Ophthamology - The Red Eye Flashcards
Is acute angle closure glaucoma an emergency?
YES
define glaucoma
a condition of increased pressure within the eyeball, causing gradual loss of sight.
what is acute angle closure glaucoma (AACG)?
A rapid rise in intraocular pressure due to sudden obstruction to the flow of aqueous humour in the eye
What is aqueous humour produced by?
Ciliary body
Function of aqueous humour?
- Maintains pressure & shape of eye
- Supplies nutrients to cornea & lens
Describe the course of flow of aqueous humour
- Produced by ciliary body
- Flows through pupil into anterior chamber (between iris and cornea)
- Drains into the trabecular meshwork to exit the eye (via canal of Schlemm)
How does AACG occur?
- Iris is pushed/pulled forward to obstruct the trabecular meshwork (pupillary block)
- Aqueous humour cannot drain from eye due to anterior chamber narrowing
- Pressure inside eye rapidly increases
- Compression of optic nerve and visual loss (optic nerve damage)
Risk factors for AACG?
- FH
- Female sex (4x)
- Older age
- Ethnicity - Asian
- Anatomical predisposition
- Pupil mid-dilation
are males or females more prone to AACG?
Females (4x)
What ethnicity is most prone to AACG?
Asian
What anatomical features can predispose you to AACG?
- Short eyeball length
- Long sightedness (hypermetropia)
Define hypermetropia
Long-sightedness
How can pupil mid dilation lead to AACG?
When the pupil is mid-dilated, the distance between the iris and the lens is the shortest, and the two structures can come into contact with each other in individuals at risk for angle closure.
e.g. dark room, medications
What medications can lead to pupil mid dilation?
- Anticholinergics (e.g. oxybutynin)
- Pupil dilating drops (e.g. atropine)
Complications of AACG?
- Permanent vision loss
- Central retinal artery or vein occlusion
- Repeated episodes of AACG
Symptoms of AACG?
ACAG is an important differential to consider in anyone presenting with a painful red eye.
- Very painful eye
- Blurred vision/halo around lights
- Headache (not relieved by simple analgesia)
- Vomiting
- Watery eyes
- Ask about medication history – drugs than can cause pupillary dilation
Signs of AACG?
- Unilateral red eye
- Fixed mid-dilated pupil – does not react to light
- Globe (eyeball) – will feel hard to touch
- Corneal oedema – cloudy cornea (later sign)
What 2 main investigations are used in AACG?
- Tonometry
- Gonioscopy
Which investigation measures angle between iris & cornea?
gonioscopy
Which investigation measures intraocular pressure?
tonometry
What is the aim of initial management of AACP?
Reduce intraocular pressure!
Which 2 medications can be used to reduce IOP in AACG?
- Pilocarpine eye drops
- Acetazolamide
Function of acetazolamide
to reduce production of aqueous humour
Definitive management of AACG?
Bilateral laser iridotomy –laser makes hole in iris to improve aqueous humour outflow
What should be avoided in patients with AACG history?
Avoid dark rooms and eye patches as this may worsen angle closure by causing mid-dilation of pupils
Differentials for a painful red eye?
- Acute angle closure glaucoma
- Scleritis
- Uveitis
- Corneal abrasion
- Episcleritis
- Corneal ulcer
Chemical eye injuries can be accidental or deliberate. What are some examples of some ‘accidental’ causes?
- Cement
- Plaster
- Household cleaners
- Industrial substances
Chemical eye injuries can be accidental or deliberate. What are some examples of some ‘deliberate’ causes?
- Ammonia
- Strong acids
Do alkalis or acids cause more severe eye injuries? Why?
Alkalis → they can liquefactive necrosis as they propagate themselves deeper into the eye, whereas acids cause coagulative necrosis and impede their own progress
What type of necrosis do alkalis cause in the eye?
Liquefactive
What type of necrosis do acids cause in the eye?
Coagulative necrosis
Symptoms of chemical eye injuries?
- Severe eye pain and watering
- Reduced visual acuity
- Skin burns – erythema, blistering
Signs seen in chemical eye injuries?
- Corneal abrasion/large epithelial deficits
- Associated skin damage
- Blanching of the limbus (the joint between the conjunctiva and cornea) which is important prognostically
Most important management step in chemical eye injuries?
Irrigate!!
Give some medications used in the treatment of chemical eye injuries and their purpose
- Topical steroids (e.g. prednisolone) → reduce inflammation
- Antibiotics (e.g. chloramphenical) → prevent 2ary infection
- Cytoplegics (e.g. cyclopentolate) → paralyse the iris and help reduce pain
- Citric and ascorbic acid → helps with healing
- Analgesia
What is chloramphenicol?
A topical eye ointment used to treatment of conjunctivitis and chemical burns
What is conjunctivitis?
Inflammation of the conjunctiva (the external layer covering the outer surface of the globe and inner surface of the eyelids)
What is the conjunctiva?
the external layer covering the outer surface of the globe and inner surface of the eyelids
How common is conjunctivitis?
Extremely common, accounts for 1% of GP consultations in UK.
Define chemosis
Swelling of conjunctiva
Define epiphora
watering eyes
What are the 3 main types of conjunctivitis?
- Bacterial (infectious)
- Viral (infectious)
- Allergic (non-infectious)
What is the most common cause of viral conjunctivitis?
Adenovirus
Transmission of viral conjunctivitis?
Extremely infectious → direct contact with contaminated skin or objects can lead to spread
Does viral conjunctivitis tend to be unilateral or bilateral?
Bilateral
Describe the discharge in viral conjunctivitis
Profuse and watery
Does tender preauricular lymphadenopathy tend to be present in viral or bacterial conjunctivitis?
viral
Is a concurrent URT infection typically seen in viral or bacterial conjunctivitis?
Viral
Adenoviral conjunctivitis can cause 2 presentations, depending on its serotype. What are these 2 presentations?
- Pharyngoconjunctival fever → pharyngitis, conjunctivitis, and fever (serotypes 3, 4 and 7)
- Epidemic keratoconjunctivitis → more severe, associated with corneal involvement and photophobia (serotypes 8,19 and 37)
Investigations for conjunctivitis?
- Rarely required – often history & examination
- Swabs rarely
Management for conjunctivitis?
- Self-limiting
- Hygiene measures e.g. washing hands, avoid sharing linen
Are complications more common in viral or bacterial conjunctivitis?
bacterial
What are the 3 most common pathogens causing bacterial conjunctivitis?
- Staphylococcus aureus
- Streptococcus pneumoniae
- Haemophilus influenzae
In which age group can conjunctivitis caused by Neisseria gonorrhoea be seen?
in neonates due to infection from mother’s birth canal
What is the classic triad of symptoms seen in reactive arthritis?
- Arthritis
- Conjunctivitis
- Urethritis
Why can unprotected sex be a risk factor for conjunctivitis?
In rare cases, can be caused by Chlamydia trachomatis or Neisseria gonorrhoea
Does bacterial conjunctivitis tend to be unilateral or bilateral?
Unilateral
Describe the discharge in bacterial conjunctivitis
Inflamed conjunctiva and sticky purulent discharge → patients may wake with eyelids ticking together
In what type of bacterial conjunctivitis can tender preauricular lymphadenopathy be seen?
Chlamydia conjunctivitis
Management of bacterial conjunctivitis?
- Supportive
- Antibiotic drops (e.g. chloramphenicol, fusidic acid) – only reserved for severe cases
- Chlamydia or gonorrhea cases – systemic antibiotics e.g. azithromycin
Which topical antibiotics are used in the treatment of severe bacterial conjunctivitis?
chloramphenicol, fusidic acid
Which systemic antibiotic is used in the treatment of severe chlamydia or gonorrhea conjunctivitis cases?
azithromycin
Give 2 complications of bacterial conjunctivitis
Keratitis and endopthalmitis – can result in reduced vision or blindness
What type of reaction is seen in allergic conjunctivitis?
type 1 hypersensitivity reaction to a particular trigger
Risk factors for allergic conjunctivitis?
Personal or FH of atopic conditions e.g. asthma and hayfever
What is the distinguishing feature of allergic conjuunctivitis?
itching
Clinical features of allergic conjunctivitis
- ITCHING – distinguishing features
- Both eyes affected
- Diffuse redness and watery discharge
- Examination of eyelid → papillae, which if large can give a ‘cobblestone’ appearance
In what type of conjunctivitis can ‘papillae’ be seen/
Allegic
what are the 4 subtypes of allergic conjunctivitis?
- Seasonal allergic conjunctivitis – 2ary to hayfever, more common in summer due to pollen
- Perennial allergic conjunctivitis – caused by allergens e.g. dust mites
- Vernal keratoconjunctivitis – more common in young males living in hot dry climates
- Atopic keratoconjunctivitis – most common in middle-aged men
Investigations for allergic conjunctivitis?
- History of atopy
- Recurring conjunctivitis in response to trigger or changes to weather
- Conjunctival scrapes – presence of eosinophils (type 1 reaction)
Management of allergic conjunctivitis?
- Allergen avoidance
- Topical & oral antihistamines
- Topical mast cell stabilisers
- Mild steroids
Complications of allergic conjunctivitis?
None
Different types of conjunctivitis compared:
When a patient presents with ocular pain, what are the 4 diagnoses requiring urgent referral that must be ruled out?
- Acute angle close glaucoma
- Scleritis
- Anterior uveitis
- Corneal ulcer
Distinguishing features of AACG?
- Red eye
- Severe eye pain
- Systemically unwell - N&V, headaches
- Blurred vision
- Haloes around lights
- Pupil in fixed dilated position
How does pupil appear in AACG?
Fixed dilated position
Distinguishing feature of the pupil in anterior uveitis?
Pupil may be irregular** due to **adhesions** between the lens and iris (**synechiae)
What is the NICE guideline for patients presenting with potentially sight threatening causes of red eye?
same day assessment by an ophthalmologist
Defining features of a corneal ulcer?
Patients may present with pain, photophobia, and excessive lacrimation
What should you always ask about in a potential corneal ulcer (or abrasion)?
Contact lens use
What is a corneal ulcer often 2ary to?
Corneal abrasion
How can contact lens use lead to a corneal ulcer?
Extended contact lens wear – lens become colonised and infect small abrasions that result from lens insertion and removal
What is are the most common causative organisms in corneal ulcers?
- Pseudomonas → common if tap water has come into contact with contact lenses
- Acanthamoeba (protozoa) → can be acquired from standing water (e.g. swimming pools) however this is uncommon
In what scenario can Pseudomonas cause a corneal ulcer?
common if tap water has come into contact with contact lenses
How can a corneal abrasion be differentiated from a corneal ulcer?
- Present similarly to corneal abrasion:
- Pain
- Watering
- Photophobia
- Symptoms can escalate:
- Worsening pain
- Decreased visual acuity
- Vision may be affected dramatically if ulcer encroaches on visual axis
How is the diagnosis for a corneal ulcer made?
- Diagnosis made via fluorescein stain:
- Stain applied to eye (yellow/orange colour) which collects in abrasions or ulcers, highlighting them
- Slit lamp examination more used in significant ulcers
management of a corneal ulcer?
admission for intensive antibiotic treatment and mydriatic eye drops
Potential complication of a corneal ulcer?
Rapid deterioration in vision and permanent corneal scarring
Define a corneal abrasion
This is damage to the corneal epithelium (as opposed to a corneal ulcer which refers to a deeper breach).
Risk factors for a corneal abrasion?
- Trauma
- Profession e.g. sheet metal working
Give some objects that can cause a corneal abrasion?
- Contact lens
- There may be an associated infection with pseudomonas
- Foreign bodies
- Fingernails
- Eyelashes
- Entropion (inward turning eyelid)
Which organism most commonly causes an infection associated with contact lenses?
Pseudomonas
Presentation of a corneal abrasion? What can be a distinguishing aspect of the history?
- Painful red eye
- Photophobia
- Reduced visual acuity (blurred vision)
- Watering eye
- Foreign body sensation
Distinguishing aspect of history → Often they mention obvious trauma/injury to the eye or may belong to a profession that puts them at risk – e.g. sheet metal working
Investigations for a corneal abrasion?
Fluorescein stain
Slit lamp examination may be used in more significant abrasions
Management for corneal abrasion?
- Removing foreign bodies
- Simple analgesia (e.g. paracetamol)
- Lubricating eye drops
- Antibiotic eye drops (e.g. chloramphenicol)
- Follow up after 24 hours
- Mydriatics – cyclopentolate eye drops
Prognosis of corneal abrasions?
Uncomplicated abrasions usually heal over 2-3 days
Key features of uveitis?
- Red eye, pain, blurred vision, and photophobia
- Increased lacrimation from eye
- Irregular pupil due to adhesions between lens and iris (synechiae)
- ‘Floaters’ in vision
What is the anterior uvea comprised of?
Iris and ciliary body
Pathophysiology behind anterior uveitis?
Anterior chamber of eye becomes infiltrated by immune cells (neutrophils, lymphocytes, and macrophages) → this is usually caused by an autoimmune process but can also be due to infection, trauma, ischaemia or malignancy.
What causes ‘floaters’ seen in patient’s vision in anterior uveitis?
Inflammatory cells
Most common cause of anterior uveitis?
Most commonly caused by inflammation elsewhere in the body.
- Ankylosing spondylitis
- Idiopathic juvenile arthritis
- Multiple sclerosis
- SLE
- IBD
- Granulomatosis with polyangiitis
- Reactive arthritis
- Infections: herpes, TB, syphilis, HIV
Presentation of anterior uveitis?
- Red eye, pain (dull, aching), blurred vision (reduced visual acuity), and photophobia (due to ciliary muscle spasm)
- Ciliary flush (a ring of red spreading from cornea outwards)
- Floaters and flashes
- Sphincter muscle contraction causes mioisis (constricted pupil)
- Patients commonly note increased lacrimation from affected eye
- Pupil may be irregular due to adhesions between the lens and iris (synechiae)
- Hypopyon → a collection of white blood cells in the anterior chamber, seen as a yellowish fluid collection settled in front of the lower iris, with a fluid level
Management for anterior uveitis?
- Steroids (topical, oral or IV)
- Cycloplegic-mydriatic medications e.g. cyclopentolate or atropine eye drops
- Immunosuppressants – e.g. DMARDS and TNF inhibitors
- Laser therapy, cryotherapy or surgery (vitrectomy) are also options in severe cases
When presented with a red eye, what are the 3 most important diagnoses to rule out?
- Acute angle closure glaucoma
- Scleritis
- Anterior uveitis
What 3 questions can be asked when a patient presents with a red eye?
- Is acuity affected?
- Is the eye painful?
- Are the pupil reflexes affected?
What are the 3 major features that distinguish scleritis from uveitis?
- Severity of pain → SCLERITIS WORSE
- Pain on ocular movement → SCLERITIS painful on movement
- Blanching → SCLERITIS does NOT blanch
What is scleritis?
Severe inflammation of the sclera. Potentially blinding
Who is scleritis most common in?
Middle-aged women most common.
What condition is scleritis most commonly associated with?
Rheumatoid arthritis (although is associated with several other connective tissue diseases).
NOT usually caused by infection
Potential complication of scleritis?
Perforation of sclera
Features of scleritis?
- Severe pain - ‘deep boring pain’, often wakes patient at night
- Pain on eye movement
- Severely red eye
- Bilateral or unilateral
- 50% patients systemically ill with rheumatological conditions → look for systemic symptoms
- Sclera vessels do NOT blanch
Why do sclera vessels NOT blanch?
Inflammation affects superficial episcleral as well as deep scleral vessels → topical vasoconstrictors (e.g. 10% phenylephrine) do NOT cause blanching of eye
Management of scleritis?
Emergency → systemic immunosuppression e.g. methotrexate in rheumatoid arthritis).
What is episcleritis?
Inflammation of the episcleral (layer underneath conjunctiva e.g. outermost layer of sclera). It is benign and self-limiting.
What is episcleritis typically associated with?
Not usually caused by infection but often associated with inflammatory disorders e.g. rheumatoid arthritis and IBD.
What are the 2 most common locations for a foreign body (FB) in the eye?
- Conjunctiva → whites of the eye or beneath the upper or lower eyelids
- Cornea → clear surface overlying iris & pupil
Common FB to get in eye?
Dust, wood chip, metal filling or shaving, insects, glass, foliage.
THINK risk factors e.g. Working with metal grinders/wood chips or foliage without proper eye protection
Presentation of a FB in eye?
- History of foreign body entering eye – wind blowing, high velocity (grinding or hammering materials), DIY, or gardening
- Typically unilateral:
- Ocular irritation / soreness or pain / foreign body sensation
- Red eye, may struggle to open fully
- Watering eye with blurred vision
- Foreign body adherent to ocular surface
- If longstanding → conjunctival infection (redness) + conjunctival or corneal abrasions
- Look out for rust rings if metal foreign body
Investigation for FB in eye?
Slit lamp examination OR direct examination with torch
Management for FB in eye?
- Loose FB → irrigate with saline
- FB on conjunctiva → gently remove with sterile cotton bud
- FB on cornea (especially in visual axis) → refer, need slit lamp to use green needle horizontally with bevel up to flick FB off
- Pharmacological:
- 7 days topical chloramphenicol post removal → prevent 2ary infection
What pathogen is most commonly associated with contact lens infection?
pseudomonas (think - tap water)
Which eye condition is most commonly associated with rheumatoid arthritis?
Scleritis
