opthamology Flashcards
How do you differentiate posterior vitreous detachment, retinal detachement and vitreous haemorrhage?
Posterior vitreous detachment:
Flashes of light/ floaters in peripheral vision.
Fundoscopy- Weiss ring
visualacuity normal
No emergency mx - will settle by self
Retinal detachment:
Same sx as vitreous detachment (flashers and floaters)
A veil over the field of vision
Straight lines appear curved.
Shadow in peripheray, progressing towards middle (as retina peels off orbit)
Central visual loss.
Fundoscopy - retinal tear, ‘tobacco dust’ in anterior chamber
Vitreous haemorrhage:
Large bleeds cause sudden visual loss.
Moderate bleeds may be described as numerous dark spots.
Small bleeds may cause floaters.
Occurs when blood leaks into the vitreous humour from damaged blood vessels in conditions such as diabetic retinopathy or retinal tears or from anti-cogulants/ bleeding disorders.
How do you differentiate central retinal vein occlusion from central retinal arterial occlusion?
Both cause painless visual loss
Retinal vein: more common, with age, can be caused by glaucoma, hypertension, polycythaemia.
Starts subtle then progresses to full loss
optic disc swelling, and multiple flame-shaped and blot haemorrhages may be seen.
occurs when there is a blockage in the central retinal vein, leading to impaired venous drainage from the retina. This results in increased pressure within the blood vessels, causing them to leak blood and fluid into the surrounding tissues.
Retinal arterial: SUDDEN blindness. Cherry spot on pale retina on fundoscopy, afferent pupillary defect,
When blood vessel is affected in ischaemic optic neuropathy?
due to occlusion of the short posterior ciliary arteries, causing damage to the optic nerve
Anterior uveitis vs acute closed angle glacuoma signs and sx?
Acute closed-angle glaucoma:
sudden unilateral eye pain and visual loss.
Haloes around lights.
Poor vision in dark.
headache.
erythematous globe with a fixed and DILATED pupil with a hazy cornea.
Can be brought on my mydriatic activity eg drops/ watching TV
Anterior uveitis (AKA iritis):
painful red eye with photophobia.
hypopyon
ciliary flush
Vairable visual loss.
CONSTRICTED pupil.
HLA-B27/ autoimmune association
What is keratitis?
microbial invasion of the cornea causing eye redness, gritty foreign sensation type pain, photophobia, increased lacrimation, corenal haziness and eyelid oedema.
can get hypopyon if severe
RF: trauma and contact lens
Emergency - topical antibiotic eye drop/ PO abx if bad
What is retinitis pigmentosa? What do u see on fundoscopy?
inherited retinal disorders
Cause progressive degeneration of the retina, leading to night blindness and peripheral vision loss (tunnel vision)
fundoscopy shows black bone spicule-shaped pigmentation in the peripheral retina and mottling of the retinal pigment epithelium
What does fundoscopy for diabetic retinopathy show?
Usually slow onset visual loss.
Fundoscopy shows microaneurysms, dot and blot haemorrhages, hard exudates, and cotton wool spots (retinal arterial obstrution causing ischaemia)
What is Argyll-Robertson pupil
small, irregular pupils
no response to light but there is a response to accommodate
Associated with neurosyphilis but most common cause in UK is DM
What is a stye vs chalazion vs blepharitis?
stye (hordeolum externum): infection of the glands of the eyelids. PAINFUL
A chalazion (Meibomian cyst) is a retention cyst of the Meibomian gland. PAINL\ESS lump normally the internal eyelid.
blepharitis: inflammation of the eyelid margins typically leading to a red eye
How do you manage a stye?
management includes hot compresses and analgesia. CKS only recommend topical antibiotics if there is an associated conjunctivitis
What is a holmes- adie pupil?
Tonically dilated pupil, slowly reactive to light with more definite accommodation response. Caused by damage to parasympathetic innervation of the eye due to viral or bacterial infection. Commonly seen in females, accompanied by absent knee or ankle jerks.
80& time is unilateral
What is a marcus-gunn pupil?
AKA Relative afferent pupillary defect, seen during the swinging light examination of pupil response. The pupils constrict less and therefore appear to dilate when a light is swung from unaffected to affected eye. Most commonly caused by damage to the optic nerve or severe retinal disease.
What is horners syndrome?
Miosis (pupillary constriction), ptosis (droopy eyelid), apparent enophthalmos (inset eyeball), with or without anhidrosis (decreased sweating) occurring on one side. Caused by damage to the sympathetic trunk on the same side as the symptoms, due to trauma, compression, infection, ischaemia or many others.
What is hutchinsons sign?
Unilaterally dilated pupil which is unresponsive to light. A result of compression of the occulomotor nerve of the same side, by an intracranial mass (e.g. tumour, haematoma)
What is open-angle glaucoma ? How does it present? RF? findings on exam?
Glaucoma = raised intraocular pressure
Open angle = peripheral iris is NOT covering trabecular meshwork –> aqueous humor can drain
RF: age, fhx, myopia, HTN, DM, steroids
Presentation: insidious, peripoheral visual field loss (nasal scotoma), decreased acuity
Fundoscopy:
1. Optic disc cupping - cup-to-disc ratio >0.7 (normal = 0.4-0.7), occurs as loss of disc substance makes optic cup widen and deepen
2. Optic disc pallor - indicating optic atrophy
3. Bayonetting of vessels - vessels have breaks as they disappear into the deep cup and re-appear at the base
4. Additional features - Cup notching (usually inferior where vessels enter disc), Disc haemorrhages
