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29/01/05 www.drmathys.be BSCRS 2005 P R K in 2005 Bernard Mathys, MD Brussels

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P R K in 2005. Bernard Mathys, MD Brussels. Brief history. 15 Y of follow-up Excimer laser Relatively easy technique Short learning curve. Limits. Pain Regression Haze ( > -6D). PRK fights back. Complications of Lasik Epithelial ingrowth Striae, folds SOS Ectasia - PowerPoint PPT Presentation


  • P R K in 2005Bernard Mathys, MDBrussels

  • Brief history15 Y of follow-upExcimer laserRelatively easy techniqueShort learning curve

  • LimitsPainRegressionHaze ( > -6D)

  • PRK fights backComplications of LasikEpithelial ingrowth Striae, foldsSOSEctasiaFlap induced HOAProblem flap size/wide OZ for hyperopia

  • PRK improvedImproved lasers: scanning, flying spot, GaussianImproved OZ, transition Z, blend ZImproved nomogramImproved tracker: centration, cyclotorsion, frequency, mechanical response ? Aspheric profile: better for HOA ?

  • AdvantagesLimits induced HOALower rate of irregular astigmatismWave-front guided: Fourier > Zernicke ?Customized treatment

  • Results

  • No higher RMS postop for high correctionNo higher RMS postop for large OZSeems to reduce RMS for OZ 6 6.5Safe and effective: no loss of VA

  • RMS changes

  • And soPRK, Lasek > Lasik ?Flap induced HOA: nomogram correctionFDA studies for Lasik. PRK ?In fact, photoablation creates HOA !!No real studies in litterature

  • PRK Follow-upPainFluctuationsHaze

  • PRK best treatmentCorneal cooling Quick removal of the epitheliumCLAINS (ketorolac) 3dTearsSterods ?

  • AINS (ketorolac)

  • PRK haze ?Activated keratocytes collagen I-IIIMore frequent if: delayed epithelial responsedeep ablation, > -9Dbroad beam, more energy, retreatment Gabbato,Ophtal. online, dec 2004Max 3 to 6 MDecreases with time: metalloprotease Kato After 1 Y: scarMMC 0.02% 2 min

  • Best healing response ?Amniotic membrane ?Interferon ?Growth factor ?PA ?

  • SoPRK indications ?Up to -5 DK < 39 and > 48KT subclinicalThin corneaDry eyesHigh astigmatismArmy, pilots, athlete

  • Even more indicationsHyperopesRefraction error after IOLRefraction error after RKRefraction error after corneal graft

  • PRK after RK

  • And PTK ?

    Irregular astigmatismRecurrent erosionReshapingHerpes (under treatment)

  • Then:Do not be ashamed to perform PRKMany indicationsHaze problems tend to diminishLasek = disguised PRKNot a single ectasia after PRKGood PRK much better than a bad Lasik !!

  • Good PRK >< Bad Lasik

  • Thin corneas

  • Follow-up 1 Y

  • Limited induced aberrations

  • High astigmatism

  • Same patient, topography

  • Thank you for your attention