Term
What is the purpose of cycloplegic refractions? |
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Definition
to evaluate the visual system with the ciliary muscle relaxed |
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Term
What are some indications to perform a cycloplegic refraction? |
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Definition
- suspected latent hyperopia
- suspected pseudomyopia
- esotropia
- children under 3
- variable or inconsistent responses
- amblyopia
- suspected malingering
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Term
What are some contraindications for performing a cycloplegic refraction? |
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Definition
- angles too narrow
- history of angle closure
- concurrent use of contraindicated medications
- allergy
- non-consent by patient or parent
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Term
What are some advantages to performing a cycloplegic refraction? |
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Definition
- makes latent refractive errors manifest
- eases determination of refractive error in amblyopia where the non-cycloplegic endpoints are difficult to determine
- allows determination of the full hyperopic refractive error of accommodative esotropes
- keeps hyper-active accommodation stable
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Term
What are some disadvantages to performing a cycloplegic refraction? |
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Definition
- retinoscopy is difficult due to peripheral aberrations (only pay attention to retinal reflex in central 4mm area)
- NOTE: if they have seizures, make sure they have taken your medications before doing ret on them
- potential adverse reaction to, and side effects of, the DPAs:
- photophobia
- blurred vision
- dry eye/mouth
- red eyes
- CNS reaction
- time consuming
- patient will be dilated for 24 hours so be sure to warn them of this and make sure they don't need to do near work during this time
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Term
What are the five parasympatholytics used for cyclopleging? |
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Definition
- Tropicamide
- Cyclopentolate
- Homatropine
- Scopolamine
- Atropine
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Term
Parasympatholytic:
Tropicamide
- Percentage:
- Cycloplegia Peak:
- Cycloplegia Recovery:
- Mydriasis Peak:
- Mydriasis Recovery:
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Definition
- Percentage: 0.5-1%
- Cycloplegia Peak: 20-30 minutes
- Cycloplegia Recovery: 4-6 hours
- Mydriasis Peak: 20-40 minutes
- Mydriasis Recovery: 4-6 hours
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Term
Parasympatholytic:
Cyclopentolate
- Percentage:
- Cycloplegia Peak:
- Cycloplegia Recovery:
- Mydriasis Peak:
- Mydriasis Recovery:
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Definition
- Percentage: 0.5-2%
- Cycloplegia Peak: 25-60 minutes
- Cycloplegia Recovery: 8 hours
- Mydriasis Peak: 30-60 minutes
- Mydriasis Recovery: 1 day
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Term
Parasympatholytic:
Homatropine
- Percentage:
- Cycloplegia Peak:
- Cycloplegia Recovery:
- Mydriasis Peak:
- Mydriasis Recovery:
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Definition
- Percentage: 2-5%
- Cycloplegia Peak: 30-60 minutes
- Cycloplegia Recovery: 1-3 days
- Mydriasis Peak: 40-60 minutes
- Mydriasis Recovery: 1-3 days
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Term
Parasympatholytic:
Scopolamine
- Percentage:
- Cycloplegia Peak:
- Cycloplegia Recovery:
- Mydriasis Peak:
- Mydriasis Recovery:
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Definition
- Percentage: 0.25%
- Cycloplegia Peak: 30-60 minutes
- Cycloplegia Recovery: 3-7 days
- Mydriasis Peak: 20-30 minutes
- Mydriasis Recovery: 3-7 days
NOTE: cycloplegic effect lasts longer than mydriatic effect
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Term
Parasympatholytic:
Atropine
- Percentage:
- Cycloplegia Peak:
- Cycloplegia Recovery:
- Mydriasis Peak:
- Mydriasis Recovery:
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Definition
- Percentage: 0.5-3%
- Cycloplegia Peak: 1-3 hours
- Cycloplegia Recovery: 6-12 days
- Mydriasis Peak: 30-40 minutes
- Mydriasis Recovery: 7-12 days
NOTE: cycloplegic effect lasts longer than mydriatic effect |
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Term
What parasympatholytic will we typically instill? |
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Definition
2 gtts 1% cyclopentolate instilled 3-5 minutes apart |
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Term
What are the medication guidelines concerning cycloplegic agents? |
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Definition
- selet a medication that provides adequate cycloplegia with minimal side effects
- infants to one year: use 0.5% cyclopentolate (also used on Down's patients)
- older children and adolescents: use 1% cyclopentolate
- people with darker eyes may require a stronger dose of medication in order to achieve the desired effect (melanin binds to medication, requiring more to be effective)
- use a smaller dose in children with Down syndrome or other central nervous system disorders
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Term
What six things must you do to prepare for a cyclopleged exam? |
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Definition
- obtain a manifest refraction
- completion of accommodative and vergence testing
- explain to patient and parent what you will be doing and why (explain they are stronger than normal dilating drops and will yield a better prescription)
- obtain patient and parental consent
- follow protocols for using DPA's
- pupils, angles, pressures, acuities
(I LOVE IT WHEN YOU CALL ME BIG PAPA) |
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Term
How do you determine that you have adequate cycloplegia? |
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Definition
NOTE: wait 30-60 minutes for full effect; must assess level of cycloplegia prior to testing
- comparing NRA and PRA recovery values:
- performed monocularly
- place +2.50 over best correction so they can see near card
- measure the NRA
- measure the PRA
- the dioptric difference between the recovery values for these two tests is the residual accommodation
- usually won't be 0 even when fully cyclopleged due to DOF
- adequate cycloplegia = < 1.00D of residual accommodation
NOTE: looking at the amount of mydriasis is NOT an effective method for this |
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Term
What should you keep in mind while performing retinoscopy? |
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Definition
the retinal reflexes may be distorted due to peripheral aberration of the dilated eye - be sure to neutralize the central 4mm reflex because this is where the pupil is! |
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Term
Will you often prescribe the entire cyclplegic refraction? |
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Definition
NO!
possible exception: accommodative esotropia
NOTE: JCC is often not accurate when cyclopleged because it will affect the axis, so don't even need to do JCC on wet refraction (get axis from dry refraction) |
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Term
Variables to take into account when prescribing:
Ciliary Tonicity |
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Definition
cut 1.00D from the wet refraction
(no matter how good the cycloplege is, there will usually be at least 1.00D of accommodation left) |
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Term
Variables to take into account when prescribing:
Age |
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Definition
cut more plus for younger patients
(puts final prescription closer to manifest refraction) |
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Term
Variables to take into account when prescribing:
Prescription History
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Definition
cut plus for adaptive reasons
(if never has had glasses, cut more plus to make adaptation easier) |
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Term
Variables to take into account when prescribing:
Residual Accommodation |
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Definition
cut more plus if you have a good cycloplegic effect |
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Term
Variables to take into account when prescribing:
Dry Refraction |
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Definition
cut more plus if the dry refraction is farther from the wet refraction |
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Term
Variables to take into account when prescribing:
Phoric Posture |
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Definition
cut less plus for an eso patient |
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Term
SIDE NOTE:
what does "cut less plus" means? |
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Definition
cut less plus = leave more plus in the final prescription |
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Term
What will the final prescription ultimately depend on? |
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Definition
- patient's needs
- what they will be able to adapt to
- what will give them the best acuity and alignment
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Term
What cylinder will you prescribe? |
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Definition
Usually the cylinder found with the dry refraction
(recall the inaccuracy of JCC when cyclopleged) |
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Term
Considerations for follow-up? |
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Definition
- likely necessary to have patient back to reassess their vision, posture and functioning with the proposed prescription
- keep in mind that they will likely accept more plus after they've been eased in
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