Red eyes Flashcards
What questions must you be sure to ask in a conjunctivitis history?
- Has the patient been in contact with anyone with red eyes?
- Has the patient been sexually active recently?
- Does the patient wear contact lenses?
- Does the patient have any allergies?
- Has the patient had an URTI recently?
What are signs suggestive of conjunctivitis?
- Normal, reactive pupils
- Mucoid discharge
- Conjuntival injection (redness)
- Normal visual acuity
What should be your initial investigations regarding conjunctivitis?
- Chlamydial swabs
- Viral swabs
- Bacterial swabs
What is fluorescein used for?
Fluorescein (sodium fluorescein):
- Orange water-soluble dye
- Used IV or topically
- Dye is visualised using a cobalt-blue filter
- The filter causes the dye to fluoresce a bright green colour
Fluorescein does not stain intact corneal epithelium BUT stains the deeper corneal stroma
- This means it can highlight areas of epithelial loss
What are you likely to see under direct opthalmoscopy with a patient with conjunctivitis caused by HSV-1?
Dendritic ulcer
- Delicate branching appearance
When clinically suspected definitive diagnosis can be arrived using:
- Immunofluorescence assay (IFA) for HSV-1 antigen
- Polymerase chain reaction (PCR) for HSV-1 DNA (1)
How can HSV-1 infect the eye?
Herpes Simplex Virus-1:
- Enveloped with a cuboidal capsule
- Linear double-strangded DBA genome
- HSV-1 and HSV-2 reside in almost all neuronal ganglia
HSV-1 typically affects above the waist, and HSV-2 below.
- HSV-1 can lie dormant in the trigeminal nerve, resulting in conjunctivitis
HSV-2 can occasionally be transmitted to the eye though infected secretions (venereally or at birth)
How are we exposed to HSV-1 and how may it present? In addition, what would the treatment be?
Herpes Simplex Virus-1:
- Primary infection usually occurs in childhood
- Spread by droplets, or sometimes direct inoculation
- Maternal antibodies mean that infection is uncommon during the first 6 months of life
Most primary infections:
- Subclinical
- Mild fever, malaise and URTI symptoms
- Blepharitis and follicular conjunctivitis may occur but are mild and self-limited
Treatment:
- Topical aciclovir ointment for the eye and cream for skin lesions
What is anterior uveitis and when do we usually see it?
Anterior uveitis/iritis
- Inflammation of the uveal tract involving the iris, ciliary body, retina and choroid
- Anterior uveitis refers to inflammation involving the iris
- Need attention by opthalmologist
- Can have devastating effects upon the eye
This is often seen in patients with seronegative arthropathies (Ank-spond, psoriatic, etc)
The opthalmologist will:
- Look for signs of intra-ocular infammation
- Cells in the anterior chamber and posterior synechiae
- Posterior synechiae is where the iris becomes stuck to the lens
- This causes an irregular pupil and raised IOP
What are the most common causes for acute bacterial conjunctivitis?
Bacterial conjunctivitis:
- Streptococcus pneumoniae
- Staphylococcus aureus
- Haemophilius influenzae
- Moraxella catarrhalis
Some cases can be caused by the sexually transmitted organism:
- Neisseria gonorrhoeae
- Severe
Rare:
- Meningococcal (Neisseria meningitidis)
- Usually affects children
PCR may be required for less severe cases that do not respond to treatment:
- Rule out possibility of chlamydial or viral infection
What can be used for management of bacterial conjunctivitis?
Topical lubricants:
- Topical antibiotics (e.g. Chloramphenicol QD for up to 1 week) are frequently administered to speed recovery and prevent re-infection and transmission
- Ointments and gels provide a higher concentration for longer periods than drops but daytime use is limited because of blurred vision
Occasionally, systemic antibiotics are required in the certain circumstances:
- Gonococcal infection is usually treated with a third-generation cephalosporin (ceftriaxone)
- Quinolones and some macrolides are alternatives
- It is advisable to seek advice from a microbiologist/genitourinary specialist
- H. influenzae infection, particularly in children, is treated with co-amoxiclav due to 25% risk of developing otitis/other systemic problems
- Meningococcal conjunctivitis:
early systemic prophylaxis may be life-saving - Up to 30% develop invasive systemic disease
- Seek specialist ID or paediatric advice
- If in doubt treatment with IM benzylpenicillin, ceftriaxone or cefotaxime
- OR oral ciprofloxacin
- Treatment should not be delayed
Also useful for treatment:
- Chloeamphenicol eye drops
- Cool compresses
About 60% of cases resolve within 5 days of treatment
What advice should be given to patients with conjunctivitis?
Patients should be advised:
- Irrigation to remove discharge may be useful in purulent cases
- Contact lens wear should be discontinued until at least 48 hours after complete resolution of symptoms
- Contact lenses should not be worn whilst topical antibiotic treatment continues
- Risk of transmission should be reduced by hand-washing
- Avoid sharing towels
- Review is unnecessary for most mild/moderate adult cases
- Seek further advice in the event of deterioration.
Statutory notification of public health authorities may be required locally in some cases.
What do contact lenses increase the risk of?
Bacterial infection
- May seen bacterial corneal ulcers
- Commonly called microbial keratitis
What is contraindicated in a patient with bacterial corneal ulcers?
- Contact lens wear
- Steroid eye drops
- Oral antibiotics
Why must bacterial keratitis be treated quickly?
Bacterial keratitis:
- Requires urgent attention
- Delayed treatment allows bacteria to replicate
- Condition progresses rapidly
- Can result in large bacterial infiltrates
- Can result in hypopyon (pus in the anterior chamber)
- Can eventually result in corneal perforation
What is the first line treatment for bacterial conjunctivitis?
Chloramphenicol eye drops
- Well tolerated
- Broad spectrum
