Red eye 2 Flashcards
What is keratitis ?
Inflammation and damage of the cornea
What are the 2 main types of keratitis ?
Infectious and non-infectious (non is not very common)
What are the causes of infectious keratitis ?
- Viral - herpes, adenovirus
- Bacterial - staph A mainly, also sometimes pseudomonas aerginosa
- Fungal
- Acanthamoeba
What are the causes of non-infectious keratitis ?
- RA
- Hypersensitivity
What is the main complication that often occurs when someone develops keratitis ?
Ulcers - corneal and dendritic
What is a major risk factor for the development of keratitis ?
- Contact lens use
- Less commonly due to a scratch on the cornea
What are the main organsism associated with contact lens induced keratitis ?
- Pseudomonas aeguinosa
What are the symptoms of keratitis/corneal ulcers?
- Pain and redness (around the cornea)
- Foreign body/gritty sensation
- Corneal or dendritc ulcers
- Profuse lacrimnation
- Photophobia
- Hypopyon (inflam cells in the anterior chamber looks white)
What causes dendritic ulcers in keratitis ?
Herpes infections
Why is it important to distinguish between a herpes infection causing keratitis and an autoimmune cause causing it ?
Because if steroids are given they can cause a corneal melt or perforation of the cornea in herpes infections
What is an adenovirus keratitis usually preceded by ?
URTI
What is the treatment for bacterial, viral or autoimmune keratitis ?
- Bacterial = ofloxacin
- Viral = aciclovir
- Autoimmune = oral/topical steroids
How is the cause of corneal ulcers/keratitis diagnosed ?
Corneal scrap
What investigation can be done to identify a corneal ucler/abrasion ?
Fluorescein dye with slit lamp
What are the 2 main types of orbital cellulitis ?
- Preseptal
- Orbital
What is pre-septal cellulitis ?
- It is an infection of the soft tissues anterior to the orbital septum - this includes the eyelids, skin and subcutaneous tissue of the face, but not the contents of the orbit.
- It is characterised by eyelid erythema and oedema
What is orbital cellulitis ?
Inflammation due to infection of the soft tissues (fat and muscles) of the orbit posterior to the orbital septum
What are the main risk factors for the development of orbital cellulitis ?
- It is usually caused by a spreading URTI from the sinuses
- Recent eyelid infection/ insect bite on eyelid (Peri-orbital cellulitis)
- Ear or facial infection
Are eye movements ok in pre-septal cellulitis ?
Yes
What are the signs/symptoms of orbital cellulitis ?
- Oedema and erythema around the eye
- Eyelid oedema and ptosis
- Visual disturbance
- Severe ocular pain & Painful eye movements
- Ophthalmoplegia - cant move the eye
- Proptosis - abnormal protrussion/displacment of the eye
- Fever
- Headache
- N&V in meningeal involvement (rare tho)
The features of orbital cellulitis and preseptal cellulitis are very similar, however what features of orbital cellulitis must be absent for it to be preseptal cellulitis ?
Orbital signs (pain on movement of the eye, restriction of eye movements, proptosis, visual disturbance, chemosis, RAPD) must be absent in preseptal cellulitis - their presence would indicate orbital cellulitis
What investigations should be done in someone with suspected orbital cellulitis ?
- Bloods - raised inflammatory markers
- Swab of any discharge present
- Contrast CT of the orbit may help to differentiate between preseptal and orbital cellulitis & determine if there is an abscess. It should be performed in all patients suspected to have orbital cellulitis
What is the treatment of orbital ceullitis ?
- Cared for by ophthalmology and ENT
- But drain if there is an abscess
- Give - Flucloxacillin + ceftriaxone +/- metronidazole
