Mydriatics Flashcards
name 3 reasons WHY you will use mydriatics on a patient
- enables more thorough examination of the eye e.g. peripheral crystalline lens, vitreous, fundus
- stereo fundus examination
- for treatment e.g. uveitis (mostly my ophthalmologists)
name 4 reasons/times WHEN you will use mydriatics on a patient
- on patients at risk of a retinal detachment
- patients with symptoms
- for screening
- inadequate fundus view
which 3 types of patients may be at risk of a retinal detachment
- high myopia
- family history
- trauma
list what types of symptoms a patient may have that you will need to use mydriatics on
- unexplained vision loss/visual field loss
- visual disturbance
- floaters
- flashes
- veils
- shadows
which 3 types of patients will you need to do screening on with mydriatics
- diabetics (neovascular vessels and tortuosity)
- high myopia
- prior to ocular surgery
which 2 reasons may you want to use mydriatics on when experiencing inadequate fundus view
- lens/media opacities
- miotic pupils (especially elderly patients, who also more likely to have cataracts and diabetes)
what are the 6 ideal properties of a mydriatic
- rapid onset
- adequate duration (lasts long enough to see back of eye)
- fast recovery
- no associated cycloplegia and adverse effects
- light reflex is abolished
- no rise in intraocular pressure (easily reversed in an emergency)
what 7 things must you do/check prior to dilation
- have a good reason to use the drug
- explain the procedure (px can’t drive after etc)
- px consent
- issue written information
- advise about the effects - glare, loss of stereo vision, driving, operating machinery
- check for contraindications (incase of an allergic reaction, check BNF)
- minimise the risk of adverse reactions (check IOPs before insertion)
list the 4 D test
- Drug
- Dosage
- Date
- Disposal
and time
all should be checked/written/done
where should the drugs be disposed
in the yellow bin
why should you note down the time that the drug was instilled
to know when the maximum effect is
list 6 general contraindications of using mydriatics
- hypersensitivity to drug
- iris clip IOLs
- narrow angles (do slit lamp examination before instilling)
- patient with symptoms suggestive (e.g. high hyperope) of sub acute or chronic closed angle glaucoma (CAG)
- patient with diagnosed CAG
- px using pilocarpine for glaucoma treatment
what happens within the eye during closed angle glaucoma
the iris is bowed forward and can touch the back of the cornea which blocks the outflow of aqueous
list the signs and symptoms of closed angle glaucoma
- blurred vision from cloudy cornea
- haloes
- headache
- painful
- vomiting/nausea
- photophobia
- sudden increase in IOP (usually >40mmHg)
- conjunctival hyperaemia
- cloudy cornea
- fixed mid-dilated pupil
- closed angle
list 4 things you will do/check to minimise the risk of a CAG
- IOP, pre and post dilation
- anterior angles
- existing symptoms?
- use of biotic drug
what will you do and how when checking IOP pre and post dilation in order to minimise risk of CAG
- check if theres a significant rise in IOP or an asymmetric rise (as CAG is most likely to happen in one eye)
- monitor rises in IOP (post dilation)
- refer to eye casualty if continues to rise
how will you check anterior angles in order to minimise risk of CAG
- gonioscopy
- van herrick
if you see narrow angles without symptoms, still refer for further checks
list 2 other names for antimuscarinic mydriatics
- muscarinic antagonists
- anticholinergic
list the three types of anti muscarinic mydriatics
- tropicamide
- cyclopentolate
- atropine
which anti muscarinic is rarely used as a mydriatic
cyclopentolate
which anti muscarinic is very unlikely to be used as a mydriatic
atropine
which anti muscarinic is most likely to be used as a mydriatic
tropicamide
which anti muscarinic mydriatic is only available to independent prescribers
atropine
how do anti muscarinic drugs work
by blocking Ach effects on muscarinic receptors
list another name for a sympathomimetic mydriatic
alpha agonist
name the type of sympathomimetic mydriatic
phenylephrine
how do sympathomimetic mydriatic drugs work
enhancing noradrenaline effects on alpha 1 adrenoceptors
what 2 other things does phenylephrine do to the eye
- makes the eyes look whiter, as it constricts the blood vessels
- widens the interpalpebral aperture, as it contracts mullers muscle
which ANS branch do antimuscarinic mydriatics work on
parasympathetic
which mydriatic is involved in affecting accommodation and why
antimascurinics as it affects the ciliary muscle as well as the sphincter
which branch of the ANS won’t affect accommodation or light reflex
sympathetic
which muscle does the sympathetic branch of the ANS affect
dilator
which ANS branch does the iris sphincter muscle innervate
parasympathetic
what do antimuscarinic drugs cause paralysis of
the parasympathetic nervous system
what do antimuscarinic drugs inhibit the action of
Ach at the end of postganglionic nerves
what three things does antimuscarinic drugs produce
- mydriasis
- cycloplegia
- reduced tear secretion
which type of drug is a alpha agonist
sympathomimetic/phenylephrine
which transmitter do sympathomimetic drugs work on
neurohumoral transmitter at most sympathetic postganglionic neuro-effector junctions
what 2 things in the body do sympathomimetic drugs have exceptions on
- sweat glands
- vasodilator fibres on skeletal muscle
list the alpha and beta receptors that sympathomimetic drugs bind with
- mainly alpha 1 receptors in dilator papillae muscle
- alpha 1 excitatory, alpha 2 inhibitory
- beta 1 excitatory, beta 2 inhibitory
in how long does tropicamide cause mydriasis within
15 minutes
after how long is recovery from tropicamide
8-9 hours
with which drug is light reflect absent
tropicamide
which drug induces a mild cycloplegic effect
tropicamide
what may tropicamide cause
a rise in IOP but likely to be transitory
which drug has fewer contraindications
tropicamide
how long does phenylephrine cause mydriasis within
30 minutes
how long does phenylephrine cause mydriasis for
12-24 hours
with which drug is light reflex retained
phenylephrine
what is phenylephrine less likely to produce
a rise in IOP as sector mydriasis
which drug is associated with numerous contraindications with other medications
phenylephrine
which category of medicine is tropicamide
a POM for use and supply by all optometrists
which two forms/packaging is tropicamide available in
- single use, minims by bausch and lomb
- multi-dose containers, mydriacyl by alcon
what single use doses is tropicamide available in
0.5% and 1.0%
at what temperature should tropicamide single use minims be stored below
25 degrees celsius
what dose of tropicamide will you use if you want to paralyse some accommodation
1.0%
what multi use doses is tropicamide available in
0.5% and 1.0%
at what temperature should tropicamide multi dose containers be stored below
2-8 degrees celsius and protect from light
what % of tropicamide is used on darker irides
1%
which mydriatic is better to use during pregnancy
Tropicamide is better to use than phenylephrine
what must women who are using tropicamide not do
breast feed
list the 4 immediate side effects or using tropicamide
- transient stinging
- transient blurring
- photophobia
- raised IOP?
list 4 side effects of tropicamide as a result of prolonged administration
- irritation
- hyperaemia
- oedema
- conjunctivitis
what is the general body side effect of tropicamide
which type of patient does it mainly affect
- CNS which effects dry mouth
- mainly affects children, with blue eyes and blonde hair
which category of medicine is phenylephrine
P medicine - such as lemsip etc
which forms/packaging is phenylephrine available in
single use, minims by Bausch & Lomb
what doses is phenylephrine available in
- 2.5%
- 10%
at what temperature should phenylephrine single use minims be stored below
25 degrees celsius and protect from light
which type of patients is 10% phenylephrine contraindicated in and why
children and the elderly (>65 years)
because of its increased risk of systemic toxicity
which type of eyes may phenylephrine be less effective on
highly pigmented
what does phenylephrine cause vasoconstriction of
conjunctival blood vessels
list 7 things that phenylephrine is contraindicated with
- medication for cardiovascular problems
- medication for depression
- thyrotoxicosis
- insulin dependent diabetes
- asthma
- pregnancy/lactation
- use of pilocarpine
list the 2 medications for cardiovascular problems that phenylephrine is contraindicated with
- anti hypertensives
- tachycardia
list the 2 medications for depression that phenylephrine is contraindicated with
- monoamine oxidase inhibitors
- tricyclic antidepressants
which type of mydriatic will you use on a insulin dependent diabetic
tropicamide
how is phenylephrine contraindicated with pregnancy/lactation
it may cause transient fatal hypoxia
how is phenylephrine is contraindicated with pilocarpine and on which type of patients
- older px = pupil block
- young px = accommodative spasm, causing contraction of the ciliary muscle
list the 6 immediate side effects of phenylephrine
- transient stinging
- transient blurring
- photophobia
- lid retraction
- conjunctival allergic reaction
- punctate keratitis
list the 5 general body side effects of phenylephrine
- palpitations
- tachycardia
- cardiac arrhythmias
- hypertension
- headaches
how does phenylephrine cause all these general body side effects
the drug gains access to systemic blood supply via the puncta, blood vessels or mucous
name the two drugs which can be used as synergistic combinations and for what purpose they’re used for
combinations of antimuscarinics and sympathomimetics
e.g. tropicamide 0.5% and phenylephrine 2.5%
this allows for lower concentrations of antimuscarinic to be used which results in less cyclo effect
what category of medicine is mydriasert
prescription only medicine POM
in what form does mydriasert come in
insoluble ophthalmic insert
what does mydriasert contain
phenylephrine and tropicamide
how fast is mydriasert released
gradually
when is mydriasert used
pre-operatively and diagnostically
how is mydriasert instructed for use
in adults insert up to max. 2 hours before procedure
remove within 30 mins of mydriasis and within 2 hours of application
name 2 other mydriatic drugs other than tropicamide, phenylephrine and mydriasert
- cyclopentolate
- homatropine
both antimuscarinics
when does the mydriatic effect of homatropine commence in
10-20 mins
when does maximal mydriasis occur with homatropine
30-40 mins
what 2 things are absent with homatropine
- light reflex
- accommodation
after how long is recovery achieved with homatropine
up to 3 days (so its rarely used)
