4 - Cycloplegic Refraction

Why do we use cycloplegia?

accommodation control

When do you ALWAYS perform cycloplegic exams?

first examination for children, strabismus, amblyopia

Why do we use cycloplegia?

accommodation control

When do you ALWAYS perform cycloplegic exams?

first examination for children, strabismus, amblyopia

Why type of strabismus do you always perform cycloplegic exams?

constant or eso

25% of children has at least _____ change from cycloplegic refraction

1D

True or False: you should cycloplege new patients

true

What are suspected accommodative problems that would indicate a cycloplegic refraction?

pseudomyopia, accommodative spasm, eso at near

What are other indications that would indicate a cycloplegic refraction?

TBI, inability to reach 20/20, suspected malingering, asthenopia, special needs, nonverbal, myopia control

What are the common topical cycloplegics?

tropicamide, cyclopentolate, atropine

Cycloplegic drops are _________

parasympatholytic

How do cycloplegic drops work?

block acetylcholine at the ciliary body muscle receptors to prevent contraction

How long does it take Tropicamide to cycloplege?

20-30 minutes

What is the duration of Tropicamide?

2-6 hours

How long does it take Tropicamide to fully cause mydriasis?

20-40 minutes

What is the duration of mydriasis in Tropicamide?

4-6 hours

How long does it take Cyclopentolate to cycloplege?

10-40 minutes

What is the duration of Cyclopentolate?

6-24 hours

How long does it take Cyclopentolate to fully cause mydriasis?

30-60 minutes

What is the duration of mydriasis in Cyclopentolate?

24 hours

How long does it take Homatropine to cycloplege?

30-60 minutes

What is the duration of Homatropine?

1-3 days

How long does it take Homatropine to fully cause mydriasis?

40-60 minutes

What is the duration of mydriasis in Homatropine?

1-3 days

How long does it take atropine to cycloplege?

1-3 hours

What is the duration of atropine?

6-12 days

How long does it take atropine to fully cause mydriasis?

30-40 minutes

What is the duration of mydriasis in atropine?

7-12 days

_______ has the most controlling effect on accommodation

atropine

What are the risks of any parasympatholytic?

hot as a hare, mad as a hatter, red as a beet, dry as a bone, blind as a bat

________ bears the most risk of side effects, ________ follows

atropine, cyclopentolate

What is atropine contraindicated in?

down syndrome

What should patients should you use caution with when considering use of Cyclopentolate?

down syndrome and CNS disorders

Instill ______ _______ of Cyclopentolate in each and repeat in ______-______ ______

1 drop, 3-5 minutes

Add 1 drop of ________ ________ for improved dilated

1% tropicamide

For <1 year old, use ______ ______

0.50% cyclopentolate

For >1 year old, use ______ ______

1% cyclopentolate

What is the recommended cycloplegic regimen for myopes?

2 gtt 1% tropicamide separated by 5 minutes is likely enough

Wait _____-______ minutes for individuals with darker pigmentation

30-40

Wait _____-______ minutes for individuals with little pigmentation

15-20

Cycloplegia is more dependent on _______ pigmentation than _______ pigmentation

skin, iris

Combination of Cyclopentolate plus Tropicamide may be ______ ______ than Cyclopentolate alone

more effective

Why you pay attention to the central reflex on wet retinoscopy?

pupil periphery will often still show with or distorted motion

What should you consider if there are reduced acuities on cycloplegic refraction?

brief subjective refraction, amblyogenic factor present

What is the purpose of calculating residual accommodation?

ensure the patient has adequate cycloplegia

Do NOT rely on __________ to determine cycloplegia

mydriasis

Up to 24% of ______ individuals show no evidence of cycloplegia with 1% cyclopentolate

black

_______ methods < ________ methods < _______ methods

objective, distance, subjective

How can you use distance blur to determine residual accommodation?

take 0.75 D off of the BSBVA and patient should report it is blurry

How can you use MEM to determine residual accommodation?

if lag is equal to working distance, than you have adequate cycloplegia

How can you use NRA/PRA to determine residual accommodation?

start with +2.50D over distance Rx, if post-cyclo the range between monocular NRA/PRA is less than or equal to 1.25 you have adequate cycloplegia

_______ change cycloplegic anisometropia

never

When do we consider cutting prescriptions?

hyperopic prescriptions

How do we cut hyperopic prescriptions?

0.75D to 2.00D

What to do we keep when cutting prescriptions?

keep full cylinder unless <3 years old

How can ciliary tone affect prescribing methods?

some patients may not tolerate full plus

Consider full plus for ______ and ______

esotropia, esophoria

Cut less plus with _______ individuals

older

What should you educate your patient on when prescribing post-cycloplegia?

the adaptation period, especially with hyperopia or astigmatism

What should you do on follow-up?

re-check vergence/accommodation/fusion, bill a medical diagnosis, re-cyclo if needed

If using Tropicamide, what should you write before refractive values?

damp

Only use Tropicamide in ________ and _____-____ returning patients

myopes, low-risk

What did the Tropicamide vs. Cyclopentolate study determine?

tropicamide did not work well enough on hyperopes