Cycloplegics Flashcards
Why do we use cycloplegics?
- Assessment of refractive error - to detect a latent hyperope
- Penalisation - instead of occlusion
- Adaptation to spectacles (rare) – vision clear only with glasses
What are the ophthalomogicalical uses of cycloplegics?
- Anterior uveitis – in order to dilate pupil and alleviate ciliary spasm
- Corneal abrasion - alleviate ciliary spasm
What are optometric indications from history and symptoms that you should use cycloplegics?
Symptoms:Asthenopia Reading difficulties
History: Manifest deviations
Family history: Refractive error at an early age + Manifest deviations
What are optometric indications from clinical skills tests that you should use cycloplegics?
Binocular vision anomaly - Manifest eso deviation Sometimes if latent deviation
Fluctuating ret –> Large difference between subjective and objective - might be indicative of a young latent hypermetrope
Poor fixation
Accommodative anomalies
Visual acuity reduced
What secondary effect do cycloplegics cause?
Mydriasis - widening of the pupil
Reduced tear secretion
How do cycloplegics work?
Paralysis of the ciliary muscle, resulting in loss of accommodation – Because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on near objects
What structures do anti-muscarinic structures affect?
• Lacrimal gland • Iris sphincter muscle • Ciliary body
What advice do you need to give before inserting a cycloplegic?
• Explain need to use • Onset • Duration • Expected side effects • Caution
Explain how drop may feel on eye
What happens if consent for cycloplegics is denied?
Explain advantages and disadvantages • Note refusal on record • If concern for child great refer to GP
In the case of a competent child:
Gillick competent • Record all discussions on notes
Do you need to fog eyes when doing a cycloplegic refraction?
No
What do you need to bear in mind when doing a cycloplegic refraction?
Observe central movement - 3/4 mm
ignore peripheral movement.
What cycloplegic drugs are available in order from strongest to weakest?
From what plant is atropine derived?
Bella donna
What is the ocular dosage for atropine?
1%
Whats the disadvantage of using atropine?
It takes long to come into effect 30 mins and takes long to recover from 3-7 days.
What considerations should be taken when using atropine?
Children < 3 months
Elderly or debilitated
Down’s syndrome
Children with brain damage
Hypersensitivity
Soft contact lenses Multi-dose containers contain benzalkonium chloride – do not use if lenses worn Intermittent manifest deviations
Pregnancy and Lactation Interactions
What are ocular side effects of atropine?
- Transient stinging • Blurring • Photophobia • Raised IOP?
- Repeated use can cause :
– Hyperaemia – Oedema – Itching, irritation – Follicular conjunctivitis
What are general body side effects of atropine?
Toxic effects ;
– Dry as a bone: Dry mouth and skin
– Red as a beetroot: Flushing, Increased body temperature
– Blind as a bat: Cycloplegia
– Mad as a hatter: CNS effects –ataxia, hallucinations, confusion, difficulty in speaking
- Tachycardia
- Death from respiratory depression – More likely in children. 3 gram tube can be fatal to a small children
Other than for refraction when may atropine be used?
For children non compliant with patching
What is the most common cycloplegic?
Cyclopentolate ydrochloride
What dosage is cyclopentolate availbale in and when is each used?
0.5% cyclopentolate HCL – 1.0% cyclopentolate HCL
Up to age 12 yrs– usually 1%,
if iris pigmentation is light then 0.5% may be suitable
What is the tonus allowance when refracting using atropine?
Allowance needs to be made for dependent tone – Spherical power only needs to be adjusted in less positive direction – -1.00DS for low myopes and hyperopes – 0.00DS for moderate and high myopes
What is the tonus allowance when refracting using cyclopentolate?
No tonus allowance made
- Almost always give full Rx found
- The only Exception to this is:
– Hyperopia and exo deviation – Myopia and eso deviation
What are the onset and duration timings for cyclopentolate?
Cycloplegia – commences after a few minutes, maximal in 30-60 minutes, Recovery 4-12 hours
In which patients do we need to be cautious about putting cyclopentolate drops in?
- Young children
- Debilitated patients
- 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 effects reported with concentrations
What are ocular side effects of cyclopentolate?
- Transient stinging
- Transient blurring
- Photophobia
- Raised IOP?
- Conjunctival hyperaemia and oedema
- After prolonged administration – Irritation – Hyperaemia – Oedema – Conjunctivitis
What are the systemic side effects of cyclopentolate?
- Dose related – Children
- CNS effects
- Dry mouth
- Flushing
- Tachycardia
- Urinary symptoms
- GI symptoms
Other than for cycloplegic refraction what may cyclopnetolate be used for?
Adaptation to spectacles - although this is rare.
Alleviating ciliary spasms.
For anterior & posterior uveitis and posterior synechiae breakdown
When would atropine be used over cyclopentolate?
Atropine sometimes used when 1% cyclopentolate doesn’t produce adequate cycloplegia
What is hematropine hydrochloride and what is it used for?
A cycloplegic
– Used for dilating pupil in anterior uveitis – Alleviation of ciliary spasm following corneal abrasion
