Opthalmology Flashcards
What is a glaucoma ?
- Optic neuropathies caused by an increase in intraocular pressure = damages the optic nerve
What are the 7 RF for open angle glaucoma ?
- Increasing age
- FHx
- Afro-Carbibbean ethnicity
- Myopia (nearsightedness)
- DM
- HTN
- Corticosteroids
What are the presenting features of open angle glaucoma ?
Gradual onset peripheral vision loss
Findings on fundoscopy in open angle glaucoma
- Optic disc cupping (Cup-to-disc ratio >0.7)
- Optic disc pallor
- Bayonetting of vessels
What is the management of open angle glaucoma ?
- First line = Laser : 360 degrees trabeculoplasty If IOP >=24mmHg
- Second = Medical management : prostaglandin analogue eye drops (Latanoprost)
- Third : BB (Timolol).
- Surgery : Trabeculectomy in refractory cases
What are the RF for acute angle closure glaucoma ?
- Hypermetropia (long-sightedness)
- Pupillary dilatation
- Cataracts
- Increasing age
What are the presenting features of acute angle closure glaucoma ?
- Sudden onset severe pain : may be ocular or headache
- Painful red eye.
- Blurred vision
- Halos around lights
- N&V.
- Symptoms worse with mydriasis (e.g. watching tv in a dark room).
What are the 6 features seen on examination in acute angle closure glaucoma ?
- Red eye
- Hazy cornea
- Decreased visual acuity
- Semi-dilated non-reacting pupil
- Fixed size pupil
- Hard eyeball on gentle palpation
What is the management of acute angle closure glaucoma ?
- Immediate admission and referral to ophthalmologise (keep pt supine without a pillow)
- Combination of eye drops : Pilocarpine 2%, Timolol, and apraclonidine.
- IV Acetazolamide
- Definitive : laser peripheral iridotomy
How does latanoprost work and what are its SE?
- Prostoglandin analogue
- Increases uveoscleral outflow (aqueous humour)
- Once daily
- SE : brown pigmentation of iris, increased eyelash length
How does timolol work and what is a contraindication ?
- BB
- Reduces aqueous humour production
- Avoided in asthmatics and pts with heart block
How does apraclonidine work, when is it avoided and what is an adverse effect ?
- Alpha-2 receptor agonist
- Reduces aqueous humur production & increases uveoscleral outflow.
- Avoided if taking MAOI or tricyclic antidepressant
- Adverse effect : hyperaemia
How does Dorzolamide work ?
- Carbonic anhydrase inhibitor
- Redices aqueous humur production
What is the mechanism of action of pilocarpine and its adverse effects ?
- Muscarinic receptor agonist
- Increases uveoscleral outflow
- Adverse effects : constricted pupil, headache and blurred vision
What happens to the macula in ARMD ?
- Frequent and larger Drusen
- Atrophy of the retinal pigment epithelium
- Degeneration of photoreceptors
What happens specifically in wet ARMD?
- Neovascularisation
- New blood vessels develop in the choroid and grow into the retina
- When they leak fluid / blood = oedema and faster vision loss
RF for ARMD
- Older age (>75)
- Smoking
- FHx
- Other cardiovascular RF (HTN, DM, dyslipidaemia).
What are the features of ARMD ?
- Loss of CENTRAL vision : gradual in dry ARMD, Subacute in wet ARMD
- Crooked or wavy appearance to straight lines (metamorphopsia).
- Deterioration in vision at night
- Flashing lights
- Fluctuations in visual disturbance that varies from day to day
What is seen on examination in ARMD ?
- Reduced visual acuity on a Snellen chart
- Scotoma
- Distortion of straight lines assessed with Amsler grid test
- Drusen on fundoscopy
What investigations are done in ARMD
- Initial : Slit lamp -> view of retina and macula.
- Optical coherence tomography : for diagnosing and monitoring
- Fluorescein angiography : shows oedema and neovascularisation in wet AMD
How is ARMD managed ?
- Slow / reduce progression
- Avoid smoking
- Control BP
- Vitamin supplementation
What specific medication can be used in wet ARMD ?
- Anti-VEGF medications (Ranibizumab)
- Target Vascular endothelial growth factor which stimulates the development of new blood vessels in the retina
Causes of an acutely red PAINLESS eye
- Conjunctivitis
- Episcleritis
- Subconjunctival haemorrhage
7 causes of an acutely PAINFUL red eye
- Acute angle-closure glaucoma
- Anterior uveitis
- Scleritis
- Corneal abrasions or ulceration
- Keratitis
- Foreign body
- Traumatic or chemical injury
PAINLESS red, bloodshot eye
Purulent discharge
Itchy / gritty sensation
Diagnosis and management
- Bacterial conjunctivitis
- Often staph aureus (or gonococcus if STI)
- If needed : chloramphenicol / fusidic acid eye drops (pregnant women)
PAINLESS red, blood shot eye
Clear discharge
Tender preauricular lymph nodes
Coryzal symptoms
Viral conjunctivits
Often adenovirus
- Bilateral swelling of conjunctival sac and eyelid
- Prominent itch
- Watery discharge
Diagnosis and management
- Allergic conjunctivits
- Oral or topical antihistamines (cetirizine)
- Topical mast-cell stabilisers (sodium cromoglicate) can be given 2nd line
What is anterior uveitis
- Inflammation of the middle layer of the eye
- Choroid, ciliary body and iris
What are the presenting features of anterior uveitis
- ACUTELY painful, red eye
- Photophobia
- Blurred vision
- Excessive lacrimation
What is seen on examination in anterior uveitis?
- Miosis +/- irregulalry shaped pupil
- Ciliary flush
- Hypopyon
What is anterior uveitis associated with ?
- HLA-B27
- Seronegative spondyloarthropathies
- Behcet’s disease
- Sarcoidosis
How is anterior uveitis managed ?
- Urgent ophthalmologist referral
- Steroids (eye drops, oral or IV)
- Cycloplegics / mydriatic (e.g. cyclopentolate or atropine eye drops = antimuscarinis)
How do cycloplegics work in anterior uveitis ?
- Antimuscarinins
- Paralyse the ciliary muscles = dilates the pupil and reduces pain
what kind of pupil is seen in neyrosyphilis ?
- Argyll-Robertson pupil
- Small, irregular pupils
- Accommodates but
- Asymmetrical slow reduction in visual acuity.
- Fading of colours
- Halos around lights
- Glaring of lights / “starbursts” around lights
Cataracts
What is cataracts and what 2 investigations are done to diagnose
- Progressively opacification of the lens
- Slit lamp : shows cataracts
- Opthalmoscope : shows loss of red reflex with normal optic nerve and fundus
Conservative and definitive management of cataracts
- conservative : glasses
- Definitve : surgery - surgical replacement with artificial lens
What are the diffferentials for sudden, painless vision loss ?
- Retinal detachment
- Central retinal artery occlusion
- Central retinal vein occlusion
- Vitreous haemorrhage due to diabetic retinopathy
what is seen on fundoscopy in central retinal artery occlusion
- Pale retina
- ‘Cherry red spot on retina’
What is a key sign of central retinal artery occlusion ?
Relative afferent pupillary defect
What are the features of retinal vein occlusion
Sudden, painless reduction or loss of visual acuity
what is seen on fundoscopy in retinal vein occlusion
- Widespread hyperaemia
- Severe retinal haemorrhages -> ‘Stromy sunset’
How is retinal vein occlusion managed ?
- Refer to opthalmologist
- Anti-VEGF (renibizumab) = macular oedema
- Laser photocoagulation = neorevascularisation
What is Blepharitis : presentation and management
- Inflammation of the eyelid margins
- Bilateral grittiness/discomfort with swollen and red eyelids
- Hot compress twice daily / cooled boiled water and baby shampoo on cotton wool
What are the 2 types of stye, presentation and management
- Hordeolum externum : infection of sebaceous or sweat glands
- Hordeolum internum : infection of meibomian glands
- Tender, red lump on eyelid
- Hot compress and analgesia
Chalazion : what, features, management
- Blocked and swollen meibomian gland (cyst)
- Firm, painless lump in eye
- Warm compress and gentle massage
Entropion : what and management
- Eyelid turned inwards
- Tape down eyelid with regular lubticating drops
- Definitive = surgery
Ectropion. : what and management
- Eyelid turned outwards
- Regular lubricating eyedrops
Trichiassis : what and management
- Inward growth of eyelashes
- Remove affected eyelashes
Periorbital cellulitis : causes and features
- Eyelid and skin infection IN FRONT of orbital septum
- Most frequently : staph aureus
- Swollen, red, hot skin around the eyelid and eye
How is periorbital cellulitis distinguished from orbital cellulitis ?
- Contrast CT
How is periorbital cellulitis managed ?
- Urgent opthalmology referral
- Oral co-amoxiclav
What is orbital cellulitis ?
Infection around the eyeball involving tissues BEHIND the orbital septum
What are the features of orbital cellulitis ?
- Redness and swelling around the eye
- Severe ocular pain
- Visual disturbance
- Proptosis -> eye bulges forwards
- Opthalmoplegia / pain with eye movements
- Eyelid oedema and ptosis
How is orbital cellulitis managed ?
IV antibiotics
Features of corneal abrasions
Eye pain
Foreign body sensation
Photophobia
Watering eye : epiphora
Red eye
How can corneal abrasions be visualised
- Fluorescein stain -> yellow-orange colour that collects in abrasions / ulcers highlighting them, especially when viewed under cobalt blue light
What are lubricating eye drops based on ?
- Hypromellose -> least viscous (effects last 10 mins)
- Polyvinyl alcohol drops -> middle viscous
- Carbomer -> most viscoius (last 30-60 mins)
What is keratitis
Inflammation of the cornea