ophthalmology Flashcards
(162 cards)
1
Q
What is anisocoria?
A
- unequal pupils
- physiological in 20% of patients
- sympathetic lesions tend to cause small pupil - often associated with Horner’s syndrome
- parasympathetic causes inc CNIII palsy, drugs, trauma
2
Q
What is the cause of ptosis in Horner’s syndrome?
A
- muller muscle is innervated by sympathetic nerves
3
Q
What does an Ishihara chart examine for?
A
colour vision
4
Q
Which is the main chromosome involved in colour blindness?
A
X chromosome
–> boys are more susceptible
5
Q
Which genetic conditions are more likely to inherit colour blindness?
A
- turner’s - 45XO
2. Kleinfelter’s - 47XXY
6
Q
What are the 5 main presenting complaints in ophthalmology?
A
- benign lid lesion
- cyst (sebacious/cyst of moll) and sty - malignant lid lesion
- BCC, SCC, malignant melanoma, sebacious gland carcinoma - lid malposition
- ectropion, entropion, dermatocalasis - watery eye
- dry eye, irritation, increased laxity - orbital disease
- tumours, compression with loss of vision
7
Q
List the main benign lid lesions.
A
- cyst
- sty
- sebacious cyst
- cyst of moll
8
Q
What is the management of styes?
A
warm compress for 5-10mins several times a day
9
Q
What are the 2 main types of sty?
A
- hordeolum externum (point outwards)
- abcess/infection of lash follicle - hordeolum internum (point inwards)
- abcess of Meibomiam glands
10
Q
What is blepharitis and what is it commonly caused by?
A
- inflammation of the eyelid
- staph, seborrhoeic dermatitis, rosacea
11
Q
What is the management of an entropion?
A
- almost always lower lid affected
- tape lower eyelid to cheek
- botulinum toxin injection
- surgery - only long term fix
12
Q
What is the cause of a true ptosis?
A
intrinsic levator weakness
13
Q
What is dermatochalasis?
A
excess lid tissue
14
Q
What are the causes of ptosis?
A
- congenital
- absent nerve to levator - mechanical
- oedema, xanthelasma, upper lid lesion - myogenic
- muscular dystrophy, myasthenia - CNS
- 3rd nerve palsy, Horner’s syndrome
15
Q
What is lagophthalmos?
A
difficulty in lid closure
–> temp Mx with liquid paraffin ointment
16
Q
Which muscle in the face closes the eye lid?
A
orbicularis oculi muscle
17
Q
What is blepharospasm?
A
the involuntary contraction of orbicularis oculi muscle
18
Q
What is Schirmer’s test?
A
- investigation of dry eyes
- put filter paper on lower lid
- normal tears soak >15mm in 5 minutes
19
Q
What are the main causes of watery eye?
A
- decreased drainage
- increased lacrimation
- pump failure
20
Q
What is the most common intraocular tumour in children?
A
retinoblastoma
21
Q
What are the 2 main signs of retinoblastoma?
A
- strabismus
- leukocoria (white pupil)
–> ALWAYS suspect with an absent red light reflex
22
Q
What is the hereditary cause of retinoblastoma?
A
mutations in the RB gene (normally a suppressor/ anti-onco gene) on chromosome 13, which is autosomal dominant
23
Q
What are the treatment options for retinoblastoma?
A
- chemo
- carboplatin + etoposide + vincristine - enucleation
- removal of eye ball - external beam radiotherapy
(SE: facial hypoplasia due to cessation of bone growth with radiotherapy) - ophthalmic plaque brachytherapy
- cryo + transpupillary thermotherapy
24
Q
What is strabismus?
A
misalignment of the visual axes gives you a squint
25
What is a pseudosquint?
when wide epicanthic folds give the appearance of a squint
26
What are the 2 main types of strabismus?
1. concomitant
- non-parolytic
- usually convergent
- usually refractory error in one/both eyes
2. non-concomitant
- paralytic
- rare
- usually due to CN palsy
- exclude intracranial lesion
NB. either can be convergent (esotropia) or divergent (exotropia)
27
What is amblyopia ?
permanent loss of visual acuity in an eye that has not received clear images in the sensitive period of visual development (<7y/o)
28
What 2 tests aid diagnosis of strabismus?
1. corneal light reflex test
- reflection from bright light should fall centrally and symmetrically if no squint
- if squint; light will fall asymmetrically
2. cover test
- cover good eye
- get movement of uncovered eye to take up fixation
29
What is the management of squints?
3 Os:
1. Optical
- spectacles to correct refractive errors if present
2. Orthoptic
- patching good eye encourages 'bad' eye
3. Operation
- resection and recession of rectus muscle
30
Which branch of the autonomic NS is responsible for pupil dilatation?
- sympathetic nervous system
| - it causes pupil dilatation via the ciliary nerves
31
What is the triad for 3rd nerve palsy (efferent defect)?
1. complete ptosis
2. fixed dilated pupil
3. eye looks down and out
- -> this is because the superior oblique (CNIV) and lateral rectus (CNVI) are still intact
32
What nerves are involved in the afferent and efferent pupillary pathways?
1. afferent - retina + optic nerve
| 2. efferent - cranial nerve III
33
List some causes of a 3rd nerve palsy.
1. cavernous sinus lesion
2. superior orbital fissure syndrome
3. posterior communicating artery aneurysm
4. diabetes
34
What are the 2 major causes of a fixed dilated pupil you want to rule out?
1. acute glaucoma
| 2. coning - uncal herniation
35
what is Holmes-Adie syndrome?
1. tonic pupil (poor constriction to light due to a lack of parasympathetic innervation)
2. absent knee/ankle jerks
3. impaired sweating
36
What 2 conditions to you get Argyll Robertson pupil?
1. neurosyphilis
| 2. diabetes
37
What is the rapid afferent pupillary defect RAPD)?
- looks for asymmetry in afferent pathways
- the swinging light test is used to detect differences between the 2 eyes in how they respond to light being shone in 1 eye at a time
- a positive RAPD means there are differences between the 2 eyes in the afferent pathway due to retinal/optic nerve disease
- shine light in good eye both will constrict (direct and consensual reaction) - shine light in bad eye and it dilates
38
What is the consensual light reflex?
- a bright light shone in 1 eye leads to the equal constriction of both pupils
- when the light source is taken away the pupils of both eyes enlarge equally
39
What is your main differential diagnosis in a young woman presenting with a painful 3rd nerve palsy?
aneurysm of the posterior communicating artery
40
What is the triad in Horner's syndrome?
1. ptosis
2. miosis
3. anhydrosis
41
What are the causes of a red eye?
1. conjunctivitis (and subconjunctival haemorrhages)
2. episcleritis
3. scleritis
4. anterior uveitis
5. acute angle-closure glaucoma
6. trauma
7. herpes simplex keratitis
42
What do contact lenses increase the risk of?
1. bacterial infections
| 2. corneal ulcers
43
Which causes of red eye require urgent referral to ophthalmology?
1. acute glaucoma
2. acute iritis (anterior uveitis)
3. scleritis
4. corneal ulcers
44
What is a scotoma?
a defect causing a part of the field of view to go missing
45
What will complete lesion of the left optic nerve lead to?
complete blindness in the left eye
46
What results from a lesion in the optic chiasm?
bitemporal hemianopia
47
What do you get with lesions in the optic tract?
- contralateral homonymous hemianopia
| e. g. if you have a right-sided optic tract lesion you would get a left temporal hemianopia and a right nasal hemianopia
48
Which eye condition are Amsler grids particularly useful?
- macular degeneration
| - the grid detects distortion in central vision
49
What visual field defect can a temporal tumour cause?
contralateral upper homonymous quadrantanopia
50
How does a patient with ophthalmic shingles present?
- pain and neuralgia in the distribution of the 1st branch of the trigeminal nerve (CNV, V1 = ophthalmic branch)
- this precedes a blistering and inflammed rash
51
What is the most common complication of ophthalmic shingles?
post-herpetic neuralgia
52
What condition should be assumed in a patient with a red eye who is a contact lens wearer until proven otherwise?
microbial keratitis
53
What is keratitis?
- corneal inflammation
- identified by white area on cornea
- indicates collection of white cells in corneal tissue
54
What is a corneal abrasion?
- epithelial breach
- pain, photophobia +/- decreased visual acuity
- non-infective from accidental scratches
- diagnosis aided with fluorescein drops and blue light on slit lamp
55
What are corneal ulcers?
- ulcerative keratitis
| - causes: bacterial, fungal, herpetic, protozoal, vasculitis
56
How do you manage corneal ulcers?
- until cultures are known give chloramphenicol drops (for gram +ve) and ofloxacin drops (for gram -ve)
57
Which eye conditions is acetazolamide used to treat?
1. benign idiopathic intracranial HTN
| 2. acute angle-closure glaucoma
58
What are the 2 main types of glaucoma?
1. acute angle-open glaucoma
| 2. acute angle-closure glaucoma
59
Where is aqueous humour produced and circulated around eye?
- produced by the ciliary body
- flows through the pupil
- empties out at the drainage angle through the canal of Schlemm
60
What time of day does acute closed-angle glaucoma occur?
- at night time
- this is when the pupil will be maximally dilated
- making angle more susceptible to closure
61
Which patients are more prone to acute angle-closure glaucoma and why?
- long-sighted patients
- they have hypermetropic eyes
- therefore a short axial length
- also: middle aged-elderly
62
What is the most common cause of glaucoma?
primary open angle glaucoma
63
What is the pathophysiology of open angle glaucoma?
sclerosis of the trabecular meshwork with age
64
What are the avascular structures of the eye?
1. iris
2. pupil
3. anterior chamber
4. lens
5. vitrious humour
65
What are the classical features of acute angle-closure glaucoma?
- raised intraocular pressure (>30mmHg)
- red, painful eye
- fixed mid-dilated pupil
- blurred vision with haloes around lights
66
What is the management of acute angle-closure glaucoma?
1. medical triad:
- timolol 0.5% = beta blocker to suppress aqueous humour production
- pilocarpine 2-4%/2hr = causes miosis which opens up a blocked/'closed' drainage angle
- 500mg IV acetazolamide stat
2. laser/surgery
- peripherial iridectomy
- remove piece of iris at '12o'clock' in both eyes to allow aqueous humour to flow
67
What are the risk factors for open angle glaucoma?
- FH (biggest risk)
- hypermetropia
- older age
- black race
68
What is the cause of a refractive error?
due to disorders of the size and shape of the eye
69
What are the 4 main refractive errors?
1. myopia (short sight)
2. hypermetropia (long sight)
3. astigmatism (irregular shaped cornea)
4. presbyopia (ciliary muscles reduce tension in the lens - seen with age)
70
What are myopes more at risk of?
1. posterior vitreous detachment
2. retinal detachment
--> due to the short longitudinal axes
71
Which conditions causing red eye require immediate referral?
1. uveitis (most commonly anterior)
2. acute angle-closure glaucoma
3. scleritis
4. corneal ulcers
72
What makes up the uvea?
1. iris (anterior)
2. ciliary body (intermediate)
3. choroid (posterior)
73
What are the vascular structure of the eye?
UVEA:
1. iris
2. ciliary body
3. choroid
74
What is anterior uveitis?
inflammation of the iris
75
what is posterior uveitis?
inflammation of the choroid
76
What is the commonest form of uveitis in the UK?
anterior uveitis
77
What are the clinical features of anterior uveitis?
- pain
- cirumcorneal infection
- photophobia
- blurred vision
- increased (non-sticky) lacrimation
78
What do you see on slit lamp examination in anterior uveitis?
leucocytes in anterior chamber
79
How do you treat anterior uveitis?
1. prednisolone eye drops
- decrease inflammation
2. cyclopentolate
- keeps pupil dilated
- therefore relieves spasm of ciliary body
80
What is scleritis?
inflammation of the white of the eye
| can be sight threatening
81
What are the complications of severe/long-standing scleritis?
- thinning of sclera
- choroid may be revealed below - blue tinge
- thinning can lead to globe perforation
- oedema of the conjunctiva
82
What is the management of scleritis?
1. non-necrotizing anterior scleritis:
- NSAIDs +/- high dose prednisolone
2. necrotizing changes/ posterior scleritis:
- DMARDs + IV methyl prednisolone
83
What is iris bombey?
- this is when the swelling of the iris narrows the angle of the anterior chamber affecting the trabecular meshwork and thus drainage of aqueous humour
- this causes increased intraocular pressure
84
What type of scleritis commonly leads to visual loss?
necrotizing scleritis
85
What are the 2 broad categories of sclera inflammation?
1. episcleritis
| 2. scleritis
86
How do you differentiate scleritis from episcleritis?
EPISCLERITIS:
- globe not overly painful
- inflamed vessels are superficial and can be moved with cotton wool bud
- vessels can be blanched with 10% phenylephrine
SCLERITIS:
- globe v painful - ocular movements painful too
- inflamed vessels are deeper and cannot be moved with cotton wool bud
- vessels will not blanch with phenylephrine
87
How do you manage episcleritis?
symptomatic relief with artifical tears and NSAIDs
88
What is the cause of keratic preciantils ?
iris bombey (inflammation of the iris blocks the trabecular meshwork) + flare (cells floating in anterior chamber begin to stick to the wall)
--> raised intraocular pressure
89
What is a hypopyon?
pus in the anterior chamber
90
What is a serious complication of peri-orbital cellulitis?
meningitis
91
What would be your main differential diagnosis in a young adults with prolonged conjunctivitis?
chlamydia
92
How does herpes simplex keratitis present?
pain and photophobia
93
What is the management of conjunctivitis?
1. usually symptomatic with artificial tears and topical anti-histamines
2. give fusidic acid drops to immunocompromised pts, contact lens wearers and if sexual disease suspected
94
What should you check for if a patient gets recurrent subconjunctival haemorrhages?
- HTN
| - bleeding disorders
95
What is orbital cellulitis?
- infection of the soft tissue posterior to the orbital septum
- spread typically via paranasal sinus infection
96
What are the complications of orbital cellulitis?
1. subperiosteal and orbital abcess
2. visual loss
3. meningitis
4. brain abcess
5. intracranial thrombosis
97
what is periorbital cellulitis?
- infection of the soft tissue anterior to the orbital septum
- commonly caused by sinusitis or facial skin lesions
98
How can you distinguish periorbital vs orbital cellulitis?
- in orbital you get painful eye movements, diplopia and visual impairment
- these are absent in periorbital
99
What is the leading cause of blindness in those aged 20-65y/o in the UK?
diabetes mellitus
100
What are the 2 subtypes of diabetic retinopathy?
1. non-proliferative
| 2. proliferative (distinguished by neovascularisation on the retina)
101
How often should diabetic patients be screened for retinopathy?
annually
102
What factors can accelerate diabetic retinopathy?
1. pregnancy
2. HTN
3. smoking
4. anaemia
5. dyslipidaemia
6. renal disease
103
How do you manage active bleeding in diabetic retinopathy?
laser eye treatment
104
What further eye complications are diabetics at risk of (other than retinopathy!)?
1. cataracts
2. weakened dilating muscles in iris
3. acute angle-closure glaucoma
105
What are the signs of non-proliferative diabetic retinopathy?
1. microaneurysms ('dots')
2. blot haemorrhages
3. cotton wool spots
4. lipid exudates (yellow patches)
5. engorged tortuous veins
106
What are the signs of proliferative diabetic retinopathy?
- new vessel formation at disc or elsewhere
| - vitrious and pre-retinal haemorrhage
107
What is diabetic maculopathy?
- leakage of vessels close to macula causes oedema
| - can significantly threaten vision
108
What are the complications of neovascularization in proliferative DR?
- neovascular glaucoma
- vitreous haemorrhage
- retinal detachment
109
What is the treatment of giant cell arteritis?
prednisolone 60mg/24hr PO (may take >1yr to treat)
110
What is dyschromatopsia?
colour vision affected
111
What are the clinical features of optic neuritis?
- unliateral loss of visual acuity (hrs-days)
- dyschromatopsia --> red desaturation
- eye movements hurt
112
List some common causes of transient visual loss?
1. vascular; TIA; migraine
2. multiple sclerosis
3. subacute glaucoma
4. papilloedema
113
Which is more common; retinal vein occlusion or retinal artery occlusion?
retinal vein occlusion
114
What are the signs of a central retinal artery occlusion?
1. cherry red spot at the macula
| 2. retina appears white
115
What is the classical fundoscopy finding in central retinal vein occlusion?
stormy sunset appearance due to hyperaemia and haemorrhages
116
What is an optic nerve drusen?
calcium deposits at optic nerve head
117
Define glaucoma.
optic neuropathy with death of many retinal ganglion cells and their optic nervre axons
118
What is endophthalmitis?
intraocular inflammation usually caused by infection affecting the aqueous or vitreous humour
119
What is retinitis pigmentosa?
- complex inherited disorder of the retinal photoreceptors and pigment epithelium
- loss of night vision and peripheral vision most common PC
- affects men > women due to frequent X-linked varieties
- treat with high conc of vit A and acetazolamide
120
What is the most commonly described phenomenon with retinal detachment?
sensation of flashing lights and floaters associated with patches of lost vision
121
How do you treat retinal detachment in a patient with proliferative diabetic retinopathy?
laser photocoagulation of peripheral parts of the retina
122
List some causes of gradual loss of vision.
1. cataract
2. macular degeneration
3. glaucoma
4. diabetic retinopathy
5. HTN
6. optic atrophy
7. slow retinal detachment
123
What is the pathogenesis of macular degeneration?
- affects 3 main structures; Bruch's membrane, retinal pigment epithelium, choriocapillaris
- pigment, drusen and sometime bleeding at the macula
- progresses to retinal atrophy and central retinal degeneration
- causing loss of central vision
124
What is the most common cause of irreversible blindness in the developed world?
age-related macular degeneration
125
List the risk factors for developing age-related macular degeneration.
1. increasing age
2. smoking
3. CVD
4. FH
5 cataract surgery
126
What is macular degeneration?
a progressive degenerative condition affecting central vision
127
What are the 2 main types of age related macular degeneration?
1. wet (exudative)
- 10%
- choroidal neovascularization which leak fluid/blood into macula
2. dry (non-exudative)
- 90%
- pigmentary changes of the retinal pigment epithelium and drusen
128
What are the symptoms of ARMD?
- difficulty with reading and making out faces
- difficulty with night vision and changing lights conditions
- visual fluctuation
- metamorphosia (common in wet ARMD) = straight lines look wavy and distorted (good screening test for monitoring wet ARMD)
129
How is ARMD managed?
- no known treatment for dry ARMD; they would be recommended to stop smoking, take vitamin supplements (vit A, vit E, zinc and lutein) and use of visual aids
- wet ARMD treated with RANIBIZUMAB = anti-VEGF
130
What are the 3 most important investigations in glaucoma?
1. intraocular pressure
2. visual fields (Humphrey perimetry)
3. optic disc
131
What is a cataract?
- any opacity in the lens
- can be diffuse/focal
- can be yellow/brown/white
132
List the risk factors for cataracts.
1. age-related
2. congenital
3. diabetes mellitus
4. smoking
5. alcohol excess
6. sunlight exposure (senile cataract related to UV-B)
7. trauma
8. radiotherapy
9. HIV +ve
133
Describe the cataract formation seen in Wilson's disease.
'sunflower cataract' which is green-brown colour due to copper deposition
134
What are the complications of cataracts?
- hypermature cataracts leak protein into the anterior chamber causing UVEITIS or PHACOLYTIC GLAUCOMA
135
What is index myopathy?
a myopic shift in patient's spectacle prescription due to cataract formation
136
What are the ophthalmoscopic classifications of cataracts?
1. nuclear cataracts
- common in old age
- affects distance vision to a greater extent
2. cortical cataracts
- spoke-like wedge shaped opacities
- deterioration of younger lens fibres
3. posterior subcapsular cataracts
- progress faster
- affects near vision more
- cause the classic glare from lights whilst driving at night
137
What is the treatment of cataracts?
- phacoemulsion + intraocular lens implant
| - antibiotics and anti-inflammatory drops for 3-6 weeks post-op
138
What is the PC of hypertensive retinopathy?
nothing! usually asymptomatic
139
What is the grading system for hypertensive retinopaty?
grade I: mild generalised arteriolar constriction and narrowing
grade II: more severe narrowing with AV nipping and silver wiring of retinal arteriols
grade III: I + II plus retinal haemorrhages, exudates, microaneurysms and cottong wool spots
grade IV: all features above with optic disc swelling +/_- macular oedema
140
What are the differential diagnoses of hypertensive retinopathy ?
- diabetic retinopathy
- retinal vein occlusion
- retinopathy of anaemia
- retinopathy associated with haem malignancies
141
List the causes of optic disc swelling.
1. papilloedema
2. malignant HTN (check BP!)
3. cavernous sinus thrombosis
4. optic neuritis (often unilateral)
5. cranial SOL
6. uveitis
142
What 3 things should you look for when examining the optic disc?
3 Cs:
- Colour; should be pinky-yellow with pale centre
- Contour; borders should be well defined
- Cup; the disc has a physiological cup which lies centrally and should occupy 1/3 of disc diameter
143
What is papilloedema?
- swelling of the optic disc caused by a raised intracranial pressure
- it is always bilateral
- not always symmetrical
- must rule out SOL with gadolinium contrast MRI
144
What is the PC of papilloedema secondary to raised ICP?
- N&V
- headache; worse in the morning and on bending
- transient visual obscurations in later stages
145
What is your main differential for young obese women with papilloedema?
idiopathic intra-cranial HTN (treat with acetazolamide)
146
What are Paton's lines?
these are retinal folds seen in optic disc swelling
147
What is papillitis?
optic disc swelling w/o raised ICP
148
What is pseudopapilloedema and what can cause it?
- may mimic papilloedema
- the disc margins are blurred and the disc appears elevated
- cause = optic disc drusen
149
What is the staging system used in papilloedema?
Frisen system which grades severity (not chronicity) from 0-5
150
What is retinal detachment?
the seperation of the neurosensory retina from the underlying retinal pigment epithelium (RPE)
151
List the 3 types of retinal detachment.
1. rhegmatogenous detachment
- full-thickness break in retina
- vitreous humourseeps between the 2 layers
- causes e.g. trauma, high myopia
2. exudative detachment
- retina detaches without tear
- causes e.g. HTN, vasculitis
3. tractional retinal detachment
- no break in retina
- tenting of retina due to contraction of overlying fibrovascular tissue
- cause e.g. proliferative diabetic retinopathy
152
How do retinal detachments present?
4 Fs:
- floaters
- flashing lights (photopsia)
- field loss
- fall in acuity
PAINLESS
153
Describe the examination finding; 'tobacco dust'.
- This is seen in retinal detachment and it is pigment in the vitreous
- this is known as Shafer's sign
154
What is the consequence of a large retinal detachment involving the macula?
rapid afferent pupillary defect
155
How do you confirm a diagnosis of cytomegalovirus retinitis?
CMV PCR from a vitreous biopsy
156
What group of patients is CMV retinitis common?
- immunocompromised
| - suspect in all HIV pts with eye symptoms ( floaters, decreased acuity, scotomas, metamorphopsia)
157
What is the treatment for CMV retinitis?
PO valganciclovir
158
What are cotton wool spots?
nerve fibre ischaemia
159
What is the nerve supply to the muscles of the eye?
LR6SO4AL3:
- abducens (CNVI) supplies lateral rectus
- trochlear (CNIV) supplies superior oblique
- occulomotor (CNIII) 'all the rest'; inferior oblique, medial, superior and inferior rectus
160
Which 2 nerves supply the levator palpebrae superioris muscle and what is its function?
- this muscle is responsible for eyelid opening
- dual supply
1. sympatetic nervous system
2. occulomotor nerve (CNIII)
161
Why do you only get a partial ptosis in Horner's syndrome?
- impaired sympathetic supply paralyses the muller muscle
| - but no affect on occulomotor nerve means you have some sparing of eyelid function
162
Why do you get a complete ptosis in a 3rd nerve palsy?
due to loss of both occulomotor and sympathetic tone because the sympathetic fibres run along the course of the occulomotor nerve.
