most of the slides i have collected from internet.

1. Cycloplegic
Refraction
MEHEDI HASAN

2. Cycloplegic refraction was first put in scientific basis by Donders, and
universally accepted after the publication of Donders - “ Anomalies of
accommodation and refraction of the eye” in 1864.
What is meant by Cycloplegic Refraction:
●Cyclo = ciliary, Plegic = Paralysis or palsy… Cycloplegic = Ciliary
Paralysis.
● Uses Anti-cholinergic agents and blocks response of ciliary muscle
and iris sphincter muscle which causes accommodation of the lens
relaxed and mydriasis .
A cycloplegic refraction is a procedure used to determine a person’s
complete refractive error by temporarily paralyzing the ciliary body
using cycloplegic eye drops . During this test the accommodation of
lens is fully relaxed .

3. Cycloplegia :
It is a condition when the accommodation is fully relaxed and the
retinoscopy findings for both distance and near remain same. The
completeness of the cycloplegia is determined by assessing the residual
accommodation by push up test. The mydriasis and cycloplegia do not
complete at the same time. Most often when there is complete
mydriasis the cycloplegia is considered to be complete for the
refraction . And the refraction may be unnecessarily delayed or
additional drug may be used unnecessarily.

4. Agents causing Cycloplegia :
Cycloplegics inhibit the action of the acetylcholine on the effectors sites
innervated by the autonomic nerves. They block the muscarinic
receptor sites. They are also called as anti- muscarinic , cholinergic
antagonists.

5. Cholinergic receptors :
The cholinergic receptors in human eye have been found in the iris
sphincter and the ciliary body, it is one of the muscarinic type. Five sub
types of muscarinic receptors(M1-M5)have been identified. The
muscarinic agonist takes action at the receptor which constricts the
pupil, contracts the ciliary muscles and in general lower IOP. The
inhibition of these receptors by the cholinergic antagonist induce the
pupillary dilatation and paralysis of accommodation.

6. Cycloplegic agents :
1. Atropine Sulfate .
2. Homatropine hydrobromide .
3. Cyclopentolate hydrochloride .
4. Tropicamide.

7. Atropine
• Natural Alkaloid.
• First isolated from the belladonna plant ( Atropa belladonna).
• Commercially available as in 1% eye drop or 1% ointment.
• Onset of action is slow ( 3 to 6 hours to reach maximum) but duration
of action lasts up to 2 to 3 weeks .
•Applied 3 times daily for 3 days (both ointment and drop) and the test
is done on 4th day.

8. Side effects :
●Direct irritation from the drug itself.
● Risk of angle closure glaucoma.
• Dry mouth and increase thirst.
• Fever
• Urinary retention
• Excitements, restlessness
• Speech disturbances.
• Ataxia
• Convulsion

9. Death of six reported cases have occurred in children 3 years
of age or younger.
Atropine contraindications:
• Hypersensitivity to the belladonna alkaloid.
• Have open angle or angle closer glaucoma
• Have tendency towards IOP elevation.
•CP and Epilepsy patients. Etc.

10. Homatropine
• One tenth as potent as atropine.
• Shorter duration of mydriasis and cycloplegia than atropine. Duration
of action lasts up to 3 to 5 days.
• It is not the drug of choice for the cycloplegic refraction most often.

11. Cyclopentolate
• Mostly used.
• Commercially available as 0.5%,1%,and 2% solution.
• Drug of choice for the routine in nearly all age group, especially
young children (5-14 years).
• Faster onset of action and shorter duration of effect.
• Cycloplegia occurs in 45-90 minutes of instillation and duration of
action lasts for 24 to 48 hours.

12. Side effects of cyclopentolate:
• Burning sensation on initial instillation.
• Allergic reaction to cyclopentolate are rare and may be seemed.
• Symptoms of irritation and diffuse redness , facial rash that develops
within minutes to hour of instillation.
• Lacrimation and blurred vision.
• Disturbance in speech .
• Restlessness.

13. Tropicamide
It is considered inadequate for children cycloplegia.
● Widely used as mydriatic agent.
● Available in 0.5 and 1% solution.
● Cycloplegia in about 30 minutes.
● Duration of action is up to 2-6 hours.

14. Side effects
1.Blurred Vision
2.Photophobia
3.Eye irritation
4.Dry mouth
5.Skin rash
6.Upset stomach or throwing up

15. Why would anyone need a cycloplegic refraction / Indications :
Cycloplegic refraction is usually performed on children as they can accommodate
too much. Also children tend to change focus at a closer object and unable to
maintain their focusing when it is needed to look at a far distance during
examination.

16. Other indications :
● Latent Hyperopia & Hyperopia
● Strabismus & Nystagmus.
●Young children who have symptoms but not significant refractive error.
●Non-cooperative patients.
●Amblyopic children.
●Suspected malingering & young children.
● Pseudo myopia , Etc.

17. Post Mydriatic Test ( PMT )
Assessment of the finding of cyclo-refraction by subjective means after
the effect of cycloplegia is eliminated. In case of cyclopentolate this test
is usually done after 3 days and 1 month later on in case of atropine.
Note :
If the patient is Hypermetropic , Give the most PLUS(+) power possible
without reducing VA.

18. What does our practice say :
●Advise atropine for cycloplegic refraction under 3 to 4 years of age.
●Advise cyclopentolate for above 5 to 15 years of age.
●In objective refraction, we will need to reduce extra more +1.00 DSP in
case of atropine and extra more +0.50 DSP in case of cyclopentolate.
● In case of esotropia, give the full correction in hyperopia and under
correction could be given in myopia .
●In case of exotropia, give the full correction in myopia and under
correction could be given in hyperopia.

19. References
●American Academy of Optometry (AAO)
●Recent Journal of Optometry Articles from ELSEVIER
●Clinical ophthalmology - Jack J Kanski
●Pediatric Ophthalmology & Strabismus - AOA
●Internet.

20. Thanks All.