Ophthalmology Flashcards
What nerve causes a RAPD?
CN2, the optic nerve
What will you see in RAPD?
Affected eye = no direct response to light, consensual response intact.
Swinging light test gives apparent dilation when moving to the pathological eye
What nerve causes an efferent defect?
CN3, occulomotor
What are the types of 3rd nerve palsy?
Surgical = Compresses the outer fibres where the parasympathetic fibres run = dilated pupil
Medical = damages vast forum = pupil sparing
Examples of medical and surgical 3rd nerve palsy?
Medical = MS and diabetes
Surgical = Posterior communicating artery aneurysm
Signs of a 3rd nerve palsy?
Down and out pupil
Affected eye will elicit a consensual response, but will not constrict itself to direct or consensual reflex
What causes Holmes-Adie pupil?
Damage to the post-ganglionic parasympathetic fibres
These fibres allow pupillary constriction and near vision
Clinical features of Holmes-Adie pupil?
Young woman with sudden blurring vision
Dilated pupil with no response to light
Sluggish response to accommodation
What is Holmes-Adie Syndrome?
The pupil + absent knee/ankle reflexes + hypotensive
What causes Argyll-Robertson pupil?
Focal lesion in pretectal nucleus.
Clinical features of AR pupil?
Small irregular pupil
Accommodates but doesn’t react to light.
What are the different causes of Horners Syndrome?
1st order = Central lesion = MS / stroke
2nd order = pre-ganglionic = Pancoasts, apical TB, cervical rib
3rd order = post-ganglionic = Herpes zoster, carotid dissection / aneurysm
What is the cause of INO?
Lesion to the medial longitudinal fasciculus, which runs between the pons and the midbrain
Connects CN3/4/6
Clinical features of INO?
Dissociated eye movements
Impaired adduction ipsilaterally
Nystagmus contra laterally on abduction
Clinical features of CN4 lesion?
Paralysis of superior oblique = when lateral eye is up and out. When medial eye is slightly elevated
Diplopia when looking down and in e.g. going down stairs
May see abnormal head tilt
Causes of CN4 lesion?
Diabetes
Cavernous sinus thrombosis
Clinical features of CN6 lesion?
Usually abducts the eye via lateral rectus
So get esotropia and diplopia
Causes of CN6 lesion?
Long course
Tumours, trauma, CVA e.g. Millard Gubler
Wernickes
mononeuritis multiplex
What is glaucoma?
Group of disorders characterised by optic neuropathy, usually due to raised IOP
RF’s for acute glaucoma?
Hypermetropia (long sighted)
Pupillary dilation
Lens growth associated with increasing age
Clinical features of acute glaucoma?
Severe pain ± headache, N&V
Decreased acuity peripherally
Haloes around lights
Fundoscopy findings in glaucoma?
Dull hazy cornea
Optic disc cupping (cup:disc ratio >0.7)
Optic disc pallor
Bayonetting of vessels
Management of acute glaucoma?
Urgent ophthalmology referral
Pilocarpine drops = miosis to open blockage
Timolol = reduce aqueous formation
Acetazolamide 500mg IV stat = reduce aqueous formation
Follow up = laser peripheral iridotomy = hole in outer edge = fluid bypasses pupil
What is anterior uveitis?
Inflammation of the iris and ciliary body
Clinical features of anterior uveitis?
Pain and photophobia
Reduced acuity
Exam findings of anterior uveitis?
Small fixed pupil, ciliary flush
Hypopynon
White precipitates on back of cornea
Anterior uveitis associated conditions?
Crohns, UC
Ankylosing Spondylitis
Bechets
Management of anterior uveitis?
Referral
Steroid eye drops
Atropine = dilate pupil = relieve pain and photophobia
What is keratitis?
Inflammation of the cornea
Causes of keratitis?
Infective = HSV, S. aureus and pseudomonas in contact lens wearers Environmental = Photokeratitis in welders
Clinical features of keratitis?
Red eye + photophobia
Foreign body / gritty sensation
Hypopynon
Management of keratitis?
Antibiotic eye drops = Gentamicin and cefazolin
Atropine for symptom relief
What is corneal abrasion
Epithelial breech without keratitis
Investigation of abrasion?
Slit lamp with fluroscein stain
Management of abrasion?
Chloramphenicol for prophylaxis
Management of scleritis?
Referral
NSAIDs
Corticosteroids
What is conjunctivitis?
Inflammation of the lining of eyeball and eyelids
Clinical features of bacterial vs Viral vs allergic conjunctivitis ?
Bacterial = purulent discharge, eyes stuck in morning
Viral = Serous discharge, recurrent URTI, LN’s
Allergic = Bilateral, itch, atopy Hx
Management of conjunctivitis
Conservative = No towel sharing, no lenses, can go to school
Medical = Topical chloramphenicol
Topical fusidic acid if pregnant
Allergic = Topical / systemic anti-histamines
Clinical features of optic neuritis?
Only painful cause of sudden visual loss
Red desaturation
Pain worse on eye movement
Central visual loss
Causes of optic neuritis?
MS
Diabetes
Syphilis
Management of optic neuritis?
High dose methylpred. IV then oral.
Clinical features of vitreous haemorrhage?
Management?
Painless sudden visual loss
Floaters and dark spots
Big bleed = No red reflex and cannot visualise retina
Often spontaneous reabsorption
Vitrectomy if dense
Central retinal artery occlusion causes?
Due to thromboembolism from atherosclerosis or temporal arteritis
Clinical features of CRAO?
Management?
Painless sudden visual loss
Afferent pupillary defect
PALE RETINA = cherry red spot
If within 6 hours = reduce IOP:
Surgical removal of aqueous
Local/systemic anti-HTN
Retinal vein occlusion causes?
Atherosclerosis
HTN
DM
Polycythaemia
Clinical features of RVO?
Painless vision loss RAPD Stormy sunset appearance Tortuous dilated vessels Haemorrhage
Retinal detachment types?
Rhematogenous = tear/break in retina lets vitreous fluid leak in = separates
Tractional = tissue grows on retina pulling it away e.g. diabetic proliferative retinopathy
Exudative = fluid under retina but no tear. rare
Clinical features?
Management?
Four F's: Floaters Flashes Field loss = curtains falling Fall in acuity = straight lines appear curved
Urgent surgery = Vitrectomy and laser coagulation to secure the retina
RF’s for age related macular degeneration?
Smoking
Female
FHx
Types of ARMD?
Dry = Drusen around Bruch’s membrane. Slow visual decline over 2 years
Wet = Aberrant vessel growth from choroid into retina = haemorrhage
Visual decline over weeks
Investigations and management for AMRD?
Optical coherence topography (OCT)
If neovascularisation = fluorescein hagiography
Conservative = stop smoking and high dose beta carotene/Vitc/Zinc (unless smoker as cancer risk)
Dry = no management
Wet = Anti VEGF intravitreal
RF’s for COAG?
FHx
Black
HTN, DM
Myopia
If FHx of glaucoma when do you screen from?
Annually at 35
COAG investigations
Tonometry = IOP > 21
Fundoscopy
Management of COAG?
Lifelong follow up
1st line = Latanoprost
2nd line or if IOP still >24 = Timolol
3rd line = Brimonidine / Acetazolamide / Pilocarpine
Still refractory = laser trabeculoplasty
Which COAG drugs reduce aqueous formation and their class?
Timolol = BB Brimodine = alpha agonist Acetazolamide = Carbonic anhydrase inhibitor
Which COAG drugs increase uveoscleral outflow and class?
Latanprost = Prostaglandin analogue Miotics = Pilocarpine
What is the leading cause of blindness <60?
Diabetes
Pathology of diabetic eye?
Blood is hyperviscous = Inner endothelial cels thicken, but outer pericytes atrophy
This atrophy = thin walls and leaky walls = micro-aneurysms and dot haemorrhages
These then cause oedema
Once the oedema clears it leaves fatty deposits = hard exudate.
Classification of pre-proliferative diabetic retinopathy?
mild = >1 microaneurysm
Moderate = Microaneurysm, dot haemorrhages and hard exudate
Severe = Dot haemorrhages and microaneurysm in 4 quadrants
Venous bleeding
Intra-retinal microvascular abnormalities = IRMA
Signs of proliferative diabetic retinopathy?
Neoangiogenesis = Can be disk or outside disc
Vitreous haemorrhage
Retinal detachment
Eye screening for diabetics?
Annually
Photographs
Refer if Maculopathy, PDR, NPDR
Management of diabetic retinopathy?
Good control
Laser photocoagulation:
Maculopathy = focal / grid
Proliferative disease = pan-retinal
Hypertensive retinopathy classification?
Keith-Wagner classification:
1 = Arteriolar narrowing and silver wiring
2= AV nipping
3 = Cotton wool exudates and flame haemorrhages
4 = Papilloedema
What is cataracts?
Opacification of the crystalline lens
Causes of cataracts?
Age
DM
Steroids
Congential e.g. Rubella
4 types of cataracts?
Nuclear = change lens refractive index
Polar = localised, in the visual axis
Subcapsular = due to steroid use, deep in the lens capsule, in visual axis
Dot opacities = common in normal lens, also seen in DM
Clinical features of cataracts?
Increasing short sightedness
Gradual vision loss, not corrected by glasses
Dazzling in light
management of cataracts?
Conservative = sunglasses and regular follow up
Surgical:
Phaecoemulsification ± intra-ocular lens implant
What is phaecoemulsification?
Complications?
Under local
Incision in eye and circular incision in membrane around cataracts
US wave used to break up and suctioned out
New folded intra-ocular lens use to replace
1% of serious e.g. retinal detachment
infection
Lens displacement
Clinical features of retinitis pigmentosa?
Night blindness
Tunnel vision
Blind by mid-30’s
What is retinitis pigmentosa?
Genetic disorder with breakdown of retinal cells
Conditions associated with RP?
Ushers
Friedrichs ataxia = Absent ankle jerk, cerebella ataxia and optic atrophy
Refsums disease = Cerebellar damage due to phytanic acid storage
Keams-Sayre
Clinical features of retinoblastoma and management?
Absent red reflex, strabismus
No vitreous seeding = chemo + laser ablation
Vitreous seeding post chemo = External beam radiation
Vitreous seeding = enucleation and prosthesis
What is blepharitis?
Cause?
Inflammation of eyelid margins
Meibomian gland dysfunction = posterior
Anterior = seborrheic dermatitis
Clinical features of blephairits and management?
Bilateral red eyes
Gritty and itchy
Scales on lashes
Clean crust with warm soaks
types of stye?
Hordeolum external = infection of the glands of Zeis
Hordeolum internal = Infection of Meibomian gland
What is a chalazion?
Retention cyst of Meibomian gland = firm painless lump
Entropion vs Ectropion
Entropion = inversion Ectropion = eversion
Orbital vs peri-orbital cellulitis?
Orbital = infectious process in muscles / fat of orbit = due to bacterial sinusitis
Peri-orbital = Infectious process in eyelid tissue superficial to orbital septum = Superficial injury e.g. bug bite
Clinical features and management of cellulitis?
Child, swelling and exophthalmos
Empirical antibitoics e.g. Cefazolin
What is myopia?
Short sighted = Eye is too long, distant object are focused to far forwards
Concave lens
Hypermetropia?
Long-sighted = eye is too short, cannot accommodate objects close up
Can cause convergent squint in children as contraction of ciliary muscles to focus images
Convex lens
Astigmatism
Cornea or lens doesn’t have same degree of curvature in horizontal and vertical planes
Images distorted vertically / horizontally
Convex lens
What is strabismus?
Misalignment of eyes
Esotropia = Convergent squint
Exotropia = Divergent squint
Non paralytic vs paralytic quint?
Diagnosis?
Corneal reflection test = if not symmetrical = squint
Cover test = Movement of uncovered eye to take up fixation demonstrates quint
If eye goes out = esotropia
If eye moves medially = exotropia
If paralytic = Eye won’t fixate on covering. Cover each eye in turn, which ever eye see the outer image is dysfunctioning
Management of strabismus?
3 O’s
Optical = correct refractive errors Orthoptic = patch over good eye Operations = Resection of rectus muscles
