Cycloplegics Flashcards
why use cycloplegics
optometric uses
- assessment of refractive error - latent hyperope - accommodative muscle are used to increase the eye focusing power
- penalisation - instead of occlusion
- adaptation to specs (rare) - vision clear only with gls
additional opthalmological uses
- ant uveitis - dilating pupil and alleviating ciliary spasm
- corneal abrasion - alleviate ciliary spasm
cycloplegics - optometric indications from h&s
symptoms - asthenopia, reading diff
history - mainfest deviations
family history - refractive error at an early age, manifest deviations
cycloplegics - optometric indications from clinical test s
binocular vision anomaly - manifest eso deviation, sometimes if latent deviation
fluctuating ret - large diff bet subjective and objective, or poor fixation
accommodative anomalies
visual acuity reduced
cycloplegic - effects
initially mydriasis
- iris located anteriorly to ciliary muscle
- unneccesary side effect
cycloplegia
- paralysis of ciliary muscle, resulting in loss of accom
- because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on near objects
- reduced tear secretion - px may complain of dry eye after instillation
what do antimuscarinic agents affect
- lacrimal gland
- iris sphincter muscle
- ciliary body
advice before instillation
for parent guardian
- explain need to use
- onset
- duration
- expected side effects
- caution
for child
- explain might feel drop on eye
- 1 drop of proxymetacaine first? - RCO guidelines
what happens if consent is denied
parent/guardian
- explain advantages/disadvantages
- note refusal on record
- if concern for child great refer to GP
child
- Gillick competent - whether child can consent themselves to procedure
- record all discussions on notes
- if concern for child great refer to gp
instiling drops and how to check for cyclo
instillation - lying down may help, sometimes drop onto eyelashes can help
checking for cycloplegia - measure accom,
cycloplegic retinoscopy
- sit younger child on px knee
- can use px to fixate upon light - ensures ret is conducted upon axis
- no need to fog other eye
- can try using lens rack
- observe central movement - 3-4mm
- ignore movement in periphery
cycloplegic drugs - strong to weak
atropine 1% - additional supply or independent prescriber status, associated with numerous side effects
cyclopentolate 0.5 and 1% - most commonly used
homatropine 1% - additional supply of independent prescriber status
tropicamide 1% - weakest drug, only effective in adults, used mainly as a mydriatic
atropine preparations
- atropine sulphate: eye drops (non proprietary) - 0.5 and 1% atropine sulphate
- atropine sulphate: eye ointment - 1% atropine sulphate, non proprietary
- minims - 1% atropine sulphate (B&L) - store below 25 degrees and protect from light
atropine dose
adults and children > 3mths
eye drops - 1 drop (1%) twice per day for 1-3 days before refraction
ointment - 2 times a day for 1-3 days before refraction
- the ointment is preferable as systemic toxic effects reduced and prolonged contact with eye
atropine - timing after instilling 1 drop of 1%
mydriasis
- commences in 10-15 mins
- maximal in 30-40mins
- recovers in 3-7 days
cycloplegia
- commences in 30 mins
- maximal at 1-3 hrs
- recovers in 3-7 days
atropine - timing after 3x twice daily instillations
mydriasis
- recovers after 10-14 days
cycloplegia
- recovers after 7-10 days
- adequate near vision recovers after 4-5 days
atropine - tonus allowance
- ciliary muscle has depndent and independent tone
- allowance needs to be madefor dependent tone - spherical power only needs to be adjusted in less positive direction
- -1.00DS for low myopes and hyperopes
- 0DS for mod and high myopes
- not applicable to cyclopentolate and tropicamide
atropine - cautions and contraindications
contraindications
- known allergy to atropine or component of the preparation. Narrow angles? in children?
cautions
- children <3 mths, elderly or debilitated, downs syndrome
- children with brain damage
- hypersensitivity
- soft contact lens
- multi dose containers containing benzalkonium chloride - do not use if lenses worn
- intermittent manifest deviations
pregnancy and lactation interactions
ocular side effects of atropine sulphate
- transient stinging
- blurring
- photophobia
- raised iop?
- repeated use leads to hyperaemia, oedema, itching and irritation, follicular conjunctivitis
general body side effects of atropine sulphate
toxic effects
- dry as a bone: dry mouth and skin
- red as a beetroot: flushing, increased body temp
- blind as a bat: cycloplegia
- mad as a hatter: cns effects - ataxia, hallucinations, confusion, diff in speaking
- tachycardia
- death from resp depression - more likely in children, 3 gram tube can be fatal to a small child
atropine - additional uses
atropine penalisation
- used to treat amblyopia
- instilled into better eye
- prevents accom
- used when child will not tolerate patching/ first choice
- excellent results
cyclopentolate hydrochloride
- commonly used cycloplegia
- stings
- synthetic drug
- not commonly used as a mydriatic by optoms - 0.5% more useful as a mydriatic
cyclopentolate preparations
POM for use and supply by all optoms
Mydrilate: eye drops
- 0.5 and 1% cyclopentolate HCL, stored bet 2-8 degrees celsius
Minims: 0.5 and 1% cyclopentolate HCL, store below 25 degrees celsius, protect from light
cyclopentolate timing
cycloplegia
- commences after a few mins, maximal in 30-60 mins, recovery 4-12hrs
mydriasis
- 30 mins, recovery 24-48hrs, residual accom <1.50D, time scale variable
cyclopentolate tonus allowance
- no tonus allowance made
- almost always give full rx found
exception: - hyperopia and exo deviation
- myopia and eso deviation
cyclopentolate cautions
- young children
- debilitated pxs
- elderly
- avoid over dosage in darkly pigmented eyes - compressing the lacrimal sac for 2-3 mins after instillation of the drops
- pregnancy and lactation - unknown use only if risk to mother outweighs risk to foetus
- ## hallucinations and CNS ffects reported with concentrations
cyclopentolate ocular side effects
- transient stinging and blurring
- photophobia
- raise iop
- conj hyperaemia and oedema
- after prolonged administration: irritation, hyperaemia, oedema, conjunctivitis
cyclopentolate general body side effects
dose related - children
- cns effects
- dry mouth
- flushing
- tachycardia
- urinary symptoms
- GI symptoms
cyclopentolate - additional uses
- adaptation to specs
- children almost always adapt well to hyperopic rx
use 1% cyclopentolate daily for 2/52 - accom abolished
- clear vision only obtained via specs wear
- child usually then accepts spec wear
- mydriasis commences after 10 mins, maximal in 30-60 mins, duration 24hrs
- for ant and post uveitis and post synechiae breakdown: 1-2 drops (1%) are instilled every 8 hrs
for alleviation of ciliary spasm: 1 drop (1%) 2-3 times a day
homatropine hydrobromide
POM - additional supply or independent prescriber
- 1% multi dose containers (non proprietary), store below 25 degrees, protect from light
- used for dilating pupil in ant uveitis
- alleviation of ciliary spasm following corneal abrasion
- mydriasis 30-40 mins
- recovery 24-48 hrs
tropicamide hydrochloride
degree of cycloplegia dependent on:
- age - only indicated for cycloplegic refracton in older px in late teens or older, 1% strength only suitable
- iris pigmentation - degree of cycloplegia dependent upon pigmentation
effects after instillation of 2 drops of 1% solution
- mydriasis after 15 mins, recovery 8-9hrs
- cycloplegia maximal after 20 mins, recovery 6 hrs
