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Four Year Results Of Corneal Crosslinling (XL) in Keratoconus. Fernando Aguilera-Zarate MD Instituto de Ojos de BC Mexicali, Baja California Mexico No Financial Interest. Objective > Corneal Rigidity Fotopolimerization colagen Fibers Combination : UV-A + Rivoflabin ( vit B2)
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FourYearResults Of CornealCrosslinling (XL) in Keratoconus • Fernando Aguilera-Zarate MD • Instituto de Ojos de BC • Mexicali, Baja California • Mexico • No FinancialInterest
Objective > CornealRigidity FotopolimerizationcolagenFibers Combination: UV-A + Rivoflabin (vit B2) > fibrilldiameter > interfibrillarjunctions > cornealrigidity < corneal ectasia progression < cornealasimetry CROSSLINKING (XL)
Definition POLIMERIZATION ChemicalReactionthattransformsmolecules of low molecular mass (monomers) producinghigh molecular weightmolecules (polymers) Used in Odontologysincetheearly 70’s Used in Tire and Textil Industriesfor more than 5 decades
WOOLENSAK,SEILER AJO,2003;135:625-627 First Report Of Humans Treated by XL Results: Regresion KC …………………….72% < Spherical Equivalent……………1.34 D < Astigmatism.. ……………………2.01 D Control Group, progression………..22 %
CROSSLINKING OBJECTIVE Document 4 yearfollow-up changes in CornealRefractive, Topography and Aberrometry; and toevaluatethe Visual QualityImprovement in Keratoconus corneas Treatedby UV-B Crosslinking
Material and Methods • 21 patients • 26 eyes (follow-up 4 years) • 18-30 years • Complete ophthalmicevaluation InclusionCriteria: No concurrentophthalmicdiseases KC (I-III withconfirmedprogressionbytopography) Cornealpaquimetry >400 um at thinnestpoint Normal Cristaline Lens Densitometry (pentacam) Normal Retinal OCT SpecularMicroscopy (Tomey SM 3000)
Surgery (CornealCrosslinking) TopicalAnesthesia (proparacaine) EpithelialremovalwithAmoilsRotatoryBrush UVA + B2, impregnatión (12 minutes) Irradiatión 30 min (3.2 J / cm2) TherapeuticSoftContact Lens (removaluntilepithelization) Followup 1-5 days, 1-3-6-9-12-18-24-36- >48 months
Results Visual Quality • MTF (modular transfer function) Measures visual quality of theeye (cornea to retina) • PSF (point spread function) Measures visual quality of anopticalsystem) (Eye-Occipital Cortex)
Topographicchanges CornealAsimetry = o´ < Anterior Elevation (eliipsoidal) Reductionor no change Posterior Elevation (ellipsoidal) reductionor no change Reduction of true net power
Elevation:Reduction Anterior/Posterior Elevation. More Reduction in EctaticAreas
CornealAberrometricChanges < Corneal HOA Coma (z3,-1; z3,1) and trifoil (z3,-3; z3,3)
Pachymetric and CornealPower:< opticpachymetry / < total cornealpower
Visual QualityImprovementRelatedwithReducedSphericalEquivalent and ReductionCorneal HOA
XL EarlyComplications (15 d) Corneal Edema……………………..8/26 EpithelialRetardation..…(>6D)……0/26 Loss > 1 Lines VA……….………….0/26 CornealHaze………………………..2/26 CornealMelting……………………..0/26 > IOP……………………………..…..0/26 EndothelialDamage……………..0/26
Late XL complications (>3 m) • Late Haze (grade I)………….……..1/26 • Loss > 1 Line Vision………………..0/26 • EpithelialDefect…………….………0/26 • CornealMelting……………………..0/26 • > IOP.………………………………...0/26 • EndothelialDamage……….……….0/26 • KC Progression……………………..1/26
Disscusion: UVA-C3 CornealCrosslinking • ImprovesCornealBiomechanics > Rigidity • < CornealAsimetry • < CornealTertiaryHigherOrder Ab (coma / trifoil) • < RefractiveCornealPower (true net power) • > Visual Quality (MTF y PSF) • < Pachimetry (CornealRemodeling)
CONCLUSION 4 YearFollowup of Corneal XL • EffectiveTherapeuticModalitytoPreventor Reduce progresion of EctaticChangesassociatedwithKeratoconus • ImprovesOpticalQualities of Cornea • MinimalSecondaryEffects
fernando aguilera-zarate md www.institutodeojos.com.mx drfaguilera@gmail.com