Opthalmology Flashcards
What are the symptoms of retinal artery or retinal vein occlusion?
In vein occlusion Blurry vision is the only complaint, not painful. No specific therapy. Vein occlusion you will see blood extravation at the back of the eye. Cannot heparinise a vein occlusion, causes further bleeding into the eye.
Central retinal artery occlusion causes a sudden, painless, unilateral loss of vision. Opthalmoscopically you’ll see a pale milky, oedematous retina with attenuated artierioles and a cherry red macula. Can treat with aspirin or heparin.
What are the two types of macular degeneration?
Dry - obstructed by drusden. No proven therapy. ,ay try vitamins A and E
Wet - obstructed by blood vessels. Treat with laser therapy
What is glaucoma?
Increased production of aqueous humour ( made in the ciliary body) and insufficient drainage through the canal of schlemm. Iris can get thicker when the iris dilates and blocks the canal of schlemm. Treat by contricting pupil with beta blockers or using prostaglandin inhibitors to stop production of aqueous humour, or putting a hole in the iris, or with acetazolomide. As the aqueous humour builds up, the cup to disk ration gets bigger ( normally cup 30% of the disk).
Cateracts
Caused by ageing, trauma, and the perception of light. The lens starts to become opacified. Treat by surgically removing lens and surgically inserting a lens. There are different types of cataracts, sub capsular, nuclear, and cortical.
What’s the difference in viral and bacterial conjunctivitis presentations?
Viral: bilateral, preauricular lymph nodes, itchy
Bacterial: unilateral purelent discharge. Tx with topical antibiotics.
Subconjunctival haemorrhage
Blood that stops at the limbus ( area between c
Sclera and cornea). Doesn’t threaten eye sight, resolves spontaneously after ten days or so. Caused by trauma and low,platelets.
Herpes keratitis
Infection of the keratin layer of the cornea. Presents with pain. Can only be visualised with fluorescein dye. Eye emergency threatens eyesight. Treated with antivirals eg acyclovir vancyclovir. If treating uveitis with steroids, always rule out keratitis first.
What is uveitis?
Uveitis is inflammation of the uveal tract. The uveal tract is the iris and the ciliary body extending back towards the retina. The inflammation of the uveal tract can be from things such as Reiters syndrome, psoriasis, sarcoidosis, syphilis. Treat the underlying disease. Give steroids after ruling out keratitis.
What are the signs of papilloedema?
- Venous engorgement
- Loss of venous pulsations
- Blurring of the optic disc margin
- Elevation of the optic disc
- Loss of the optic cup
- Paton’s lines:concentric/radial lines cascading from the optic disc.
What are the causes of papilloedema?
Papilloedema = Increased ICP -Space occupying lesion -Idiopathic ICP -Hydrocephalus -Malignant Hypertension -Hypercapnia Rare causes: Hypoparathyroidism, hypocalcaemia, vitamin A toxicity.
What are the causes of optic neuritis?
- MS
- Diabetes
- Syphilis
What are the features of optic neuritis?
- Unilateral visual decrease over hours to days
- Painful on eye movement
- Relative afferent pupillary defect
- Central Scotoma
- Poor discrimination of colours ‘red desaturation’
How do you manage optic neuritis?
High dose steroid. Resolution usually take 4-6 weeks. Also order MRI to see whether there are other white matter lesions and assess risk of multiple sclerosis.
What is blepharitis?
inflammation of the eyelid margins typically leading to a red eye
What is a stye?
infection of the glands of the eyelids
