Four Year Results Of Corneal Crosslinling (XL) in Keratoconus Fernando Aguilera-Zarate MD Fernando Aguilera-Zarate MD Instituto de Ojos de BC Instituto de Ojos de BC Mexicali, Baja California Mexicali, Baja California Mexico Mexico No Financial Interest No Financial Interest

CROSSLINKING (XL) Objective Objective 1. > Corneal Rigidity Fotopolimerization colagen Fibers Fotopolimerization colagen Fibers Combination: UV-A + Rivoflabin (vit B2) Combination: UV-A + Rivoflabin (vit B2) > fibrill diameter > fibrill diameter > interfibrillar junctions > interfibrillar junctions > corneal rigidity > corneal rigidity < corneal ectasia progression < corneal ectasia progression < corneal asimetry < corneal asimetry

BIOCHEMICAL CORNEAL XL CHANGES

Definition POLIMERIZATION Chemical Reaction that transforms molecules of low molecular mass (monomers) producing high molecular weight molecules (polymers) Used in Odontology since the early 70’s Used in Tire and Textil Industries for more than 5 decades

WOOLENSAK,SEILER AJO,2003;135: 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 year follow-up changes in Corneal Refractive, Topography and Aberrometry; and to evaluate the Visual Quality Improvement in Keratoconus corneas Treated by UV- B Crosslinking

Material and Methods 21 patients 21 patients 26 eyes (follow-up 4 years) 26 eyes (follow-up 4 years) years years Complete ophthalmic evaluation Complete ophthalmic evaluation Inclusion Criteria: No concurrent ophthalmic diseases KC (I-III with confirmed progression by topography) KC (I-III with confirmed progression by topography) Corneal paquimetry >400 um at thinnest point Corneal paquimetry >400 um at thinnest point Normal Cristaline Lens Densitometry (pentacam) Normal Cristaline Lens Densitometry (pentacam) Normal Retinal OCT Normal Retinal OCT Specular Microscopy (Tomey SM 3000) Specular Microscopy (Tomey SM 3000)

Surgery (Corneal Crosslinking) Topical Anesthesia (proparacaine) Epithelial removal with Amoils Rotatory Brush UVA + B2, impregnatión (12 minutes) Irradiatión 30 min (3.2 J / cm2) Therapeutic Soft Contact Lens (removal until epithelization) Followup 1-5 days, >48 months

Results Visual Quality MTF (modular transfer function) MTF (modular transfer function) Measures visual quality of the eye (cornea to retina) PSF (point spread function) PSF (point spread function) Measures visual quality of an optical system) (Eye-Occipital Cortex)

Topographic changes Corneal Asimetry = o´ < Corneal Asimetry = o´ < Anterior Elevation (eliipsoidal) Reduction or no change Posterior Elevation (ellipsoidal) reduction or no change reduction or no change Reduction of true net power

Elevation Reduction Anterior/Posterior Elevation. More Reduction in Ectatic Areas Elevation: Reduction Anterior/Posterior Elevation. More Reduction in Ectatic Areas

Corneal Aberrometric Changes < Corneal HOA Coma (z3,-1; z3,1) and trifoil (z3,-3; z3,3)

Refractive: < Irregular Ast./change in axis<10°

Pachymetric and Corneal Power: < optic pachymetry / < total corneal power

Visual Quality: mtf improvement at lower frequencies(5-10 c/d)

Visual Quality Improvement Related with Reduced Spherical Equivalent and Reduction Corneal HOA

Reduction Corneal Irregularity Indices

XL Early Complications (15 d) Corneal Edema……………………..8/26 Epithelial Retardation..…(>6D)……0/26 Loss > 1 Lines VA……….………….0/26 Corneal Haze………………………..2/26 Corneal Melting……………………..0/26 > IOP……………………………..…..0/26 Endothelial Damage……………..0/26

Late XL complications (>3 m) Late Haze (grade I)………….……..1/26 Late Haze (grade I)………….……..1/26 Loss > 1 Line Vision………………..0/26 Loss > 1 Line Vision………………..0/26 Epithelial Defect…………….………0/26 Epithelial Defect…………….………0/26 Corneal Melting……………………..0/26 Corneal Melting……………………..0/26 > IOP.………………………………...0/26 > IOP.………………………………...0/26 Endothelial Damage……….……….0/26 Endothelial Damage……….……….0/26 KC Progression……………………..1/26 KC Progression……………………..1/26

Disscusion: UVA-C3 Corneal Crosslinking Improves Corneal Biomechanics > Rigidity Improves Corneal Biomechanics > Rigidity < Corneal Asimetry < Corneal Asimetry < Corneal Tertiary Higher Order Ab (coma / trifoil) < Corneal Tertiary Higher Order Ab (coma / trifoil) < Refractive Corneal Power (true net power) < Refractive Corneal Power (true net power) > Visual Quality (MTF y PSF) > Visual Quality (MTF y PSF) < Pachimetry (Corneal Remodeling) < Pachimetry (Corneal Remodeling)

CONCLUSION 4 Year Followup of Corneal XL Effective Therapeutic Modality to Prevent or Reduce progresion of Ectatic Changes associated with Keratoconus Effective Therapeutic Modality to Prevent or Reduce progresion of Ectatic Changes associated with Keratoconus Improves Optical Qualities of Cornea Improves Optical Qualities of Cornea Minimal Secondary Effects Minimal Secondary Effects

fernando aguilera-zarate md fernando aguilera-zarate mdwww.institutodeojos.com.mx