Ophthalmology Flashcards
What are 4 signs on examination of uveitis?
- ciliary (circumcorneal) injection
- aqueous flare - leakage of protein + leukocytes into anterior chamber
- keratic precipitates - on posterior surface of cornea
- posterior synechiae
What is Talbot’s test?
pain on pupil constriction when tested with convergence - moving finger closer to eyes
What is the commonest cause of orbital cellulitis in children and why?
Ethmoidal sinusitis - relatively thin medial wall of the orbit
What are 5 risk factors for orbital cellulitis?
- childhood - mean age of hospitalisation 7-12 years
- previous sinus infection
- lack of haemophilus influenzae type b (Hib) vaccination
- recent eyelid infection / insect bite on eyelid (periorbital celllulitis)
- ear or facial infection
What are 4 things that differentiate orbital from preseptal cellulitis?
- reduced VA
- propotosis
- ophthalmoplegia / pain with eye movements
- RAPD
How much does family history increase the risk of age-related macular degeneration?
first degree relatives 4x more likely to inherit
What is the normal optic disc to cup ratio?
0.4 - 0.7
What are 6 risk factors for age-related macular degeneration?
- advancing age, particularly >75y
- smoking
- family history
- factors increasing risk of ischaemic heart disease - hypertension, dyslipidaemia, diabetes mellitus
- female gender
What proportion of cases of AMD are dry?
90%
What investigations are indicated for wet AMD and why?
fluorescein angiography (+- indocyanine green angiography to visualise choroidal circulation) - can guide intervention with anti-VEGF therapy
What treatment option is there for dry AMD?
zinc and anti-oxidant vitamins A + C + E (best in patients with extensive drusen, at least moderate category)
What is the treatment of a corneal abrasion?
topical chloramphenicol to prevent infection
What are 2 options for treatment of wet ARMD and what is the drawback of the less preferred option?
- anti VEGF e.g. ranibizumab, bevacizumab, pegaptanib
- laser photocoagulation - risk of acute visual loss after treatment (especially sub-foveal ARMD)
What are the criteria for someone to be registered as severely sight impaired?
Visual acuity <3/60 with full visual field wearing glasses as prescribed - in better eye
How can you distinguish between causes of Horner’s syndrome clinically?
- central: anhidrosis down one side of face, arm and trunk
- preganglionic: anhidrosis of face
- postganglionic: no anhidrosis
What characterises mild/moderate/severe non-proliferative retinopathy?
- mild: 1 or more micro aneurysm
- moderate: microaneurysms, blot haemorrhages, hard exudates, cotton wool spots, venous beading, IRMA
- severe: blot haemorrhages and microaneurysms in 4 quadrants, venous beading in at least 2 quadrants, IRMA in at least 1 quadrant
What characterises diabetic maculopathy?
Hard exudates and other background changes on macula
In which diabetes type is maculopathy more commonly seen?
T2DM
In which diabetes type is proliferative retinopathy more commonly seen?
T1DM
What are the treatment options for diabetic:
- maculopathy
- non-proliferative retinopathy
- proliferative retinopathy
- anti-VEGF
- PRP if severe
- anti-VEGF, PRP, vitreoretinal surgery
What are 2 complications of PRP?
- reduction in peripheral vision
- poor night vision (more rods in peripheral retina)
Why is diabetes a risk factor for developing cataract? Give the 3 explanations
- increased intracellular accumulation of sorbitol (from glucose metabolism) leads to hyperosmotic effect, resulting in hydropic lens fibres that degenerate and form cataract
- osmotic stress due to swelling of cortical lens fibres (esp T1DM)
- autoimmune hypothesis in bilateral T1DM cataracts
What are the 2 commonest aetiologies for rubeosis iridis?
- central retinal venous occlusion
- diabetic retinopathy
What type of glaucoma can develop due to rubeosis iridis?
initially secondary open angle glaucoma - vessels impair aqueous humour outflow; can progress to secondary closed angle glaucoma as fibrotic membranes develop and contract
What is the gold-standard treatment for rubeosis iridis?
pan-retinal photocoagulation (PRP) to reduce neovascularisation
[recently anti-VEGF also shown to have benefit]
What are treatment options are there for CRVO/BRVA?
- anti-VEGF (macular oedema)
- intravitreal steroids
- laser photocoagulation (retinal neovascularisation)
What causes ocular ischaemic syndrome?
ocular hypoperfusion due to stenosis or occlusion of the common or internal carotif arteries (atherosclerosis = major cause)
What is asteroid hyalosis?
form of vitreous degeneration in which calcium aggregates in the vitreous body (see little white flecks in vitreous) - rarely affects visual acuity, no treatment required
What are 5 risk factors for developing diabetic retinopathy?
- severity of hyperglycaemia (no specific threshold)
- duration of hyperglycaemia
- hypertension + other cardiovascular risk factors
- renal disease
- pregnancy (rapid progression)
What is non-high risk proliferative diabetic retinopathy vs. high risk proliferative DR?
- non-high risk: NVD or within 1 disc diameter of it, or NVE
- high risk: large NVD or NVE, or presence of pre-retinal haemorrhage
What are 3 types of diabetic maculopathy?
- focal or diffuse macular oedema
- ischaemic maculopathy
- clinical significant macular oedema (CSMO) - thickening of retina + hard exudates withi a specific distance of the fovea OR of a certain size
What is the screening process for diabetic eye disease in T1 and T2DM?
- T1DM - children 12y and over - annual monitoring
- T2DM - all patients should be referred for monitoring
What are 4 elements of the treatment of diabetic eye disease?
- Laser (PRP)
- Anti-VEGF intravitreal injection
- Intravitreal steroids - CSMO
- Surgery - vitrectomy if vitreal haemorrhage
What are 5 investigations that can be performed in suspected chronic glaucoma?
- automated perimetry (visual field)
- slit lamp + mydriasis
- applanation tonometry
- central corneal thickness
- gonioscopy
What are 4 facotrs that influence risk of future visual impairment in glaucoma?
- IOP
- central corneal thickness (CCT)
- family history
- life expectancy
What is the most commonly associated condition with scleritis?
rheumatoid arthritis
What are 4 conditions associated with scleritis?
- RA
- SLE
- sarcoidosis
- GPA
What are 4 aspects of the management of scleritis?
- same day ophthal assessment
- NSAIDs first line
- steroids if severe
- imunosuppressive drugs if resistant / for underlying disease
Per NICE guidelines what’s the first line for primary open angle glaucoma?
360° selective laser trabeculoplasty (SLT)
What are second and third line treatments for POAG per NICE?
after SLT:
* prostaglandin analogue (PGA)
* next line: beta blocker drops, carbonic anhydrase inhibitor drops, sympathomimetic drops
What surgery can be considered in refractive cases of POAG?
trabeculectomy
What is the mechanism of action of prostaglandin analogues (e.g. latanoprost)?
increase uveoscleral outflow
What are 2 adverse effects of PGA eyedrops?
- brown pigmentation of iris
- increased eyelash length
What is the mechanism of action of beta blocker eye drops e.g. timolol?
reduce aqueous production
What are 2 contraindications to beta blocker eye drops?
- asthma
- heart block
What is the mechanism of action of sympathomimetic eye drops e.g. alpha-1 adrenoceptor agonists such as birmonidine?
reduce aqueous production AND increase aqueous outflow
What is an adverse effect of alpha-2-adrenceptor agonist drops e.g. brimonidine?
hyperaemia
What is a key drug interaction of alpha-2 adrenoceptor agonists e.g. brimonidine?
MAOI or tricyclic antidepressants
What is the mechanism of action of carbonic anhydrase inhibitors e.g. dorzolamide?
reduces aqueous production
What is an adverse effect of carbonic anhydrase inhibitors?
may cause sulphonamide like reactions
What is the mechanism of action of miotics e.g. pilocarpine for POAG?
muscarinic receptor agonist - increases uveoscleral outflow
What are 3 side effects of miotics e.g. pilocarpine?
- constricted pupil
- headache
- blurred vision
What is the typical presentation of conjunctivitis?
sore, red eyes, sticky discharge (purulent if bacteria, serous if viral)
What is the management of infective conjunctivitis?
- normally self-limited, settles without treatment within 1-2 weeks
- topic abx often offered e.g. chloramphenicol
- chloramphenicol drops 2-3 hourly initially; ointment QDS initially
When should chloramphenicol drops be avoided and what is an alternative?
pregnant women - topical fusidic acid (BD)