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Long-term Results of Thin Corneas After Refractive Laser Surgery

      Purpose

      To report the long-term refractive results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with thin corneas.

      Design

      A long-term, retrospective, non-randomized follow-up study.

      Methods

      Sixty-three patients (124 eyes) (28 males and 35 females), who had a preoperative central corneal thickness (CCT) of less than 500 microns and completed at least one year of follow-up examinations after surgery. Thirty-five patients (68 eyes) underwent PRK and 28 patients (56 eyes) underwent LASIK.

      Results

      Mean preoperative corneal pachymetry was 484.95 ± 6.65 μm (range, 470 to 498 μm) and 482.38 ± 10.73 μm (range, 453 to 499 μm) for LASIK and PRK, respectively. No intraoperative complications were found in both groups. None of the included eyes developed postrefractive corneal ectasia. The mean predictability for the PRK group was 0.08 diopters (D) with a standard deviation of 0.40 D (range, −1.38 to 1.00 D), and the mean predictability for the LASIK group was 0.14 D with a standard deviation of 0.55 D (range, −1.25 to 1.33 D).

      Conclusions

      Refractive laser surgery with LASIK or PRK in patients with thin corneas (less than 500 μm) seems to be a safe and predictable technique for myopic refractive corrections.
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      References

        • Sharma N.
        • Singhvi A.
        • Sinha R.
        • Vajpayee R.B.
        Reasons for not performing LASIK in refractive surgery candidates.
        J Refract Surg. 2005; 21: 496-498
        • Guirao A.
        Theoretical elastic response of the cornea to refractive surgery: risk factors for keratectasia.
        J Refract Surg. 2005; 21: 176-185
        • Kohnen T.
        Iatrogenic keratectasia: Current knowledge, current measurements.
        J Cataract Refract Surg. 2002; 28: 2065-2066
        • Comaish I.F.
        • Lawless M.A.
        Progressive post-LASIK keratectasia: biomechanical instability or chronic disease process?.
        J Cataract Refract Surg. 2002; 28: 2206-2213
        • Rao S.N.
        • Epstein R.J.
        Early onset ectasia following laser in situ keratomileusus: case report and literature review.
        J Refract Surg. 2002; 18: 177-184
        • Binder P.
        Ectasia after laser in situ keratomileusis.
        J Cataract Refract Surg. 2003; 29: 2419-2429
        • Tabbara K.F.
        • Kotb A.A.
        Risk factors for corneal ectasia after LASIK.
        Ophthalmology. 2006; 113: 1618-1622
        • Pallikaris I.G.
        • Kymionis G.D.
        • Astyrakakis N.
        Corneal ectasia induced by laser in situ keratomileusis.
        J Cataract Refract Surg. 2001; 27: 1796-1802
        • Twa M.D.
        • Nichols J.J.
        • Joslin C.E.
        • et al.
        Characteristics of corneal ectasia after LASIK for myopia.
        Cornea. 2004; 23: 447-457
        • Malecaze F.
        • Coullet J.
        • Calvas P.
        • et al.
        Corneal ectasia after photorefrective keratectomy for low myopia.
        Ophthalmology. 2006; 113: 742-746
        • Randleman J.B.
        • Caster A.I.
        • Banning C.S.
        • Stulting R.D.
        Corneal ectasia after photorefractive keratectomy.
        J Cataract Refract Surg. 2006; 32: 1395-1398
        • Lin N.
        • Yee S.B.
        • Mitra S.
        • Chuang A.Z.
        • Yee R.W.
        Prediction of corneal haze using an ablation depth/corneal thickness ratio after laser epithelial keratomileusis.
        J Refract Surg. 2004; 20: 797-802
        • Guirao A.
        Theoretical elastic response of the cornea to refractive surgery: risk factors for keratectasia.
        J Refract Surg. 2005; 21: 176-185
        • Harper C.L.
        • Boulton M.E.
        • Bennett D.
        • et al.
        Diurnal variations in human corneal thickness.
        Br J Ophthalmol. 1996; 80: 1068-1072
        • Amoils S.P.
        • Deist M.B.
        • Gous P.
        • Amoils P.M.
        Iatrogenic keratectasia after laser in situ keratomileusis for less than 24.0 to 27.0 diopters of myopia.
        J Cataract Refract Surg. 2000; 26: 967-977
        • Lin N.
        • Yee S.B.
        • Mitra S.
        • et al.
        Prediction of corneal haze using an ablation depth/corneal thickness ratio after laser epithelial keratomileusis.
        J Refract Surg. 2004; 20: 797-802
        • Randleman J.B.
        Post-laser in situ keratomileusis ectasia:current understanding and future directions.
        Curr Opin Ophthalmol. 2006; 17: 406-412
        • Montes-Mico R.
        • Rodriguez-Galietero A.
        • Alio J.L.
        Femtosecond laser versus mechanical keratome LASIK for myopia.
        Ophthalmology. 2007; 114: 62-68
        • Moller-Pedersen T.
        • Li H.F.
        • Petroll W.M.
        • Cavanagh H.D.
        • Jester J.V.
        Confocal microscopic characterization of wound repair after photorefractive keratectomy.
        Invest Ophthalmol Vis Sci. 1998; 39: 487-501

      Biography

      George Kymionis, MD, PhD, graduated from the Medical School of University of Athens, Greece and three years later he finished his first PhD (apoptosis in human carotid atheroma) in the same university. He worked as a fellow in Ophthalmology in Vardinoyiannion Eye Institute of Crete for several years in which he finished his second PhD (ocular rigidity in AMD patients). Dr Kymionis has concluded his residency training in the University Hospital of Crete, and currently he is doing a fellowship in Bascom Palmer Eye Institute in Miami, Florida.

      Biography

      Sonia H. Yoo, MD, is a corneal and refractive surgeon at Bascom Palmer Eye Institute in Miami, Florida. Dr Yoo is an Associate Professor of Clinical Ophthalmology and serves as the cornea fellowship director at Bascom Palmer Eye Institute of the University of Miami Miller School of Medicine.

      Linked Article

      • Is There a “Magic Number” to Reduce the Risk of Ectasia after Laser In Situ Keratomileusis and Photorefractive Keratectomy?
        American Journal of OphthalmologyVol. 144Issue 2
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          Between 1998 and 2005, 182 cases of ectasia after refractive surgery were reported (Stulting RD. Ectasia: how serious is the problem? Refractive Surgery Interest Group: Las Vegas, Nevada, 148. Personal communication, November 2006). Most of these cases can be traced to surgery performed on eyes with abnormal preoperative topography suggestive of keratoconus or pellucid marginal degeneration.1,2 In this issue of the journal, Kymionis and associates examines the potential ectasia risk factors of central corneal thickness and postablation residual stromal bed (RSB) thickness after laser in situ keratomileusis (LASIK).
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