
Hot compress, analgesia, topical abx (only if obvious signs of infection like mucopurulent discharge and conjunctivitis)
What is entropion vs ectropion?
entropion = eyelid turns in ectropion = eyelids turns outwards
What is periorbital vs orbital cellulitis?
Periorbital = skin and eyelid infection in front of eye
Orbital = medical emergency as it is an infection around that involves tissues behind orbital septum - so will cause painful eye movement, visual changes, proptosis, abnormal pupil reactions etc.
How does conjunctivitis present?
Discharge Red eye bilateral Itchy/ gritty feeling Will effect inner and outer eyelid (so will see red when pull eyelid foward) - unlike blepharitis
How do you differentiate between viral and bacterial and allergic conjunctivits?
Viral: clear discharge, systemic sx
Bacterial: purulent discharge
Allergic: itchy, mucus discharge, swelling
What is the mx of conjunctivitis?
Clean eye and careful not to spread
If bacterial - fuscidic acid or chloramphenicol drops
If allergic - antihistamines
What is the uvea?
Iris, ciliary body and choroid (layer between retina and sclera)
What is anterior uveitis? What is the cause?
Inflammation and infiltration of immune cells in the uvea
Usually autoimmune
Causes of acute and chronic uveitis?
Acute: HLA B27 conditions e.g. Ank Spond; IBD; reactive arthirits
Chronic: Sarcoidosis, syphilis, lymes, TB, HSV
How does anterior uveitis present?
Unilateral sx Painful red eye Ciliary flush (Ring of red spreading out from the cornea) Reduced acuity Floaters Miosis Photophobia Lacrimation Abnormally shapred pupil Hypopyon (Collection WBC in anterior chamber so can see yellow fluid in lower iris)
Mx of anterior uveitis?
Steroids
atropine drops - antimuscarinic so will block action of iris sphincter muscles
Immunosuppressants
Differentials for a red eye
Painless: conjunctivits, episcelritis, subconjunctival haemorrhage (conjunctiva vessel reuptures releasing bld after trauma/ strenuous activity)
Painful: glaucoma, anterior uveitis, corneal ulcer/ abrasion, keratitis, foreign body, trauma
What is episcleritis?
Inflammation of episclera (located between sclera and conjunctiva)
How does episcleritis present?
Young Segmental (small patch redness) Feels like foreign body but NO pain watering but NO discharge dilated vessels May have IBD/ RA
How do you mx episcleritis?
Self-limiting
Safety net - if pain could be scleritis so then they need to go hospital
What is scleritis?
Inflammation of the whole sclera - much more serious than episcleritis as can perforate
What are some associated conditions with scleritis?
IBD RA SLE Sarcoidosis GPA - previously wegeners
How does scleritis present?
SEVERE pain Photophobia blue/ violet hue to sclera Eye watering Decresed acuity abnormal pupil reaction to light tender to palpation
Mx of scleritis?
Any red eye that is potentially slight threatening needs same day opthamologist referral and assessment where they will use NSAIDs/ steroids. immunosuppression
How do you diagnose a corneal abrasion?
Use fluorescein stain which will show ulcer/ abrasion in yellow-orange colour
What is herpes keratits?
Corneal inflammation specifically caused by herpes but keratitis can be caused by any infection
How does herpes keratitis present?
Painful red eye Photophobia Vesicles around the eye Foreign body sensation Watering eye Reduced visual acuity Dendritic ulcer seen on fluorescein staining
What is the mx of herpes keratits?
Refer to opthamology who can give aciclovir and steroids
What is retinal detachment?
Retina detaches from choriod - this is a sight threatening emergency as retina needs choriod for blood supply
What are the RF for retinal detachement?
Age Fhx Diabetic retinopathy Posterior vitreous detachment (where the gel in the eye that pushes the retina up against the choriod becomes less firm with age) Retinal malignancy eye trauma
How does retinal detachement present?
Sudden peripheral visual loss
Blurred vision
PAINLESS
floaters and flashes
Mx of retinal detachement?
Immediately refer to opthamology who will try to reconnect retina and choriod with lazer/ cryotherapy or with surgery eg vitrectomy
What is central retinal vein occlusion?
Clot in central retinal vein causing blood to pool in the retina –> macular oedema; haemorrhage and neovascularisation
Presents with sudden painless loss of vision and needs immediate opthamology assessment
What is central retinal artery occlusion?
Occlusion of the artery via atherosclerosis/ GCA which presents with sudden painless loss of vision AND RAPD; fundoscopy shows pale retina and cherry red spot
Need immediate opthamology input
What is a RAPD?
a relative afferent pupillary defect. This is where the pupil in the affected eye constricts more when light is shone in the other eye compared when it is shone in the affected eye. This occurs because the input is not being sensed by the ischaemic retina when testing the direct light reflex but is being sensed by the normal retina during the consensual light reflex.
What is retinosa pigmentosa?
Congenital degenerations of rods and cones which presents with night blindness!
What is vitreous haemorrhage?
Vitreous haemorrhage is bleeding into the vitreous humour. It is one of the most common causes of sudden painless loss of vision. BIG LINK WITH DM! Can’t see retina upon fundoscopy unlike retinal vein/ artery occlusion
Findings on fundoscopy for diabetic retinopathy
Microaneurysms, flame-shaped haemorrhages, hard exudates, engorged tortuous veins.
Findings on fundosocpy for hypertensive retinopathy
Arteriolar constriction (silver/copper wiring), arteries nipping veins where they cross (AV nipping), cotton wool spots or exudates, flame-shaped haemorrhages, papillloedema.
What are you worried about with shingles and the eye?
Involvement of nasociliary branch –> Hutchinsons sign –> may involve cornea and lead to lack of corneal sensation i.e. when you touch it it doesnt blink –> risk of corneal ulcer
