Revision Flashcards
(70 cards)
Anterior segment of the eye is in front of the lens
It is divided into the anterior and posterior chamber.
Anterior to iris = anterior chamber
Posterior to iris = posterior chamber
Both contain aqueous humour which is produced by the ciliary body
Posterior segment of the eye is posterior to lens and contains vitreous
Remember conjunctivitis can cause a red eye but it is not usually painful. What is the differential?
Eyes are red and watery but vision is OK
Viral - adeno, herpes (follicles) Bacterial - staph/ strep Trauma - dry eyes Allergy - seasonal Toxins - chlorine etc
How would you expect a corneal ulcer to present?
Acute, painful red eye
Reduced visual acuity and photophobia
Foreign body sensation
Visible opacity/ hypopyon
Always ask about cold sores and contact lenses
Remember to always stain with fluorescein and never give a steroid without aciclovir and recommendation from ophthalmologist
95% of cases of iritis are idiopathic. What are the other 5% linked to?
System disease such as HLAB27 e.g. Ank Spon
Consider further investigation if iritis is severe, bilateral or recurrent
Features of iritis?
Painful red eye
Redness is often around iris most
Synechia (iris stick to the cornea or lens and therefore is distorted)
Reduced visual acuity and photophobia
How do you treat iritis?
Topical steroid
Dilate pupils to stop iris and lens sticking and reduce pain e.g. cyclopentolate or atropine
How do you differentiate between scleritis and episcleritis
Episcleritis:
- usually localised
- mild pain
- can be associated with IBD flare but usually idiopathic
- usually self limiting but lubricants/ topical steroids may be useful
Scleritis:
- serious condition with risk of necrosis and perforation
- widespread redness, possible blue/ violet hue
- intensely painful, often boring pain
-usually associated with rheumatological/ vascular condition
—> do screen = FBC, CRP, ANCA, Rh
- requires topical steroids + systemic NSAID + systemic steroid
Having a shallow anterior chamber —> be long sighted (a hypermetrope) is a RF for AACG. What are the key features?
Painful red eye
Haloes
Mid-dilated pupil
Headache, vomiting —> very unwell
Increased IOP and gonioscopy shows occluded iridocorneal angle
Treatment aims are to lower IOP with topical and systemic treatments
Management of AACG
- refer to ophthalmology as an emergency
- analgesia + anti-emetic
- pilocarpine drops to constrict the pupil
- acetazolamide to reduce production of aqueous humou
- laser iridotomy (both eyes)
What is the mechanism of acetazolamide?
It is a carbonic anhydrase inhibitor - it causes excretion of bicarbonate ions and water —> lowers BP
CI =low Na, low K, hyperchloraemic acidosis etc
What is the cardinal feature of ARMD?
Gradual blurring of central vision
Distortion of straight lines (metamorphosia)
Sudden loss of vision due to haemorrhage
Treatment is with anti-VEGF —> prevents new vessel formation
What are the features of background diabetic retinopathy?
HOME
H - haemorrhage (dot, blot, and flame)
O - oedema (transudate)
M - micoraneurysms
E - exudate (yellow deposits)
What are the features of pre-proliferative diabetic retinopathy?
HOME features maybe be present (haemorrhage, oedema, microaneuysms and exudate)
But CV definitely will be - cotton wool spots and vein abnormalities e.g. looping, beading and engorgement are characteristic
Remember that cotton wool spots are local infarcts
What are the features of proliferative diabetic retinopathy?
HOME CV features will usually be present (haemorrhage, oedema, microaneurysms, exudate, cotton wool spots and vein abnormalities)
BUT new vessel growth on retina, optic disc or iris is characteristic
What is the treatment of diabetic retinopathy?
1) Optimise glycaemic control
2) regular monitoring - yearly
3) laser photocoagulation
What are the 4 grades of diabetic hypertension?
1 - narrowing of arterioles (silver wiring)
2 = AV nipping
3 = flame shaped haemorrhage
4 = papilloedema
Increasing age, DM and steroid therapy are RF for cataract. How does it present?
Blurred vision with haloes and glare
Loss of red0refles
The superior oblique does depression, adduction and intortion)
DADI (superior oblique = Depression, ADduction and Intortion_
Inferior oblique does elevation, adduction and extortion
Eye is ‘down and out’
Third nerve palsy
Will also be ptosis as levator palpabrae superioris is also innervated by 3rd nerve
RF = CV risk factors e.g. HT, DM etc and increased ICP
How does a 4th nerve palsy present?
The eye cannot look down and in
In the primary position, the affected eye is elevated to lack of function of superior oblique
Dx = head trauma, congenital IV palsy, CV risk factors
How does a 6th nerve palsy present?
Eye deviate medially
Cannot abduct
RF = CV, increased ICP
What are the 3 features which should be examined on the optic disc?
Cup - should be a paler disc within the optic disc, about 1/3 of the total disc size. Enlarge cup may suggest glaucoma
Colour - the optic disc should be orange-pink in colour. Pale discus suggest optic atrophy e.g. neuritis, ischaemia, advanced glaucoma, compression etc
Contour - should be clear and well defined —> if not it is papilloedema
Causes of papilloedema
Local:
- optic neuritis/ vasculitis
- disc infarct
Systemic:
- increased ICP (SOL)
- severe HT
Remember optic disc atrophy presents with a pale disc due to loss of fires within the optic nerve
Optic neuritis is inflammation of nerves within eye and presents with reduced vision and loss of colour vision —> most common in MS
