Ophthalomolgy Flashcards
What is Non Arteritic anterior ischemic optic neuropathy (AION)?
Occlusion of the short posterior ciliary arteries resulting in infarction of the optic nerve head.
What are the risk factors for non arteritic AION?
Male Systemic ateriopathy 40-60yrs Small hypermetropic optic discs Hypertension Diabetes
What are the symptoms and signs of non ateritic AION?
Painless, monocular sudden loss of vision
Can be asymptomatic if good vision in other eye Moderate to severely reduced visual acuity in the affected eye
Swollen optic nerve with splinter or flame shaped haemorrhages
Relative afferent pupillary defect
Visual field defect - most common inferior altitudinal defect
How do you manage no arteritic AION and what is the prognosis?
Refer to ophthalmology - needs to exlcude GCA
R/V and treat all cardiovascular risk factors
Consider asprin
30% make substantial improvment
15-50% risk in other eye
Optic disc swellign resolves to leave optic disk pallor (loss of neural tissue)
What is another name for giant cell arteritis?
Arteritic anterior ischemic optic neuropathy - optic nerve is damaged as the posterior ciliary arteries are blocked by inflammation
How does GCA present?
Sudden loss of vision associated with headache
jaw and tongue claudication
tender scalp and temporal arteries
Loss of appetite and weight loss
symptoms of polymyalgia rheumatica
O/E: swollen optic disc and RAPD, flame shaped haemorrhages and cotton wool spots - retinal nerve fibre layer infarction
How do you manage giant cell arteritis?
Ophthalomology referal
bloods for ESR (>47)
High dose steroids - prednisolone 80mg/24hrs ASAP
Temporal artery biopsy
Describe the anatomy and physiology of the aqueous production of the eye
The CILIARY BODY - joins the iris to the choroid, it produces the aqueous humor and controls lens convexity
The ANTERIOR CHAMBER - the space between the cornea and the iris (shallower in the hypermetropic eyes as the eyes or smaller)
TRABECULAR MESHWORK - sieve like structure through which aqueous drains into the SCHLEMMS CANAL and out of the eye
The aqueous humour is produced and drained to maintain an appropriate intraoccular pressure.
What is the mechanism in acute angle glaucoma?
Failure of the aqueous humour to pass through the pupil and drain out through the trabecular meshwork.
Occurs when:
- the iris is pushed forward and blocks the meshwork
- the aqueous fails to pass through the pupil (a pupil block)
The result is raised intraoccular pressure
What are the risk factors for acute closed angle glaucoma?
Hypermetropia - eyes are normally smaller than usual and therefore have a shawllow anterior chamber which a narrower angle that is more prone to closure
Family history
Narrow anterior chamber angles
>30yrs - the lens thickens with age
Race - shallower angles in asians and eskimos
Women
What are the symptoms and signs of acute closed angle glaucoma?
Unilateral sudden loss of vision
Painful red eye
Halos around lights
Nausea and vomiting
O/E: corneal oedema, oval unreactive pupil, raised IOP
What is gonioscopy?
Uses prisms and a slit lamp to visualise the iridocorneal angle in 4 quadrants simultaneously
How do you treat acute angle glaucoma?
acetazolamide 500mg IV STAT - decreases the aqeous formation
timolol 0.5% and apraclonidine 1% eye drops - misosis opens the blocked drainage angle.
Laser - YAG peripheral iridotomy to create an alternative outflow tract for the aqueous to drain through
What is the anatomy of the retina?
Two main layers:
Neurosensory retina - in contact with the vitreous
The pigment layer - in contact with the choroid
The centre = the macula (5.5mm) and the fovea is the central area of the macula (high density of cones)
What are the different types of retinal detachment?
rhegmatogenous - a seperation of the vitreous layer causing a tear in the retina and detachment. The sensory retina separates from the retinal pigment epithelium
Tractional retinal detachment: secondary to intraocular problems - melanoma or fibrous bands in the vitroeous, seen in DM
post cataract surgery or trauma
What are the risk factors for retinal detachment?
MYOPIA - the higher the degree the higher the risk
previous retinal detachment in other eye
Trauma
What are the symptoms of retinal detachment?
Floaters, Flashes, Field loss, Fall in acuity
Usually field loss unless the macula is affected and then there will be a central loss of vision
How do you manage a retinal detachment?
REFER TO OPHTHALMOLOGY
the aim is to treat before the macula detaches.
Cyrobuckle surgery - silicome explant which indents the sclera to push back the retinal pigment epithelium against the retina and a cryotherapy probe to create a scar that seals the retinal break
Pars Plana vitrectomy - threet port pars plana cetrectomy involves removal of the vitreous, cryotherapy or laser to seal the break and then a bubble of gas to push the retina back against the retinal pigment epithelium.
Describe the visual pathway:
Nerve fibres from each retina leave the eye at the optic disc and travel along the optic nerve
The optic nerves of each eye join at the optic chiasm
Nerve fibres from the nasal retina of each eye cross over at the chiasm and travel down the contralateral optic tract
Nerve fibres from the temporl retina do NOT cross over so travel down the ipsilteral tract
The optic tracts connect with the lateral geniculate body. At this point synapses are formed with the neurones passing through the optic radiations to reach the visual cortex.
Describe the postion of lesions and what type of visual field defects they produce:
What is a homonymous hemianopia?
Field loss affecting the corresponding half fields of each eye. eg left homonymous hemianopia, the left side of the visual field is affected which means the right side of the visual pathway is damaged.
Must be posterior to the chiasm as the loss is bilateral.
Stroke is most common cause, others include tumours
What is a quandrantanopia?
Loss of a quarter of field of vision.
Bilateral to posterior to the chaism
Normally due to damage to the optic radiations.
A right homonymous inferior quadrantopia is due to lesion in the upper optic radiation in the left parietal lobe
What causes a bitemporal hemianopia?
Lesions in the optic chiasm
eg pituitary tumours - usually cause bi-temporal superior quadrantopia.
What causes central visual field defects?
Commonest cause = age related macula degeneration
Can be caused by optic nerve disease, often associated colour vision defects and visual acuity reduction
When a patient presents with visual field defect what are the differentials?
Retinal detachment
Central retinal vein occulsion
Optic nerve disease
Visual pathway pathology
Glaucoma
Stroke
Pituitary tumour
What causes diplopia?
When the visual axes of the two eyes deviate from fixating straight ahead or become misaligned during eye movement.
Displacement of globe in socket: tumours, trauma, infection
Cranial nerve palsies III, IV, VI
Cranial nerve palsies caused by DM and HTN
Decompensation of a latent squint
Extraocular muscle disease: MG
Thyroid eye disease
What is the difference between monocular and binocluar diplopia?
Monocular - doube vision persists when one eye is covered. Caused by corneal abnormalities, uncorrected refractive error, cataractcs
Binocular - occurs when the two eyes become misaligned,
Whic nerves supply the extraoccular muscles?
III:
Superior rectus, inferior rectus, medial rectus and inferior oblique
IV:
Superior oblique
VI:
Lateral rectus
What would you see in a III nerve palsy?
exo hypo deviation - down and out postion
Due to superior oblique and lateral rectus working unoppsed.
Superior obiques main function is to internally rotate the eye, and depress and abduct it
What are the causes of a IV nerve palsy?
DM, HT, demylinating disease, GCA, tumours, aneurysms
What are the signs of a IV nerve palsy?
abnormal head posture - head tilts away from the lesion
Eye deviating upwards as it moves towards the nose
What are the signs of a VI nerve palsy?
Patient suffereing with double vision especially when looking to the affected side.
Eye fails to abduct
What are the causes of VI nerve palsy?
Adults: HTN, DM, MS, neoplasm, head trauma, infection, raised ICP
Children: transient in neonates, benign causes may occur 1-3 weks after viral infection
How do you assess optic nerve function?
Visual acuity
Visual fields
Colour vision
Pupil reactions
What are the causes of optic disc swelling?
Unilateral:
Central retinal vein occlusion, AION, papillits (inflammation of the optic nerve head), neuroretinitis
Bilateral:
Intracranial mass causing raises ICP, malignant hypertension, optic disc drusen
What is the upper limit of size difference between the pupils that is physiological?
Up to 0.5mm of aniscoria (difference in size)
Physiological anisocria is the same in all levels of light where as pathological varies between light and dark conditions
What determines pupil size?
The iris sphincter muscle is innervated by the parasympathetic division of cIII (occulmotor n). It constricts the pupil, miosis. Neurotransmitter is acetlycholine.
The pupillary reflex is a 4 neurone arc:
1st neurone passes from retina to the pretectal nucleus. 2nd neurone passes from the pretectal nucleus to the Edinger-Westphal nucleus. 3rd neurone passes from the EW nucleus to the cilary gangilon via the cIII. 4th neurone passes from the ciliary ganglion to the sphincter mucles via the ciliary nerves.
The dilator muscle is innervated by the sympathetic nervous system. Dilates the pupil, mydriasis.
Pupil mydrasis is a 3 neurone arc:
1st neruone passes from the posterior hypothalamus to the ciliospinal centre at the Budge at C8-T2. 2nd neruone passes from the spinal cord to the superior cervical ganglion. 3rd neurone passes from the superior cervical ganglion along the internal carotid artery through the cavernous sinus to the short posterior ciliary nerves and the dilator muscle.
What is RADP and was does it signify?
Relative afferent pupillary defect.
Swing a light from one eye to the other, allow 3secs of illumination per eye. When the light is swung to the healthy eye both pupils will contstrict, but when it is moved to the defected eye both pupils constrict less and may appear to dilate.
It indicates asymmetrical optic nerve or retinal disease, the afferent signal is reduced. The efferent pathway is in tact as the defected eye has a consensual relfex when the light is shone in the other eye.
What are the causes for an abnormally large pupil?
Holmes Adie pupil: poor reaction to light but constricts on accomodation. Part of Holmes Adie syndrome if there are reduced deep tendon relfexes.
Occulomotor palsy
Dilating eye drops
Traumatic mydriasis
Iris rubeosis: new blood vessel growth on the surface of the iris
In a bright room the larger pupil is likely to be the defect one.
What are the causes of an abnormally small pupil?
Horner’s syndrome: disruption of the sympathetic supply to the eye. Associated with ptosis, and anhidrosis.
Pilocarpine eye drops
Uveitis/ posterior synechiae: inflammation causes adhesions between the pupil margin and the lens. The pupil is small and stuck down so cant dilate.
Physiological
In a dark room the small pupil is likely to be the defect
What are the causes of Horner’s syndrome?
Posterior inferior ceebller artery or basilar artery occlusion
MS
Cavernous sinus thrombosis
Pancoast’s tumour
Hypothalamic lesions
Cervical adenopathy
Mediatinal masses
Pontine syringomelia
Kulmpke’s palsy
Aortic aneurysm
What is an Argyll Robertson pupil?
Bilateral miosis, pupil irregularity and no response to light but there is a response to accomodation.
Seen in neurosyphilis and diabetes
What is light near dissociation and what are the causes of it?
Where the pupil doesn’t respond to light but does respond to accomodation.
Causes: Argyll Robertson pupil. Holmes- Adie syndome, meningitis, alcoholism, tectal lesions, mesencephalic or thalamic lesions
What is ptosis?
Drooping of the upper eyelid.
The eye lid is intervated ny occulmotor nerve.
What presentations can give the false impression of ptosis?
Enophthalmous - posterior displacement of the eye makes the upper lid sulcus look deeper.
Dematochalsis: excess skin of the upper eyelid
Contralateral eyelid retraction
Contralateral proptosis
What are the causes of ptosis?
Congential: Levator dystropy, Horner’s syndrome
Levator disinsertion: Age or trauma
Mechanical due to eye lid trauma
Occulomotor palsy: usually has an divergent squint, eye is down and out, and pupil may be dilates and unreactive
Myasthenia gravis: becomes worse throughout the day
Horner’s syndrome
Crhonic progressive external ophthalmoplegia (mitochonrial myopathy)
How does light get focused onto the retina?
The cornea is the most refractive surface
The lens has variable focusing power: when near objects are focused on the ciliary body contratcs, relaxing the lens zonules so the lens becomes more convex and powerful.
The axial length helps determine focusing power.
What is Emmetropia?
When there is no refractive error
What is presbyopia?
Where with increasing age the lens looses its ablity to change shape and the point of closest focus moves further away for the eye.
Reading glasses are convex, providing extra power to focus the light on to the retina.
What is hypermetropia?
Long sightedness - when the refractive power of the eye is too weak and light from distant objects falls behind the retina.
What is myopia?
Short sightedness….the image falls in front of the retina
What is astigmatism?
Where the eye has different refractive power in different meridians so there are mutlipe focal points on the retina.
The cornea is shaped liked a rugby ball rather than a football.
What is keratoconus?
corneal collagen disorder where the cornea things and distorts.
Increase in corneal astigmatism and myopia, abnormal retinoscopy reflex (looks like a oil droplet), retinoscope reflex shows scissors movement.
Central corneal thinning and conical shape.
Bulging of the lower lif on dow gaze
Vertical lines in the corneal stroma
What syndromes are associated with keratoconus?
Downs syndrome
Ehlers Danlos syndrome
Marfans syndrome
How do you manage keratoconus?
Contact lens fit with Rigid gas permeable
Photorefractive surgery is contraindicated
Corneal graft may be needed in later stages if scaring is present
What three bacteria ,ay cause neonatal conjuctivitis and how can you differentiate between them?
Chalmydia - creamy white discharge 5-12 days after birth
Gonorrhoea - 2-5days after birth, rapidly progressing, can lead to corneal ulceration.
Staphlococcus - yellow discharge
In a baby with recurrent conjunctivits what must you consider?
Nasolacrimal duct obstruction - where the nasolacrimal duct fails to canalise by birth. Often resolves by its self in the first year of life but if not children may bee to be given a GA and have saline injected into the punctum to see if the canuli are open, and if not have a metal probe inserted to open them up.
Describe some of the ocular presentations of non accidental injury:
Swelling or buising of the external eye
Lid swelling, bruising or cuts
Infestation of eyelashes with lice
Conjunctiva haemorrhages
Scaring or perforation of the cornea
Caracts
Vitreous haemorrhages
Retinal haemorrhages (normally in the posterior pole) or detachment
Papilloedema
What is leucocoria?
White pupil
In children what are the causes of leucocoria?
Congenital cataract - needs ophth referral ASAP and TORCH screen
Coats disease - rare idiopathic unilateral retinal telangiectasia. more common in boys around 5 yrs.
Persistent hyperplastic primary vitreous - when the embryonic vitreous fails to regress, usually unilateral, and vision is related to the extent of posterior retinal involvement.
Toxocariasis - rare worm infection, usually unilateral. Causes posterior or peripheral retinal granuloma. May be associated with chronic intraocular inflammation
Retinoblastoma - rare but most common intraocular malignanacy in children. Can be bilateral and hereditary. Needs urgent ophth referral.
What is the inheritence pattern of retinoblastoma?
Hereditary retinoblastoma is different from non hereditary.
There is mutation of the RB gene on 13q14.
Autosomal dominant with 80% penetrance.
Those with the hereditary condition have only 1 allele in each cell and if the other allele develops a mutation then the conditiona arises
The RB is a tumour suppressor gene.
What is the difference between a latent and a manifest squint?
Latent squint (phoria) is when there is an underlying tendency for the eyes to be misaligned but this can be controlled through subconscious effort.
Manifest squint (tropia) is when the eyes can not be controlled and they deviate
How do you describe squints?
If the misaligned eye diverges in (towards the nose) when supposed to be looking straight ahead - convergent, this is called an ESO deviation. Esophoria or esotropia
If the misaligned eye diverges out (towards the temporal) when supposed to be looking straight ahead - divergent, this is an EXO deviation. Exophoria or exotropia.
If the visual axis is higher (the eye turns upwards) this is called a hypertropia.
Describe the cover test:
The cover test is used to show squints.
When you cover the dominant eye the eye with the squint will move to correct itself. eg with a left exotropia when you cover the right eye the left eye will move inwards to correct the outward gaze.
How do you treat squints?
Need to treat as soon as it is noticed.
Assess refractive state of the eyes using cyclopentolate 1% drops. and then corect this refractive error
Patch the good eye - helps to correct the loss of vision that occurs in the eye that is not aligning. the brain stops processing signals from that eye to reduce double vision in children, the process can be reversed if noticed soon enough.
Operations may be needed.
What is retinopathy of prematurity?
Changes that happen to the retina in preterm babies.
The retina has no blood vessels until the 4th month of gestation, they grow from the optic disc towards to the peripheral retina.
Supplementary oxygen that is given to the preterm babies contributes to its development
>50% if babies weighing <1000g will have some ROP
What are the stages of retinopathy of prematurity?
- demarcation line
- formation of three dimensional ridge
- fibrovascular proliferation at ridge
- partial retinal detachment (macula on v macula off)
- total retinal detachment
- agressive posterior retinopathy of prematurity
What are the 3 parts of the lens?
Capsule (think outermost basement membrane)
Cortex (outer layer of lens epithelial cells)
Nucleus (central lens fibres
What is a cataract?
Loss of transparency of the lens
What are the symptoms and signs of cataracts?
Gradual reduction in visual acuity
Increasing myopia (short sightedness)
Glare
O/E - reduced visual acuity (usually in one eye)
diminished red relfex
difficult view of the fundus
What are the risk factors for cataracts?
Most are age related - UV light and smoking increase risk
Cataracts occur earlier in DM, prolonged steriod use, trauma to eye, high myopia, dystrophia myotonica
What causes congential cataracts?
1/3 are inherited, autosomal dominant
1/3 are caused by birht trauma, or maternal infection during pregnancy
What different types of cataracts are there?
Nuclear
Cortical - spoke like from the edges
Posterior subcapsular - just deep to the lens capsule
What are the risks with cataract surgery?
Development of posterior capsule opacification - can be treated by laser
Very rare
Rupture of the posterior lens capsule
Endophthalmitis (severe intraocular infection)
Suprachorodial haemorrhage ( severe)
Descibe the procedure of cataract surgery:
Local anaestheisa
Self sealing corneal incision into the anterior chamber
Circular opening of the anterior lens capsule
Break up and aspiration of the lens material
Insertion of intraocular lens with chosen power to correct for any refractive error
What are the different parts of the retina?
Macula - posterior pole of the eye, responsible for central vision
Fovea - in the centre of the macula, specialsed for high acuity vision
The rest of the retinal provides peripheral vision - only has rods
What are the differences between the two types of Age related Macula Degeneration?
Both affect central vision, peripheral vision remains intact
Dry AMD-
Slowly progressing atrophy of the macular retinal pigment epitheial cells.
Drusen, mottled macular (hypo and hyper pigmentation) and atrophy on fundoscopy
Wet AMD-
New choroidal blood vessels grow into and under the retina. these then bleed or leak fluid causing macular oedema and scaring. Progresses quickly.
Green grey lesions consiting of new vessles, yellow exudates and retinal haemorrage on fundoscopy
What is the main symptoms of age related macular degernation?
Loss of central vision
What special tests can be done to confrim AMD?
Fluorescein angiography - identifies the areas of microvascular leakage
Optic coherence tomography - laser scanner is used to capture the cross section of the macular
How do you manage AMD?
Use Amsler chart to monitor progress
Stop smoking
Counselling
Low vision aids
Dry AMD - no treatment
Wet AMD - regular intravetreal injections of anti-VEGF drugs
What is primary open agle glaucoma?
Progressive optic neuropathy associated with optic nerve head damage (disc cupping) and visual field loss (usually peripheral) with raised IOP (21mmHg is the upper limit of normal)
Normal cup to disc ratio = 0.2/0.3, if above 0.6 needs investigating.
As the head of the optic nerve gets damaged the neuroretinal rim ges thinner so the cup gets bigger
What is the pathogeneis of open angle glaucoma?
The trabecular meshwork may not drain as well with age so the IOP pressure rises.
This raised IOP can damage the nerve fibres of the optic nerve.
* can have increased IOP without optic nerve damage = ocular hypertension*
** can have normal IOP but optic nerve cupping and visual field loss = normal tension glaucoma**
What are the risk factors for primary open angle glaucoma?
high IOP
family history
age
diabetes
myopia
black african or caribbean
* screening is very important as IOP is often raised asympotmatically, and when symptoms occur the damage is done*
What is the treatment for primary open angle glaucoma?
Suppress the aqueous humour production: B blockers, carbonic anhydrase inhibitors and alpha agonist eye drops
OR
Increase the aqueous outflow: prostaglandin analogues
What is Trachoma?
Bilateral follicular, non purulent conjunctivitis
Caused by Chlamydia trachomatis - spread by flys
Follicles develop on the superor tarsal conjuctiva and superior limbus after 2 -3 weeks
Repeated episodes leads to conjunctival scaring (cicatrisation), which causes entropian, trichiasis (eye lashes grow towards the cornea) and a dry eye.
How do you diagnosis and trest Trachoma?
Diagnose using conjunctival scrapes and treat with oral antibiotics.
To reduce chronic development use tetracycline eye drops BD for 5 days each month for 6 months
What is the other name for onchoceriasis and what causes it?
River Blindness
Caused by a naematode microfilaria (Onchocerca volvulus) transmitted by black flys of the Simulium species.
The flies bite and subcutaneous nodules form, the adult female worm sheds microfilariare which then migrate through the skin, eye involvement occurs when there is chronic infestation via the conjuctiva.
What are the ocular signs of Onchoceriasis?
Lid nodules and depigmentation
Chronic conjunctivits and punctate keratitis
Corneal opacification
Iritis
Cataract
Gluacoma
Optic neuritis
What caues xerophthalmia?
Vitamin A deficiency
It results in night blindess, corneal and conjunctival dryness and keratinisation. Corneal ulcers which can lead to perforation, and in its advance form - cornal necrosis.
Bitots spots form - small foamy plaques
What signs might be present to suggest a person with a gradual loss of vision had choroiditis?
Acutely:
Blurred vision, grey white raised patch see on retina, vitreous opacities, cells in the anterior chamber.
Chronically:
Choroidoretinal scar - white patch with pigmentation around, will be symptomless unless they involve the retina
What would you use fluorescein staining for?
To visualise any corneal abrasions
What does linear vertical fluorescein staining on the superior cornea suggest?
Sub tarsal foreign body
What is the difference between a penetrating eye injury and a perforating eye injury?
A penetrating describes an entrance wound only (need to assess for intraocular foreign body)
A perforating describes an entrance and exit wound to the eye
Why is important to find out the history of what metal a person was working with when they injured their eye?
Ferrous metals can cause siderosis which leaks toxic ions into the eye, these ions are retinotoxic and can impair retinal function irreversibly.
What are the signs of a ruptured globe?
Severe sub conjuctival haemorrhage
Hyphaema - blood in the anterior chamber
Restriction of eye movements, often with diplopia
Extruded intraocular contents
Collapsed globe
Irregular pupil and subluxed lens
Commotio retinae - retinal oedema
Traumatic optic neuropathy and retinal breaks
Vitreous haemorrhage
What is the main treatment for chemical injury to the eye?
Irrigation - DO NOT DELAY
What is traumatic optic neuropathy?
Damage often indirect to the optic nerve
Usually caused by a blow to the head face or orbit
What is the most common orbital fracture?
A blow out of the orbital floor - can lead to herniation of inferior rectus into the maxillary sinus, restricting upward gaze
Bacterial conjuctivitis:
Common causative organisms?
Signs and symptoms?
Management?
Staph aureus and strep pneumoniae are the most common
Patients complain of irritation and tearing, discharge, eyelids stuck together in the morning, red eye, often starts in one eye and spreads to the other.
O/E - mucopurulent discharge, lid erythema and oedema, conjunctival injection, papillae
Use chloramphenicol QDS for 1 week, ensure good higene
Viral conjunctivitis:
Causative organisms
Symptoms and signs
Adenovirus type 3 = common
Patient complain of: acute red eye, watering, irritation and soreness, systemic viral symptoms, bilateral in 40%, intermittent blurred vision.
O/E: conjuctival injection, chemosis, watery discharge, eye lid swelling, follicules, preauricular adenopathy. May develope punctate keratitis.
Allergic conjuctivitis:
Hx?
Symptoms and signs?
Management?
History of atopic disease, acute contact with allergen or seasonal
Patient complains of itching, tearing and intermitted bluring vision.
O/E: bilateral, eyelid oedema, normal cornea, conjuctival injection, papillae, watery/stringy mucoid discharge
Management: cold compresses, artificial tears, topical mast cell stabilisers Sodium cromoglicate
When should a diagnosis of chlamydial conjuctivitis be considered and how is it confirmed?
If a viral or bacteral conjunctivitis has lasted over 3 weeks.
Fluorescent antibody stain, Giemsa stain: intracytoplasmis inclusion bodies in epithelial cells, polymorphonuclear leukocytes and lymphocytes.
What is bacterial keratitis?
Risk factors?
Signs O/E?
Management?
Serious unilateral corneal infection
Risk factors: hx of trauma, corneal foreign body, contact lenses, corneal exposure
Signs: White corneal infiltrate with overlying epithelial defect, conjunctival injection, mucopurulent discharge, anterior chamber cells, hypopyon.
Refer to ophthalmology for: corneal scrapings, stop wearing contact lenses, hourly topical antibiotics
What sign is diagnostic for herpes simplex in the eye?
Dendritic ulcers on staining
What is the uvea?
The pigmented part of the eye.
The iris and cilary body are the anterior uvea and the choroid is the posterior component
What are the symptoms of anterior uveitis?
What are the complications of anterior uveitis?
Painful red eye (circum corneal injection)
Photophobia
Normal/mildly decreased vision
O/E keratic precipitates, distorted or contricted pupil, hyponyon
Complications: posterior synechiae, secondary glaucoma, secondary cataract
What are some of the causes of anterior uveitis?
Idiopathic - most common
Autoimmune HLA B27 - ank spond etc
Juvenile chronic arthritis
IBD
Non infectious systemic disease - sarcoidosis, MS
Infections - TB, syphilis, herpes zoster
Traumatic
Post op
What is worrying with regards to a subconjuctiva haemorrhage?
When there is no posterior margin - may be associated with an intracranial bleed
What are the signs and symptoms of episcleritis?
The episclera is the most superficial layer of the sclera.
Patients complain of localised redness in eye, associated with an ache or grittiness. They have normal acuity or mild bluring.
May nee NSAIDs to manage but normally self limiting
Usually idiopathic but may complicate rheumatic fever, SLE, polyarteritis nodosum
What are the symptoms and signs of scleritis?
Gradual onset of pain and redness in the eye.
Very severe pain, assoicated with photophobia, but normal or only mildly blurred vision.
O/E: localised or diffuse scleral hyperaemia which is tender to palpation. If there are pale areas within the red zones this may indicate necrtoising scleritis
What systemic illness’ are associated with scleritis?
Herpes zoster ophthalmicus
RA
Relapsing polychondritis
Wegner’s granulomatosis
Polyarteritis nodosa
SLE
What is a chalazion?
Chronic condition caused by inflammation of the meibonium glands with secondary lipogranulomatous inflammtion.
Causes a swelling on the eyelid
What is the difference between preseptal and orbital cellulitis?
Preseptal is an infection of the subcutaneous tissue anterior to the orbital septum
Orbital is inflamamtion of the soft tissue posterior to the obital septum
Both are medical emergencies
What are the signs on fundoscopy of a central retinal artery occulusion?
White retina, cherry red spot at the macula.
Causes sudden loss of vision and afferent pupil defect.
What are the signs of a retinal vein occulsion on fundoscopy?
ischemic retinal vein occulsion - cotton wool spots, swollen optic nerve, macular oedema, neovascuarlization
What is retinitis pigmentosa?
Inherited degeneration of the retina.
Different forms of inheritence, results in reduced visual acuity
What does toxoplasmosis look like in the eye?
Punched out pigmented chorioretinal scars
What are the staged in thyroid eye disease?
No symptoms or signs
Only lid retraction +/- lid lag
Soft tissue involvement
Proptosis
Extraocular muscle involvement (diplopia)
Corneal disease (due to inability to close eye lids)
Sight threatening optic neuropathy
What eye symptoms can patients with MS present with?
Optic neuritis - reduced visual acuity and colour vision (red desaturation), pain on moving eye
Visual field defects
Cranial nerve palsies - normall 6th
Nystagmus
What does CMV retinitis present as?
HIV, low CD4 count
Paravascular retinal opacification from retinitis with associated haemorrhage
What is HIV retinopathy?
Cotton wool spots
Retinal microhaemorrhages may occur
What are the signs of hypertensive retinopathy?
Flame haemorrhages
Focal arteriolar narrowing
Cotton wool spots
Lipid exudates
Coper and silver wiring of the vessels
Normal optic disc
** often asymptomatic**
How do you classify hypertensive retinopathy?
Grade 0 = normal
Grade 1 = arteriolar narrowing
Grade 2 = focal arteriolar narrowinf and AV crossing changes (AV nipping)
Grade 3 = haemorrhages, exudates and cotton wool spots
Grade 4 = grade 3 plus disc swelling
What are the ocular manifestations of diabetes?
Diabetic retinopathy - due to microangiography in the capillaries, pre capillary arterioles and the venules leading to occulsion and leakage
Diabetic maculopathy - oedema of the macula from vessel leakage
Extraocular muscle palsy - an isolated 3rd, 4th or 6th palsy with paina round the eye. Usually if there is a 3rd it will spare the pupil
Retinal vein occulsions
Cataract - posterior subcapsular
What is the likelihood of a diabetic patient getting eye problems?
20yrs after diagnosis - virtually ALL type 1 and 60% of type 2 will have retinopathy
30 yrs after diagnosis - 30% of type 1 and 3% of type 2 will have proliferative disease
What are the retinal signs on fundoscopy of diabetic retinopathy?
Microaneurysms
Dot haemorrhages
Blot haemorrhages
Exudates
Cotton wool spots
Retinal oedema
Venous changes
Neovascularisation
How is diabetic retinopathy classified?
Degree of retinopathy is taken into account
Presence of maculopathy is stated
If there is any evidence of previous photocoagulation this is stated
What signs are seen at fundoscopy in diabetic maculopathy?
Macular odema, exudates, ischemia
