Opthamology Flashcards
What does Levator palpebrae superioris do?
Elevates the upper eyelid
What nerve innovates Levator Palpebrae Superioris?
the oculomotor nerve (CN III)
The superior tarsal muscle (located within the LPS) is innervated by the sympathetic nervous system.
What is Horner’s syndrome?
Triad of symptoms produced by damage to the sympathetic trunk in the neck:
Partial Ptosis, Miosis and Anhydrosis
Which muscle of eye movement is innervated by CN VI?
Lateral Rectus
Which muscle of eye movement is innervated by CN IV?
Superior oblique
Which nerve innovates the superior oblique muscle of the eye?
CN IV - Trochlear nerve
Which nerve innovates Lateral Rectus of the eye?
CN VI - Abducens nerve
Where do the Recti muscles of the eye originate?
The common tendinous ring
Where does Superior oblique attach?
Originates from the body of the sphenoid bone. Its tendon passes through a trochlear, and then attaches to the sclera of the eye, posterior to the superior rectus
What is the action of Superior Oblique?
Depresses, abducts and medially rotates the eyeball.
Which muscle depresses, abducts and medially rotates the eyeball?
Superior oblique
Where does the inferior oblique attach?
Originates from the anterior aspect of the orbital floor. Attaches to the sclera of the eye, posterior to the lateral rectus
What is the main action of Inferior oblique?
Elevates, abducts and laterally rotates the eyeball
Which muscle elevates, abducts and laterally rotates the eyeball?
Inferior oblique
Which nerve innovates the Inferior Oblique muscle?
Oculomotor nerve (CN III)
Which muscles does CN III (occulomotor) innervate?
Medial Rectus
Superior Rectus
Inferior Rectus
Inferior Oblique
What would a third nerve palsy look like?
The affected eye is displaced laterally by the lateral rectus and inferiorly by the superior oblique. The eye adopts a position known as ‘down and out’.
Which palsy produces the effect of a ‘down and out’ eye?
A third nerve palsy
Which palsy presents with the patient complaining of double vision and tilting of the head to try and rectify this?
Fourth nerve palsy - paralysis of the superior oblique muscle
How does a fourth nerve palsy present and which eye muscle(s) are affected?
A lesion of CN IV will paralyse the superior oblique muscle.
There is no obvious affect of the resting orientation of the eyeball. However, the patient will complain of diplopia (double vision), and may develop a head tilt away from the site of the lesion.
What does a sixth nerve palsy look like and which muscle is affected?
A lesion of CN VI will paralyse the lateral rectus muscle
The affected eye will adducted by the resting tone of the medial rectus.
Which nerve palsy presents with the eye being adducted medially
Sixth nerve palsy (paralysis of Lateral Rectus)
What is the muscle responsible for superior eyelid movement?
Levator palpebrae superioris.
What is Entropion?
When the eyelid (typically the lower lid) turns inward. In turned eyelashes cause irritation to the cornea
What is Ectropium?
When the eyelid turns outwards causing irritation, watering +/- exposure keratitis
What are the commonest causes of optic atrophy?
MS and glaucoma
What is Acute Closed Angle Glaucoma?
Blocked drainage of aqueous from anterior chamber via the canal of Schlemm. Causes the intraocular pressure to rapidly rise. This is an emergency to try and prevent permanent vision loss
How does Acute Closed Angle Glaucoma present?
Acute uniocular attacks sometimes with headache, nausea and a painful red eye.
Often preceded by blurred vision or halos around lights, at night
What are the commonest causes of Red Eye?
Conjunctivitis Corneal abrasions and ulcers Acute Iritis Scleritis Acute Glaucoma Subconjunctival haemorrhage
How does conjunctivitis present?
Gritty irritation/itchiness, watery/purulent discharge, diffuse injection, usually bilateral
What is the most likely diagnosis?
Bilateral, Gritty irritation/itchiness, watery/purulent discharge, diffuse injection
Conjunctivitis
What are the main causes of conjunctivitis?
Viruses - Adenoviruses
Bacteria - more purulent discharge (Chlamydia - must be treated immediately)
Allergic
What is the treatment for conjunctivitis?
Allergic conjunctivitis may respond to antihistamines or self resolve when the allergen is removed
Bacterial conjunctivitis - abx - chloramphenicol
Viral conjunctivitis will disappear on its own
What are the main infective causes of corneal ulceration?
Bacterial: Chlamydia, Pseudomonas
Viral: Herpes Simplex virus (causes a dendritic ulcer), Herpes Zoster virus
Fungal: candida, aspergillus
Protozoan: Acanthamoeba in contact lens wearer
What is ulcerative keratitis?
Ulceration with inflammation of the cornea and must be treated as an emergency to prevent permanent scarring or visual loss
What is anterior uveitis?
Inflammation of the anterior uvea, comprising the coloured iris and ciliary body.
How does anterior uveitis present?
Photophobia, cirumcorneal redness (due to ciliary congestion), acute pain, lacrimation, decreased vision (due to precipitates in the aqueous), small pupil (due to iris spasms and adhesions)
What is the most likely diagnosis?
Photophobia, cirumcorneal redness, acute pain, lacrimation, decreased vision, small pupil
Anterior uveitis?
What systemic diseases is Anterior Uveitis associated with?
Seronegative arthropathies: Ank. spond, IBD, Psoriatic arthritis, Reiter’s syndrome
Infection: TB, Syphillis, HIV, Herpes zoster, Toxoplasmosis, Toxocariasis
Autoimmune: Sarcoidosis, Behcets
Malignancy: Non-Hodgkin’s lymphoma, Leukaemia, Retinoblastoma, Ocular melanoma
What is Talbot’s test?
Ask the patient to watch their finger approach their nose. Pain increases as the eyes converge and pupils constrict if the test is positive.
What is Episcleritis?
Superficial irritation and inflammation of the episclera, a thin layer of tissue covering the sclera of the eye.
Often assymptomatic or with mild pain.
What is the treatment for Episcleritis?
Self-limiting without treatment within 1-2 weeks or topical corticosteroid eye drops may relieve the symptoms faster. Rarely, scleritis may develop.
What is Scleritis?
Inflammation of the sclera causes a severely deep boring pain that wakes the patient at night, lacrimation, photophobia
What is the most likely definition?
Inflammation causing a severely deep boring pain that wakes the patient at night, lacrimation, photophobia
Scleritis
What are the causes of Scleritis?
Idiopathic Collagen vascular disease - RA, Ank. Spond, SLE, Wegener’s, Polyarteritis nodosa) Herpes Zoster Sarcoidosis IBD Gout
How does Episcleritis differ from Scleritis?
Self limited, often local area, typically younger patients. No systemic disease association
Scleritis - more diffuse, more painful, often older patients with systemic disease eg RA, often bilateral
What is the treatment for Scleritis?
Systemic treatment with NSAIDs (or oral Prednisolone if severe) Corticosteroid eye drops/ oral corticosteroids help reduce the inflammation.
Consider investigating for or treating the underlying cause to prevent recurrence.
What is a Subconjunctival haemorrhage?
Diffuse or localised collection of blood under conjunctiva
What is the most likely diagnosis?
Diffuse or localised collection of blood under conjunctiva
Subconjunctival haemorrhage?
What are the common causes of sudden painless loss of vision?
Ischaemic optic neuropathy Occlusion of central retinal vein Occlusion of central retinal artery Vitreous haemorrhage Retinal detachment
What are the main causes of retinal vein occlusion?
Glaucoma
Polycythaemia
HTN
What are the main causes of retinal artery occlusion?
Thromboembolism (from atherosclerosis)
Arteritis
What are the main characteristic features of acute angle glaucoma?
Severe pain (ocular or headache)
Decreased visual acuity, patient sees halos
Semi-dilated pupil
Hazy cornea
What is the likely diagnosis? Severe pain (ocular or headache),Decreased visual acuity, patient sees halos, semi-dilated pupil, Hazy cornea
Acute angle closure glaucoma
What are the main characteristics of anterior uveitis?
Acute onset
Pain
Blurred vision and photophobia
Small, fixed oval pupil, ciliary flush
What is the most likely diagnosis?
Acute onset, Pain, Blurred vision and photophobia, Small, fixed oval pupil, ciliary flush
Anterior uveitis
What is Herpes Zoster Ophthalmicus? (HZO)
Reactivation of the varicella zoster virus in the area supplied by the ophthalmic division of the trigeminal nerve
What is the management for HZO?
Oral antiviral treatment for 7-10 days, ideally within 72 hours.
Ocular involvement requires urgent ophthalmology review
What are drusen?
Yellow round spots in Bruch’s membrane which characterise Dry macular degeneration
What are the main features of age-related macular degeneration?
Reduced visual acuity - blurred, distorted vision, central vision is affected first
Central scotomas
Fundoscopy - drusen, pigmentary changes
What is an Hyphaema?
Blood in the anterior chamber of the eye.
Appears as blood in a small pool at the bottom of the iris
What is the main potential serious complication of a Hyphaema?
Secondary Glaucoma
