Cycloplegics

Question 1

Why do we use cycloplegics?

Answer 1

• Assessment of refractive error - to detect a latent hyperope
• Penalisation - instead of occlusion
• Adaptation to spectacles (rare) – vision clear only with glasses

Question 2

What are the ophthalomogicalical uses of cycloplegics?

Answer 2

• Anterior uveitis – in order to dilate pupil and alleviate ciliary spasm
• Corneal abrasion - alleviate ciliary spasm

Question 3

What are optometric indications from history and symptoms that you should use cycloplegics?

Answer 3

Symptoms:Asthenopia Reading difficulties

History: Manifest deviations

Family history: Refractive error at an early age + Manifest deviations

Question 4

What are optometric indications from clinical skills tests that you should use cycloplegics?

Answer 4

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

Question 5

What secondary effect do cycloplegics cause?

Answer 5

Mydriasis - widening of the pupil

Reduced tear secretion

Question 6

How do cycloplegics work?

Answer 6

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

Question 7

What structures do anti-muscarinic structures affect?

Answer 7

• Lacrimal gland • Iris sphincter muscle • Ciliary body

Question 8

What advice do you need to give before inserting a cycloplegic?

Answer 8

• Explain need to use • Onset • Duration • Expected side effects • Caution

Explain how drop may feel on eye

Question 9

What happens if consent for cycloplegics is denied?

Answer 9

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

Question 10

Do you need to fog eyes when doing a cycloplegic refraction?

Answer 10

No

Question 11

What do you need to bear in mind when doing a cycloplegic refraction?

Answer 11

Observe central movement - 3/4 mm

ignore peripheral movement.

Question 12

What cycloplegic drugs are available in order from strongest to weakest?

Answer 12

Question 13

From what plant is atropine derived?

Answer 13

Bella donna

Question 14

What is the ocular dosage for atropine?

Answer 14

1%

Question 15

Whats the disadvantage of using atropine?

Answer 15

It takes long to come into effect 30 mins and takes long to recover from 3-7 days.

Question 16

What considerations should be taken when using atropine?

Answer 16

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

Question 17

What are ocular side effects of atropine?

Answer 17

• Transient stinging • Blurring • Photophobia • Raised IOP?
• Repeated use can cause :

– Hyperaemia – Oedema – Itching, irritation – Follicular conjunctivitis

Question 18

What are general body side effects of atropine?

Answer 18

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

Question 19

Other than for refraction when may atropine be used?

Answer 19

For children non compliant with patching

Question 20

What is the most common cycloplegic?

Answer 20

Cyclopentolate ydrochloride

Question 21

What dosage is cyclopentolate availbale in and when is each used?

Answer 21

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

Question 22

What is the tonus allowance when refracting using atropine?

Answer 22

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

Question 23

What is the tonus allowance when refracting using cyclopentolate?

Answer 23

No tonus allowance made

• Almost always give full Rx found
• The only Exception to this is:

– Hyperopia and exo deviation – Myopia and eso deviation

Question 24

What are the onset and duration timings for cyclopentolate?

Answer 24

Cycloplegia – commences after a few minutes, maximal in 30-60 minutes, Recovery 4-12 hours

Question 25

In which patients do we need to be cautious about putting cyclopentolate drops in?

Answer 25

• 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

Question 26

What are ocular side effects of cyclopentolate?

Answer 26

• Transient stinging
• Transient blurring
• Photophobia
• Raised IOP?
• Conjunctival hyperaemia and oedema
• After prolonged administration – Irritation – Hyperaemia – Oedema – Conjunctivitis

Question 27

What are the systemic side effects of cyclopentolate?

Answer 27

• Dose related – Children
• CNS effects
• Dry mouth
• Flushing
• Tachycardia
• Urinary symptoms
• GI symptoms

Question 28

Other than for cycloplegic refraction what may cyclopnetolate be used for?

Answer 28

Adaptation to spectacles - although this is rare.

Alleviating ciliary spasms.

For anterior & posterior uveitis and posterior synechiae breakdown

Question 29

When would atropine be used over cyclopentolate?

Answer 29

Atropine sometimes used when 1% cyclopentolate doesn’t produce adequate cycloplegia

Question 30

What is hematropine hydrochloride and what is it used for?

Answer 30

A cycloplegic

– Used for dilating pupil in anterior uveitis – Alleviation of ciliary spasm following corneal abrasion