The Orthokeratolgy Company GOV & VIPOK Updates

The Ideal Patient

The Ideal Ortho-K Patient Suitable candidates for Ortho-K Age of Patient – older than 6 years Spherical refractive power +5D to -10.00D Cylindrical refractive power: -1.50D or less W-T-Rule astigmatism -0.75D or less A-T-Rule astigmatism Children with progressive myopia Patients free of corneal pathology Patients that are committed to initial and ongoing cost of treatment

Screen for a healthy cornea Don’t fit when: Cornea is distorted Eye Rubbing (treat allergies & habit) Soft or RGP imprints (allow rehabilitation) Corneal abnormalities Irregular corneal astigmatism Keratoconus Pellucid Marginal Degeneration Lid or corneal pathology is present

Calibrate Topographer!

Topographer Accuracy depends on: Software algorithms used to reconstruct corneal shape (update software) Stability of the patient’s tear film during capture (use wetting drops) Head position & movement during capture Lid aperture (open eyes) Number of reading done to get statistically significant accuracy Take multiple readings Omit high & low values

Cylinder Rules <1.50D W-T-R <0.75D A-T-R Cyl ≤ ½Sph -0.50 / -1.50 – Problem -3.00/-1.00 – Fine

Fitting the Ortho-K Lens

Empirical fitting vs. Systemised Fitting Systems

Empirical Fitting Systems Corneal information is given to lab Lab designs lens Lens works Or it doesn’t!

Systemised Fitting Systems General fitting process: Initial lens is chosen from chart Fit with diagnostic trial lenses and evaluate NaFL pattern – Look for Bull’s eye pattern Initial lens should not be too flat and should move 1 – 2mm on blink Evaluate after 30 min using the topographer Does the Px show a central flattening effect ?

Systemised Fitting Systems General fitting process If diagnostic lens looks acceptable, allow Px to wear overnight and evaluate the next morning If the lens is too tight or too loose a different lens can be chosen from trial set and refitted

Systemised Fitting Systems Lens adaptation and follow-up Centration is critical. Movement: 1 – 2 mm with blinking. Flourescein pattern: Bulls eye pattern.

Fitting the Ortho-K Lens Flourescein patterns:

The Orthokeratology Company GOV – Global Ortho-K Vision Vipok II – Non Conformed <-5.00D XMJ– Conformed <-5.00D XM – Conformed >5.00 <10.00D H – Hyperopia HP – Hyperopia Presbyopia MP – Miopic Presbyopia Post Lasik & Keratoconus Website (Plan Date Jan 2008) Ordering Blog Px & Prac Education

The GOV System Advanced inventory system Multi-curve aspheric conformed Reverse Geometry Lenses Simple method for myopia & hyperopia correction You are in control of the lens fit – not laboratories Correct from +5.00D to -10.00D GOAL A simple method to start Orthokeratology allowing for growth into fitting higher powers with the confidence that there is a support group.

Benifits Simple effective system You choose the appropriate lens and make changes Immediate dispensing – (full trial set) Efficient and effective method to increase turnover Develop a specialty Ortho-k practice Confidently fit with GOV support

GOVTM lens details Base curve Hydraulic massage to central cornea Conformed fitting curve (1st reverse zone) Space for tear circulation & tissue molding Alignment curve (2nd reverse) Peripheral compression & centration Peripheral curve Tear reservoir for cornea wetting

Predetermined OAD (lens size) OADs of trial lenses are predetermined Flatter Ks accompany larger corneas Steeper Ks accompany smaller corneas KM range OAD % of HVID Best-fit HVID 40.00 ~ 42.25 11.2 mm 96% 11.3~11.9 mm 42.50 ~ 43.75 10.8 mm 94% 11.2~11.6 mm 44.00 ~ 47.50 10.4 mm 93% 10.8~11.4 mm

Fitting GOVTM Lenses External ocular exam Measure refraction, keratometry & HVID Select K-code by Mean K Select Power-code by S.E. Order lenses Empirically and/or with trial fit K-code / Power-code / Color / Material / OAD Lens size Predetermined Match Corneal size by Best-fit HVID

Orthokeratology The GOV System K-code: Mean K = (Steep K + Flat K) / 2 Carry value up to 2 decimal places (0.01) Km in Diopters Power Calculation: SE = Spherical Spec power – [K astigmatism / 2] Spherical power must not be vertexed K astigmatism = steep K – flat K (in Dioptres)

OAD 11.2 mm Best fit cornea 11.3~11.9 mm (OAD=95-97% of HVID) Mean K/ S.E -1.50 -2.00 -2.50 -3.00 -3.50 -4.00 -4.50 -5.00 OAD 11.2 mm Best fit cornea 11.3~11.9 mm (OAD=95-97% of HVID) A 39.87~40.11 (40.00) 40.00/-1.5 40.00/-2.0 40.00/-2.5 40.00/-3.0 40.00/-3.5 40.00/-4.0 40.00/-4.5 40.00/-5.0 B 40.12~40.36 (40.25) 40.25/-1.5 40.25/-2.0 40.25/-2.5 40.25/-3.0 40.25/-3.5 40.25/-4.0 40.25/-4.5 40.25/-5.0 C 40.37~40.66 (40.50) 40.50/-1.5 40.50/-2.0 40.50/-2.5 40.50/-3.0 40.50/-3.5 40.50/-4.0 40.50/-4.5 40.50/-5.0 D 40.67~40.86 (40.75) 40.75/-1.5 40.75/-2.0 40.75/-2.5 40.75/-3.0 40.75/-3.5 40.75/-4.0 40.75/-4.5 40.75/-5.0 E 40.87~41.11 (41.00) 41.00/-1.5 41.00/-2.0 41.00/-2.5 41.00/-3.0 41.00/-3.5 41.00/-4.0 41.00/-4.5 41.00/-5.0 F 41.12~41.36 (41.25) 41.25/-1.5 41.25/-2.0 41.25/-2.5 41.25/-3.0 41.25/-3.5 41.25/-4.0 41.25/-4.5 41.25/-5.0 G 41.37~41.66 (41.50) 41.50/-1.5 41.50/-2.0 41.50/-2.5 41.50/-3.0 41.50/-3.5 41.50/-4.0 41.50/-4.5 41.50/-5.0 H 41.67~41.86 (41.75) 41.75/-1.5 41.75/-2.0 41.75/-2.5 41.75/-3.0 41.75/-3.5 41.75/-4.0 41.75/-4.5 41.75/-5.0 I 41.87~42.11 (42.00) 42.00/-1.5 42.00/-2.0 42.00/-2.5 42.00/-3.0 42.00/-3.5 42.00/-4.0 42.00/-4.5 42.00/-5.0 J 42.12~42.36 (42.25) 42.25/-1.5 42.25/-2.0 42.25/-2.5 42.25/-3.0 42.25/-3.5 42.25/-4.0 42.25/-4.5 42.25/-5.0 OAD 10.8 mm Best fit cornea: 11.2~11.6 mm (OAD=93-95% of HVID) K 42.37~42.66 (42.50) 42.50/-1.5 42.50/-2.0 42.50/-2.5 42.50/-3.0 42.50/-3.5 42.50/-4.0 42.50/-4.5 42.50/-5.0 L 42.67~42.86 (42.75) 42.75/-1.5 42.75/-2.0 42.75/-2.5 42.75/-3.0 42.75/-3.5 42.75/-4.0 42.75/-4.5 42.75/-5.0 M 42.87~43.11 (43.00) 43.00/-1.5 43.00/-2.0 43.00/-2.5 43.00/-3.0 43.00/-3.5 43.00/-4.0 43.00/-4.5 43.00/-5.0 N 43.12~43.36 (43.25) 43.25/-1.5 43.25/-2.0 43.25/-2.5 43.25/-3.0 43.25/-3.5 43.25/-4.0 43.25/-4.5 43.25/-5.0 O 43.37~43.66 (43.50) 43.50/-1.5 43.50/-2.0 43.50/-2.5 43.50/-3.0 43.50/-3.5 43.50/-4.0 43.50/-4.5 43.50/-5.0 P 43.67~43.86 (43.75) 43.75/-1.5 43.75/-2.0 43.75/-2.5 43.75/-3.0 43.75/-3.5 43.75/-4.0 43.75/-4.5 43.75/-5.0 OAD 10.4 mm Best fit cornea: 10.8~11.4 mm (OAD=92-94% of HVID) Q 43.87~44.11 (44.00) 44.00/-1.5 44.00/-2.0 44.00/-2.5 44.00/-3.0 44.00/-3.5 44.00/-4.0 44.00/-4.5 44.00/-5.0 R 44.12~44.36 (44.25) 44.25/-1.5 44.25/-2.0 44.25/-2.5 44.25/-3.0 44.25/-3.5 44.25/-4.0 44.25/-4.5 44.25/-5.0 S 44.37~44.66 (44.50) 44.50/-1.5 44.50/-2.0 44.50/-2.5 44.50/-3.0 44.50/-3.5 44.50/-4.0 44.50/-4.5 44.50/-5.0 T 44.67~44.86 (44.75) 44.75/-1.5 44.75/-2.0 44.75/-2.5 44.75/-3.0 44.75/-3.5 44.75/-4.0 44.75/-4.5 44.75/-5.0 U 44.87~45.11 (45.00) 45.00/-1.5 45.00/-2.0 45.00/-2.5 45.00/-3.0 45.00/-3.5 45.00/-4.0 45.00/-4.5 45.00/-5.0 V 45.12~45.36 (45.25) 45.25/-1.5 45.25/-2.0 45.25/-2.5 45.25/-3.0 45.25/-3.5 45.25/-4.0 45.25/-4.5 45.25/-5.0 W 45.37~45.66 (45.50) 45.50/-1.5 45.50/-2.0 45.50/-2.5 45.50/-3.0 45.50/-3.5 45.50/-4.0 45.50/-4.5 45.50/-5.0 X 45.67~45.86 (45.75) 45.75/-1.5 45.75/-2.0 45.75/-2.5 45.75/-3.0 45.75/-3.5 45.75/-4.0 45.75/-4.5 45.75/-5.0 Y 45.87~46.11 (46.00) 46.00/-1.5 46.00/-2.0 46.00/-2.5 46.00/-3.0 46.00/-3.5 46.00/-4.0 46.00/-4.5 46.00/-5.0 Z 46.12~46.36 (46.25) 46.25/-1.5 46.25/-2.0 46.25/-2.5 46.25/-3.0 46.25/-3.5 46.25/-4.0 46.25/-4.5 46.25/-5.0 ZA 46.37~46.66 (46.50) 46.50/-1.5 46.50/-2.0 46.50/-2.5 46.50/-3.0 46.50/-3.5 46.50/-4.0 46.50/-4.5 46.50/-5.0 ZB 46.67~46.86 (46.75) 46.75/-1.5 46.75/-2.0 46.75/-2.5 46.75/-3.0 46.75/-3.5 46.75/-4.0 46.75/-4.5 46.75/-5.0 ZC 46.87~47.11 (47.00) 47.00/-1.5 47.00/-2.0 47.00/-2.5 47.00/-3.0 47.00/-3.5 47.00/-4.0 47.00/-4.5 47.00/-5.0 ZD 47.12~47.36 (47.25) 47.25/-1.5 47.25/-2.0 47.25/-2.5 47.25/-3.0 47.25/-3.5 47.25/-4.0 47.25/-4.5 47.25/-5.0 ZE 47.37~47.66 (47.50) 47.50/-1.5 47.50/-2.0 47.50/-2.5 47.50/-3.0 47.50/-3.5 47.50/-4.0 47.50/-4.5 47.50/-5.0 Trial set

Prescribe Empirically Km: 42.87 x 44.75 @ 90 RX: - 3.50 - 1.50 x 180 Determine K-code Mean K=(42.87 + 44.75) / 2 = 43.81 K-code = 43.75 Determine Power-code S.E.= - 3.50 – [(44.75-42.87) / 2] = -4.44 Power-code= -4.50 Empirically ordered by XMJ / (43.75) / -4.50 / 10.8 mm

Empirically with trial fit Prescribe a looser lens empirically Subtract 0.50D from K code (flatter K code) Add +0.50 D to power-code (less minus) Order lens by: XMJ / (43.25) / -4.00 / 10.8 mm Prescribe a tighter lens empirically Add 0.50 D to K code (steeper K code) Add -0.50 D to power code (more minus) Order lens by: XMJ / (44.25) / -5.00 / 10.4 mm

Prescribe by over refract trial lens Select first trial lens by mean K XMJ/(43.75)/-3.00, if fit is loose try XMJ/(44.25)/ -3.00 to tighten AC Over refraction of XMJ/(44.25)/-3.00 = –1.50 D Power-code = -3.00 + (-1.50) = -4.50 Order M4 lens by: XMJ/(44.25)/-4.50/10.4 mm (Predetermined OAD)

As simple as 1-2-3 Select K-code Determine Power-code Verify OAD (Lens size)

The Aligned Fit

Aligned Fit Good compression Good Seal off Good Seal off

Trouble Shooting Ideal fit

Trouble Shooting Bull’s Eye Pattern

Trouble Shooting Alignment Fit

Too Steep Fit

Alignment Fit

Steep Fit No Compression

Flatten alignment curve Up the column

Steep Fit 4 Steps

Steep Fit Steep fit – 6 Steps

Trouble Shooting Central Islands

Steep Fit No Compression

Central Island Small areas of distortion along or near the visual axis

Central Island Cause: Alignment curve too tight Excessive uncorrected astigmatism resulting in unequal forces on the cornea Solution: Decrease sagittal depth of lens by flattening alignment curve move up the column Decentered lens must be centered Flatten the BC if caused by uncorrected astigmatism move one column right.

Too Flat Fit

Alignment Fit

Flat Fit Too much bearing Sideway force induced Poor Seal off

Flat Fit Decentred Good compression Poor compression Good Seal off Poor Seal off

Steepen alignment curve Down the column

Trouble Shooting Flat Fit – 4 Steps

Trouble Shooting Smiley Face

Flat Fit Decentred Good compression Poor seal off Good Seal off

Flat Fit Smiley Face Flat fitting lens decentered superiorly

Flat Fit Cause: Alignment curve too loose Solution: Smiley Face Cause: Alignment curve too loose Solution: Increase sagittal depth of lens by steepening alignment curve move down the column

Lens Fitting Loose 1.0 D Loose 0.50 D Optimal Tight 0.50 D Tight 1.0 D

Verifying tightness Tight 4 steps Properly fitted Loose 2 steps Loose

Power Changes

Power Changes

Power Changes Moving Right = More myopia reduction

Power Changes Moving Left = Less myopia reduction

Size Matters !

Estimate lens size Obtain white to white corneal Diameter by Topography Verify Visible Iris Diameter (VID), horizontal & vertically manually Compare VID to Best-fit VID of the K-code If VID too large (larger cornea, smaller lens) Loose fit, Decentration, Poor effect If VID too small (smaller cornea, larger lens) Tight fit, Lens Bridging, Central island

Standard lens sizes Default OAD based on KM KM ranges 40.00 ~ 42.25 11.2 mm 42.50 ~ 43.75 10.8 mm 44.00 ~ 47.50 10.4 mm

Big Corneas KM =< (flatter) 42.25D KM between 42.50 – 43.75D Rule of thumb: KM =< (flatter) 42.25D 95% to 97% coverage of VID KM between 42.50 – 43.75D 93% to 95% coverage of VID KM => (steeper) 44.00D 92% to 94% coverage of VID 93% - 95% coverage of VID would suit most corneas most of the time.

Big Corneas Use existing trial lenses to evaluate alignment curves Determine lens Diameter (OAD) 93% of VID if KM =>44.00 94% of VID if KM 42.50-43.75 96% of VID if KM =<42.25 It is NOT necessary to alter K-kode (alignment) when adjusting for OAD In high minus lenses (±40% of cases) a flatter alignment lens will be need later on

Big Corneas Example: V (45.25D) Lens best fit. VID: 12mm 93% VID coverage = 11.2mm 94% VID coverage = 11.4mm 96% VID coverage = 11.6mm V lens (KM steeper than 44.00D) = 11.2mm

Big Corneas Example how to order: V Lens best fit. VID: 12mm V lens (KM steeper than 44.00D) = 11.2mm Eg. 2V04, 11.20mm or XMJ/45.25/-3.00/11.2mm

Lens Size 86% too small 89% too small 95% Optimal 98% slightly large 這張圖片，比較鬆緊不同的配鏡狀態，提供給各位醫師做鏡片選擇時的參考。 95% Optimal 98% slightly large 105% very large

Case 1 – Big Cornea

Case 1 – Big Cornea Male, Age 21 RIGHT LEFT KM= 41.72 = H (41.75) SE= -1.50D = 01 (-1.50) Trial 2H01, 10.4mm or XMJ/41.75/-1.50/10.4mm LEFT KM= 41.56 = G (41.50) Trial = 2G01, 10.4mm or XMJ/41.50/-1.50/10.4mm

Case 1 – Big Cornea

Case 1 – Big Cornea (Small lens)

Case 1 – Big Cornea HVID = 12.9 KM > 42.25D Rule 95% of 12.9 = 12.25mm Final lens ordered: R: 2H01, 12.2mm L: 2G01, 12.2mm

Case 1 – Big Cornea

Thank you For more information please e-mail met at: charl@eyevision.co.za