Four Year Results Of Four Year Results Of Corneal Crosslinling Corneal Crosslinling (XL) in Keratoconus(XL) in Keratoconus

Fernando Aguilera-Zarate Fernando Aguilera-Zarate MDMD

Instituto de Ojos de BCInstituto de Ojos de BCMexicali, MexicoMexicali, Mexico

drfaguilera@gmail.com

No Financial InterestNo Financial Interest 1

The The ObjectiveObjective of Crosslinking is to Increase of Crosslinking is to Increase Corneal Rigidity Corneal Rigidity and Halt the Progression and and Halt the Progression and Even Achieve Regression of KC by Even Achieve Regression of KC by Photopolimerization of Corneal Collagen Fibers Photopolimerization of Corneal Collagen Fibers Using Rivoflabin (B2 Vit) + UltraViolet Radiation Using Rivoflabin (B2 Vit) + UltraViolet Radiation of 370 nm of 370 nm (Wolensak lab. Studies)(Wolensak lab. Studies)

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WOOLENSAK,SEILERWOOLENSAK,SEILER

AJO,2003;135:625-627AJO,2003;135:625-627First Report Of Humans Treated by XLFirst Report Of Humans Treated by XL

Their Results at 12 months:Their Results at 12 months:

Regresion KC ………………………72%Regresion KC ………………………72%

< Spherical Equivalent…………….1.34 D< Spherical Equivalent…………….1.34 D

< Astigmatism.. …………………….2.01 D< Astigmatism.. …………………….2.01 D

Control Group, progression……...22 %Control Group, progression……...22 %

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STUDY OBJECTIVESTUDY OBJECTIVE

Document 4 year follow-up Changes in Corneal Document 4 year follow-up Changes in Corneal Refractive, Topography and Aberrometry; Refractive, Topography and Aberrometry; And to Evaluate the Visual Quality Changes And to Evaluate the Visual Quality Changes in Keratoconic Corneas Treated by UV-B in Keratoconic Corneas Treated by UV-B CrosslinkingCrosslinking

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Material and Material and MethodsMethods

21 patients Dx KC (Usher I-II)21 patients Dx KC (Usher I-II) 26 eyes 26 eyes (follow-up 4 years)(follow-up 4 years) 18-30 years - 12 men / 9 female18-30 years - 12 men / 9 female Complete ophthalmic evaluation Complete ophthalmic evaluation Inclusion Criteria for Epithelium Off Crosslinking Treatment:Inclusion Criteria for Epithelium Off Crosslinking Treatment:

Siena University XL Protocol (12 minute B2 impregnation / Siena University XL Protocol (12 minute B2 impregnation / 30 minute UV-A 370 nm Radiation with limbal area 30 minute UV-A 370 nm Radiation with limbal area protection) protection)

No concurrent ophthalmic diseasesNo concurrent ophthalmic diseases Steepest Steepest KM < 58.5DKM < 58.5D KC with confirmed progression by topography (>0.5 D of astigmatic KC with confirmed progression by topography (>0.5 D of astigmatic

power, axis, asimetry or pachymetry change in 1 year (2 year preop. power, axis, asimetry or pachymetry change in 1 year (2 year preop. followup) followup)

Corneal paquimetry Corneal paquimetry >400 um >400 um at thinnest point ..(Scheimpflug)at thinnest point ..(Scheimpflug) Normal Cristaline Lens Densitometry…………... (Scheimpflug)Normal Cristaline Lens Densitometry…………... (Scheimpflug) Normal Retinal OCT ………………………………...(Fourier Domain)Normal Retinal OCT ………………………………...(Fourier Domain) Corneal Specular Microscopy……………….........(Cell count, Shape, Corneal Specular Microscopy……………….........(Cell count, Shape,

etc)etc)5

Results: Visual QualityResults: Visual QualityMTFMTF (Modular Transfer Function) (Modular Transfer Function)PSFPSF (Point Spread Function) (Point Spread Function)Both were improved after XL and have Both were improved after XL and have continued to improvecontinued to improve over time in 98% of over time in 98% of patients patients

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Topographic Changes 4 Topographic Changes 4 yearsyears Corneal Asimetry and KC Indices Corneal Asimetry and KC Indices were were Reduced (93%) Reduced (93%) or Unchanged or Unchanged

(5%) (5%) Anterior Elevation Anterior Elevation (eliipsoidal) (eliipsoidal) Reduction (85%) Reduction (85%) or No change (13%)or No change (13%) Posterior Elevation Posterior Elevation (ellipsoidal) (ellipsoidal) Reduction (78%) Reduction (78%) or No change (19%)or No change (19%) True Net PowerTrue Net Power (Ray Tracing) (Ray Tracing) Reduction (98%) Reduction (98%) or No Change (2%)or No Change (2%)

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ELEVATIONELEVATION: Reduction Anterior/Posterior Reduction Anterior/Posterior ElevationElevation. More Reduction in Ectatic Areas . More Reduction in Ectatic Areas (ARROWS)(ARROWS)

REFRACTIVEREFRACTIVE: : Reduction Irregular Ast / Change Ast. Axis < Reduction Irregular Ast / Change Ast. Axis <

5 5 Mean Astigmatism Corneal Change: Mean Astigmatism Corneal Change: 2.37 KM D2.37 KM D

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PACHYMETRIC AND CORNEAL POWER:PACHYMETRIC AND CORNEAL POWER:< Optic pachymetry / < Total Corneal Power< Optic pachymetry / < Total Corneal Power (Ray Tracing) (Ray Tracing)

ABERROMETRIC CHANGESABERROMETRIC CHANGES::Reduction in COMA…………….. (z3,-1 / z3,1) Reduction in COMA…………….. (z3,-1 / z3,1) Reduction of TRIFOIL……………(z3,-3 / z3,3)Reduction of TRIFOIL……………(z3,-3 / z3,3)

PACHYMETRIC DIFFERENCEPACHYMETRIC DIFFERENCECORNEAL HOACORNEAL HOA

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Visual Quality:Visual Quality: MTF MTF Improvement at lower frequencies Improvement at lower frequencies (5-10 (5-10 c/d)c/d) SVA SVA Improvement (Reduction Corneal LOA and Improvement (Reduction Corneal LOA and HOA)HOA)

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XL Early Complications (15 d)XL Early Complications (15 d)Corneal Corneal Edema………………………8/26Edema………………………8/26

Epithelial Retardation..…(>5D)…….0/26Epithelial Retardation..…(>5D)…….0/26

Loss > 1 Lines VA……….…………...0/26Loss > 1 Lines VA……….…………...0/26

Corneal Haze……………………….…2/26Corneal Haze……………………….…2/26

Corneal Melting……………………....0/26Corneal Melting……………………....0/26

IOP >…………………………..………..0/26 IOP >…………………………..………..0/26

Endothelial Damage………………..0/26Endothelial Damage………………..0/26

NO LATE COMPLICATIONSNO LATE COMPLICATIONSNo Haze, No Scars, No InfiltratesNo Haze, No Scars, No Infiltrates1 KC Progression……….….1/26 KC Progression……….….1/26

Reticular HazeTransient

OCT DEMARCATION LINE LESS 300 um DEPTH

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Disscusion: UVA-C3 Disscusion: UVA-C3 Corneal Crosslinking Corneal Crosslinking Improves Corneal Biomechanics Improves Corneal Biomechanics > Rigidity> Rigidity < Corneal Asimetry < Corneal Asimetry < Corneal Tertiary Higher Order Ab < Corneal Tertiary Higher Order Ab (coma / trifoil) and LOA (astigmatic reduction) (coma / trifoil) and LOA (astigmatic reduction) < Refractive Corneal Power (True Net Power - Ray Tracing)< Refractive Corneal Power (True Net Power - Ray Tracing) > Visual Quality (MTF y PSF)> Visual Quality (MTF y PSF) < Pachimetry (Corneal Remodeling) that Starts to Increase after 18 Months (Keratocite < Pachimetry (Corneal Remodeling) that Starts to Increase after 18 Months (Keratocite

Collagen Production?)Collagen Production?)

CONCLUSIONS 4 YEAR PO CONCLUSIONS 4 YEAR PO XL:XL:•Effective Long Term Therapeutic Modality to Prevent or Effective Long Term Therapeutic Modality to Prevent or Reduce progresion of Ectatic Changes associated with Reduce progresion of Ectatic Changes associated with Keratoconus (97%)Keratoconus (97%)

•No Changes in Cristalline Densitometry nor in Retinal OCTNo Changes in Cristalline Densitometry nor in Retinal OCT•Improves Optical Qualty of Cornea (Reducing HOA and Improves Optical Qualty of Cornea (Reducing HOA and LOA)LOA)

•Safe Procedure with Minimal Secondary Effects Safe Procedure with Minimal Secondary Effects (Transient Early Reticular Haze 8%, less 3 month (Transient Early Reticular Haze 8%, less 3 month duration)duration)

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