Ophthalmology Flashcards
What is the most common cause of blindness?
Age related macular degeneration
What are the risk factors for age related macular degeneration?
Advanced age Family history smoking obesity cardiovascular disease
What are the two types of AMD?
Dry AMD - nonexudative AMD or atrophic AMD - slow progressive atrophy
characterised by drusen - yellow round spots in Bruch’s membrane
Wet AMD - exudative AMD - sudden localised elevation of the macula
leakage of serous fluid and blood can subsequently result in a rapid loss of vision
What are the symptoms of AMD?
- A reduction in visual acuity, particularly for near field objects
- Difficulties in dark adaptation with an overall deterioration in vision at night
- Fluctuations in visual disturbance which may vary significantly from day to day
- They may also suffer from photopsia, (a perception of flickering or flashing lights), and glare around objects
What are the factors pre-disposing patients o acute angle closure glaucoma?
- Hypermetropia (long-sightedness)
- Pupillary dilatation
- Lens growth associated with age
What are the features of acute angle glaucoma?
- severe pain: may be ocular or headache
- decreased visual acuity
- symptoms worse with mydriasis (watching TV in dark room)
- hard, red eye
- halos around lights
- semi dilated non-reacting pupils
- corneal oedema - dull or hazy cornea
What is the first line treatment for AACG?
urgent referal to an ophthalmologist
combination of eye drops -
- direct parasympathomimetic - pilocarpine - causes contraction of the ciliary muscle –> opening the trabecular meshwork
- beta blocker - timolol - decreases aqueous humour production
- an alpha -2 agonist - apraclonidine - decreasing aqueous humour production and increasing
IV acetazolamide- reduces aqueous secretions
What is the definitive management of AACG?
Laser peripheral iridotomy - creates a tiny hole in the peripheral iris –> aqueous humour flowing to the angle
What conditions are associated with anterior uveitis?
- Ankylosing spondylitis
- Reactive arthritis
- Ulcerative colitis, Crohn’s disease
- Behcet’s disease
- Sarcoidosis: bilateral disease may be seen
What is the management of iritis/anterior uveiitis?
Urgent review by ophthalmology
- cycloplegics - dilates the pupil which helps to relive pain and photophobia - atropine, cyclopentolate
- steroid eye drops
What are the features of herpes zoster ophthalmicus?
- Vesicular rash around the eye, which may or may not involve the actual eye itself
- Hutchinson’s sign - rash on the tip or side of the nose. indicates nasociliary involvement
What are the complications of herpes zoster opthalmicus?
- Ocular - conjunctivitis, keratitis, episcleritis, anterior uveitis
- Ptosis
- Post -herpetic neuralgia
What is the management of herpes zoster ophthalmicus?
- oral antiviral treatment for 7-10days
Ideally started within 72 hours
IV antivirals - if very severe infection or if the patient is immunocompromised
- Topical antiviral treatment is not given in HZO
- Topical corticosteroids - used to treat any secondary inflammation of the eye
What is seen during fundoscopy of AACG?
Cupping of the optic disc
What is the common presentation of orbital cellulitis?
- Redness and swelling around the eye
- Severe ocular pain
- visual disturbance
- proptosis
- eyelid oedema and ptosis
- Drowsiness +/- Nausea/vomiting in meningeal involvement (Rare)
How do you differentiate periorbital cellulitis from orbital cellulitis?
reduced visual acuity, proptosis, ophthalmoplegia/pain with eye movements are NOT consistent with preseptal cellulitis
What are the investigations to be ordered if orbital cellulitis is suspected?
- FBC
- CT with contrast
- Blood cultures and microbiological swab
What is the triad seen in horner syndrome?
Ptosis + constricted pupil - miosis and anhydrosis
Causes of papilloedema?
- Space-occupying lesion, neoplastic, vascular
- Malignant hypertension
- IIH
- Hydrochephalus
- Hypercapnia
What are the causes of optic neuritis?
- Multiple sclerosis
- Infections - Tb, syphilis, Lyme disease
- Toxic - ethambutol and methanol poisioning
What are the features of optic neuritis?
- unilateral decrease in visual acuity over hours or days
- poor discrimination of colours - red desaturation
- pain worse on eye movement
- RAPD
- central scotoma
What is the causative organism in anterior blepharitis?
- Staphylococci
what is the cause of posterior blepharitis?
Meibomian gland dysfunction
what are the symptoms of blepharitis?
- symptoms are usually bilateral
- grittiness and discomfort - around eyelid margins
- eyes sticky in the morning
- styes and chalazions are common in patients with blepharitis
What is the Mx of blepharitis?
- Softening of the lid margin - hot compresses twice a day
- lid hygiene - mechanical removal of the debris
- artificial tears are given as symptom relief
What is hyphema and why is it an emergenecy?
Hyphema (blood in the anterior chamber of the eye) - especially in the context of trauma warrants urgent referral to an ophthalmic specialist for assessment and management.
The main risk to sight comes from raised intraocular pressure which can develop due to the blockage of the angle and trabecular meshwork with erythrocytes.
What is the management of hyphema?
Strict bed rest is required as excessive movement can redisperse blood that had previously settled
Mr Green is a 57-year-old man who presents to eye casualty with sudden loss of vision in his left eye. He mentions that he had noticed some dark spots within his vision over the last few days. He is not experiencing any pain and has a past medical history of diet-controlled type 2 diabetes mellitus and hypertension.
What is the cause of his visual loss?
Vitreous haemorrhage
What are the causes of vitreous haemorrhage?
- proliferative diabetic retinopathy (over 50%)
- posterior vitreous detachment
- ocular trauma: the most common cause in children and young adults
What is the presentation of vitreous haemorrhage?
- Painless visual loss or haze
- red hue in the vision
- Floaters or shadows spots in the vision
What is the first line treatment used in open angle glaucoma?
Prostaglandin analogues - latanoprost - increases uveoscleral outflow
What is the cause of corneal ulcer?
Microbial keratitis - infection caused by a bacteria, fungi and protists
A 60-year-old man presents to your clinic with typical features of seborrhoeic dermatitis. He also complains of having itchy eyes.
Which eye condition is closely related to seborroeic dermatitis?
Blepharitis
Blepharitis may be associated with seborrhoeic dermatitis, dry eye syndrome and acne rosacea.
What do you suspect when a patinet has a sudden appearance of floaters and flashes of light in the vision?
Posterior vitreous detachment
What are some cycloplegic drugs and what do they do to the eye?
Atropine and cyclopentolate are cycloplegic drugs - they dilate the pupil which helps with the pain and photophobia in some conditions
Following an uneventful pregnancy, a 19-year-old woman delivers a male child vaginally. At assessment one week later the child is noted to have purulent discharge and crusting of the eyelids. What is the next step in the management of the child?
A urgent swab of the discharge is required for microbial investigation
Although minor conjunctivitis with encrusting of the eyelids is common and often benign, a purulent discharge may indicate the presence of a serious infection (for example, with chlamydia or gonococcus
How do you differentiate central retinal vein occlusion from central retinal artery occlusion?
Central retinal artery occlusion is difficult to distinguish clinically from venous occlusion. On fundoscopy, a ‘cherry red spot’ can often be seen in the macula where the retina is thinner. However, central retinal vein occlusion is a more common cause of painless vision loss, and the findings on ophthalmoscopy are retinal haemorrhages
What is the role of betablockers in the management of glaucoma??
They reduce the production of aqueous humour
Examples include timolol, betaxolol and levobunolol.
It is sometimes used as first-line pharmacological therapy or may be added to a prostaglandin analogue (as in this patient) as second-line treatment if monotherapy is unsuccessful.
What is the role of prostaglandin analgoues in the management of glaucoma?
Increases uveoscleral outflow - latanoprost
what are the side-effects of prostaglandin analogues?
Hyperaemia
Increased eyelash growth
Periocular skin pigmentation - Epithelial keratopathy
Increased iris pigmentation
what are the drugs that act by reducing the aqueous humour synthesis?
- Beta blockers
- Alpha 1 agonist - epinephrine
- alpha 2 agonists - apraclonidine , brimonidine
- carbonic anhydrase inhibitor - acetazolamide
what increases the aqueous humour outflow?
- Prostaglandin analogue - latanoprost
2. direct parasympathomimetics - pilocarpine
what are the iatrogenic ocular manifestations seen in rheumatoid arthritis?
- steroid-induced cataracts
2. chlorquine retinopathy
what are the causes of keratitis?
Bacterial. - staphylococcus aureus and pseduomonas aeruginose - contact lens wearers
Fungal
Amoebic - acanthamoeba castellanii
Parasitic - onchocercal keratitis
Viral - herpes simplex keratitis
what are the risk factors for open angle glaucoma?
- increasing age
- genetics - first degree relative
- afro caribbean ethnicity
- myopia
- hypertension
- diabates mellitus
- corticosteorids
what are the common causes of vitreous haemorrhage?
- proliferative diabetic rethinopathy
- posterior vitreous detachment
- ocular trauma - most common cause in children and young adults
what are the possible casuses of cataract other than age?
- smoking
- increased alcohol consumption
- trauma
- diabetes mellitus
- long term corticosteroids
- radiation exposure
- myotonic dystrophy
- hypocalcaemia
how does herpes simplex keratitis present?
- red, painful eye
- photophobia
- epiphora
- visual acuity decreased
- fluorescein staining - epithelial ulcer
how to differentiate CRVO from retinal detachment/PVD?
CRVO is painless visual loss. Pts have vascular risk factors.
Detachment - causes flashes and floaters. darkening of peripheral vision and disruption of straight lines
what is the difference between third nerve palsy and horner syndrome?
Ptosis + dilated pupil = third nerve palsy
ptosis + constricted pupil + anhidrosis = Horner’s
what are the signs of papilloedema on fundoscopy?
- venous engorement - first sign
- loss of venous pulsation
- blurring f the optic disc margin
- elevation of the optic disc
- loss of the optic cup
- paton’s lines: concentric retinal lines cascasding through the optic disc
what is the tx for conjunctivitis?
- topical antibiotics - chloramphenicol drops
Following an uneventful pregnancy, a 19-year-old woman delivers a male child vaginally. At assessment one week later the child is noted to have purulent discharge and crusting of the eyelids. What is the next step in the management of the child?
take urgent swabs of the discharge for microbiological investigations
what is the fundoscopy finding of open angle glaucoma?
- optic disc cupping - cup-to-disc ratio > 0.7 (norma = 0.4-0.7
