challenges in pediatric refraction. Practical approach pptx

Description about pediatrics Refraction

1. Sarbind Kumar Yadav M.Optom , CLEP (J &J Vison care, India) Senior Consultant Optometrist Ramlal Golchha Eye Hospital Foundation, Biratnagar CHALLENGES IN PEDIATRIC REFRACTION

2. Introduction

3. what is required in pediatric refraction?? This technique must be appropriate for non- verbals , un-cooperatives, non- communicatives in child’s parts. This technique must provide important information in refractive state of eye repeatably and reliably in instrumental part. Must be understandable, easily assessable and accessible. Practitioner must be competent enough to deliver a perfect judgement .

4. How is it different from normal refraction??? Objective refraction is usually used to determine refractive status of infants and preverbal children. Meticulously and accurately done Great expertise is necessary Should understand emmetropization and relation between state of BSV and refractive status of child Techniques must me easily understandable Cycloplegic refraction is preferable due to active accommodation in child

5. Pediatric vision development Age Visual characteristics Stereoacuity Birth – 4 months Conscious fixation on near object Development of sensory and motor fusion Not present 5 – 8 months Good colour vision Fovea well developed Some sensory & motor fusion Begins at 5 months 9 -12 months Able to grasp objects Sensory and motor fusions well developed Can judge distances fairly well and throw things with precision 1 – 2 years Highly interested in exploring their environment looking and listening Well developed

6. Emmetropization “ The total emmetropization process occurs mostly during the first 4 -5 years of life with both initial myopia and hyperopia converging on low hyperopia and by 6 years, 80% of children are found to be emmetropic ” Thorn B, Bauer J et al, 1996 “ At birth, the average amount of astigmatism is predicted to be 2.98D, decreasing to 0.50D by 2.5 – 5 years of age” Mohindra I ,Held R, 1991 Active process Passive process Regulated by retinal image Visual deprivation causes the eye to elongate Physical and genetic determinants of normal eye growth “ development of high ametropia , usually because of genetic inheritance” Sorby et al 1998

7. TYPES OF PEDIATRIC REFRACTION Objective Refraction Static Retinoscopy Dyanamic Retinoscopy Manifest Cycloplegic MEM Bell BOOK Chromoretinoscopy Subjective Refraction with/without cycloplegic

8. CHOICE OF REFRACTION FOR DIFFERENT AGE GROUPS inf ii Infants Preschool School A ged Mohindra retinoscopy Retinoscopy with/without cycloplegic Photorefraction Keratometry Retinoscopy with/without cycloplegic MEM retinoscopy Subjective refraction Book retinoscopy Keratometry Manifest / cycloplegic retinoscopy Dyanamic retinoscopy Subjective refraction

9. Indication of Cycloplegic Refraction Indications With strabismus Uncooperated patients (8 years or younger) Latent hyperopia Pseudomyopia Inconsistent end point of refraction

10. Additional Indication Every nonverbal and non communicative children Patient with high heterophoria Accommodative esotropia ( atropine is the best choice) Accommodative asthenopia Poor reliability between dry retinoscopy objective finding with subjective finding

11. MEASUREMENTS TO BE DONE BEFORE INSTILLING CYCLOPLEGICS Visual Acuity (near /distance) History Medical Allergic Emotional ` Hyperemia in conjunctiva Accommodation and Binocular Status AC/A Ratio AC angle and IOP Manifest refraction Pupillary reflex and Size under room illumination

12. Guidelines for Cycloplegic agents Atropine cycloplegic refraction is advised in the younger than 5 years Atropine is advised in esotropic children (accommodative type) up to 4 years After 5 years, cyclopentolate is advised up to 25 – 30 years. Above 30 years of age, amplitude and lag of accommodation is checked and cycloplegic refraction is advised

13. WHY CYCLOPLEGIC REFRACTION?? To stop eye’s ability to auto focus or accommodate in order to determine true prescription. When the eye contracts and relaxes, the lens shape changes its shape. Cycloplegics paralyses ciliary muscle and the lens can no longer change its shape and hence there is no chance of accommodation. In children they have the great ability to vary their accommodation.

14. Contraindications Narrow angle glaucoma Hyper sensitivity to specific cycloplegic drugs Adverse Effects Blurred Vision Photophobia Systematic side effect except tropicamide

15. Caution Cyclopentolate may produce oedma , follicular conjunctivitis & dermitis in some patients Cyclopentolate may produce exaggerated seizure in children’s with epilepsy Overdose of cycloplegic agent has to be avoided in children with Down’s syndrome or other affected cerebral plasy , trisomy 13 & 18, and other central nervous system (CNS) disoders because it produces hallucinogenic effect

16. Subjective Refraction Indications cooperated patients (8 yrs & older) Without strabismus Consistent BCVA

17. 5 W’s of Refraction W ho W hat W here W hen W hy

18. Difficulty in retinoscopy

19. Possible causes Solutions Opaque / hezy ocular media In most cases, it is overcome by use of mydriatics * Small pupil size Use of mydriatics * High degree of refractive errors Follow up case: check PGP to get a rough estimation First examination: if reflex is dull, try -7 first and then +7. if reflex is still dull proceed to 15D or 20D , untill the reflex is visible and proceed from there * Perform all the indicated investigation and rule out contraindication before dilating

20. Possible causes Solutions Wandering fixation Give a specific fixation target Abnormally active accommodation Fogging technique Cycloplegic refraction may be required

21. Possible causes Solutions High astigmatism Rotate the retinoscopic beam to find angle where scissor reflex is minimum Nebular corneal opacity Increase retinoscopic illumination to decrease pupil diameter . Spot retinoscopy may be helpfull

22. Possible causes Solutions Irregular astigmatism Do keratometry and prescribe minimum power that gives maximum visual acuity. Subjective refraction may also be done in school going children. Keratoconus Relate refraction to visual acuity Perform corneal topography Perform keratometry

23. Possible causes Solutions Positive aberration (in normal accommodating lens) Increase retinoscope illumination to decrease pupil diameter Concentrate on the centrral bright glow and ignore the peripheral glow Negative aberration (more in lenticular nuclear sclerosis Increase retinoscopic illumination Perform cycloplegic refraction

24. What is the greatest challenges to pediatric refraction A great ability of a child to maintain wide range of accommodation Un-cooperation Greater range of accommodation Difficulty in quantifying visual status Risk of visual deprivation Difficulty in making a child understand to wear glass. so, cycloplegic refraction must be carried out in every patient with or without strabismus

25. Additional challenges of pediatric refraction Nystagmus Strabismus Aphakia Small pupil Cataract Corneal opacity Faint retinoscopic reflex

26. In case of nystagmus , retinoscopy should performed in the null zone if such is present In case of strabismus, the child is asked to alter gaze to another fixation (or close to eye) so that the tested eye is better positioned And should perform retinoscopy slightly off axis In case of aphakia , the retinoscopy should performed after dilatation

27. Redical retinoscopy This technique is applied in case of small pupils, cataract, media opacity and faint retinoscopic reflex Instead of performing at usual working distance, the examiner move closer to the patient. So, that observable reflex can be obtained May involve working distance as close as 20 cm or 10 cm Finally, the dioptric poer of the WD is deducted from the retinoscopic value

28. Example – the retinoscopy value = +3.00DS/ -1.50X 90 Working distance = 20cm i.e. +5.00D Net retinoscopy value = - 2.00DS/ -1.50X90

29. GUIDELINES FOR PRESCRIPTION IN HYPEROPIA Infants (0 -1 yrs) Isometropic Hyperopia Deviation + ce ( eso ) Deviation – ce Full cycloplegic correction given when error is (>or = 2D) and regular F/U for error bellow this Prescribe only when error is (>= 5D ) i.e. partial or or 3/3 rd prescription is advised

30. Cont…. Infants (0 – 1 yrs) Hyperopic anisometropia <2.50D > Or = 2.50D No prescription needed ( follow up 3 - 6 monthly Partial prescription (no deviation) Full prescription ( esodeviation + ce )

31. Cont….. Toddlers (1 – 3 yrs) Isometropic Hyperopia Deviation + ce ( eso ) Deviation - ce Full cycloplegic correction given when reeor is (> or = 2D) and regular F/U for error below this Prescribe only when error is (> or = 3.5 D i.e. 3/3 rd prescription is advised

32. Cont…. Toddlers (1 – 3 yrs) Hyperopic anisometropia < 2.00 D > Or = 2.00 D No prescription is required ( F/U 3-6 monthly) Partial prescription ( no deviation) Full prescription ( eso deviation + ce ) Note : if exodeviation is associated plus correction must be reduced

33. Cont… Preschool (3 – 6 yrs) Isometropic hyperopia Deviation + ce ( eso ) Deviation - ce Full cycloplegic correction given when error is (> or = 1.5 D) and regular F/U for error below this Prescribe only when error is ( > or = 2.50 D) i.e. partial or 2/3 rd prescription is advised

34. Cont… Preschol (3 – 6 yrs) Hyperopia ( Anisometropic ) < 1.50 D > Or = 1.50 D No prescription required ( F/U 3-6 monthly) Partial prescription (no deviation) Full prescription ( esodeviation + ce ) Note: if exodeviation is associated plus correction must be reduced

35. School age ( above 6 years) Cycloplegic refraction is always recommended when hyperopia is present in initial retinoscopy . Science good vision is necessary for both near and distance, proper correction is needed for better academic performance. At school age children are expected to be nearly emmetropic . Isometropic error (> or = 1.00 D) without symptoms is indicated for correction. A full or near full correction may be given at this age, as emmetropization ended. Hyperopic anisometropia (> or = 1.00 D) needs full correction

36. Guidelines for prescription in myopia Infants (1 – 3yrs ) Infants with low to moderate myopia may not need prescription. Because they don’t need to view things in fine details. But AAO gives prescription guidelines in such condition as:- Isometropic Myopia < - 5.00 D > Or = -5.00 D Not required to prescribe ( constant monitoring) Required prescription ( reduced by 1-2 D) AAO suggests prescription of glasses when myopic anisometropia is (> or = 2.50 D) in infants to reduce chances of amblyopia . High amount of myopia at birth is likely to produce esotropia becoz far point is very close to eye.

37. Toddlers ( 1 – 3 yrs) No prescription is given for low myopia in toddlers but given for moderate and high myopia. Prescription guidelines as per AAO Isometropic myopia < - 4.00 D > Or =-4.00 D No need to precribe ( constant monitoring) Needs prescription ( reduced by 1- 2 D) ( Fr no deviation) Example : highly myopic children appear to do well without correction and cannot always tolerate their full prescription. A 1.5 year myope requiring -10.00 D may cope better with -7.00 D for a few months before, gradually increasing the prescription.

38. For muscle imbalances For eso deviation : minimum minus for clear vision For exo deviation : maximum minus for clear vision AAO suggests anisometropic Mypia of > = 2.50 D needs prescription in toddlers to prevent probable chance of amblyopia & deviation

39. Preschool age (3 - 6 yrs) Isometropic Myopia < - 3.00 D > Or = -3.00D No need to prescribe ( costant Monitoring) Needs prescription (reduced by 1-2 D) For no deviation

40. for muscle imbalances For eso deviation : minimum minus for clear vision For exo deviatio : maximum minus for clear vision AAO suggests anisometropic myopia > or = 2.00D needs prescription in preschool to prevent probable chance of amblyopia an deviation. Similarly if amblyopia is associated with myopia but no strabismus 2/3 rd of cycloplegic correction can be given for children’s below 6 yrs.

41. School age (above 6 years) Full prescription must be given to abolish amblyopia , deviation & avoid symptoms like squinting eyes. Over correction must be avoid becoz overcorrecting myopia can be determined and may cause accommodative spasm leading to severe asthenopia and esotropia . Slight under correction is done in esophoric children of more than 6 yrs. In high myopia (> or = 10.00) full correction can be can not be tolerated so under correction is recommended. for muscle imbalances For eso deviation: minimum minus for clear vision For exo deviation: maximum minus for clear vision Similarly in anisometropic myopia (> or = -3.00D ) must be prescribed to prevent amblyopia .

42. Guidelines for prescription in Astigmatism Infants (0 – 1 yrs) Isometropic Astigmatism < 3.0D > or=3D Not required prescription (constant monitoring) Required prescription i.e. 3/4 th can be given (prefer to monitor in F/U) Anisometropic Astigmatism <2.50D > Or=2.5D Not required to prescribe (constant monitoring ) Required prescription Prescribe only after monitorung and without hampering emmetropization

43. Toddlers (1 – 3 yrs) > or = 2.5 D Isometropic Astigmatism Anisometropic Astigmatism < 2.50D < 2.00D >Or = 2.00D Not required prescription (constant monitoring) Required prescription i.e. 3/4 th can be prescribe Not required prescription (constant monitoring) Required prescription Prescribe full if amblyopia is present

44. Preschool (3 – 6 yrs) Isometropic Astigmatism Anisometropic Astigmatism < 1.50D < 1.50D >or= 1.5D Not required to prescribe (constant monitoring) Needs full prescription (reduced prescription can be given first to adapt) Not required prescription (constant monitoring and F/U) Needs full prescription if amblyopia is present & if no amblyopia , partial can be given shifting later to full Rx > Or = 1.5 D

45. School going children Isometropic Astigmatism Anisometropic Astigmatism < 0.75D >or= 0.75D <1.50D >or= 1.50D Not required to prescribe (constant monitoring) Needs full prescription (prescribe if symptomatic) Not required to prescribe ( consatant monitoring & F/U) (Prescribe if symptomatic) Needs full prescription if amblyopia & if No amblyopia prescribe partially later shift to full Rx

46. Guidelines for prescribing aphakic children In first few months overcorrected by (2D to 3D), becoz the child’s worlds in near. Later at about 1 yrs of life overcorrection is reduced to (1D to 1.5D) to single vision intermediate add. After 1 yrs of age (preschool age) bifocal prescription can be considered. Laurence gave a formula to predict spectacle power in aphakic children’s F apakic = +11.00D+1/2(F preoperative) Example: A child is B/L hyperopic by 3.00D before surgery and power must be given to him after surgery is +12.5D

47. Conditions for prescribing bifocals in pediatrics Accommodative Esotropia Constant Esotropia or IET Congenital Aphakia Down’s Syndrome Esophoria Pseudophakic child

48. Commonly Encountered conditions in pediatric clinic with type of refractive errors seen in those Albinism – astigmatism in all subtypes (myopic or hyperopic) ROP – high myopia Down’s Syndrome – hyperopia with or without WTR astigmatism Nanophthalmos – high hyperopia upto +20D Sclerocornea & cornea plana – high hyperopia Congenital defects like Marfan’s syndrome, homocystinuria – myopic error ( most commonly).

49. References Primary care optometry, Theodorer P. Grosvenor, 3 th edition Borish’s clinical refraction, William J.Benjamin , 2 nd edition Optometric Clinical Guidelines for pediatric eye and vision examination; American optometric Association Clinical pediatric optometry, Leonard J. Press, Bruce D. Moore, 2 nd edition Principles and practice of pediatric optometry, Alfred A. Rosenbloom , Meredith W. Morgan Essential of pediatric optometry, Goutam Dutta Comprehensive pediatric eye and vision examination, American optometric Association Pediatric optometry, David Taylor A Textbooks for optics and refractive Anomalies, AK Jain

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