Opthalmology Flashcards
What is keratitis?
Corneal inflammation
What are the causes of keratitis and their respective treatments?
- Viral: HSV (dendritic shape when use fluorescein) - topical acyclovir
- Bacterial: s.aureus/pseudomonas - abx drops
- Trauma/foreign body: remove after topical analegesics
- Allergic ‘marginal keratitis’
What are corneal abrasions and how do you treat them?
Corneal abrasions are small scratches on the cornea (causing a gritty feeling, in a red eye with photophobia)
Rx: topical abx erythromycin and NSAIDs
How do corneal ulcers present?
Extreme pain, squinting, reduced vision, increased tears
+/- anterior uveitis signs - miosis, aqueous flare and redness
How would you dx corneal ulcers?
Slit lamp with fluorescein dye
How do you treat corneal ulcers?
Remove infective cause - abx
(G+ve - chloramphenicol // G-ve - ofloxacin)
- Patch/bandage contact lens as aggrevated by dryness
- If not healing they may need surgical debridement
What is glaucoma?
Optic neuropathy due to raised IOP
Define acute-closed angle glaucoma
when the anterior angle of the anterior chamber narrows causing a sudden increase in IOP
How does scleritis present?
Very painful red eye
Headache, photophobia
Generalised inflammation of the sclera with oedema of the conjunctiva
Scleral thinning - makes it look blue
Non-blanching with cotton bud/phenylephrine
50% of people with scleritis have systemic disease.
Give examples of the systemic diseases
- Sjogrens
- Ra
- Wegeners (granulomatosis with polyangitis)
How do you treat scleritis?
Reduced the inflammation
PO prednisolone
- If they have systemic disease you can use methotrexate/azathioprine or rituximab
What is the urea made up of?
Iris
Ciliary body
Choroid
What diseases is anterior uveitis associated with?
AI diseases - ank spondylitis, IBD, reactive arthritis
JIA in children
How might the presentation of anterior uveitis differ from ACAG?
AU - may have an irregular constricted pupil
Less hazy cornea
Ciliary flush
How do you treat anterior uveitis?
Steroid drops
0.5%-1% prednisolone drops
How would you treat a bacterial cause of conjunctivitis?
Chloramphenicol drops
or fusidic acid drops
How would you treat a chlamydial infection of the conjunctiva/trachoma?
PO Azithromycin
What is keratitis usually caused by?
HSV
What is the key feature of viral keratitis?
Dendritic ulcers that stain with fluorescein
How do you treat viral keratitis?
Topical aciclovir
What are some of the causes of corneal ulcers?
Inflam: vasculitis/RA Infective: B V - HSV/varicella F - candida/aspergillus Parasites
How do you treat acute closed angle glaucoma
M:
1) T BB = timolol
2) T carbonic anhydrase inhibitors = acetazolamide
3) Pilocarpine (miosis - constriction of pupil)
4) IV mannitol (osmotic diuresis)
S: lazer iridotomy
How do you investigate acute closed angle glaucoma?
1) Gonioscopy
2) Slit lamp (shallow anterior chamber)
3) Static perimetry (look for visual field loss)
Describe diabetic retinopathy
Retinal disease due to progressive diabetic microvascular leakage (loss of pericytes) + occlusion (due to endothelial cell damage, RBC changes and increased platelet stickiness)
How do you treat diabetic retinopathy?
Intravitreal anti-VEGF (ranibizumab + afilbercept)
Macular laser therapy
Pan retinal photocoagulation
How do you screen for chronic open angle glaucoma
1) Tomometry - IOP
2) Perimetry - visual field defect
3) Fundoscopy - Disc/cupping
Give an example of a topical carbonic anhydrase inhibitor
T carbonic anhydrase inhibitors
= acetazolamide
or dozolamine
How does retinal detachment present?
4F's Flashing lights Floaters Field loss Fall in acuity
‘A dense shadow that starts peripherally and progressed towards the centre of vision.’
Give some causes of painless sudden loss of vision
Ischaemic optic neuropathy
Occlusion of central retinal artery/vein
Viterous haemorrhage
Retinal detachment
How can retinal detachment be treated?
With lazer photocoagulation therapy
- vitrectomy + gas tamponade
What is a vitreous haemorrhage?
Its the extravasation of blood into areas around the vitreous humour of the eye
Bleeding into the vitreous humour
Give some of the common underlying causes of vitreous haemorrhage
- Proliferative diabetic retinopathy
- Posterior vitreous detachment
- Ocular trauma
- Neovascular age-related macular degeneration
How would you examine someone with vitreous haemorrhage?
Measure:
- Intraocular pressures + Visual acuity
- Dilated fundoscopy
- Slit lamp - would show blood in the anterior vitreous
- Gonioscopy ? new vessels in the angular drainage?
- USS
- Orbital CT
Management of vitreous haemorrhage
Urgent referral to ophthalmology
- X retinal detachment - bed rest with head up
- Laser photocoagulation
- Anterior retinal cryotherapy
What are the fundoscopy signs of primary open-angle glaucoma?
1) Optic disc cupping
2) Optic disc pallor
3) Bayonetting of vessels (vessels have breaks as they disappear into the cup and reappear at the base)
4) Disc haemorrhages
What would you see on fundoscopy with papilloedema?
Venous engorgement Loss of venous pulsation Blurring of the optic disc margin Elevation of optic disc Loss of optic cup
Give some RF for age-related macular degeneration
Advancing age
Smoking
FHx
Others: ischaemic CVD - HTN, DM and high cholesterol
How does age-related macular degeneration present?
Reduction in visual acuity - near things
Difficulties in dark adaptation
Fluctuations in visual disturbance
- Photopsia = perception of flickering/flashing lights
What investigations do you do with ARMD?
- slit lamp microscopy
- Fluorescein angiography (for neovascular ARMD and can guide the anti-VEGF rx)
How do you treat dry ARMD?
Zinc with anti-oxidant vitamins A, C, E (reduce the progression of disease in 1/3rd)
How do you treat wet ARMD?
1) Anti-Vascular endothelial GF (VEGF) - intravitreal injections
= Ranibizumab / afilbercept
2) Laser photocoagulation
