Orthokeratology by Optom Ankit Varshney

1. Optom. Ankit S. Varshney B.Optom, M.Optom, Ph.D. in Optometry (pursuing) Fellow of IACLE (Aus.), Fellow of ASCO(Mum.) Prof. at (Shree Bharatimaiya College of Optometry & Physiotherapy, Surat) Life Member of Indian Optometric Association (IOA) Associate Member of Association of Schools and Colleges of Optometry(ASCO) Member of Optometry Council of India(OCI) Educator Member of International Association of Contact lense Educators (Australia)(IACLE) Mail id: ankitsvarshney@yahoo.com Whatsapp no. +918155955820

2.  I have no affiliation, nor do I received financial compensation from any of the companies or brands used in this presentation. 14 July 2020 Optom.AnkitVarshney 2

3.  SPECTACLES  CONTACT LENSES  LASIK/ZYOTIX  PRK  SMILE  ICL 14 July 2020 Optom.AnkitVarshney 3

4. Purpose Cosmetic Spherical Toric Presbyopic Optical Keratoconus Bandage Lens Drug Delivery Myopia Control Therapeutic Enhances Performance Color Filters 14 July 2020 Optom.AnkitVarshney 4

5. Greek derivation  Aim is to ‘reshape’ the cornea  Non-surgical, topographical approach to effecting a correction  Sometimes abbreviated to OK ORTHO KERAT OLOGY straight cornea knowledge 14 July 2020 Optom.AnkitVarshney 5

6.  Kerns (1976): ‘a purposeful attempt to modify the corneal curvature to result in a reduction or elimination of a refractive anomaly by a programmed application of contact lenses’ 14 July 2020 Optom.AnkitVarshney 6

7.  In some ways it is similar to the use of dental braces by an orthodontist to straighten crooked teeth.  The main difference is that if a tooth position is corrected for some months it will usually stay in the new position. 14 July 2020 Optom.AnkitVarshney 7

8.  Ortho-K  OK  Overnight Corneal Reshaping (OCR)  Corneal Reshaping Therapy™ (CRT™)  Vision Shaping Treatment™ (VST™)  Corneal Refractive Therapy™ • Gentle Vision Shaping System™ • Overnight Orthokeratology (OOK) 14 July 2020 Optom.AnkitVarshney 8

9.  An effective & relatively safe way of ↓ or eliminating manifest refractive error  Mainly for myopia  Hyperopia not yet treated routinely  Not permanent  Subject to significant variability ‒ within an individual ‒ between individuals 14 July 2020 Optom.AnkitVarshney 9

10. 14 July 2020 Optom.AnkitVarshney 10

11.  School age children benefit greatly:-No more lost contact lenses or broken frames. 14 July 2020 Optom.AnkitVarshney 11

12.  Contact lens wearers that have developed dry eyes, discomfort or sensitivity to their lenses.  Surgery is not in your comfort zone. 14 July 2020 Optom.AnkitVarshney 12

13.  The main purpose : free of both contact lenses and spectacles for all waking hours.  Ideal for sportsmen and women, swimmers or those who work in dusty or dirty environments like:- Firemen, Farmers, Builders To have a lens free day.!!! 14 July 2020 Optom.AnkitVarshney 13

14.  In late 2004 a study published in an international journal found that Orthokeratology can slow myopia progression by an average of 50% 14 July 2020 Optom.AnkitVarshney 14

15.  Reversible  Both eyes ‘altered’ at the same time  No disruption to vision during treatment  Less (or no) pain compared with Refractive Sx.  Therapy can be halted if unfortunate effects are experienced  Option for children  may slow myopia progression ADVANTAGES OF OK 14 July 2020 Optom.AnkitVarshney 15

16.  Not a ‘permanent’ solution  Patient may become a regular RGP lens wearer, i.e. uses OK lens conventionally  Amount of refractive error correctable by OK is limited  Potential for non-compliance DISADVANTAGES OF OK 14 July 2020 Optom.AnkitVarshney 16

18. 1508 Leonardo da Vinci illustrates the concept of contact lenses 1823 British astronomer Sir John Herschel conceptualizes practical lens design 1887 First contact lens manufactured from glass, and fitted to cover the entire eye 1939 Contact lenses first made from plastic 1948 Plastic contact lenses designed to cover only the eye's cornea 1971 Introduction of soft contact lenses 1978 Introduction of GP contact lenses 1981 FDA approval of new soft contact lenses for extended (overnight) wear 1986 Overnight wear of GP contact lenses becomes available 1987 Introduction of disposable soft contact lenses 1987 GP contacts available in next-generation fluorosilicone acrylate materials 1996 Introduction of one-day disposable soft lenses 2002 Silicone-hydrogel contact lenses first marketed 2002 Overnight orthokeratology approved by FDA 2010 Custom-manufactured silicone-hydrogel lenses become available 14 July 2020 Optom.AnkitVarshney 18

19.  Ancient Chinese thought to sleep with (small sand bags) on the eyes to correct vision.  Jessen Method introduced in 1962 outlined the fundamental theory. after Coon, 1982 14 July 2020 Optom.AnkitVarshney 19

20.  2002: Paragon CRT approved for O/N corneal reshaping  2004: Euclid Orthokeratology lens approved for O/N corneal reshaping  2004: B&L acquires Euclid (and its FDA approval)  2004: JZS Orthokeratology lens licensed from Euclid 14 July 2020 Optom.AnkitVarshney 20

21.  First attempt to change refractive error  Technique used plano PMMA lenses  Flat central fitting (Flattest k fitting) 14 July 2020 Optom.AnkitVarshney 21

22.  Failed due to Disadvantages of PMMA lens  Decentration of lens inducing astigmatism  Took long time to achieve a small amount of reduction  Lens fit was unstable 14 July 2020 Optom.AnkitVarshney 22

23.  Ortho-K is used for the temporary correction of low to moderate myopia.  It uses four- or five curve reverse-geometry lenses in high Dk materials in an overnight lens-wearing modality 14 July 2020 Optom.AnkitVarshney 23

24.  Centre well  Lens are supported by their periphery curves.  Having different zones 1. Base curve 2. Reverse (steeper) curve 3. Fitting (alignment) curve 4. Peripheral curve 4-Zone Design 14 July 2020 Optom.AnkitVarshney 24

25. Chosen 0.30 mm to 1.40 mm flatter than the flattest corneal curvature (flat “K”). Reverse curve of the shaping lens is chosen steeper than the base curve radius. Slightly flatter 14 July 2020 Optom.AnkitVarshney 25

27. BOZD 6.0 to 6.5 mm 14 July 2020 Optom.AnkitVarshney 27

30. Layer Thickness (mm) Epithelium 60 Bowman’s layer 6 Stroma 450 Descemet’s membrane 10 Endothelium 6 14 July 2020 Optom.AnkitVarshney 30

32.  Significant change in corneal curvature  Topographical change in corneal thickness: 1. primarily epithelial 2. central thinning 3. mid-peripheral thickening 4. possible alteration to corneal sagittal height 14 July 2020 Optom.AnkitVarshney 32

33.  When the pre-corneal tear film is distributed : thinner in the center, thicker in the periphery, a pressure is created as the fluid tries to find equilibrium.  This pressure is a positive (push force) in the center of the cornea and a negative (pull force). Positive Push Force Negative Pull Force 14 July 2020 Optom.AnkitVarshney 33

35. Ortho-k inhibit myopiaprogression byinducingperipheralretinalmyopic defocus*. Peripheral hyperopic defocus acceleratesaxial growth Peripheral myopic defocus can reduceaxial growth* Ortho-K Treatment zone AreaofPeripheral Myopic Defocus 14 July 2020 Optom.AnkitVarshney 35

36. An example: For a 1 D effect over a 6 mm zone, you will ‘lose’ (or redistribute) 12 mm of corneal tissue S = Change in corneal sagittal height (mm) td = Treatment zone diameter (mm) D = Desired dioptric change (dioptres) 2 3 D d s t  BOZD 6.0 mm Sag in mm 14 July 2020 Optom.AnkitVarshney 36

37. ORTHOKERATOLOGY -TREATMENT ZONE DIAMETER • Controls degree of myopia reduction • Smaller zone required for higher Rxs 14 July 2020 Optom.AnkitVarshney 37

38. Treatment Treatment Expected depth diameter change (Flattening / thinning) (‘Optic zone’) 20 mm 6.0 mm –1.75 D 20 mm 5.0 mm –2.50 D 20 mm 4.0 mm –3.75 D 20 mm 3.0 mm –6.75 D 2 3 D d s t  14 July 2020 Optom.AnkitVarshney 38

39. Treatment Treatment Expected depth diameter change (Flattening/thinning) (‘Optic zone’) 5 mm 2-3 mm –1.00 D 7 mm 3-4 mm –1.00 D 9 mm 4-5 mm –1.00 D 11 mm 5-6 mm –1.00 D 13 mm 6-7 mm –1.00 D 15 mm 7-8 mm –1.00 D 2 3 D d s t  14 July 2020 Optom.AnkitVarshney 39

40.  High motivation is required  Level of patient’s desire for 6/6 (20/20)  Previous contact lens wear  Pupil diameter ▫ measure under a range of illuminations ▫ Too large pupils are problematic 14 July 2020 Optom.AnkitVarshney 40

41. 1. No age restriction 2. Spherical refractive error: (-1.00 D to -5.00 D) 3. Cylindrical refractive error: a. 1.50 D or less “with-the-rule” corneal astigmatism b. 0.75 D or less “against-the-rule” astigmatism 4. Free of corneal dystrophies , degeneration and contra indication to CL wear 14 July 2020 Optom.AnkitVarshney 41

42.  Previous failure(s) with RGP lens wear  Diseases of the cornea, conjunctiva, or adnexa  e.g. dry eye  Anterior chamber inflammation/infection  Systemic disease that affect the eye or can be worsened by lens wear  e.g. diabetes  Keratoconus 14 July 2020 Optom.AnkitVarshney 42

43.  Older patients (long-term CL wearers?)  cornea less likely to respond well  Unrealistic patient expectations  Low sphere power with high cylinder  Limbus to limbus astigmatism 14 July 2020 Optom.AnkitVarshney 43

44.  Very loose/flaccid lids  Poor responder to initial lens wear trial 14 July 2020 Optom.AnkitVarshney 44

45.  Motivation  What do they want from OrthoK ▪ No glasses or CL’s while awake ▪ Myopia control ▪ Slower eye growth with OrthoK (Walline J, et al Br J Ophthalmol 2009;93:1181-1185) ▪ CL induced dry eye relief ▪ Presbyopia ▪ Monovision  Prior lens wear  SCL can be fit now  RGP fit after 3 weeks of lens removal 14 July 2020 Optom.AnkitVarshney 45

46.  Unaided visual acuity  Right, left and both  Accurate Refraction: sphere-cylinder  balanced to BVA  Reduction of 2.00 D. myopic realistic  Approval -1.00 to -5.00, goal -2.00 to -3.00 ▪ -1.50 or less WTR astigmatism ▪ -0.75 or less ATR astigmatism 14 July 2020 Optom.AnkitVarshney 46

47.  Keratometry Readings  Make sure the refraction matches up to the corneal measurements.  moderate K’s: 41.00-46.00 best ▪ steeper & flatter do not respond as well  Topography  Type of corneal cylinder  Screen out any potential problems.  Big differences in cylinder.  Oblique axis that do not match up.  ATR cylinder may need special attention 14 July 2020 Optom.AnkitVarshney 47

48.  Accurate measurement of corneal diameter: HVID  Normal is 10.5-12.5 mm  Pupil size  Dim and normal light ▪ Usually 4-9mm ▪ Best if <6 in normal light 14 July 2020 Optom.AnkitVarshney 48

49.  Slit lamp exam  Lids & lashes ▪ No Blepharitis ▪ No GPC ▪ No Meibomian Gland blockage 14 July 2020 Optom.AnkitVarshney 49

50.  Cornea ▪ No staining ▪ No edema  Tear film analysis ▪ Significant dryness can be a problem  The eye should be healthy. 14 July 2020 Optom.AnkitVarshney 50

51.  Custom designed lenses or trial set  Define the Diameter & CurveWidths  Calculate the AlignmentCurve  Calculate the Peripheral Curve  Calculate the Base Curve  Calculate the Reverse Curve 14 July 2020 Optom.AnkitVarshney 51

52.  Base curve flatter than reverse curve  Reverse curve  Alignment curve is the “fitting” curve  Peripheral curve provides edge lift 14 July 2020 Optom.AnkitVarshney 52

53.  Soak lenses prior to being place on the eye, Lens must be hydrated!!!!!  Look at eye before placing lens on  Insert lenses  Judge lens centration  Evaluate Fluorescein pattern 14 July 2020 Optom.AnkitVarshney 53

54.  Lateral centration  Flat center  Reserve Pooling  Mid-peripheral Alignment 3-6 mm  Minimal inferior edge lift  Movement to allow tear exchange 14 July 2020 Optom.AnkitVarshney 54

55. Peripheral Curve Alignment Curve Fitting Curve Base Curve 14 July 2020 Optom.AnkitVarshney 55

56. Ideal Fit Steep Fit 14 July 2020 Optom.AnkitVarshney 56

57. Ideal Fit Flat Fit 14 July 2020 Optom.AnkitVarshney 57

58.  Lenses MUST center  Better to be slightly tight & centered than loose & decentered  Over-refraction  Practice Insertion & Removal  Sleep at least 6 hours wearing the lenses  Return next day in morning 14 July 2020 Optom.AnkitVarshney 58

59.  Have PATIENCE  No changes until one week post. 14 July 2020 Optom.AnkitVarshney 59

60.  Day 1  Weeks 1-3  Every 6 -12 months  Check all  Replace lenses 14 July 2020 Optom.AnkitVarshney 60

61.  Keep the lenses clean.  Reduces the risk of Central Staining.  Instruct the patient carefully on lens cleaning.  Stress the importance of conditioning the lens surface prior to wear.  Use only the recommended solutions 14 July 2020 Optom.AnkitVarshney 61

62.  “The final contact lens that allows adequate tear exchange and stable uncorrected vision is considered to be the retainer lens.”  Determine that the ‘end point’ has been reached  Finalize the treatment lenses  Determine the wear schedule  Consider ordering a spare pair  cessation of wear for whatever reason will result in regression of gains 14 July 2020 Optom.AnkitVarshney 62

63.  Final set of lenses used to achieve and maintain desired result  Overnight wear capability  fitting characteristics  need good centration  oxygen supply  lens adherence a consideration  lenses removed in the morning after one hour open eye 14 July 2020 Optom.AnkitVarshney 63

64.  Paragon CRT, ZCRT (ParagonVis. Sci.: paflufocon B & D, tisilfocon A )  Bausch & LombVST (Bausch & Lomb Inc. : oprifoconA) 14 July 2020 Optom.AnkitVarshney 64

65.  The technique involves the provision of specialist Orthokeratology contact lenses and a number of visits to your practitioner.  Each practitioner sets their own fees which may vary dependent on the Rx being treated. 14 July 2020 Optom.AnkitVarshney 65

Orthokeratology by Optom Ankit Varshney

Orthokeratology by Optom Ankit Varshney

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