Opthalmology Flashcards
(183 cards)
1
Q
glaucoma definition
A
optic nerve damage by increased intraocular pressure
caused by blockage in aqueous humour drainage
2
Q
2 types of glaucoma
A
open-angle
acute angle-closure
3
Q
chamber of eye filled with
A
vitreous humour
4
Q
where anterior chamber
A
between cornea and iris
5
Q
where posterior chamber
A
between lens and iris
6
Q
between anterior and posterior chamber filled
A
aqueous humour
7
Q
passage of aqueous humour
A
aqueous humour produced by ciliary body, supplies nutrients to cornea. flows through posterior chamber and around iris to anterior chamber. drains through trabecular meshwork to canal of schlemm at angle between cornea and iris. then enters circulation
8
Q
intraocular pressure
- normal
- created by
A
10-21 mmHg
created by resistance to flow through trabecular meshwork
9
Q
pathophysiology of open angle glaucoma
A
there is a gradual increase in resistance to flow through the trabecular meshwork. The pressure slowly builds within the eye.
10
Q
patho acute angle closure glaucoma
A
the iris bulges forward and seals off the trabecular meshwork from the anterior chamber, preventing aqueous humour from draining. There is a continual build-up of pressure and an acute onset of symptoms
11
Q
how serious acute angle closure glaucoma
A
opthalmological emergency
12
Q
fundoscopy glaucoma
A
cupping of optic disc
optic cup in centre of optic disc….this becomes wider and deeper - cupping
cup-disk ratio >0.5 = bad
13
Q
risk fx for open angle glaucoma
A
Increasing age
Family history
Black ethnic origin
Myopia (nearsightedness)
14
Q
clinical fx glaucoma
A
asx - detected by routine eye test
gradual onset tunnel vision (peripheral vision affected)
fluctuating pain
headaches
dipolopia
halos around lights, worse at night
15
Q
how measure intraocular pressure
A
non contact tonometry - puff of air at cornea and measure corneal response
goldmann applanation tonometry (gold standard) - device makes contact and applies pressure to cornea
16
Q
diagnosis based on glaucoma
A
Goldmann applanation tonometry for the intraocular pressure
Slit lamp assessment for the cup-disk ratio and optic nerve health
Visual field assessment for peripheral vision loss
Gonioscopy to assess the angle between the iris and cornea
Central corneal thickness assessment
17
Q
glaucoma when tx
A
> 24mmHg
18
Q
mx options of glaucoma
A
360 degrees selective laser trabeculoplasty - improve drainage
prostaglandin analogue eye drops (latanoprost) - increase uveoscleral outflow
Beta-blockers (e.g., timolol) reduce the production of aqueous humour
Carbonic anhydrase inhibitors (e.g., dorzolamide) reduce the production of aqueous humour
Sympathomimetics (e.g., brimonidine) reduce the production of aqueous fluid and increase the uveoscleral outflow
19
Q
surgery tx of glaucoma
A
trabeculectomy - creating a new channel from the anterior chamber through the sclera to a location under the conjunctiva, causing a bleb on the conjunctiva. From here, it is reabsorbed into the general circulation.
20
Q
s/e of prostaglandin eye drops
A
eyelash growth, eyelid pigmentation and iris pigmentation (browning)
21
Q
risk fx for acute angle closure glaucoma
A
Increasing age
Family history
Female (four times more likely than males)
Chinese and East Asian ethnic origin
Shallow anterior chamber
22
Q
marked difference in risk fx of glaucoma
A
Open-angle glaucoma is more common in black people, while angle-closure glaucoma is rare in this group
23
Q
certain meds precipitate acute angle closure glaucoma
A
Adrenergic medications (e.g., noradrenaline)
Anticholinergic medications (e.g., oxybutynin and solifenacin)
Tricyclic antidepressants (e.g., amitriptyline), which have anticholinergic effects
24
Q
clinical fx acute angle closure glaucoma
A
Severely painful red eye
Blurred vision
Halos around lights
Associated headache, nausea and vomiting
25
examination acute angle closure glaucoma
Red eye
Hazy cornea
Decreased visual acuity
Mid-dilated pupil
Fixed-size pupil
Hard eyeball on gentle palpation
26
acute angle closure glaucoma mx
emergency admission
Lying the patient on their back without a pillow
Pilocarpine eye drops (2% for blue and 4% for brown eyes)
Acetazolamide 500 mg orally
Analgesia and an antiemetic, if required
27
MOA pilocarpine
muscarinic recepors in sphincter muscles in iris and causes pupil constriction (miotic agent)...ciliary muscle contraction...open up pathway for flow of aqueous humour from ciliary body and into trabecular meshwork
28
acetozolamide moa
carbonic anhydrase inhibitor that reduces the production of aqueous humour
29
secondary care mx of acute angle closure glaucoma
Pilocarpine eye drops
Acetazolamide (oral or intravenous)
Hyperosmotic agents (e.g., intravenous mannitol) increase the osmotic gradient between the blood and the eye
Timolol is a beta blocker that reduces the production of aqueous humour
Dorzolamide is a carbonic anhydrase inhibitor that reduces the production of aqueous humour
Brimonidine is a sympathomimetics that reduces aqueous humour production and increases uveoscleral outflow
30
definitive tx of acute angle closure glaucoma
Laser iridotomy ....allows aqueous humour to flow from posterior to anterior chamber
31
age related macular degeneration definition
a progressive condition affecting the macula
32
2 types of AMD
Wet (also called neovascular), accounting for 10% of cases
Dry (also called non-neovascular), accounting for 90% of cases
33
macula where found
centre of retina
34
macula role
high definition colour vision in central visual field
35
macula layers
4 layers -
Choroid layer (at the base), which contains the blood vessels that supply the macula
Bruch’s membrane
Retinal pigment epithelium
Photoreceptors (towards the surface)
36
AMD fundoscopy
Drusen - yellowish deposits of proteins and lipids between retinal pigment epithelium and Bruch's membrane...frequent and larger amounts
Atrophy of the retinal pigment epithelium
Degeneration of the photoreceptors
37
pathophysiology wet AMD
new vessels develop (VEGF) from the choroid layer and grow into the retina (neovascularisation). These vessels can leak fluid or blood, causing oedema and faster vision loss
38
risk fx AMD
Older age
Smoking
Family history
Cardiovascular disease (e.g., hypertension)
Obesity
Poor diet (low in vitamins and high in fat)
39
AMD clinical fx
unilateral
Gradual loss of central vision and ability to read small text
Reduced visual acuity
Crooked or wavy appearance to straight lines (metamorphopsia)
40
WET AMD v DRY AMD
wet - more acutely within days, and progress to complete vision loss within 2-3 yrs and progress to b/l
41
glaucoma v AMD
Glaucoma is associated with peripheral vision loss and halos around lights. AMD is associated with central vision loss and a wavy appearance to straight lines. This helps you tell them apart in exams.
42
AMD examination
Reduced visual acuity using a Snellen chart
Scotoma (an enlarged central area of vision loss)
Amsler grid test can be used to assess for the distortion of straight lines seen in AMD
Drusen may be seen during fundoscopy
Slit lamp exam
Optical coherence tomography
Flurescein angiography
43
AMD mx
specialist opthalmological review
dry - no tx, monitor, avoid smoking and control BP, vitamin supplement
wet - anti-VEGF meds((e.g., ranibizumab, aflibercept and bevacizum) - intravitreal, once/mth
44
pathophysiology diabetic retinopathy
hyperglycaemia...damages retinal small vessels and endothelial cells
increased vascular permeability, leaky blood vessels, blot haemorrhages, hard exudates (lipids and proteins)
and microaneurysms and venous beading
damage to nerve fibres...cotton wool spots on retina
Intraretinal microvascular abnormalities form - dilated and tortous capillaries act as shunt between arterial and venous vessels
Neurovascularisation - release of growth factors
45
characteristic fx of diabetic retinopathy on fundoscopy
cotton wool spots
microaneurysms
neovascularisation
blot haemorrhages
hard exudates
46
diabetic retinopathy grading fundus
Background – microaneurysms, retinal haemorrhages, hard exudates and cotton wool spots
Pre-proliferative – venous beading, multiple blot haemorrhages and intraretinal microvascular abnormality (IMRA)
Proliferative – neovascularisation and vitreous haemorrhage
47
key fx of proliferative diabetic retinopathy
neovascularisation
48
diabetic maculopathy fx
Exudates within the macula
Macular oedema
49
complications diabetic retinopathy
Vision loss
Retinal detachment
Vitreous haemorrhage (bleeding into the vitreous humour)
Rubeosis iridis (new blood vessel formation in the iris) – this can lead to neovascular glaucoma
Optic neuropathy
Cataracts
50
diabetic retinopathy mx
non proliferative - diabetic control and monitor
proliferative - Pan-retinal photocoagulation - laser tx (little spots on background of fundus), anti-VEGF, vitrectomy
macular oedema - dex
51
two causes of hypertensive retinopathy
slowly with chronic hypertension or develop quickly in response to malignant hypertension
52
clinical fx on fundus hypertensive retinopathy
silver/copper wiring - walls of arterioles thinkened and sclerosed
AV nipping - compression of veins from arterioles
cotton wool spots - ischaemia of retina
hard exudates - damaged vessels leaking lipids onto retina
retinal haemorrhages - damaged vessels rupturing
papilloedema - ischaemia to optic nerve
53
classification hypertensive retinopathy
Keith-Wagener Classification
Stage 1: Mild narrowing of the arterioles
Stage 2: Focal constriction of blood vessels and AV nicking
Stage 3: Cotton-wool patches, exudates and haemorrhages
Stage 4: Papilloedema
54
hypertensive retinopathy mx
control BP
manage risk fx
55
role of lens
focus light on retina
56
lens location
held in place by suspensory ligaments attached to ciliary body
57
lens size change
The ciliary body contracts and relaxes to change the shape of the lens. When the ciliary body contracts, it releases tension on the suspensory ligaments, and the lens thickens. When the ciliary body relaxes, the suspensory ligaments tension, and the lens narrows.
58
how lens nourised
aqueous humour
59
congenital cataracts screen
red reflex tested during neonatal exam
60
risk fx for cataracts
Increasing age
Smoking
Alcohol
Diabetes
Steroids
Hypocalcaemia
61
cataracts defin
opaque eye lens...reduce visual acuity
62
presentation cataracts
usually asymmetrical
Slow reduction in visual acuity
Progressive blurring of the vision
Colours becoming more faded, brown or yellow
Starbursts can appear around lights, particularly at night
loss of red reflex
63
cataracts mx
Cataract surgery involves drilling and breaking the lens to pieces, removing the pieces and implanting an artificial lens. It can be performed as a day case under local anaesthetic
64
cataracts after tx monitor for
continued reduced visual acuity...
macular degeneration
diabetic retinopathy
65
endopthalmitis define
inflammation of inner corners of eye...usually caused by infections
rare but serious confplication of cataract surgery....lead to vision loss
tx with intravitreal abx
66
causes of abnormal pupil shape
trauma to sphincter muscles in iris
anterior uveitis resulting in adhesions
acute angle closure glaucoma (vertical oval)
rubeosis iridis (associated with poorly controlled DM)
coloboma (congenital malformation)
tadpole pupil (muscle spasm in part of dilator muscle or iris, also present with migraines and horners syndrome)
67
causes of mydriasis
Congenital
Stimulants (e.g., cocaine)
Anticholinergics (e.g., oxybutynin)
Trauma
Third nerve palsy
Holmes-Adie syndrome
Raised intracranial pressure
Acute angle-closure glaucoma
68
causes of miosis
Horner syndrome
Cluster headaches
Argyll-Robertson pupil (neurosyphilis)
Opiates
Nicotine
Pilocarpine
69
third nerve palsy clinical fx
Ptosis (drooping upper eyelid)
Dilated non-reactive pupil
Divergent strabismus (squint) in the affected eye, with a “down and out” position
70
causes of third nerve palsies
can be idiopathic
not affect pupil - microvascular cause as parasympathetic fibres spared...due to DM, HTN, ischaemia
if fully affected..compression of parasympathetic fibres....due to trauma, tumour, cavernous sinus thrombosis, posterior communicating artery aneurysm, raised ICP
71
oculomotor nerve pathway
The oculomotor nerve travels directly from the brainstem to the eye in a straight line. It travels through the cavernous sinus and close to the posterior communicating artery.
72
horners syndrome triad
Ptosis
Miosis
Anhidrosis (loss of sweating)
may have exopthalmus
73
patho of horners syndrome
by damage to the sympathetic nervous system supplying the face.
The sympathetic nerves arise from the spinal cord in the chest. These are pre-ganglionic nerves. They enter the sympathetic ganglion at the base of the neck and exit as post-ganglionic nerves. The post-ganglionic nerves travel to the head alongside the internal carotid artery.
74
location of horners syndrome and clinical fx
central lesions - before exit spinal cord...anhidrosis of arm, trunk and face
pre ganglionic lesions...anhidrosis of face
post ganglionic lesions...not cause anhidrosis
75
cause of horners syndrome
- central lesions
S – Stroke
S – Multiple Sclerosis
S – Swelling (tumours)
S – Syringomyelia (cyst in the spinal cord)
76
cause of horners syndrome
- pre ganglionic lesions
T – Tumour (Pancoast tumour)
T – Trauma
T – Thyroidectomy
T – Top rib (a cervical rib growing above the first rib and clavicle)
77
causes of horners syndrome
- post ganglionic lesions
C – Carotid aneurysm
C – Carotid artery dissection
C – Cavernous sinus thrombosis
C – Cluster headache
78
congenital horner syndrome marked characteristic
heterochromia
79
tx of horner syndrome
cocaine eye drops - stops NA re uptake. causes a normal eye to dilate as noradrenalin stimulates the dilator muscles of the iris
low-dose adrenalin eye drops (0.1%) will dilate the pupil in Horner syndrome but not a normal pupil.
80
holmes-adie pupil patho
damage to post ganglionic parasympathetic fibres
81
holmes-adie pupil sx
Dilated
Sluggish to react to light
Responsive to accommodation (the pupils constrict well when focusing on a near object)
Slow to dilate following constriction (“tonic” pupil)
82
holmes-adie syndrome
a Holmes-Adie pupil with absent ankle and knee reflexes.
83
argyll-robertson pupil finding in
neurosyphilis
84
argyll-robertson pupil clinical fx
is a constricted pupil that accommodates when focusing on a near object but does not react to light. They are often irregularly shaped
85
blepharitis define
inflammation of eyelid margins
can be associated with dysfunction of the Meibomian glands, which are responsible for secreting meibum (oil) onto the surface of the eye
86
blepharitis sx
a gritty, itchy, dry sensation in the eyes
can lead to styes and chalazions
87
blepharitis mx
warm compress
gentle cleaning of eye to remove debris
88
stye infection cause
Hordeolum externum is an infection of the glands of Zeis or glands of Moll. The glands of Moll are sweat glands at the base of the eyelashes. The glands of Zeis are sebaceous glands at the base of the eyelashes.
Hordeolum internum is infection of the Meibomian glands. They are deeper, tend to be more painful and may point inwards towards the eyeball underneath the eyelid.
89
stye sx
tender red lump along eyelid may contain pus
90
stye tx
hot compresses and analgesia
topical abx (chloramphenicol)
91
chalazion patho
meibomian gland blocked and swells...aka meibomian cyst
92
chalazion sx
swelling in eyelid, not tender usually
93
chalazion tx
warm compress and gentle message towards eyelashes to encourage drainage
94
entropion what
eyelid turns inwards with lashes pressed against eye...pain, corneal damage, ulceration
95
entropion mx
tape eyelid down to prevent it from turning inwards and lubricating eye drops
definitive - surgery, same day referral to opthal if sight affected
96
ectropion what
eyelid turns outwards, exposing inner aspect. affects bottom lid usually...can result in exposure keratopathy...not enough lubrication
97
ectropion mx
regular lubricating eye drops
may require surgery
same day opthalmology referral if risk to sight
98
trichiasis what
inward growth of the eyelashes. It results in pain and can cause corneal damage and ulceration
99
trichiasis mx
removing the affected eyelashes. Recurrent cases may require electrolysis, cryotherapy or laser treatment to prevent them from regrowing. A same-day referral to ophthalmology is required if there is a risk to sight.
100
periorbital cellulitis what
an eyelid and skin infection in front of the orbital septum (in front of the eye)
101
periorbital cellulitis sx
red hot swollen skin around eyelid and eye
102
how differentiate pre orbital or orbital cellulitis
referred urgently to ophthalmology for assessment. A CT scan can help distinguish them.
103
peri orbital cellulitis tx
systemic abx
consider admission as can develop orbital cellulitis if immunocompromised
104
orbital cellulitis what
an infection around the eyeball involving the tissues behind the orbital septum
105
orbital cellulitis sx
pain with eye movement, reduced eye movements, vision changes, abnormal pupil reactions, and proptosis (bulging forward of the eyeball).
106
orbital cellulitis mx
requires emergency admission under ophthalmology and intravenous antibiotics. Surgical drainage may be needed if an abscess forms.
107
source of infection conjunctivitis
bacterial
viral
allergic
108
presentation conjunctivitis
uni/or bi
Red, bloodshot eye
Itchy or gritty sensation
Discharge
bacterial - purulent discharge, worse in morning when stuck together, highly contagious
viral - clear discharge, URTI sx, tender pre auricular LN's
allergic - itching and watery discharge
109
causes of acute painful red eye
Acute angle-closure glaucoma
Anterior uveitis
Scleritis
Corneal abrasions or ulceration
Keratitis
Foreign body
Traumatic or chemical injury
110
causes of acute painless red eye
Conjunctivitis
Episcleritis
Subconjunctival haemorrhage
111
mx of conjunctivitis
1-2 weeks
hygeine
clean eyes with cooled boiled water and cotton wool
chloramphenicol or fusidic acid eye drops
<1 yr - urgent opthalmology assessment ,may be caused by gonococcal infection, can result in permanent visual loss
112
allergic conjunctivits mx
antihistamines
topical mast cell stabilisers
113
uvea consists of
iris, ciliary body and choroid
114
choroid is layer between
retina and sclera
115
cause of anterior uveitis
autoimmune
infection
trauma
ischaemia
malignancy
116
anterior uveitis patho
inflammation in anterior chamber of eye...infiltrated by neutrophils, lymphocytes and macrophages.
117
O/E anterior uveitis
Hypopyon refers to a fluid collection containing inflammatory cells seen at the bottom of the anterior chamber on inspection.
118
anterior uveitis associations
Seronegative spondyloarthropathies (e.g., ankylosing spondylitis, psoriatic arthritis and reactive arthritis)
Inflammatory bowel disease
Sarcoidosis
Behçet’s disease
119
anterior uveitis presentation
Painful red eye (typically a dull, aching pain)
Reduced visual acuity
Photophobia (due to ciliary muscle spasm)
Excessive lacrimation (tear production)
120
anterior uveitis examination findings
Ciliary flush (a ring of red spreading from the cornea outwards)
Miosis (a constricted pupil due to sphincter muscle contraction)
Abnormally shaped pupil due to posterior synechiae (adhesions) pulling the iris into abnormal shapes
Hypopyon (inflammatory cells collected as a white fluid in the anterior chamber)
121
anterior uveitis mx
urgent assessment by opthalmologist
1st line - steroids, cycloplegics (eg: atropine eye drops...reduce ciliary spasm)
122
episcleritis define
benign and self-limiting inflammation of the episclera, the outermost layer of the sclera, just below the conjunctiva.
123
age episcleritis
young and middle age adults
124
episcleritis associated conditions
RA, IBD
125
episcleritis presentation
acute-onset unilateral features:
Localised or diffuse redness (often a patch of redness in the lateral sclera)
No pain (or mild pain)
Dilated episcleral vessels
126
sx indicating scleritis
photophobia
discharge
affected visual acuity
127
how differentiate episcleritis and scleritis
phenylephrine eye drops helps differentiate between episcleritis and scleritis. It will cause blanching of the episcleral vessels, causing the redness to disappear. It will not affect scleral vessels and will not impact the redness in scleritis
128
episcleritis mx
self limiting, resolve in 1-2 weeks
mild - no tx
sx relieved with analgesia, lubricating eye drops
severe - steroid eye drops
129
scleritis define
inflammation of sclera
130
most severe type of scleritis
necrotising scleritis, which can lead to perforation of the sclera
131
scleritis causes
most idiopathic
less commonly an infection - pseudomonas or staph aureus
132
scleritis associated conditions
RA
vasculitis - granulomatosis with polyangiitis
133
scleritis presentation
gradual onset
Red, inflamed sclera (localised or diffuse)
Congested vessels
Severe pain (typically a boring pain)
Pain with eye movement
Photophobia
Epiphora (excessive tear production)
Reduced visual acuity
Tenderness to palpation of the eye
134
scleritis mx
urgent referral for assessment from opthalmologist
assessed for underlying systemic condition
NSAIDS
steroids
immunosuppression
if infectious - abx
135
corneal abrasions causes
Damaged contact lenses
Fingernails
Foreign bodies (e.g., metal fragments)
Tree branches
Makeup brushes
Entropion (inward turning eyelid)
136
chemical abrasions clinical fx and mx
vision loss
irrigation and opthalmology input
137
which infection abrasions with contact lenses
pseudomonas
138
presentation abrasions
hx of trauma
Painful red eye
Photophobia
Foreign body sensation
Epiphora (excessive tear production)
Blurred vision
139
inv of corneal abrasion
flourescein stain -yellow/orange stain and collect...viewed under cobalt blue light
140
corneal abrasions mx
heal over 2-3 days
Management options include:
Removing foreign bodies
Simple analgesia
Lubricating eye drops
Antibiotic eye drops (e.g., chloramphenicol)
Close follow-up
Hypromellose drops are the least viscous (the effects last around 10 minutes)
Polyvinyl alcohol drops are the middle viscous choice
Carbomer drops are the most viscou
141
keratitis define
inflammation of cornea
142
keratitis causes
Viral infection (e.g., herpes simplex)
Bacterial infection (e.g., Pseudomonas or Staphylococcus)
Fungal infection (e.g., Candida or Aspergillus)
Contact lens-induced acute red eye (CLARE)
Exposure keratitis, caused by inadequate eyelid coverage (e.g., ectropion)
143
most common cause of keratitis
herpes simplex
can primary or recurrent - when virus lied dormant in trigeminal ganglion
can lead to stromal necrosis, vasculariation and scarring...corneal blindness
144
keratitis clinical fx
mild symptoms of blepharoconjunctivitis (inflammation of the eyelid margins and conjunctiva).
if recurrent -
Painful red eye
Photophobia
Vesicles (fluid-filled blisters)
Foreign body sensation
Watery discharge
Reduced visual acuity
145
how keratitis diagnosed
slit lamp exam with florescein staining shows dendritic corneal ulcer
corneal scrappings - viral testing
146
keratitis mx
urgent assessment
topical or oral antiviral
corneal transplant
147
subconjuctival haemorrhage patho
small blood vessel within conjuctiva ruptures...release blood into space between sclera and conjunctiva
after episodes of strenuous activity or trauma or idiopathic
148
subconjunctival haemorrhage risk fx
Hypertension
Bleeding disorders (e.g., thrombocytopenia)
Whooping cough
Medications (e.g., antiplatelets, DOACs or warfarin)
Non-accidental injury
149
clinical fx of subconjuctival haemorrhage
bright red blood patch underneath conjunctiva
painless and does not affect vision
precipitating event
150
subconjunctival haemorrhage mx
clinical hx diagnosed
check BP and INR
resolve spontaneously without tx
lubricating eye drops for irritation
151
posterior vitreous detachment define
the vitreous body comes away from the retina
152
posterior vitreous detachment age
older age more common
153
patho posterior vitreous detachment
The vitreous humour is the gel inside the vitreous chamber of the eye. It maintains the structure of the eyeball and keeps the retina pressed on the choroid. With age, it becomes less firm and able to maintain its shape.
154
presentation posterior vitreous detachment
painless
floaters
flashing lights
blurred vision
155
mx posterior vitreous detachment
no tx, brain adjusts
156
predisposing conditions from posterior vitreous detachment
retinal tears and detachment
157
retinal detachment patho
involves the neurosensory layer of the retina (containing photoreceptors and nerves) separating from the retinal pigment epithelium (the base layer attached to the choroid). This is usually due to a retinal tear, allowing vitreous fluid to get under the neurosensory retina and fill the space between the layers.
158
why retinal detachment serious
neurosensory retina relies on blood vessels of choroid for blood supply...so then disrupt and can cause permanent damage to photoreceptors...sight threatening
159
risk fx retinal detachment
Lattice degeneration (thinning of the retina)
Posterior vitreous detachment
Trauma
myopia
Diabetic retinopathy
Retinal malignancy
Family history
160
retinal attachment clinical fx
painless
peripheral vision loss sudden and shadow
blurred or distorted vision
flashes and floaters
161
retinal detachment mx
immediate opthalmology referral
retinal tears - laser therapy, cryotherapy
retinal detachment - reattach retina and reduce traction or pressure via vitrectomy, scleral buckle or pneumatic retinopexy
162
retinal vein occlusion patho
when thrombus form in retinal veins, blocking drainage of blood from retina...in central retinal vein or branch retinal veins
this blockage causes venous congestion...increased pressure and blood leaking into retina...macular oedema and retinal haemorrhages
163
sites of retinal vein occlusion
The branch retinal veins drain into the central retinal vein, which runs through the optic nerve to drain into either the superior ophthalmic vein or cavernous sinus. Blockage of one of the branch veins affects the area drained by that branch. Blockage in the central vein causes problems with the whole retina.
164
2 types of retinal vein occlusion
ischaemic or non ischaemic
ischaemia - release of VEGF...neovascularisation
165
risk fx retinal vein occlusion
Hypertension
High cholesterol
Diabetes
Smoking
High plasma viscosity (e.g., myeloma)
Myeloproliferative disorders
Inflammatory conditions (e.g., SLE)
166
clinical fx retinal vein occlusion
painless blurred vision or vision loss
if branch retinal vein = affected area of retina
if branch draining macula = central vision lost
167
fundoscopy retinal vein occlusion
Dilated tortuous retinal veins
Flame and blot haemorrhages
Retinal oedema
Cotton wool spots
Hard exudates
168
ddx fundoscopy of retinal vein occlusion
retinal vein occlusion - 'blood and thunder' appearance
CMV retinitis - 'pizza pie' appearance
169
retinal vein occlusion mx
referred immediately
tx macular oedema and prevent neovascularisation = anti VEGF (ranibizumab and aflibercept), dexamethasone intravitreal implant, laser photocoagulation
170
central retinal artery branch
branch of opthalmic artery which is brain of ICA
171
causes central retinal artery occlusion
atherosclerosis
giant cell arteritis
172
risk fx central retinal artery occlusion
for CVD - atherosclerosis
for giant cell arteritis - white ethnicity, older age, female, polymyalgia rheumatica
173
central retinal artery occlusion clinical fx
sudden painless loss of vision 'curtain coming down'
a relative afferent pupillary defect, where the pupil in the affected eye constricts more when light is shone in the other eye than when it is shone in the affected eye. The input is not sensed by the ischaemic retina when testing the direct light reflex but is sensed during the consensual light reflex.
174
central retinal artery occlusion fundoscopy
pale retina with cherry red spot...spot is fovea which has thinner surface
175
ddx for sudden painless vision loss
retinal detachment
central retinal artery occlusion
central retinal vein occlusion
vitreus haemorrhage
176
central retinal artery occlusion initial mx
referred immediately
giant cell arteritis - ESR nand temporal artery biopsy, tx with high dose steroids
177
central retinal artery occlusion mx options
Ocular massage (massaging the eye)
Anterior chamber paracentesis (removing fluid from the anterior chamber to reduce the intraocular pressure)
Inhaled carbogen (5% carbon dioxide and 95% oxygen) (to dilate the artery)
Sublingual isosorbide dinitrate (to dilate the artery)
Oral pentoxifylline (to dilate the artery)
Intravenous acetazolamide (to reduce the intraocular pressure)
Intravenous mannitol (to reduce the intraocular pressure)
Topical timolol (to reduce the intraocular pressure)
178
retinitis pigmentosa define
a genetic condition causing degeneration of the photoreceptors in the retina, particularly the rods...many different genetic causes
179
presentation retinitis pigmentosa
varies
mostly start in childhood
rods more than cones degenerate - night blindness and peripheral vision loss
180
retinitis pigmentosa fundoscopy
'bone spicule' pigmentation - sharp ponted appearance in mid periphery
narrowing of arterioles and waxy or pale appearance to optic disc
v characteristic for osce's
181
retinitis pigmentosa associated systemic disease
Usher syndrome also causes hearing loss
Bassen-Kornzweig syndrome also causes progressive neurological impairments
Refsum disease also causes peripheral neuropathy, hearing and ichthyosis (scaly skin)
182
retinitis pigmentosa mx
referral
genetic counselling
vision aids
sunglasses to protect retina
DVLA inform
183
