Cycloplegic Refraction PDF

Cycloplegic Refraction Ariette Acevedo Rodríguez, O.D. Principles and Practice of Primary Care Optometry 4 1 Cycloplegic Refraction Static retinoscopy provides information, while controlling accommodation to some extent. Patie...

Cycloplegic Refraction Ariette Acevedo Rodríguez, O.D. Principles and Practice of Primary Care Optometry 4 1 Cycloplegic Refraction Static retinoscopy provides information, while controlling accommodation to some extent. Patients with significant hyperopia, latent hyperopia or accommodative esotropia may mask much of their hyperopia during non-cycloplegic retinoscopy (Dry refraction). Additional latent hyperopia may be uncovered using a fogging procedure or cycloplegia. have Bee's high A good indicator that there is latent hyperopia is a “lag” of accommodation determined with different methods (including MEM retinoscopy). 2  T 11 Hyperopia Classification M2 11 FA According to the role of Accommodation in Visual Function Manifest Facultative amount : can compensate that Absolute · amount absolute minimum that's needed & can't compensate Latent Total Facultative Hyperopia: hyperopia which can be compensate by accommodation. Absolute Hyperopia: hyperopia that cannot be compensate with accommodation. 3  Hyperopia Classification s what we find Manifest Hyperopia= Absolute + Facultative Latent hyperopia is when all or part of the patient’s hyperopia is ↑compensated by the tonicity of the ciliary muscle. out comes This is very common in young hyperopes, they do a great job accommodating in wet refraction and this accommodation cannot be relaxed during routine refraction, thus needing cycloplegia. 4 Example 6 y/o HF CC: no complaints, but parents notice patient gets tired quickly while studying. Objective Refraction: OD: +3.00DS OS: +3.00DS Subjective Refraction: OD: +2.00DS OS: +2.00DS - Manifest Uncorrected +3.00 D hyperopia with 1.00D of accommodation. Absolute hyperopia: 2.00D abs > - , clearly Minimum to see Facultative hyperopia: 1.00D williningly to accommodate - After Cyclorefraction (Wet refraction) OD: +5.00DS OS: +5.00DS Latent hyperopia: 2.00D that > - hidden & were Ayllo. came outin Total hyperopia: 2.00D (absolute) + 1.00D (facultative) + 2D (latent)= 5.00D 5 Absolute vs Facultative Hyperopia Facultative hyperopia can (at will) be compensated by accommodation. Anything not manifested in dry refraction (objective) is latent hyperopia. The patient cannot control the compensation by accommodation as a result of increased tonicity of the ciliary muscle (either by constant spasm of accommodation or intermittent [clonic] spasm). Latent hyperopia needs cycloplegic refraction or fogging techniques to unmask. 6 Cycloplegic Refraction It is the refractive procedure used to evaluate a patient’s refractive error in the absence of accommodation. This is performed by using cycloplegic drugs: effect w/minimum best Atropine Homatropine Cyclopentolate Tropicamide Scopolamine 7 Cycloplegic Agents Cycloplegic agents act by antagonizing the muscarinic action of acetylcholine (cholinergic antagonist).blocking acctylcholine Indry effects paralyze body : cil. &iris Block muscarinic receptors thus causing inhibition of all muscarinic functions. Cholinergic receptors are found in the iris and ciliary body. These agents paralyze the iris sphincter causing mydriasis and the ciliary muscle causing cycloplegia. mydhatic - not not 85-90 % dilate well but Cyclo's · but thatdoes not will complain photophobia anable to see near all pupils dilate mean they're not cyclo 8  sympathetic : fight flight or Cycloplegic Agents Cycloplegic agents inhibit the action of acetylcholine → block the muscarinic receptor sites → block the parasympathetic system → balance/vest digest sympathetic system predominates: ↳ Thus producing mydriasis and cycloplegia The sphincter muscle is innervated by cholinergic fiber to muscarinic receptors. Its contraction under the influence of an agonist results in miosis, and its blockade by cycloplegic/mydriatic agents results in mydriasis The radial muscle is innervated by adrenergic fibers to alpha-1 receptors. Its contraction by an agonist results in mydriasis and its blockade results in miosis. 9 When Ach Stimulates Muscarinic receptors All these are parasympathetic Digestive Tract: effects from acetylcholine Saliva secretion stimulating the muscarinic Stomach acid secretion receptors. Peristalsis Muscarinic receptor types mediate slow metabolic response and nicotinic Other effects: mediate a fast synaptic transmission. Decreased heart rate Bronchial constriction Eyes: Enhanced urination Miosis Lacrimation Accommodation Decreasing IOP 10 Cycloplegics Anticholinergics: inhibit muscarinic receptors in the iris sphincter and ciliary body. Cyclopentolate Atropine Homatropine Scopolamine Tropicamide d acenagics Sympathomimetics: stimulate adrenergic alpha receptors. Phenylephrine, Hydroxyamphetamine Snuge Good mydriasis, but POOR cycloplegia 10 mm dilation 11 Atropine Doc for cyclo. Lued in extreme cases of nveitis (avoid post Synechiae 3 N inflammation). Naturally occurring alkaloid. First isolated from the belladonna plant (Atropa belladonna). Nonselective muscarinic antagonist. Most potent mydriatic and cycloplegic agent presently available. Depending on the concentration, mydriasis may last up to 10 days and cycloplegia for 7 to 12 days. Commercially available as a sulphate derivative in 1% solution or 1% ointment. I can take 770d to Nd can take 1-2 days to take effect 12 Atropine Mode of Action Reduce pain from ciliary spasm. Prevents the formation of posterior synechia from secondary iridocyclitis. Increases the blood supply to anterior uvea Brings more antibodies in the aqueous humor Reduces exudation by decreasing hyperemia and vascular permeability 13 Atropine use in cyclorefraction Often used for cycloplegic refraction in young, actively accommodating children with suspected latent hyperopia or accommodative esotropia. 0.5% up to 1% Also used for myopia control - prevention of myopia control Othol's also 0.01%, 0.02%, 0.025%, 0.05% (MiSight, placebo according to research ↳same as Atropine is not typically used for routine cycloplegic refraction in school aged children or adults due to the prolonged paralysis of accommodation which handicaps the patients near vision and prolonged mydriasis leading to photophobia. 14 Atropine use in cyclorefraction Use in the case of esotropia with suspected accommodative component, which may lead to a permanent deviation. Treatment of myopia: to prevent or slow down the progression of myopia by placing the ciliary muscle at rest accommodation is relaxed and the tension that produces elongation of the eye may be reduced. Treatment of amblyopia: penalization treatment for mild and moderate amblyopia treatment. Atropine the better VA eye, thus producing blur and forcing the patient to use to amblyopic eye. 15 Atropine Side Effects Ocular side effects Direct irritation: drug instillation without anesthesia irritates. If the patient complains add anesthesia before cyclopentolate. Allergic contact dermatitis Risk of angle closure glaucoma ALWAYS CHECK… as children are not exempt from this Elevation of IOP in patients with open angles Check post dilation IOP 16 Atropine Side Effects Systemic Side Effects Atropine Contraindications common Diffuse cutaneous flush Hypersensitivity to belladonna Dry mouth, thirst and dry eyes alkaloid Fever OAG or CAG Urinary retention High IOP Tachycardia, arrythmia, myocardial infraction Excitement, restlessness Speech disturbance Ataxia (loss of muscle coordination) Seizure Personality changes 17 Cautions when using Atropine Repeated use of parasympatholytic is contraindicated because of teratogenic effects. Contraindicated in breastfeeding mothers due to anticholinergic and hypertensive effects.D Use with caution in pediatric patients due to low margin for toxicity. Antidote is physostigmine. 18 Other Agents Homatropine vX for ivitis uveitis 1/10th as potent as atropine. Shorter duration of mydriasis and cycloplegia than Atropine. It is not the drug of choice for cycloplegic refraction due to its prolonged mydriatic and cycloplegic effect. 1-3 days mydriasis Not the drug of choice for cycloplegic refraction or dilated fundus exam but good for anterior uveitis. 19 Other Agents for Scopolamine motionsickness-pupi used dilates Nonselective antagonist. Maximum cycloplegic effect in 40 minutes and lasted for at least 90 minutes. Can take up to 3 days for accommodation to return back to a level where the average patient can read. Mostly used for patients with a sensitivity to Atropine to treat anterior uveitis. aHematropine 20 Cyclopentolate - Golden child" Available in 0.5%, 1% and 2%. > - reserved for uveitis or inflammatory purpsens Cyclogyl It is the drug of choice for routine cyclorefraction in nearly all age group, especially in infants and young school aged children. Faster onset of action with a shorter duration of effect. Cycloplegia occurs in 30-45 minutes. Full recovery of mydriasis and cycloplegia within 24 hours. For children under the age of 3: 1 or 2 gtt 0.5% - For children above the age of 3: 1 or 2 gtt 1% Not recommended for use in infants, small children, children with brain damage, spastic paralysis or Down’s Syndrome. - Spina bifida or any newso. effects 21 Cyclopentolate Ocular Side Effects: Transient stinging on initial instillation Lacrimation Blurred vision Allergic reactions to cyclopentolate are rare and may be unrecognized by practitioner. Symptoms of irritation and diffuse redness, facial rash that develops within minutes to hour of instillation. 22 Cyclopentolate Systemic Side Effects: Drowsiness Ataxia Disorientation Disturbance in speech Restlessness Cyclopentolate tends to have more CNS side effects than Atropine. These are more common in children with the use of 2%, but multiple instillations of 1% may cause the same symptoms. 23 Tropicamide Available in 0.5% and 1% concentration. Mydriacyl Short duration cycloplegic Cycloplegic effect in about 30 minutes Recovery occurs within 2- 6 hours. Considered inadequate for cycloplegia in children Widely used as a mydriatic agent we combine tropicamice Cyclo for fulleffect children a in · does not talk more than 24 ms for dilation togo anay 24 45 min is the perf time to. 25 do wet refal. 26 General Rules Select the drug that provides adequate cycloplegia with minimal toxicity risk. Light irises are more responsive to drugs. Dark irises tend to need stronger doses or multiple instillation. Not always the case, different patients react differently Low weight infants (premature) use lower doses Children with CNS disorders may have increased reactions to cycloplegics Dapiprazole (Rev-Eyes) used to reverse mydriasis but has no effect on cycloplegia (not available anymore) 27 General Rules The need for cyclorefraction decreases markedly with age. Patients over 40 years of age are not expected to have latent hyperopia. Perform cyclorefraction in young adults only if latent hyperopia is suspected. If patient presents with asthenopia complaint for near work but has no uncorrected refractive error or binocular abnormalities. 28 Uses of Cyclorefraction Determine refractive error It is standard of care in children. Be careful with overminusing Detect latent hyperopia have lov amplitude blo High hyperopia Small pupils for age (possibly due to accommodation) Differential Diagnosis Strabismus (especially esotropias or high esophorias) Low AoA for age Fluctuations of accommodation or refraction Rule out pseudomyopia 29 Uses of Cyclorefraction Non-responsive patients Objective and subjective findings do not correlate Ex: Entrance VAsc 20/25 OD/OS/OU Refraction -1.50D OD and OS 30 Cyclorefraction Procedure Always perform a dry refraction and a trial frame for maximum plus most VA before performing cyclorefraction. Trial Frame Start with subjective refraction. Take VAs Do +/- 0.25DS for MPMVA Do axis and cylinder power checks (spherical equivalents) Review VAs at distance and near Have patient walk around and asked them for any discomfort Before Cycloplegia every patient needs: Blood pressure Van Herrick angles IOP (Goldmann, NCT, Icare) Pupils check VA at D and N Medicolegal aspect 31 Cyclorefraction Procedure Every patient needs to be E&U on the procedure. If child, the parent must be educated, and the child explained what you are going to do. Parent must consent and child must at least assent to the procedure. Instill 1 gtt Proparacaine 0.5% OU Provides better absorption of the drug due to the disruption of epithelial cells leading to better penetration of the drug. Provides less discomfort when instilling cycloplegic. 1 gtt Cyclopentolate 0.5% or 1% Depends on the case Do punctum occlusion for less systemic absorption Repeat in 5 minutes in necessary Before instilling any drop verify drug name, concentration and expiration date.* 32 Recommended Regime for a DFE Adults: purely a mydatic good mydlatic s has cyclo. Phenylephrine 2.5% + Tropicamide 1% Repeat in 15 to 30 minutes if not dilation achieved Children if over 3 y/0 Phenylephrine 2.5% + Tropicamide 1% + Cyclopentolate 1% Repeat in 25 to 30 minutes if eye is not dilated or if patient has good nearUAVA myopes may still have nea Infants > 3ylo ; everything cut by2 good Phenylephrine 1% + Tropicamide 0.25% + Homatropine 2% or Cyclopentolate 0.5% (for infants older than 1-2 months up to 3 y/o) Repeat in 35 to 45 minutes if eye is not dilated 33 Cyclorefraction Procedure problem : once dilated-photophobic Do retinoscopy after cycloplegia is reached reflexes are a confusing- Scissor reflex little I must look a center of pupil Check near VAs but careful with myopes Objective refraction with VA Document Wet Retinoscopy 20125 when cyclo is still good Subjective, if necessary, without binocular balance Be careful with cylinder, changes may occur due to spherical aberration due to larger pupil and loss of accommodation. No trial frame after cycloplegic refraction when dilated L they won'thave the definition to tell. diff trial frame I blink pt back another day for always do trial frame before dropping ↳ 34  +5 00 Cyreflac 20/20 DEN happy Cyclorefraction Procedure -. ,. +9. 00 - wet AR do NOT +9 00 ! give. - bling back 3-6 mo 3 ↑ until theytolerate Patient may not accept the full wet retinoscopy. - give +5 00. TF done before is starting point, if no significant change is seen final SRx may be released If a big change is seen, TF has to be repeated at least one day after cyclorefraction and SRx to MPMBVA Prescription general rules accomm Is not accomm : eso's once cyclo. - Significantly NN or disappears Children: Full Rx. Accommodative strab, accommodative anomalies and hyperopia Normal findings include and increase of +0.50 to +0.75, anything over this is considered latent hyperopia. Consider symptoms always Young adults/adults SRx to MPMBVA where the patient is comfortable and can tolerate 35 Record Keeping Patient consent, if patient does not consent record the reason why. Ex: Driving, has children to take care, must return to work, patient declined due to time constraint, ect… Pharmacological agent Amount of drops instilled in each eye Time administered IOP post procedure Example: “Patient and parent were E&U cycloplegic and dilation procedure and side effects. Dilation consent form was signed/consent was given. 1 gtt Proparacaine 0.5% OD and OS @ 1:00pm 1 gtt Tropicamide 1% OD and OS @ 1:05pm 1 gtt Cyclopentolate 1% OD and OS @ 1:10pm, then 1 gtt OD and OS @ 1:15pm.” 36 Downside of Cycloplegia Painful, unwanted drops Incomplete absorption and effect Prolonged exam time Pediatric and developmentally delayed patient often dislike or are emotionally traumatized by cycloplegic instillation, especially repeated instillation. 37 Why is it Important? In hyperopes, VA may be reduced at times, especially at near but in latent hyperopia VA is usually normal. These patients tend to have inconsistent levels of N and occasional D VA when having visual fatigue. Patients with moderate and high hyperopia are at a significantly increased risk for refractive and strabismic amblyopia. Hyperopia above +3.50D is a recognized risk factor Those that have never been optically corrected are at risk for isoametropic amblyopia. It is likely that latent hyperopia is a better predictor of amblyopia than cycloplegic hyperopia because many children compensate for their hyperopia with a robust accommodation. amblyopia : metropic ~ 38 Delayed Subjective Refraction, Cyclodamia and Mohindra Retinoscopy Techniques for maximum relaxation of accommodation without cycloplegia 39 Delayed Subjective done after rubj. refraction Done to maximize relaxation of accommodation and acceptance of plus. Good for hyperopes and accommodative spasms This is performed AFTER the routine subjective refraction 40 Method 1 Fog with +2.00DS OD and OS Present 20/200 letter If not blurry, add more plus until blurred Ask the patient to keep looking at the letters trying to focus (binocularly) Wait 5 minutes If the patient cannot focus the letters: reduce -0.25DS steps (MPMVA) If the patient can focus the letters: go to the next line, do MPMBVA Continue procedure until patient sees 20/20 Confirm with duochrome 41 Method 2 Will use the value of Negative Relative Accommodation (NRA), which has to be determined in the near tests. Use near rod at 40cm and 20/20 line Binocularly add plus until sustained blur of the letters. Keep the NRA and ask the patient to look at the ≥20/200 distance target (should be blurry) Reduce plus in -0.25DS steps until patient can achieve 20/20 (this is MPMBVA) Confirm with duochrome test 42 Cyclodamia Cyclodamia: relaxing accommodation without cycloplegia Was known as maximal accommodation relaxation After retinoscopy keep the fogging lenses used to relax accommodation Slowly reduce spheres BINOCULARLY until MPMBVA Refine cylinder using fogging techniques (clock dial), with opposite eye uncovered Ametropia revealed will be very close to the one under cycloplegia 43 Mohindra “Near” Retinoscopy The Mohindra technique (also referred as near retinoscopy) is a very useful technique with children Studies have shown a good correlation between this technique and “wet” retinoscopy in low/medium hyperopia However, a poor correlation is shown in children with esophoria or esotropia and the actual hyperopia present. 44 Procedure Darken the room lights as much as possible Position yourself 50cm away from the patient on the same height and visual axis Dim the retinoscope light to be comfortable to the patient Have the child fixate the light Preferably use skiascopy bars or loose lenses Neutralize the two principal meridians and do an optical cross Use adjustment power of 1.25D (not 2.00D) This is because of the lag of accommodation when performed at 50cm is ~0.75D. 45