12 - Ophthalmology Conditions 2 Flashcards
What are some causes of optic neuritis?
- MS
- Infection e.g syphillis
- Drugs e.g ethambutol, methanol
- Diabetes
- Vitamin deficiency
What are some risk factors for developing optic neuritis?
- Age 20-40
- Female
- Caucasian
- FHx of MS
How does optic neuritis present?
- Unilateral loss of vision over hours or days
- Dyschromatopsia/Red desaturation
- Eye movements painful
- Flashing lights
- RAPD
What is the prognosis with optic neuritis?
- Usually resolves in 2-6 weeks
- 50-80% go on to develop MS in next 15 years
What is the treatment for optic neuritis?
- High dose methylprednisolone IV for 72hrs
then
- PO Prednisolone for 11 days
What is the difference between orbital and periorbital cellulitis?
(IMAGE IMPORTANT)
Orbital: Infection of the tissues posterior to the septum and it is life threatening so an emergency. Usually from paranasal sinus, dental or occular infection
Periorbital: Infection of the tissues anterior to the septum. Usually from sinus infections or facial skin lesions
What is the presentation of periorbital cellulitis and how can you rule out orbital cellulitis?
- Swollen red hot eyelids
- Features that rule out orbital: absence of painful eye movements, absence of visual impairment, absence of diplopia
- If in doubt treat as orbital cellulitis as this is life threatening
What is the treatment of periorbital cellulitis?
- PO co-amoxiclav
- Admit if child or high risk of progression to orbital cellulitis
- Safety net to return if any red flags or not responding after 48 hours
How does orbital cellulitis present?
- Swollen red eye
- Pain on eye movement and reduced eye movements
- Diplopia
- Proptosis
- RAPD
- Fever
- Reduced visual acuity
What are the complications with orbital cellulitis that make it an emergency?
- Subperiosteal and orbital abscess
- Visual loss due to optic neuritis and CRAO
- Meningitis
- Brain abscess
- Cavernous sinus thrombosis
When should you CT in orbital cellulitis and what are some red flags that an orbital cellulitis needs urgent action?
Eyelid oedema and erythema OR failure to respond to 48hr abx PLUS ONE RED FLAG:
- Proptosis
- Chemosis
- Ophthalmoplegia
- Relative afferent pupillary defect (RAPD)
- Systemically unwell 6. Painful eye movement
- Altered visual acuity
How is orbital cellulitis managed?
- Admit for promt CT (if indicated as radiation exposure to young), ENT and Optho assessment
- IV Abx (Ceftriaxone +/- Metronidazole if sinus infection)
- Surgical drainage of any abscesses to prevent meningeal involvement and cavernous sinus thrombosis
How can you tell the difference between episcleritis and scleritis?
Episclera lies superficially so the vessels will move when probed with a cotton bud and blanch when 10% phenylephrine is put on them
This won’t happen with sclerla vessels as they are deeper
How does episcleritis present?
- Typically not painful but can be mild pain
- Segmental redness (rather than diffuse) in lateral sclera
- Foreign body sensation
- Dilated episcleral vessels
- Watering of eye
- No discharge
What types of patients does episcleritis usually present in?
MOSTLY IDIOPATHIC
- Young middle aged women
- Inflammatory disorders e.g IBD, RA
How is episcleritis managed?
- Self limiting in 1-4 weeks
- Symptomatic relief with simple analgesia, cold compresses, artificial tears
- Safety net
What is scleritis and why is it more serious than episcleritis?
- Generalised inflammation of the sclera with oedema of the conjunctiva
scleral thinning, and vasculitic changes
- URGENT REFERRAL as necrotising scleritis can lead to perforation of the sclera and is sight threatening
What are the causes of scleritis?
Usually not infectious, it is autoimmune related
How does scleritis present?
- Diffuse red eye
- Severe dull pain made worse on occular movements
- Headache
- Photophobia
- Reduced visual acuity
How is scleritis managed?
URGENT OPHTHO REFERRAL
Anterior/Non-necrotising:
- Oral high-dose prednisolone
- Oral NSAIDs
Posterior or Necrotising:
- Immunosuppression for underlying autoimmune condition e.g clophosphamide or rituximab
- Course of methylprednisolone
- If globe perforation need surgery
How can you detect a cataracts with a pen torch?
COME BACK TO
What are indications of cataract surgery and what can you expect to change with your vision from it?
Indications: Symptoms are troubling, lifestyle is restricted, or if unable to read a number-plate at 20 metres (and they need to drive)
Changes:
- Improve colour vision
- Dazzle/glare often remains after
- Improved visual acuity as put refractive lens in, may need distance glasses
- Visual acuity may not return to normal as may be underlying co-existing AMD
What are Drusen in AMD?
- Soft Drusen lift RPE from Bruch’s membrane. This can cause VEGF release so encourages neovascularisation and progression from dry to wet AMD
How does neovascularisation in wet AMD cause vision loss?
- Disciform scar in macula that leads to a blind spot (scotoma)
What is Charles Bonnet synrome?
Most people with AMD may experience this
Vivid hallucinations in response to central vision loss
Reassure them it is normal
What is the pathophysiology of retinal detachment and why is it an emergency?
Retins separates from the choroid, usually due to a tear allow vitreous humour to get under retina.
Sight threatening as outer retina gets its blood supply from choroid
Rhegmatogenous retinal detachment—tear in retina causes fluid to pass
from vitreous space to subretinal space between sensory retina and
the retinal pigment epithelium. Caused by trauma
Exudative retinal detachment - Retina detaches without
a tear, eg hypertension, vasculitis, macular degenerative conditions, tumour
Tractional retinal detachment—pulling on the retina, eg proliferative reti- napathy, myopic eyes
What are some of the risk factors for retinal detachment?
- Posterior vitreous detachment
- Diabetic retinopathy
- Trauma to the eye
- Retinal malignancy
- Older age
- Family history
- Myopia
- Cataract surgery (vitreous haemorraghe)
If a retinal tear is found before retinal detachment, what can you do to prevent this from developing into retinal detachment?
Cryotherapy or Laser Retinopexy
Creates adhesions between the retina and the choroid
How does a retinal detachment present?
4 F’s!!!
- Flashes
- Floaters
- Field loss (usually peripheral)
- Fall in acuity (painless vision loss like a curtain or shadow over vision)
How does retinal detachment look on fundoscopy?
- Grey opalescent retina ballooning forward
- May see tear
- Crinkling of retinal tissue