Ophthalmology Conditions Flashcards
What is blepharitis?
Range of conditions causing eyelid inflammation
What is the difference between anterior and posterior blepharitis?
Anterior - involve the lashes
Posterior - involve meibomian glands
What complications are associated with blepharitis?
Dry eye
Conjunctivitis
Keratitis
What is the pathophysiology of blepharitis?
Build up of bacteria on lash follicle or gland orifice
Immune response to this causes collateral damage and further inflammation
How does blepharitis present?
Bilateral Burning watery eyes (with foreign body sensation if cornea involved) Worse in morning - eyes may stick Red inflamed eyelid Crusts/scales along eyelashes Tear film deficiency
How is blepharitis managed?
Lid hygiene and topical chloramphenicol
+Stop mascara use, remove crusts, warm compress, tear supplements
What makes up the uvea/vascular layer of the eye?
Iris
Choroid
Ciliary body
What is the difference between causes of unilateral and bilateral uveitis
Unilateral - infectious, acute cause
Bilateral - chronic systemic cause
How can anterior uveitis be further categorised?
Iritis - just iris
Iridocyclitis - iris and ciliary body
When do most patients present with anterior uveitis?
Between 20-50yo
What can cause anterior uveitis?
Idiopathic - 50%
Inflammatory - ank spond. sarcoidosis, Behcet’s, IBD, Kawasaki, SLE
Infectious - Lyme disease, herpes
Trauma
Where does the most severe injections in anterior uveitis occur?
At the limbus - opposite to conjunctivitis (further away from limbus)
What is the pathogenesis of uveitis?
Antigen thought to provoke inflammatory response that breaks down eye-blood barrier. This enables WBC and proteins to enter anterior chamber
How does uveitis present?
Symptoms occur over hours-days Painful - worse pain on eye movement Red Photophobia Blurred vision Watery eye - may overflow
What signs are seen on examination in a patient with uveitis?
Reduced visual acuity Perilimbal injection Direct photophobia Keratic precipitates - WBC visible as little white spots Small fixed oval pupil
How is uveitis managed?
Refer to ophthalmology within 24hrs
Cycloplegic dilating agents
Corticosteroids
Why and what are cycloplegia dilating agents used for uveitis?
Relieve pain
Prevent adhesions
Atropine and Cyclopentolate
Why are corticosteroids used for uveitis?
Reduce inflammation
Prevent adhesions
What complications are associated with uveitis?
Relapse
Posterior synechiae (adhesions from lens to iris)
Cataract
Glaucoma (due to steroids)
What are posterior synechiae?
Inflammatory adhesions between lens and iris
What must you examine for if a patient has uveitis?
Back pain - ank spond Rash/bite - lyme Resp. Symptoms - Sarcoidosis GI symptoms - IBD Cold sore - herpes Oral/genital ulcers - Behcet's
What is affected in intermediate uveitis?
Posterior ciliary body
Peripheral retina
Choroid
What features are associated with intermediate uveitis?
Painless floaters
Decreased vision
Minimal redness and pain
What is affected in posterior uveitis?
Retina and choroid
What features are associated with posterior uveitis?
Bilateral
Painless floaters
Gradual visual loss
Absence of redness, pain and photophobia
What is infectious keratitis and what is it also known as?
Infection of the cornea
Corneal ulcer
What causes infectious keratitis?
Microorganisms getting in via defect in corneal epithelium
What must be done if a patient has a corneal ulcer?
Take swab under topical anaesthesia
What risk factors are associated with corneal ulcers?
Wearing contact lenses
Dry eyes and blepharitis
Diabetes and immunosuppression
Topical corticosteroid use
How do corneal ulcers present?
Severe pain
Photophobia
FB sensation
Reduced vision
How are corneal ulcers managed?
Topical broad spectrum quinolone
What can be seen on examination of a corneal ulcer?
Hypopyon - white fluid in anterior chamber
White lesions on cornea - infiltrate
What is the prognosis of corneal ulcers?
Good prognosis
Increased risk of long term visual disability in:
Elderly, Contact lens wearers, Fungal disease
What causes herpetic keratitis?
HSV1
What happens in herpetic keratitis?
What is the hallmark feature on examination?
Virus travel along trigeminal nerve to ophthalmic division to corneal nerve
Dendritic ulcer pattern seen
How is herpetic keratitis treated?
Topical aciclovir
What is an acanthamoeba? Who does it most often affect?
Rare sight threatening protozoal infection
Seen in contact lens wearers
How does acathamoeba present?
Pain out of proportion to clinical signs
How is acanthamoeba treated?
Propamidine
Chlorhexadine
Several months
What risk factors are associated with corneal abrasion?
Inability to close eyes
Wearing contact lenses
How does corneal abrasion present?
Watery red eye Unable to keep open/repeated blinking Photophobia Decreased visual acuity FB sensation
What investigations would you request for someone with a corneal abrasion?
None normally needed
CT = 1st choice
X-ray if metallic FB
MRI contraindicated for metallic FB
Fluorescein examination
What would you see on fluorescein examination of a corneal abrasion?
Yellow stained abrasion
Usually visible to naked eye
How is corneal abrasion managed?
Topical NSAID’s
Topical Chloramphenicol - prevent bacterial infection
Tetanus prophylaxis
Follow up and review
How are corneal foreign bodies managed?
Remove (IF EXPERIENCED)
Topical anaesthetic
Irrigate eye or remove with cotton wool bud
Then treat as abrasion (NSAIDs, chloramphenicol, tetanus prophylaxis)
How are contact lens wearers who have a corneal abrasion managed?
Topical anti-pseudomonas antibiotics
No contact lens for 2 weeks
What is the prognosis for a corneal abrasion on the visual axis?
Potential for loss of visual acuity - scarring
What must you exclude with penetrating corneal injury?
Full thickness injury - this means ruptured globe
What mustn’t you do if a patient has a penetrating corneal injury?
Apply pressure to the globe
What is Seidel’s test (ophthalmology)?
Used to assess leakage from cornea, sclera or conjunctiva
If see paler fluid within pool or dye leaks then injury has penetrated anterior chamber
What are the red flags associated with penetrating corneal injury?
Obvious deep laceration
Subconjunctival haemorrhage
Pupil or iris deformity
How would you manage a patient with penetrating corneal injury?
Urgent referral to ophthalmologist
Eye shield
Advise not to cough, blow nose or strain
What is glaucoma?
Damage to the optic nerve head with progressive loss of retinal ganglion cells and their axons
Associated with raised IOP
How does aqueous humour normally drain in the eye?
Ciliary epithelium secrete aqueous humour
Pass through trabecular meshwork at the iridocorneal angle
Pass through canal of scheme
Into aqueous veins and episcleral venous system
Where is flow reduced in open angle primary glaucoma?
Trabecular meshwork
What IOP is seen in open angle primary glaucoma?
> 21mmHg
What risk factors are associated with open angle primary glaucoma?
Age Afro-caribbean Myopia Retinal disease Family history
How can primary open angle glaucoma be managed?
Topical drops
Laser trabeculoplasty
Surgical trabeculectomy
What is the pathophysiology of primary open angle glaucoma?
Poorly understood Could be: Raised IOP reduce blood flow to nerve head leading to vascular perfusion problem or Autoimmune damage of the nerve head
What examinations would you carry out if you suspect primary open angle glaucoma?
Goldman tonometry - IOP measurement Corneal thickness Gonloscopy - measure iris-corneal angle Visual field assessment Optic disk examination
What signs could be seen on optic disk examination in a patient with primary open angle glaucoma?
Cupping Pallor Bayoneting of vessels Cup notching Disc haemorrhage
How common is primary open angle glaucoma?
10% of >75yo
How does primary open angle glaucoma present?
Initial visual field loss peripheral - asymptomatic for long time
Usually picked up on routine optician appointment
By checking Visual Fields and Intra Ocular pressure of relatives
What conditions does the open angle glaucoma spectrum include?
Ocular hypertension - IOP>21 but nerve and VF normal
Normal tension glaucoma - IOP<21 but cupping optic disc and visual field defect
What is the prognosis for open angle glaucoma?
Treatment stall progression but doesn’t stop or reverse it
Good compliance normally means vision retained for lifetime
What is secondary open angle glaucoma?
A primary disease causes raised IOP and optic neuropathy
What are the causes of secondary open angle glaucoma?
Neurovascular
Corticosteroid induced
Pseudoexfoliative - deposits in drainage angle
Pigment dispersion - pigment deposit block drainage angle
What is the pathophysiology of neurovascular caused open angle glaucoma?
Ischaemia of the eye leads to new vessels growing and fibrosing in the drainage angle
How is secondary open angle glaucoma treated?
Neurovascular cause - laser treatment and anti-VEGF injections
Others - stop corticosteroids and drops
What happens in acute closed angle glaucoma?
Acutely raised IOP
Obstructed irido-corneal angle
Lens pushed against iris
What risk factors are associated with closed angle glaucoma?
Age
Chinese
Women
Hypermetropes
What are the possible complications of closed angle glaucoma?
Loss of vision
Central retinal artery/vein occlusion
What are the causes of closed angle glaucoma?
Severe hypermetropes - narrow angle so vulnerable to blocking off
Lens grow as we age - narrow angle
Short axial length
Thick lens
Thin iris
Pupil dilation - push iris into angle
Alpha-adrenergic agonists and other systemic drugs
Lens dislocation
Diabetes and Uveitis - meshwork blocked by vasculature and proteins
How does closed angle glaucoma present?
Severe acute pain
Blurred vision –> vision loss
Coloured haloes around lights
N&V
What can be seen on examination of a patient with closed angle glaucoma?
Red eye Hazy cornea Mid-dilated and non-reactive pupil Globe feels hard Shallow anterior chamber Closed irido-corneal angle RIOP (40-70)
What is the immediate management for acute closed angle glaucoma?
Immediate referral Topical drops IV acetazolamide - carbonic anhydrase inhibitor IV mannitol Analgesia and anti-emetics
What is the definitive closed angle glaucoma management?
Laser iridotomy
What is age related macular degeneration?
Central retina changes without obvious precipitating cause occurring in >55yo
What are the types of macular degeneration? How common are they?
Dry - geographic atrophy - 90%
Wet - neovascularisation - 10%
What is the most common cause of UK blindness?
Age related macular degeneration
25% develop in other eye within 4 years
What are the risk factors for age related macular degeneration?
Age Smoking Family Hx Diet and Obesity Caucasian CVS risk factors
How does age related macular degeneration present?
Painless loss of central vision Near vision affected most Can't discern between different shades of colour Difficulty adapting from light to dim Photopsia Visual hallucinations
What is the main differential for age related macular degeneration?
Diabetic maculopathy
How is age related macular degeneration diagnosed?
Slit lamp
OCT
Fundus fuorescein angiography
How does dry macular degeneration appear?
Soft druse
Changes in pigmentation of retinal epithelium
Atrophy
How does wet macular degeneration appear?
New vessel growth seen
Leakage from vessels - esp in periphery
Red patches - haemorrhages
How do symptoms of wet and dry macular degeneration vary?
Dry - gradual vision loss, partial vision loss
Wet - sudden symptom, straight lines appear wavy
How is age related macular degeneration managed?
Dry
- no treatment
- Vision rehab, smoking cessation help, vitamin supplements
Wet
- Intravitreal anti-VEGF injections (ranibizumab)
What are the ADR’s associated with anti-VEGF injections?
Retinal detachment
Endophthalmitis
Allergic reaction
What is retinitis pigmentosa?
Inherited eye disease that is characterised by black pigmentation and gradual degeneration of the retina
How does retinitis pigmentosa present?
Night blindness
Ring scotoma - loss of all peripheral vision –> tunnel vision –> blindness
Black bone spicule pigmentation of the peripheral retina
Mottling of retinal pigmented epithelium
Waxy looking disc
What is the pathogenesis of retinitis pigmentosa?
Photoreceptor death - rods first
Cell death lead to inflammation of vitreous humour
What is the epidemiology of retinitis pigmentosa?
Some cases X linked - more men
Peak ages - 7.5, 17 and >50yo
Why do you not get a relative afferent pupillary defect in Retinitis Pigmentosa?
It is bilateral and symmetrical
What is the prognosis for Retinitis pigmentosa?
Most legally blind by 40yo
How is Retinitis pigmentosa managed?
Visual rehab
Counselling
No way to stop disease progression
What is retinoblastoma?
Most common childhood ocular cancer originating from primitive retinal cells
Describe the epidemiology of retinoblastomas
Autosomal dominant
Average age of diagnosis - 18 months
10% of cases hereditary
What is the pathophysiology of retinoblastoma?
Mutation in retinoblastoma tumour suppressor gene on chromosome 13
Follow 2 hit model:
Sporadic - both mutations at fertilisation
Inherited - one mutation inherited, other occur after birth
How does retinoblastoma present?
Absence of red-reflex - Leukocoria (white pupil)
Strabismus - squint
Varied ocular symptoms as disease progress - red eye, nystagmus, vision loss
How are retinoblastoma managed?
Range of options: Enucleation External beam radiation therapy Chemo Photocoagulation
How is retinoblastoma diagnosed?
Examination under general anaesthesia with fully dilated pupil
MRI
What is the prognosis of retinoblastoma?
Excellent - >90% survive
Increased risk of other malignancy - Ewing’s sarcoma, osteosarcoma, neuroblastoma
Metastasis to bone and brain rare
Long term decrease in visual acuity and visual fields
What do the central retinal and posterior ciliary arteries supply?
Central - optic disc and central retina
Posterior - Outer retina
Both must function to maintain retinal function
What causes retinal artery occlusion?
Equivalent to cerebral stroke with end organ ischaemia:
Atheroma related thrombus Emboli Inflammatory cause - giant cell, SLE, wegener's Thrombophilic disorder COCP and cocaine Vasospasm
What is the peak age of retinal artery occlusion?
60-80yo
Describe the vessels that supply the retina
Internal carotid – ophthalmic –> Central retinal and Posterior ciliary arteries
Circle of zinn formed from posterior ciliary arteries
How is retinal artery occlusion diagnosed?
Clinical diagnosis
ESR, CRP and vasculitis screen req. if suspect giant cell arteritis
Full CVS exam
How does retinal artery occlusion present?
Sudden unilateral painless loss of vision
Amaurosis fugax history
What can be seen on examination of a patient with retinal artery occlusion?
Relative afferent pupillary defect
Pale retina with cherry red spot
Centre of macula thin, can see underlying vascular choroid
Oedematous retina
How is retinal artery occlusion managed?
NEEDS TO BE STARTED WITHIN 100 MINS - still make attempts upto 24hrs after event
Giant cell arteritis suspected - IV steroids Treatments have very little evidence: Ocular massage Inhale high CO2 content Topical glaucoma drops Anterior chamber paracentesis
What is the long term management of retinal artery occlusion?
Reduce CVS and atherosclerotic risk factors
What is the prognosis for retinal artery occlusion?
Only 1/3 get improved vision even with rapid treatment
What causes retinal vein occlusion?
Disruption to virchow’s triad:
- Thrombus
- Increased viscosity of blood
- Disease of the vein wall
- Compression from outside - arterial hypertension
What are the key risk factors for retinal vein occlusion?
Advancing age Hyperlipidaemia Hypertension Diabetes Raised IOP Inflammatory disease Hyperviscosity syndromes Renal disease
What are the types of retinal vein occlusion?
Branch retinal vein - more common
Central retinal vein - less common
How do branch and central retinal vein occlusion vary?
Branch - Image distortion, visual field defect
50% get 6/12 vision back
Central - Start on walking
Cotton wool spots, flame haemorrhages and RAPD (if ischaemia) on fundoscopy
What signs and symptoms are seen with both branch and central retinal vein occlusion?
Unilateral painless loss of vision
Vascular dilatation and Tortuous vessels on fundoscopy
How is retinal vein occlusion investigated?
BP Lipid profile ESR Blood glucose (Thrombophilia screen)
How can retinal vein occlusion be managed?
Manage CVS risk factors
Laser treatment - if associated macula oedema or neovascularisation
Intravitreal anti-VEGF - neovascularisation
What complications are associated with retinal vein occlusion?
Macula oedema
Retinal neovascularisation - due to hypoxia
Secondary glaucoma - due to neovascularisation
What is the normal sequence of events in retinal detachment?
1 Vitreous liquefies and shrinks with age
2 Posterior vitreous detachment
3 Traction on retina lead to tear
4 Vitreous seep underneath causing detachment
What are the symptoms of posterior vitreous detachment?
Flashing lights
Floaters - often temporal side of central vision
How may retinal detachment present?
Shadow start peripherally and progress centrally
Begin slowly and progress over hours to weeks
Black curtain come down and obstruct view
Central vision loss - macula involved
Straight lines appear curved
What signs would be seen on examination of a patient with retinal detachment?
RAPD if severe Loss of red reflex Reduced visual acuity Shafer's sign - vitreous lined with brown pigmented material Tears visible White appearance of detached retina
What risk factors are associated with retinal detachment?
Age Myopes - long eye Family Hx Previous tears Marfan's
How is retinal detachment diagnosed?
Slit lamp examination
Ultrasound or OCT
How is retinal detachment managed?
Same day urgent Ophthalmology review
Tear - laser or cryotherapy to make adhesions between neural and pigmented layer
Detachment:
- Vitrectomy - air/oil injected to push retina back
- Scleral buckling - silicone placed on sclera to push eye closer to detached retina
- Pneumatic retinopexy - Gas bubble injected - expand
What are the complications associated with retinal detachment?
Vision loss Scar tissue can fibrose - further detachment Macula oedema Infection Haemorrhage
What is the prognosis for retinal detachment?
85% successful reattachment
Can take months for vision to improve again
Managing tears stop 95% from detaching
What is a squint (strabismus)?
Eyes don’t point in the same direction
What are the types of squint?
Congenital/acquired - onset before/after 6 months
Concomitant/incomitant
Manifest/latent
What is a concomitant squint?
Angle between eyes remain same through all positions of gaze
What is a manifest squint?
Present when both eyes are open and being used
What is a latent squint?
Present only when other eye is shut
How can the angle between the eyes in a squint be described?
Exo - divergent angle
Eso - convergent angle
Hypo - downward deviation
Hyper - upward deviation
What are concomitant squints associated with?
Poor fine motor skills
Hypermetropes or Anisometropia (different refraction in each eye)
Opacities
What is accommodative esotropia?
Excessive inward turning of eye during accommodation
Need drops or patch to correct
What tests can be done to examine concomitant squints?
Hirschberg’s - hold pen torch at arms length - see where light reflection lies
Cover/uncover - cover one eye and observe open eye while the other one is uncovered
Alternate cover test - focus on object with occluder rapidly switching between eyes
When should concomitant squints be examined?
2 months of age if constant or progressive
How are concomitant squints managed?
Correct refractive errors
<8 - correct any amblyopia
If all fails and squint large - surgery
What usually causes incomitant strabismus?
Extra-ocular muscle or nerve damage
How are incomitant squints managed?
If due to small vessel disease - conservative with CVS risk factor reduction for 6 months
Prisms can be fitted to glasses
Surgical correction may be needed
How would a cranial nerve 3 palsy appear?
Eye down and out
Ptosis
Dilated pupil
How would a cranial nerve 4 palsy appear?
Vertical diplopia
How would a cranial nerve 6 palsy appear?
Eye in
What is a hyphema?
Blood in the anterior chamber
What can cause a hyphema?
Usually trauma
Sickle cell
Haemophilia
How would hyphema’s present?
Painful
Can cause vision loss
How would you manage a hyphema?
Steroid drops
Cyclopentolate - dilate pupil
Limited eye movement
Bed rest
What is the main complication associated with a hyphema?
Raised IOP
What is a hypopyon?
Pus in the anterior chamber
What can cause a hypopyon?
Anterior uveitis
Behcet’s
Drug reaction - rifampicin
what organism would you expect to be the cause of infectious keratitis in
a) contact lens wearer
b) general population
c) following exposure to dirty water
a) pseudomonas
b) staph aureus
c) amoebic
