Opthalmology Flashcards
What is the physiology of maintaining pressure within the eye?
1) AH produced by capillary networks in ciliary body
2) flows up between the iris and anterior lens and through the pupil
3) Flows out the drainage angle of the eye
4) flows into the trabecular meshwork and then the Canal of Schlemm
5) However, some aqueous has a novel route and flows into the roots of the ciliary muscle/iris and into the scleral circulation
Which receptors can be activated to affect IOP?
a-2-adrenoreceptors - ↓ IOP by reducing aqueous production + ↑uveoscleral outflow
ℬ-2-adrenergic receptors = ↑ IOP by increasing aqueous production
2 because you have 2 eyes
What is intra-ocular pressure?
Intra-Ocular Pressure is the force needed to flatten the corneal surface. Usually measured using Tonometry.
The normal range of IOP is 11-21mmHg.
What is Glaucoma?
Optic neuropathy with death of many retinal ganglion cells and their optic nerve axons.
Leads to irreversible vision loss
OP might be raised but this is not a necessity to be diagnosed with Glaucoma.
What are the 2 types of glaucoma?
Primary open angle
Acute closed angle
What is primary open angle glaucoma?
Angle between cornea and iris is open but the trabecular meshwork slowly clogs
Leads to a gradual increase in IOP and initial atrophy of the outer rim of CNII
Gradual ↓ in peripheral vision then central vision
What is acute closed angle glaucoma?
Ophthalmic emergency!
Angle between cornea and iris becomes too small due to lens being pushed against iris
Rapid ↑ in pressure
How does acute closed angle glaucoma normally present?
eye -Sudden onset, severe eye pain, eye is RED, haloes
pupil - non-reactive and mid-dilated
N&V
What are the non-modifiable and modifiable risk factors for POAG?
Non-modifiable
Age >40
Family History (genetics)
Ethnicity (afro-carribean)
Modifiable Diabetes Thyroid Eye Disease Hypertension Drugs (Corticosteroids, Pilocarpine/atropine, Tricyclic antidepressants)
What are the non-modifiable and modifiable risk factors for AACG?
Non-modifiable
Ethnicity - eastern asian/south eastern asian
Age
Female
Modifiable Hypermetropia (long eye and shallow anterior chamber)
What investigations should be done to investigate Glaucoma?
Visual fields - loss of peripheral vision
Dilated eye exam on slit lamp
Cupping of the optic disc - loss of disc substance makes the cup look larger
Tonometry
What is the conservative management of POAG?
Advice on driving, drop usage (emphasise importance and lifetime treatment)
What is the medical management of POAG?
Prostaglandin Analogue e.g. Latanoprost
B-Blocker - Timalol
⍺ agonists e.g. Brimonidine also used (reduced production and small increase in drainage) but less so I think
What is the management of AACG?
Urgent referral to eye casualty
Medication - CBA
Acetazolamide
B-Blocker
Alpha agonist - Brimonidine
+/- Pilocarpine +/- latanoprost
Surgery - laser iridotomy
What is the role of a B-blocker in AACG?
REDUCE AH PRODUCTION
inhibits adrenergic stimulation (B2 adrenoceptors) to produce AH
What is the role of Acetazolamide in AACG?
REDUCE AH PRODUCTION
carbonic anhydrase inhibitor
What is the role of Pilocarpine in AACG?
Anti-muscarinic
INCREASE AH DRAINAGE
pupillary constriction to increase angle
What is presbyopia?
Reduction in ability of lens to accommodate as ageing happens.
↓ lens elasticity + ciliary body atrophy
This can be overcome by prescribing convex lenses for near work.
What is a cataract? What is the pathophysiology?
Any opacity within the lens
Protein denaturation is involved but largely unknown
What is a cortical cataract?
Cortex of lens involved
Astigmatic changes
More problems in the dark when pupil dilates = more cataract exposure
What is a nuclear cataract?
Lens Nucleus becomes yellowish-brown due to pigment deposition
Myopic changes due to increased refractive index
Reduced saturation of colours
What is a posterior capsular cataract?
Subcapsular
Grandular or plaque like
Near vision affected more
What are the causes of cataracts?
SPELLS CATARACTS
C ongenital (infection e.g. rubella, familial e.g. Wilson’s
A ge >65 T rauma A fter cataract (post intraocular surgery) R adiation A vitaminosis C hemical/ Metabolic T oxic (smoking, alcohol) S ystemic (DM, neurofibromatosis type 2)
Which drugs can cause cataracts? (Chemical)
Allopurinol Amiodarone Corticosteroids Myotics Antipsychotics (chlorpromazine)
Which metabolic conditions can cause cataracts?
DM
Galactosaemia
Hypocalcaemia
Wilson’s
What are the visual changes associated with cataracts?
Visual changes
Blurred vision/ ↓ in visual acuity
Unilateral - often asymptomatic
Bilateral - gradual, painless + frequent prescription changes. +/- monocular diplopia
Faded colours
↓ night vision
Glare from lights +/- halo
What are the eye investigations to diagnose cataracts?
Visual tests
Snellen’s
Keeler’s
Stereotest - may have loss of stereopsis (distance judgement)
Tonometry
Dilated eye exam (fundoscopy)
What is the management of cataracts?
Only definitive management is surgery really (phacoemulsification)
When should cataract surgery be offered?
Gets to <6/12 is when surgery is usually offered
Patient choice/ affecting QOL. Ask about reading, driving, watching telly, hobbies, faces
When should the DVLA be informed in a cataract patient?
Only if bilateral
What is the pre-op management of cataracts?
Optical biometry to measure axial length of eye
Keratometry to measure curvature of cornea
Corneal topography if cornea is abnormal
What is the post-op management of cataracts?
Can drive again when can read a number plate 20m away with both eyes open
Can usually go back to normal daily activities within a day but everyone is different
Abx and NSAID drops for 3-6 weeks
What are the general surgical complications of cataract surgery?
Infection - endopthalmitis
Bleeding - vitreous haemorrhage
Damage to other structures - Retinal Detachment
What are the surgical complications that are specific to a phaco?
Secondary Glaucoma
Post capsule thickening
Post op eye irritation
Crystoid macular oedema
What is the retina?
Innermost layer of the eye and is comprised of 2 layers: an outer, pigmented layer and an inner, neural layer.
What is the RPE?
retinal pigment epithelium
outer layer of the pigment layer
nutrition and structure
has melanin to prevent reflection in the eyeball
what is the RPE attached to?
The choroid via Bruch’s membrane (significant for ARMD)
What is the inner neural layer of the retina made up of?
Several types of photoreceptors but mainly Rods and Cones:
Rods = For vision in dim light but no colour perception
Cones = Colour perception in normal light conditions
Describe the distribution of rods and cones throughout the retina
Rods are the predominant cell type throughout the Retina EXCEPT FOR at the Fovea
@ fovea = highest concentration of cones therefore giving the area of highest visual acuity.
what is the blood supply to the retina?
Inner 2/3 = Central Retinal Artery
Outer 1/3 = Choroidal Blood Supply
(end arteries)
Macula is dense with capillaries whereas the Fovea is a capillary free zone
How do you present fundoscopy?
1) Surface Anatomy
2) Red Reflex
3) Present the Optic Disc
- Colour (pink-grey is normal)
- Swelling/Clear margins?
- Cup:disc ratio (normal is 0.3-0.5 so cup should be roughly half of the disc area)
What is age related macular degeneration?
Eye condition that occurs where the Retinal Pigment Epithelium attaches to Bruch’s Junction at the macula
What are the 2 types of ARMD?
Dry
Unknown pathophysiology
No new vascular growth
Wet
Angiogenesis into Bruch’s epithelium + sub-retinal fluid or haemorrhage
What are the non-modifiable risk factors for ARMD?
Age >65
Sex (female)
Ethnicity - more common in caucasian and eastern asian population
Family history/genetics
What are the modifiable risk factors for ARMD?
Smoking
Cardiovascular risk factors e.g. hypertension, T2DM
Hypermetropia
What are the visual changes associated with ARMD
Central blurring of vision. Peripheral vision is normal.
Can manifest in difficulty reading or recognising faces. Also get problems with night vision and changing light conditions
PAINLESS
How do the visual changes differ between wet and dry ARMD?
Dry = gradual i.e. over years.
Wet = sudden + wiggly distortion
How do wet and dry ARMD differ on fundoscopy?
Dry = Drusen’s seen
Wet = new blood vessels and exudate
What are the Ix for ARMD?
OCT - see intraretinal fluid and disruption of the RPE
What is the treatment of dry ARMD?
No cure so have to focus on conservative measures/prevention
Stop smoking
Green, leafy vegetables (vitamin A, E, zinc)
Signpost to registering as blind to get full support
Using big text/magnifiying glass
What is the treatment for wet ARMD?
Medical = intravitreal injections of VEGF inhibitors - stops angiogenesis. Have to keep redoing
Surgical = Photodynamic/laser photocoagulation. Not that effective. More for chronic.
What are the complications of ARMD?
Wet = retinal detachment and blindness
Charles Bonnet syndrome
Why are central retinal arteries bad?
Is an end artery so there is no collateral blood supply to preserve tissues.
Vision loss can be irreversible in around 1-2 hours.
What are the main symptoms of central retinal vein/artery occlusion?
Sudden loss of central vision
Painless
How does central retinal artery/vein occlusion normally present on fundoscopy?
Artery = Retina becomes pale and oedematous (macular oedema)
Fovea remains bright red due to choriocapillary supply (cherry red spot)
Vein = Haemorrhages seen
What are the investigations for CRVO/CRAO?
Mainly clinical but can also use OCT and Fluoresceine Angiography
What is the management of central retinal vein/artery occlusion?
Vein - Intravitreous VEGF inhibitor injections
Artery - ↓IOP, anticoagulation?
What is a retinal detachment?
A hole or tear in the Retina allowing fluid to accumulate between the Retinal Pigment Epithelium and Vitreous humour
(rhegmatogenous = most common)
How does retinal detachment normally present?
4 Fs + painless
Flashes
Stimulation of the neural layer
Floaters
Field Loss
Loss of peripheral vision
Moves centrally like a curtain
Macula on = more of an emergency as can still save sight but gravity can pull down a superior tear more
Fall in acuity
What are the investigations for retinal detachment?
Dilated eye exam
See a grey, opalescent retina that balloons forward
What is the management of retinal detachment?
Treat lying flat
Refer to eye casualty/ to specialist surgery (Vitrectomy, Laser photocoagulation, Gas Tamponade)
What are the borders of the orbit?
Roof = frontal bone medial = nasal, lacrimal and ethmoidal bones lateral = sphenoid bone floor = maxillary bone
what lies directly behind the orbit?
ICA, cavernous sinus & brainstem
What is scleritis?
vasculitis of the sclera.
Occurs throughout the entire thickness
non-infective and granulomatous = associated with inflammatory conditions
How does scleritis normally present?
Red eye
REALLY PAINFUL ESP ON EYE MOVEMENT (DEEP BORING PAIN)
Associated watering and photophobia
Gradual decrease in vision
Elderly, associated with systemic disease
How does episcleritis present?
Red eye (acute onset)
Foreign Body sensation
Watering
Normal acuity
What conditions are associated with scleritis?
Uveitis
Retinal detachment
Cataracts
Glaucoma
What conditions are associated with episcleritis?
anterior uveitis (10% of cases)
How should scleritis and episcleritis be investigated?
Examination - Retract the lids and slit lamp. Phenylephrine drops - episcleritis will blanch but scleritis will not
Bloods - all the normal ones + rheumatoid + syphyllis
What serology should be done for [epi]scleritis?
RA = rheumatoid factor + anti CCP
SLE = ANA, anti-dsDNA
Wegners = c-ANCA
Reactive arthritis = HLA-B27
Churg-Strauss = p-ANCA
What is the conservative management of scleritis?
Refer to ophthalmology
What is the medical management of scleritis?
Oral NSAIDS»_space; Oral Prednisolone
? immunosuppressants if ineffective
What are the complications of scleritis?
Scleral thinning (scleromalacia)
Anterior segment ischaemia
Raised IOP
Retinal detachement
Cataracts
How can squints be classified?
Where the eye deviates to
the nose: esotropia (ESOOOO = NOSE)
temporally: exotropia
superiorly: hypertropia
inferiorly: hypotropia
What is the usual pathophysiology of a squint?
Imbalance in the extra ocular muscles
How is a squint detected?
Corneal light reflection test
Hold the light up to the eye (about 30cm away) and see if it reflects equally in both eyes
Which medication can be used to differentiate scleritis and episcleritis?
phenylephrine drops may be used to differentiate between episcleritis and scleritis.
Blanches the conjunctival and episcleral vessels but not the scleral vessels.
What is the cornea?
Transparent, AVASCULAR structure
Separates the tear film from the anterior chamber
Has a rich nerve supply from the ophthalmic branch of the trigeminal nerve
What are the layers of the cornea? (5)
ABCDE
Anterior corneal epithelium Bowman's Layer Corneal Stroma Descemet's Membrane Endothelium
What are the 3 types of corneal injury?
Partial thickness e.g. minor trauma due to grit etc
Superficial keratitis e.g. UV/chemical injury
Full thickness - high velocity injury
How does injury to the cornea normally present?
White eye
Pain
Lacrimation
Blurred vision
Foreign body sensation
What are the investigations for corneal foreign bodies?
Slit lamp exam
Fluoresceine dye
How should corneal foreign bodies be managed?
Remove under slit lamp
+ topical anaesthetic + topical chloramphenicol
How do corneal abrasions differ in presentation from FB?
Have photophobia in addition to pain and lacrimation
What are the complications of corneal abrasions?
Keratitis
Recurrent erosions
What is the pathophysiology of a corneal ulcer + keratitis?
Loss of epithelium exposes nerve endings = severe pain
Inflammation = increase in peri-corneal vascularity = red and discharges
What are the risk factors for corneal ulcer?
Non-modifiable onlu
Contact lens
Immunocompromised
Diabetes
What are the most common types of keratitis?
Bacterial - Coagulase negative Staph, pseudomonas
Viral - HSV or VZV
How does bacterial keratitis present?
Red eye
Pain + photophobia + FB
Reduced acuity
Epiphoria
Hypopyon?
What is the management of bacterial keratitis?
Conservative - don’t wear contact lenses
Medical - intensive abx (avascular so no WCC clearance)
What is the pathophysiology of ophthalmic shingles (herpes simplex opthalmicus)?
Primary VZV infection = chickenpox
Virus then lies dormant in Dorsal Root Ganglion
Reactivates in the sensory ganglion leading to HSV/shingles in a specific dermatome
What are the clinical features of opthalmic shingles?
Think of that old lady in Dr Eames’ teaching you saw
Dermatomal rash - papules > vesicles > pustules > scab. affected top quarter of face and just stopped so in CN V
Hutchinson’s sign - tip of nose indicating nasociliary nerve involvement alluding ocular complications
Viral prodrome
Pre-herpatic neuralgia (tingling or electric pain)
What are the complications of opthalmic shingles?
Ocular, systemic
Basically all of the opthalmic ‘itis’es e.g conjunctivitis, scleritis etc.
Acute retinal necrosis (ARN) or Progressive outer retinal necrosis (PORN)
Systemic = strokes and Post-herpatic neuralgia
What is the management of opthalmic shingles?
Start an antiviral as soon as rash appears e.g. Aciclovir PO
? steroid eye drops
Emotional complications of post-herpatic neuralgia e.g. depression - gabapentin and that
What are the different types of discharge seen in conjunctivitis and what do they mean?
Purulent - Pus + morning crusty and difficult to open = BACTERIAL
Mucopurulent - pus + caught in eyelashes = BACTERIAL USUALLY CHLAMYDIAL
Watery - viral or allergic
Mucoid (stringy) - dry eye
Why does hyperaemia of the eye occur?
dilated blood vessels due to inflammation
generalised - conjunctivitis, CL, scleritis
localised - episcleritis, FB, corneal abrasion
circumcorneal - keratitis, anterior uveitis
What are papillae in the eye?
Vascular response
oedema surrounding a core of vessels
When do papillae occur?
Conjunctivitis - bacterial and allergic (not viral)
Blepharitis
Contact lens use
What are follicles?
Hyperplasia of lymphoid tissue
Occur in viral or chlamydial conjunctivitis
What is keratoconjunctivitis sicca also known as
Dry eye!
loss of homeostasis of the tear film + ocular symptoms
reduced lubrication + altered tear film composition
+ hypersensitivity of pain receptors on ocular surface
How does dry eye normally present?
burning + pain +/- itchy
blurred vision if cornea is involved
FB sensation
What is the conservative management of dry eye?
Limit contact lense wearing
lid hygiene - warm compress + massage
Avoid using a computer for too long
What is the medical management of dry eye?
artificial tears
if infection present then can use topical abx + steroids
What is the systemic condition that can cause keratoconjunctivitis sicca ?
Sjorgen’s
What are the 5 most common bacterial pathogens associated with conjunctivitis?
Staph epidermidis
Staph aureus
Strep pneumoniae
H influenzae
Moraxella lacunata
When is periauricular lymphadenopathy associated with conjunctivitis?
If the infection is
viral
chlamydial
When are papillae associated with conjunctivitis?
bacterial
allergic
when are follicles associated with conjunctivitis?
viral
chlamydial
toxic e.g. oven cleaner
how does allergic conjunctivitis normally present? (5)
seasonal
bilateral red eye (painless)
puffy eye lids
itchy
cobblestoning on underside (papillae)
How does bacterial conjunctivitis normally present/
mucopurulent discharge
red eye (painless)
eyes stick together upon waking
unilateral (usually)
How does viral conjunctivitis normally present?
lots of watery discharge
red eye (painless)
unilateral then becomes bilateral
+/- flu like symptoms
When should conjunctivitis be investigated?
severe
recurrent
resists treatment
vulnerable patient
What is the management of bacterial conjunctivitis?
topical abx for 1 week
chloramphenicol/sodium fusidate/ trimethoprim
don’t touch eye, don’t share towels etc.
What are the clinical features of gonococcal conjunctivitis?
more common in adults and neonates
severe purulent discharge
lid is really swollen
pre-auricular lymphadenopathy
How should gonococcal conjunctivitis be investigated?
conjunctival swab for gram staining, culture and sensitivities
refer to GUM + contact tracing
What is the treatment for gonococcal conjunctivitis?
adults - topical abx (ofloxacin every 2 hours), irrigate
neonates - cefotaxime + frequent irrigation + refer mam and partner to GUM
How does neonatal chlamydial conjunctivitis differ to gonococcal?
see papillae due to delayed development of lymphoid tissue (i.e. not follicles)
How is neonatal chlamydial conjunctivitis managed?
Erythromycin for 2 weeks
refer mam and partner to gum
What are the common viral agents that cause conjunctivitis? (3)
Adenovirus
Molluscum Contagiosum
Herpes Simplex
What is the management of viral conjunctivitis?
Conservative - cool compress, artificial tears, wash hands frequently, take time off school (red = contagious)
Medical - need abx if there is a secondary bacterial infection
What are the 5 main types of allergic conjunctivitis?
Seasonal e.g. grass/tree pollen (spring and summer)
Perennial e.g. house dust mites (peaks in autumn)
Vernal (spring)
Atopic
Giant papillary
How can allergic conjunctivitis be investigated?
Essentially try and find the allergy - skin prick testing/IgE
What is the conservative management of allergic conjunctivitis?
Identify and avoid allergen
Don’t rub eyes
Cold compress
Ocular surface lubricants
What is the medical management of allergic conjunctivitis?
Mild = artificial tears to dilute allergen
moderate = mast cell stabiliser/ antihistamines
severe = short course of a mild topical steroid
What is the uvea?
structure consisting of the iris, ciliary body and choroid
pigmented and vascular
What is the iris?
Pigmented structure that divides the anterior and posterior chamber
Attached to the lens and controls the amount of light entering the eye
changes size of pupil
What class of medication are the following and how do they affect the pupil?
Tropicamide
Phenylephrine
Pilocarpine
Tropicamide = antimuscarinic = mydriasis (dilated)
Phenylephrine = sympathomimetic = mydriasis
Pilocarpine = muscarinic agonist = miosis (constriction)
How does sympathetic and parasympathetic stimulation affect the iris and pupil size?
parasympathetic e.g. due to bright light = constriction of the pupil (miosis)
sympathetic e.g. due to low light = dilation of the pupil (mydriasis)
What is the ciliary body?
Pigmented structure for accommodation, aqueous humour production and suspensory ligament attachment
What is the choroid?
Covers posterior eye and divides retina from sclera
Prevents reflection within the eye and nutrition to retina
Attaches to retina via Bruch’s membrane
What is uveitis?
Inflammation of the uveal tract i.e. iris, choroid and ciliary body
What is anterior uveitis?
Inflammation of the anterior uveal tract i.e. iris and ciliary body
What is posterior uveitis?
Inflammation of the posterior uveal tract i.e. choroid, optic nerve head and retina
What is the triad of symptoms seen with anterior uveitis?
Red eye
Pain
Photophobia
(also watery, normal vision etc)
What are the associated conditions with anterior uveitis? (5)
PAIR seronegative conditions (HLA-B27) - Psoriasis, Ank Spons, IBD, Reactive arthritis
IBD
Sarcoidosis
Behcet’s (eye casualty man)
infection - TB, Syphyllis, CMV, Toxoplasmosis
What is the management of anterior uveitis?
Refer to opthalmology
Topical antimuscarinics to dilate the pupil and prevent posterior synechiae
Topical steroids
essentially want to reduce inflammation
How does posterior uveitis normally present?
Painless and blurred vision
Floaters
Blind spots
Can progress to vision loss
How is posterior uveitis normally managed?
Oral/ injected steroids
immunosuppressants if this doesn’t work
What is the vitreous?
Fluidy kind of stuff that is behind the lens and supports the eye
How does the vitreous change with age?
Fluid fills space between vitreous and retina
Vitreous also shrinks = flashes as v pulls on retina = stimulation of nerves
opacities can form which drift around = floaters
What are the differentials for painless sudden loss of vision? (5)
CRAO: cherry red spot
CRVO: stormy sunset
Retinal Detachment: curtain folding
Vitreous haemorrhage: can see haemorrhage
Papilloedema : swelling of optic disc
What are the key questions to assess sudden loss of vision?
HELLP
Headache: GCA Eye movements painful: optic neuritis Lights before: RD Like a curtain: amaurosis fugax, GCA, RD Poorly controlled DM: vit haemorrhage
What is the pathophysiology of a vitreous haemorrhage?
3 possible mechanisms
- bleeding from diseased retinal vessels (fluid in)
- Abnormal new vessels
- bleeding into vitreous from outside (fluid out)
What are the 3 most common causes of vitreous haemorrhage?
Proliferative diabetic retinopathy
Posterior vitreous detachment
Ocular trauma
How does Proliferative diabetic retinopathy lead to a vit haemorrhage?
Ischaemia = VEGF expression and angiogenesis
BUT new vessels are fragile
How does vitreous haemorrhage normally present?
Sudden, painless loss of vision
Red hue
Floaters
in the morning
How should vit haemorrhage be investigated?
Dilated eye exam - can see haemorrhage + RBCs in anterior vitreous
Tonometry - asses IOP
OCT
Fluorescin angiography
What is the conservative management of vitreous haemorrhage?
Avoid strenuous activity
Elevate head of bed
Aspirin?
What is the surgical management of vitreous haemorrhage?
laser photocoagulation if proliferative retinopathy
Vitrectomy
What are the complications of vitreous haemorrhage?
Proliferative vitreoretinopathy
Ghost cell/haemolytic glaucoma
What are the differentials of painful loss of vision?
- Optic neuritis
- Episcleritis
- Closed angle glaucoma
- Anterior uveitis
What is the deal with screening and diabetic eye disease?
Should be screened annually
Photograph the fundus
Any abnormality found = opthalmology referral
What is the pathophysiology of cataract formation in diabetic eye disease?
Hyperglycaemia = increase uptake of glucose into the lens
Increased sorbitol production in the lens
Depletes the eye of NADPH = reduces glutathione = more susceptible to oxidative stress
Also causes a water influx = opacity and damage
What are the risk factors for diabetic eye disease/
non-modifiable - race and family hx, age
modifiable - DM, HTN, steroids, no protective factors e.g. oestrogen
What is diabetic retinopathy?
Obstruction of the microvascular structures within the retina
Essentially hyperglycaemia damages the pericytes - weaker and leaky walls
Micro-aneurysms and lipid leakage
Abnormal vessel formation
Define Keratitis
Inflammation and damage to the corneal epithelium, stroma, or endothelium.
Characterised by a white area on the cornea indicating a collection of white cells in the corneal tissue
Define corneal abrasion
A breach of the corneal epithelium causing pain, photophobia +/- reduction in vision
What is the management a corneal abrasion?
Ix = Fluorescin drops + blue light on slit lamp = green staining
Tx = Topical local anaesthetic. Should heal within 48hr
How does a corneal ulcer normally present?
FB sensation, photophobia, red eye, lacrimation, ↓ visual acuity
What are the likely causative agents of a corneal ulcer?
Bacterial = pseudomonas
Viral - HSV1 = dendritic ulcer
Protozoal = acanthamoeba (swimming in contacts)
Fungal = candida, aspergillus
What is the management of a corneal ulcer?
Refer to eye casualty within 24hr
Chloramphenicol + ofloaxcin (covers gram +ve and -ve)
What is the definition of the sclera and what are scleritis and episcleritis
The outermost, fibrous layer of the eyeball that provides attachment to the extraocular muscles.
Scleritis = Inflammation of the sclera
Episcleritis = more superficial inflammation of the sclera
How does episcleritis normally present?
Acute onset of red eye and pain (dull ache and is tender over the affected area)
Focal area of engorged vessels - Can move these with a cotton bud as are superficial + blanche with phenylephrine
Visual acuity not affected
How does scleritis present?
A constant, dull but severe ‘boring’ pain that worsens on eye movement [as extra-ocular muscles attach into sclera]
Visual acuity is initially unaffected
+/- headache +/- photophobia
How does scleritis differ from episcleritis?
Scleritis = Generalised inflammation of the sclera + conjunctival oedema + scleral thinning + vasculitic changes
Which diseases are scleritis associated with?
Systemic ones e.g. Rheumatoid arthritis, Granulomatosis with polyangitis
What is the management of scleritis?
Urgent referral to eye casualty (within 24hr)
NSAIDS or steroids
Necrotising type requires systemic therapy e.g. Rituximab
About to perforate requires surgical intervention
Define anterior uveitis
inflammation affecting the iris (iritis) +/- the ciliary body (iridocyclitis)
Define intermediate uveitis
inflammation of the posterior part of the ciliary body and nearby peripheral retina and choroid
Define posterior uveitis
inflammation of the retina and choroid
Define panuveitis
inflammation of the whole uveal tract
most associated with sight loss
How does anterior uveitis present?
Onset over hours to days
Red eye
Photophobia - progressive
Pain
Reduced vision
Watery eye that may overflow (epiphora)
Which conditions is anterior uveitis associated with?
HLA-B27 (PAIR)
Psoriasis
Ankylosing Spondylitis
IBD
Reactive Arthritis
What is anterior uveitis like on examination?
Corneal injection @ angle of sclera and cornea
Irregular pupil/dilates irregularly - due to adhesion formation between lens and iris. These can also obstruct the passage of aqueous humour so can increase risk of glaucoma!
Slit lamp = inflammatory cells in anterior chamber
What is the medical management of anterior uveitis?
Topical Prednisolone (eye drops to reduce the inflammation)
Cyclopentolate (paralyses the ciliary muscle - Muscarinic antagonist so causes pupil dilation. This reduces pain and also prevents the adhesions forming
What is an Adie pupil?
Tonically dilated pupil
Slowly reactive to light
More definite accommodation response
Damage to parasympathetic innervation (infection)
Commonly seen in females + absent knee jerks
What is a Marcus-Gunn pupil?
Relative afferent pupillary defect
Most commonly caused by damage to the optic nerve or severe retinal disease
What is Hutchinson’s pupil?
Unilaterally dilated pupil which is unresponsive to light
Compression of the occulomotor nerve of the same side, usually due to an intracranial mass
What is an Argyll-Robertson pupil?
Bilaterally small pupils that accommodate but don’t react to bright light
Neurosyphyllis and Diabetes Mellitus
‘Accommodates but doesn’t react’
What are the stages of hypertensive retinopathy?
I = Arteriolar narrowing and tortuosity. Increased light reflex - silver wiring
II = Arteriovenous nipping
III = Cotton-wool exudates. Flame and blot haemorrhages
IV = Papilloedema
What are the stages of non proliferative diabetic retinopathy?
Mild NPDR
1 or more microaneurysm
Moderate NPDR microaneurysms blot haemorrhages hard exudates cotton wool spots, 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
Intraretinal microvascular abnormalities (IRMA) in at least 1 quadrant
What are the features of proliferative diabetic retinopathy?
Proliferative retinopathy
retinal neovascularisation - may lead to vitrous haemorrhage
fibrous tissue forming anterior to retinal disc
More common in type 1
What are the features of macula diabetic retinopathy?
Same as normal but @ the macula
More common in type 2
How does blepharitis normally present?
Kind of like allergic conjunctivitis
Bilateral itchy eyes + crusting at lid margins + red + swelling
Worse first thing in the morning
How should blepharitis be managed?
Good eye hygiene - warm compress, keep clean
Chloramphenicol if this doesn’t work