Ectatic Conditions. Train Wrecks! Get on track with innovative designs. GP Lens Designs for Keratoconus

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Amelia Eustacia Parker
7 years ago
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1 Train Wrecks! Get on track with innovative designs. Mark Andre, FAAO Associate Professor of Optometry Pacific University Also affiliated with CooperVision, Inc. as a consultant and speaker. Ectatic Conditions Tri-Curve Design Piggyback Design Hybrid Design Aspheric Design Lens Options for Patients with Keratoconus Reverse Geo Design Keratoconus Pellucid Marginal Degeneration Keratoglobus Posterior Keratoconus Scleral Design Custom SCL Design Multi-Curve Design Normal Keratoconus PMD Keratoglobus GP Lens Designs for Keratoconus 1

2 Optical Zone and Peripheral Lens Design Keratoconus Lens Design Optical Zone Sizes for Base Curves of 6.75, 6.10, 5.60, 5.20 T H E C H A L L E N G E D mm D mm D 2.90 mm Difference Anterior Segment OCT CL s and Keratoconus 2

3 Right Eye Left Eye Apical Radius Apical Radius D D mm 7.40 mm Ectasia Normal Large Diameter V-Kone Design Anterior and posterior aspheric design mm, 9.8 mm Boston XO Adjustable periphery 14 lens fitting set V-Kone Diagnostic Fitting 14 Lens Diagnostic Set Initial Base Curve fit on Steep K reading 1. centration 2. central clearance Example: K s / 115 Start with D lens 5.92 mm (57.00 D) Too Flat Too Steep V-Kone Design Advantages of Large Diameter GP Lenses for KC Aspheric Optics Controls spherical aberration Reduces lens mass Larger Diameter Distributes weight more evenly across corneal surface Reduces glare / halos Improves lens stability 3

4 Unilateral Keratoconus Right Eye Left Eye Right Eye Left Eye 22 / / 90 How do we avoid a steep base curve and high minus power? Apical Radius D? Unilateral Keratoconus GP lens wear OD only c/o Haloes and Glare, especially PM c/o Occasional lens displacement Patient wants to explore alternative non-surgical options. Unilateral Keratoconus K s: 108 / / 18 Reverse Geometry Lens Designs for Keratoconus Apical Radius D 4.30 mm? CL: D (4.82 mm) I-Kone 4

5 Advanced Keratoconus K s 108 / D D 11.0 mm K-Vault Reverse Geometry Design For Keratoconus Apical Radius 4.30 mm D 7.67 mm D 26 Diopters less than previous lens. 7 Vaults 1 to 7 Base Curve: (7.67 mm) Power: D. Diameter: 11.0 mm Unilateral Keratoconus K-Vault: Vault 5 Right Eye Left Eye (24.75 diopters less than previous lens) Apical Radius Apical Radius D D mm 7.40 mm Ectasia Normal K s OD: 55 / 145 OS: 158 / 68 Soft Lenses for Keratoconus Piggyback lenses designs Soft torics in early KC Special geometry soft lens designs Hybird (combination) designs Custom Soft Lens Parameters Base Curve Power Diameter Thickness Optical Zone Asphericity Reverse Geometry 5

6 Custom SCL for Keratoconus Without Contact Lens With KC Soft Lens Custom Keratoconus Soft Lens Design Base Curve Fitting Curve Supernova Hydrokone Diagnostic Set Base / Fitting Power Diameter 8.5 / mm 8.1 / 8.9 Plano 14.8 mm 7.7 / mm 7.3 / mm 6.9 / mm 6.5 / mm 6.1 / mm 5.7 / mm Soft KC Fitting Guide Determine Mean K Example: / 135 Mean K is D Convert Dioptric power to mm s D = 6.75 mm Add 1.0 mm to Mean K Example: = 7.75 mm Base / Fitting Power Diameter 8.5 / mm 8.1 / 8.6 Plano 14.5 mm 7.7 / mm 7.3 / mm 6.9 / mm 6.5 / mm 6.1 / mm 5.7 / mm 6

7 Patient: MH Age: 35 M History: Bilateral KC, 6 month history of decreasing discomfort with RGP s. VA s: OD 20/80 OS 20/70 K s: Approx D (4.70 mm) RGP s: OD mm OS mm Right Eye Normal Eye Left Eye Patient: MH Custom SCL s for KC Flat K : D 4.70 mm Dia. Factor: mm Base Curve: 5.60 mm Lens Dia. Fit Flatter By 12.5 mm 0.10 mm 13.0 mm 0.30 mm 13.5 mm 0.50 mm 14.0 mm 0.70 mm 14.5 mm 0.90 mm 15.0 mm 1.10 mm 15.5 mm 1.30 mm 16.0 mm 1.50 mm 16.5 mm 1.70 mm OD: 5.60 mm mm OS: 5.60 mm mm VA s: 20/40 OD, OS Pre-Fit Topography Pre-Fit Topography Topography over SCL 6 months Post-Fit Topography 7

8 Custom SCL for Keratoconus NovaKone Alden Optical Patient: ES Unilateral KC Unilateral KC 46 / / / / 72 Apex D mm Apex D mm Left Eye Keratoconus Eye Normal Eye NovaKone 6.50 / VA20/40 8

9 Custom Soft Lens Designs & Silicone Hydrogel Materials Contact Lens Cornea KeraSoft IC Design Designed for Quarterly Replacement Diagnostic Set Initial Lens Selection 9

10 Patient: DG Keratoconus with Intacts - OD only KeraSoft (Bausch + Lomb) Dual Aspheric Design Adjustable (Asymmetric) Periphery 8.6 / 14.5 KeraSoft On-Eye Patient: DG KeraSoft Right Eye Ectatic Conditions Keratoglobus Keratoconus Pellucid Marginal Degeneration Keratoglobus Posterior Keratoconus 10

11 Patient: JW Keratoglobus OU Custom Soft Contact Lenses Custom Soft Lens base of Piggyback System Base Curve 5.6 mm Diameter 15.5 mm Power

12 Ectatic Conditions Posterior Keratoconus Keratoconus Pellucid Marginal Degeneration Keratoglobus Posterior Keratoconus Orbscan Normal Anterior Cornea Normal Posterior Cornea Treatments for Corneal Ectasia Anterior Cornea Posterior Cornea 12

13 Intrastromal Ring / Intacs Reverse Geometry Soft Contact Lens Designs Refractive Surgery RK PRK LASIK Penetrating Keratoplasty Flat Grafts Reverse Geometry SCL Fitting Set Base / Fit Curve Power Diameter 9.1 / 8.6 Plano / / / * 7.8 mm POZ Patient: VB Age: 45 F History: Bilateral RK s in 1989 MR: OD sph. 20/50 OS x /40 HVID: OU 12.6 mm Unsuccessful with traditional RGP s, reverse geometry RGP s, & MacroLens. 13

14 Patient: VB Custom Reverse Geometry SCL s OD: OS 9.70 / 8.60 Base Curve: 9.70 / D. Power: sph mm Diameter: 14.8 mm 20/25 20/20 CT: 0.30 Anterior Aspheric Optics Photokeratoscopy No CL Wear Photokeratoscopy With SCL Incisional Neovascularization Material oxygen transmissability Mechanical pressure of the SCL Long wearing periods Advances in Scleral Lens Designs in 2012 Some corneal shapes CAN NOT be optimally fitted with corneal lenses 14

15 The Re-Birth of Scleral Lenses Because they result in fluorescene patterns that look like this! 1888 Switzerland, Germany and France Adolph Fick August Muller Eugene Kalt Today s Indications Irregular Astigmatism Keratoconus Pellucid Marginal Degeneration Post Corneal Trauma Post keratoplasty Post Refractive Surgery RK, PRK and LASIK Post HSV and HZV GP centration issues GP comfort issues ) Pathologic Ocular Surface Disease Chemical Burns Ocular Pemphigoid Stevens-Johnson Syndrome Symblepharon formation Graft vs Host Disease Persistent Epithelial Defect Exposure Keratitis Neurotrophic Keratopathy Severe Dry Eye Sjogren s Syndrome, Filamentary Keratitis Limbal Stem Cell Deficiency Traditional Corneal / Scleral Shape 15

16 Scleral Shape New Understandings ICD-16.5 Scleral Lens Design Central Clearance Zone (CCZ) Limbal Clearance Zone (LCZ) Scleral Landing Zone (SLZ) Zone #1, Central Clearance Zone (CCZ) Central Clearance Zone 300 to 400 microns of Apical Clearance Central Clearance Zone Limbal Clearance Zone Scleral Landing Zone Overall Diameter 16.5 mm Appropriate Apical Clearance Inadequate Apical Clearance 16

17 Bulbar Conjunctiva Anatomy Apical Clearance at Dispensing 250 microns Apical Clearance Post 8 Hours 150 microns Zone #2, Limbal Clearance Zone (LCZ) White Light Cobalt Light Central Clearance Zone Tangent Angle Limbal Clearance Zone Overall Diameter 16.5 mm Limbus Initial Application Inadequate Limbal Clearance Four Hours Post Application 17

18 Inadequate Limbal Clearance Adjusting Limbal Clearance Zone A change in the scleral clearance from Standard to +5 degrees will help to clear the limbus and increase the sagittal height of the lens by 125 um. Appropriate Apical Clearance Standard LCZ +5 Degree Change Zone #3, Scleral Landing Zone (SLZ) Scleral Landing Zone (SLZ) Concave Radius Central Clearance Zone Limbal Clearance Zone Scleral Landing Zone Overall Diameter 16.5 mm 18

19 Appropriate Scleral Landing Zone Inappropriate Scleral Landing Zone Conjunctival Impingement Plan: Flatten SLZ 1 step or more if necessary Scleral Landing Zone / Edge Lift Description Sag Change Edge Lift at 15.0 mm Change at 16.5 mm Increase (Flatten) 25um less sag 35um more EL Edge Lift One Step 1. The lens should clear the entire cornea 2. The lens should clear the limbus (360 degrees or as much as possible) 3. The lens should land on the sclera (the full weight, pressure and bearing of the lens, should rest on the sclera). Standard Edge 1 Step Flatter Edge Lift 35 microns additional lift Scleral Lens Fitting by Sagittal Height Landing Cord 15.0mm 19

20 Sag at 15.0 mm Cord 4.00 mm ICD-16.5 Diagnostic Lens Parameters ICD-16.5 Diagnostic Lens Parameters Lens Application Preservative-free saline and sodium fluorescein Preservative Free Tears Lens Application Have the patient look down.patient holds their upper and lower lids & the lens is applied 20

21 Application Bubble Apical Clearance = 350 microns Re-Application Topography Scleral Simulation Adjusted Parameters Fit Assessment Temporal Nasal 21

22 Scleral Angle Measured at 15.0 & 20.0 mm 15.0 mm Average Angle from 10 to 15mm Average mm T N Tina Graff, Patrick Caroline, Eef van der Worp, Randy Kojima, Mark Angle 10.0 mm To 15.0 mm Temporal 18.2 mm Lens Design Angle Angle 15.0 mm To 20.0 mm Pellucid Marginal Degeneration 22

23 Right Eye PMD Adjusting Limbal Clearance Zone A change in the; scleral clearance from Standard to +5 degrees, will help to clear the limbus and increases the sagittal height of the lens by 125 um Right Eye PMD Standard LCZ +5 Degree Change ) Pathologic Ocular Surface Disease Chemical Burns Ocular Pemphigoid Stevens-Johnson Syndrome Symblepharon formation Graft vs Host Disease Persistent Epithelial Defect Exposure Keratitis Neurotrophic Keratopathy Severe Dry Eye Sjogren s Syndrome, Filamentary Keratitis Limbal Stem Cell Deficiency Ocular Graft vs Host Disease 3 Months Post Scleral Lens 23

24 Ocular Cicatricial Pemphigoid Pre Scleral Lens Conclusion Post Scleral Lens 24

PRACTITIONER S FITTING GUIDE. Keratoconus Irregular Cornea Post Graft

PRACTITIONER S FITTING GUIDE. Keratoconus Irregular Cornea Post Graft PRACTITIONER S FITTING GUIDE Keratoconus Irregular Cornea Post Graft Four lens designs to fit all corneal shapes... One simple systematic approach to fitting Featuring Easy-to-fit using a simple systematic