Ophthalmology Flashcards
Most common cause of blindness in 35-65 y/o?
Diabetic retinopathy
Diabetic retinopathy classification?
- Non-proliferative (NPDR)
- Proliferative (PDR)
- Maculopathy
NPDR classification?
- Mild
- Moderate
- Severe
Mild NPDR?
1 or more microaneurysms
Moderate NPDR?
- Microaneurysms
- Blot haemorrhages
- Hard exudates
- Soft exudates = cotton wool spots (areas of retinal infarction), venous beading/looping and intraretinal microvascular abnormalities (IRMA) less severe than in severe NPDR
Severe NPDR?
- Blot haemorrhages and microaneurysms in 4 quadrants
- Venous beading in at least 2 quadrants
- IRMA in at least 1 quadrant
Proliferative DN?
- Retinal neovascularisation - may lead to vitrous haemorrhage
- Fibrous tissue forming anterior to retinal disc
- More common in Type I DM, 50% blind in 5 years
Diabetic maculopathy?
- Based on location rather than severity, anything is potentially serious
- Hard exudates and other ‘background’ changes on macula
- Check visual acuity
- More common in T2DM
Diabetic retinopathy all pts Rx
- Optimise glycaemic control, BP and hyperlipidaemia
- Regular review by ophthalmoplegia
Diabetic maculopathy Rx?
If there is change in visual acuity –> Intravitreal VEGF inhibitor
Diabetic NPR Rx?
- Regular observation
- If severe/very severe consider panretinal laser photocoagulation
Diabetic PR Rx?
- Panretinal laser photocoagulation
- Intravitreal VEGF inhibitors = often used in combination with PRLP, e.g. ranibizumab
- If severe or vitreous haemorrhage –> vitreoretinal surgery
Iritis AKA?
Anterior uveitis
Anterior uveitis definition?
Inflammation of the anterior portion of the uvea - the iris and ciliary body
Anterior uveitis association?
HLA-B27 linked conditions
1. Ankylosing spondylitis
2. Reactive arthritis
3. IBD
4. Behcet’s disease
5. Sarcoidosis: bilateral disease
Anterior uveitis features?
- Acute onset
- Ocular discomfort and pain (may increase with use)
- Pupil may be small +/- irregular due to sphincter muscle contraction
- Photophobia (often intense)
- Blurred vision, red eye, lacrimation
- Ciliary flush = a ring of red spreading outwards
- Hypopyon = pus and inflammatory cells in the anterior chamber, often resulting in a visible fluid level
- Visual acuity initially normal –> impaired
Anterior uveitis Rx?
- Urgent ophthalmology review
- Cycloplegics (dilates the pupil which helps to relieve pain and photophobia) = atropine, cyclopentolate
- Steroid eye drops
Most common cause of blindness in the UK?
Age-related macular degeneration (ARMD)
ARMD mushkies?
Degeneration of the central retina (macula) is the key feature with changes usually bilateral. ARMD is characterised by degeneration of retinal photoreceptors that results in the formation of drusen which can be seen on fundoscopy and retinal photography. It is more common with advancing age and is more common in females.
ARMD RFs?
- Age
- Smoking
- FHx
- IHD = HTN, lipids, DM
ARMD classification?
- Dry = 90%, AKA atrophic, drusen (yellow round spots in Bruch’s membrane)
- Wet = 10%, AKA exudative/neovascular, characterised by choroidal neovascularisation, leakage of serous fluid and blood can subsequently result in a rapid loss of vision, carries the worst prognosis
ARMD updated classification?
- Early ARMD (non-exudative, age-related maculopathy): drusen and alterations to the retinal pigment epithelium (RPE)
- Late ARMD (neovascularisation, exudative)
ARMD features?
Subacute onset of visual loss with:
1. Reduction in visual acuity, particularly for near field objects (gradual in dry ARMD, subacute in wet ARMD)
2. Difficulty in dark adaptation with an overall deterioration in vision at night
3. Fluctuations in visual disturbance which may significantly vary from day to day
4. Photopsia = a perception of flickering or flashing lights, and glare around objects
5. Charles Bonnet syndrome
ARMD signs?
- Distortion of line perception may be noted on Amsler grid testing
- Fundoscopy = drusen, may become confluent in late disease to form a macular scar
- In wet ARMD well demarcated red patches may be seen which represent intra-retinal or sub-retinal fluid leakage or haemorrhage
ARMD Ix?
- Slit-lamp = identify any pigmentary, exudative or haemorrhagic changes affecting the retina which may identify the presence of ARMD. This is usually accompanied by colour fundus photography to provide a baseline against which changes can be identified over time
- Fluorescein angiography = used if neovascular ARMD is suspected, as this can guide intervention with anti-VEGF therapy. This may be complemented with indocyanine green angiography to visualise any changes in the choroidal circulation
- Ocular coherence tomography is used to visualise the retina in three dimensions because it can reveal areas of disease which aren’t visible using microscopy alone
ARMD Rx?
- Zinc with Vitamins A,C,E reduce disease progression by 1/3rd
- Anti-VEGF for wet ARMD, within first 2m of diagnosis if possible
- Laser photocoagulation does slow progression, but risk of acute visual loss after treatment, therefore anti-VEGF therapies usually preferred
Anti-VEGF agents?
Usually administered by 4 weekly injection
1. Ranibizumab
2. Bevacizumab
3. Pegaptanib
Amsler grid testing?
ARMD - distortion of line perception
Holmes-Adie pupil mushkies?
- Benign condition most commonly seen in women
- Dilated pupil, once the pupil has constricted it remains small for an abnormally long time
- Slowly reactive to accommodation but very poorly (if it all) to light
Holmes-Adie syndrome?
Association of Holmes-Adie pupil with absent ankle/knee reflexes
Blepharitis?
Inflammation of the eyelid margins.
Causes of blepharitis?
- Meibomian gland dysfunction = common, posterior blepharitis
- Seborrheoic dermatitis/staphylococcal infection (less common, anterior blepharitis)
Blepharitis association?
Rosacea
Meibomian gland function?
Secrete oil onto eye surface to prevent rapid evaporation of the tear film. Any problem affecting the meibomian glands (as in blepharitis) can hence cause drying of the eyes which in turns leads to irritation
Blepharitis features?
- Usually bilateral grittiness and discomfort, particularly around eyelid margins
- Eyes may be sticky in the morning
- Eyelid margins may be red, swollen eyelids may be seen in staphylococcal blepharitis
- Styes and chalazions are more common in pts with blepharitis
- Secondary conjunctivitis may occur
Blepharitis Rx?
- Softening of lid margins using hot compresses BD
- Lid hygiene = mechanical removal of the debris from lid margins = cotton wool buds dipped in a mixture of cooled boiled water and baby shampoo is often used, an alternative is sodium bicarbonate, a teaspoonful in a cup of cooled water that has recently been boiled
- Artificial tears may be given for symptom relief in people with dry eyes or an abnormal tear film
How to differentiate scleritis from episcleritis?
Scleritis is painful
Scleritis features?
- Red eye
- Classically painful, but sometimes only mild pain/discomfort is present
- Watering and photophobia common
- Gradual decrease in vision
Fixed dilated pupil with conjunctival injection?
Acute closed-angle glaucoma
Glaucoma definition?
Glaucoma is a group of disorders characterised by optic neuropathy due, in the majority of patients, to raised intraocular pressure (IOP). It is now recognised that a minority of patients with raised IOP do not have glaucoma and vice versa
Acute angle-closure glaucoma (AACG) definition?
Rise in IOP secondary to an impairment of aqueous outflow
AACG predisposing factors?
- Hypermetropia (long sightededness)
- Pupillary dilatation
- Lens growth associated with age
AACG features?
- Severe pain = may be ocular or headache
- Decreased visual acuity
- Symptoms worse with mydriasis (e.g. watching TV in dark room)
- Hard, red-eye
- Haloes around lights
- Semi-dilated non-reacting pupil
- Corneal oedema results in dull or hazy cornea
- Systemic upset may be seen e.g. N&V and even abdominal pain
AACG Rx Principles?
Emergency, refer to ophthalmologist, need to lower IOP acutely with more definitive surgical Rx once acute attack has settle
AACG Acute Rx?
Combination of eye drops:
1. Pilocarpine = direct sympathomimetic, contraction of the ciliary muscle → opening the trabecular meshwork → increased outflow of the aqueous humour
2. Timolol = BB, decreases aqueous humour production
3. Apraclonidine = A2 agonist, dual mechanism, decreases aqueous humour production and increases uveoscleral outflow
Also: IV Acetazolamide = reduces aqueous secretions
AACG Definitive Rx?
Laser peripheral iridotomy = creates tiny hole in the peripheral iris –> aqueous humour flowing to the angle
Chorioretinitis which test must be done?
HIV
Chorioretinitis causes?
- Syphilis
- CMV
- Toxoplasmosis
- Sarcoidosis
- TB
Orbital cellulitis definition?
An infection affecting the fat and muscles posterior to the orbital septum, within the orbit but not involving the globe. It is usually caused by a spreading upper respiratory tract infection from the sinuses and carries a high mortality rate. Orbital cellulitis is a medical emergency requiring hospital admission and urgent senior review.
Periorbital cellulitis definition?
A less serious superficial infection anterior to the orbital septum, resulting from a superficial tissue injury (chalazion, insect bite etc…). Periorbital cellulitis can progress to orbital cellulitis.
Orbital cellulitis RFs?
- Childhood = mean age of hospitalisation 7-12 years
- Previous sinus infection
- Not HiB vaccinated
- Recent eyelid infection/insect bite on eyelid (periorbital cellulitis)
- Ear or facial infection
Orbital cellulitis presentation?
- Redness and swelling around the eye
- Severe ocular pain, visual disturbance, proptosis
- Ophthalmoplegia/pain with eye movements
- Eyelid oedema and ptosis
- Drowsiness +/- N&V in meningeal involvement (rare)
Differentiating orbital from preseptal cellulitis?
Reduced visual acuity, proptosis, ophthalmoplegia/pain with eye movements are NOT consistent with preseptal cellulitis
Orbital cellulitis Ix?
- FBC
- Clinical examination involving complete ophthalmological assessment = decreased vision, RAPD, proptosis, dysmotility, oedema, erythema
- CT with contrast = Inflammation of the orbital tissues deep to the septum, sinusitis
- Blood culture and swab to determine causative organism
Most common bacterial causes of orbital cellulitis?
Strep, Staph A, HiB
Orbital cellulitis Rx?
Admission for IV Abx
Orbital compartment syndrome Rx?
Immediate canthotomy
Hyphaema?
Blood in the anterior chamber of the eye
Hyphema Rx?
Urgent referral to ophthalmology (main risk to sight comes from raised intraocular pressure which can develop due to the blockage of the angle and trabecular meshwork with erythrocytes. Strict bed rest is required as excessive movement can redisperse blood that had previously settled; therefore high-risk cases are often admitted. Even isolated hyphema will require daily ophthalmic review and pressure checks initially as an outpatient)
Orbital compartment syndrome cause?
E.g. Retrobulbar haemorrhage
Orbital compartment syndrome featrues?
- Eye pain/swelling
- Proptosis
- Rock-hard eyelids
- RAPD
B-scan US?
Imaging technique to look at posterior compartment of the eye, helpful for retinal detachment or posterior vitreous haemorrhage
Immediate IV acetazolamide used for?
AACG
Sore, red eyes with sticky discharge?
Conjunctivitis - either viral or bacterial
Bacterial conjunctivitis features?
Purulent discharge, eyes may be ‘stuck together’ in the morning
Viral conjunctivitis features?
Serious discharge, recent URTI, preauricular lymph nodes
Infective conjunctivitis Rx?
- Usually self-limiting 1-2 weeks
- Chloramphenicol drops 2-3h or ointment QDS
- Topical fusidic acid BD for pregnant women
- Contact lens users = topical fluorescein to identify any corneal staining, lenses should not be work
- Don’t share towels
- School exclusion not necessary
Optic neuritis causes?
- MS (most common associated disease)
- DM
- Syphilis
Optic neuritis features?
- Unilateral decrease in visual acuity over hours or days
- Poor discrimination of colours, ‘red desaturation’
- Pain worse on eye movement
- RAPD
- Central scotoma
Red desaturation?
Optic neuritis
Optic neuritis Ix?
MRI brain and orbits with gadolinium contrast
Optic neuritis Rx?
- High dose steroids
- Recovery usually takes 4-6 weeks
Optic neuritis prognosis?
MRI: If >3 white matter lesions, 5 year risk of developing MS is 50%
Most common cause of a persistent watery eye in an infant?
Nasolacrimal duct obstruction
Nasolacrimal duct obstruction cause?
Imperforate membrane, usually at the lower end of the lacrimal duct. 1/10 have symptoms at 1m/o.
Nasolacrimal duct obstruction Rx?
- Teach parents to massage lacrimal duct
- Symptoms resolve in 95% by 1 y/o, unresolved cases should be referred to an ophthalmologist for consideration of probing, which is done under a light general anaesthetic
Eyelid problems?
- Blepharitis = inflammation of the eyelid margins typically leading to a red eye
- Stye = infection of the glands of the eyelids
- Chalazion = Meibomian cyst
- Entropion = in-turning of the eyelids
- Ectropion = out-turning of the eyelids
What is a Chalazion/Meibomian cyst?
A retention cyst of the Meibomian gland. It presents as a firm painless lump in the eyelid. The majority of cases resolve spontaneously but some require surgical drainage
Stye classification?
- External = hordeolum externum = infection (usually staphylococcal) of the glands of Zeis (sebum producing) or glands of Moll (sweat glands)
- Internal = hordeolum internum = infection of the Meibomian glands, may leave a residual chalazion
Stye Rx?
- Hot compresses and analgesia
- Topical Abx only if associated conjunctivitis
Transient monocular visual loss (TMVL)?
Sudden, transient loss of vision that lasts less than 24 hours
Most common causes of sudden painless loss of vision?
- Ischaemic/vascular
- Vitreous haemorrhage
- Retinal detachment
- Retinal migraine
Ischaemic/vascular visual loss?
- AKA Amaurosis fugax
- Wide differential including large artery disease (atherothrombosis, embolus, dissection), small artery occlusive disease (anterior ischemic optic neuropathy, vasculitis e.g. temporal arteritis), venous disease and hypoperfusion
- May represent a form of TIA, so Rx with 300mg aspirin
- Altitudinal field defects often seen e.g. curtain coming down
- Ischaemic optic neuropathy is due to occlusion of the short posterior ciliary arteries, causing damage to the optic nerve
Ischaemic optic neuropathy cause?
Occlusion of short posterior ciliary arteries
CRVO?
- Incidence increases with age, more common than CRAO
- Causes = glaucoma, polycythaemia, hypertension
- Severe retinal haemorrhages on fundoscopy
CRAO?
- Due to thromboembolism (from atherosclerosis) or arteritis (temporal arteritis)
- Features include RAPD, ‘cherry red’ spot on pale retina
Cherry red spot on pale retina?
CRAO
Vitreous haemorrhage?
- Causes = DM, bleeding disorders, anticoagulants
- Features may include sudden visual loss, dark spots
Retinal detachment?
Features of vitreous detachment, which may precede retinal detachment, include flashes of light or floaters
Differentiating between posterior vitreous detachment, retinal detachment and vitreous haemorrhage?
- PVD = flashes of light and floaters
- RD = Dense shadow starts peripherally and progresses towards central vision
- VH = sudden visual loss, numerous dark spots
CRAO features?
- Sudden, painless unilateral visual loss
- RAPD
- Cherry red spot on pale retina
CRAO Rx?
Rx is difficult and prognosis is poor
1. Underlying conditions should be identified and treated e.g. IV Steroids for temporal arteritis
2. If presents acutely then intraarterial thrombolysis may be attempted but currently trials show mixed results
Severe retinal haemorrhages on fundoscopy?
CRVO
Cheese and tomato pizza?
CRVO
CRVO risk factors?
- Age
- HTN
- CVD
- Glaucoma
- Polycythaemia