Ophthalmology Flashcards
What else should you look for in swollen optic discs?
Venous congestion
What else should you do in clinic with a patient who has optic disc swelling?
Blood pressure
What is the natural history of idiopathic intracranial hypertension?
Disc swelling subsides, discs become atrophic and pale
Loss of visual function occurs and blindness may result
Which two muscles control eye opening?
What is the nerve supply to each?
Levator palpebrae superioris - CN III
Muller’s muscle - under sympathetic control
What is Horner’s syndrome?
Why does it cause ptosis and miosis
A combination of symptoms that arises when the sympathetic trunk is damaged
Mullers muscle is supplied by sympathetic nerves - ptosis
Dilator pupillae is supplied by sympathetic nerves - miosis
What lies just posterior to orbicularis oculi?
Orbital septum
What are the two types of conjunctiva?
Palpebral - on inner surface of eyelid
Bulbar - lines the eyeball
How do corneal endothelial cells regenerate?
They don’t - born with them and you can’t grow more
How is near focusing achieved by the ciliary body and zonules?
Ciliary body contracts, pulling the border of the choiroid towards the lens
Zonules (suspensory ligaments) relax
Lens becomes thicker and rounder
How is far focusing achieved by the ciliary body and zonules?
Ciliary body relaxes, border of choroid moves away from the lens
Zonules (suspensory ligaments) contract
Lens becomes thinner and longer
Give two differentials for painful Horner’s syndrome
- Pancoast tumour - compresses sympathetic fibres at the apex of the lung
- Paraganglioma - occurs at carotid
Eye positioned down and out with ptosis = ?
Complete CN III palsy
Posterior communicating artery aneurysm = which nerve palsy?
CN III
What will a lesion in the left trochlear nucleus produce?
Contralateral muscle palsy
What is Hutchison’s sign?
Herpes zoster on the tip of the nose - likely that the ye will be involved through nasociliary nerve
Start on oral acyclovir asap
Which ocular nerve palsy can occur in raised ICP?
CN VI - abducens
Where do the rectus muscles arise from?
Clinical significance?
Common tendinous ring
Attached to the optic nerve sheath - this is why optic neuritis causes pain on eye movement
What does the ophthalmic artery branch off of?
Internal carotid
Where do the ophthalmic veins drain into?
Cavernous sinus
Where do the supraorbital nerve and vessels pass through?
Supraorbital notch
What is central scomata?
Loss of central vision - occurs in macular degeneration
What is rubeosis iridis?
Aka neovascular glaucoma
Retina is so ischaemic that new vessels grow on the iris
Occurs in retinal vein occlusion and severe diabetic retinopathy
You cannot recover from this
Which cells die in retinitis pigmentosa?
Rods
Which two layers of the eye separate in retinal detachment?
Sensory retina
Retinal pigment epithelium
What is the most common type of retinal detachment?
Rhegmatogenous
What happens in Rhegmatogenous retinal detachment?
What causes it?
A tear in the retina causes vitreous to pass into the subretinal space
Typically caused by trauma
What happens in exudative retinal detachment?
Blood or fluid from the choroid separates the two layers of the retina
It does not involve tears in the retina or traction from the vitreous
What happens in tractional retinal detachment?
Most common cause?
Scar/abnormal tissue grows on the surface of the retina, pulling it away from the layer beneath it
Diabetic retinopathy
How does retinal detachment present?
- Flashes
- Floaters
- Field loss
- Fall in acuity
It is painless
May describe curtain falling down over lower half as the retina detaches upward
Treatment for retinal detachment?
If detachment is superior, rest flat etc
Laser photocoagulation therapy
Vitrectomy and gas tamponade
What is the most commonly inherited degenerative condition of the retina?
Retinitis pigmentosa
Symptoms of retinitis pigmentosa?
Night blindness followed by peripheral and central daytime vision loss
List four risk factors for ARMD
Older age
Smoking
CVD
Cataract surgery
Pathophysiology of wet ARMD?
New blood vessels grow under the retina - leakage causes build up of fluid/blood and eventually scarring
Treatment of wet ARMD?
Anti-VEGF injected into vitreous cavity
Pupil involving CNIII palsy is what until proven otherwise?
Circle of Willis aneurysm
If pupil is not involved in CN III palsy, what is the likely cause?
Microvascular - in middle of nerve bundle
What type of trauma causes CN IV palsy?
Blunt head trauma
CN IV has a long path forward and so is sensitive to stretching injury when head is knocked forward
What head movement do you get in bilateral CN IV palsy?
Torsion and chin depression to get single vision
What diagnosis is important to keep in mind in VIth nerve palsy?
If this is the diagnosis, what other symptoms might the patient have?
Raised ICP
Headache, vomiting
Headache, vomiting, convergent squint = ?
Raised ICP
Failure to adduct one eye and abducting nystagmus in the other = ?
Who is this common in ?
Medial longitudinal fasiculus problem
MS patients
Describe the aqueous pathway
Produced in ciliary body
Passes behind iris/in front of lens
Then through pupil
In front of the iris
Out of eye via irido-corneal angle in the anterior chamber
Filters back into blood through the trabecular meshwork and canal of Schlemm
What is the defining feature of glaucoma?
Progressive optic neuropathy
Which vision tends to be spared in open angle glaucoma?
Central vision is spared
Peripheral blindness
Prostanoids in glaucoma
- example
- mode of action
Latanoprost
Increases aqueous outflow
Beta blockers in glaucoma
- example
- mode of action
Timolol
Reduce aqueous production
Carbonic anhydrase inhibitors in glaucoma
- example
- mode of action
Dorzolamide (topical)
Acetazolamide (systemic)
Decreases aqueous production
List three things which predispose to acute closed angle glaucoma
Hyperopic eyes - naturally shallow anterior chambers
Night time - pupil is dilated and so iris is thicker
Medications that cause pupil dilatation e.g. antihistamines
Is the pupil dilated or constricted in acute closed angle glaucoma?
Sluggish and dilated
Name a miotic drug (used in acute closed angle glaucoma)
Pilocarpine
What operation should you do in acute closed angle glaucoma?
High intensity laser to burn hole through iris to create communication between anterior and posterior chambers
What happens when you shine light in an eye with afferent defect?
The pupil won’t respond to light, but constricts when light is shone in the other eye (consensual response)
Egg yolk macula = ?
Best disease
Give a risk factor for spontaneous rhegmatogenous retinal detachment
Short sightedness (myopic)
Long or short sightedness is a risk factor for acute closed angle glaucoma?
Long sightedness
What is ectropion and entropion?
Give a complication of each
Ectropion = out turning of the lower eyelid - can lead to corneal exposure and drying Entropion = in turning of lower eyelid - can lead to corneal abrasion
Tender, red, hot, raised lump just medial to medial canthus = ?
Dacrocystitis
Predominant symptom of herpes simplex keratitis?
Photophobia
Which conditions in the eye can cause local lymphadenopathy?
Adenoviral conjunctivitis or keratitis
Treatment of neonatal conjunctivitis?
Erythromycin + referral to paediatrician for risk of pneumonitis
Photophobia with reduced visual acuity in the absence of itch or discharge = ?
Anterior uveitis
Patient with clubbing + eye disease = ?
Think about malignancy which has metastasized to the choroid
Intermittent double vision worse towards the end of the day associated with a variable bilateral ptosis = ?
Myasthenia gravis
What is investigation of CN VI palsy aimed at?
Identifying CVS risk factors e.g. BP, urinalysis, cholesterol, fasting BG
Which glaucoma patients should you not give beta blockers?
Asthmatic ones
Complete left homonymous hemianopia = ?
Right occipital lobe stroke
What is aniscoria?
Unequal sized pupils
What type of disease is scleritis?
What is a systemic association?
Immune complex deposition
Any type III hypersensitivity vasculitic disease
In myopia, where is a distant image focussed?
Type of corrective lens?
In front of the retina
Divergent lens
More prone to spontaneous retinal detachment
Which type of conjunctivitis can cause pain on eye movement?
Viral
