title: [Impact of Different Percent Tissue Altered Values on Visual Outcome after Refractive Small Incision Lenticule Extraction (ReLEx SMILE)].
abstract: PurposeTo compare the visual outcomes after ReLEx SMILE treatment of eyes with low and high PTA values (PTA: percent tissue altered) within a follow-up period of up to 3 years and to assess whether a high PTA value might contribute to the development of keratectasia, as is the case for LASIK.MethodsThis retrospective analysis comprises results from 313 eyes (189 patients) with a PTA value of less than 40 % and of 373 eyes (213 patients) with a PTA value of at least 40 %. Preoperatively and up to 3 years after SMILE surgery, refraction values, monocular corrected (CDVA) and uncorrected distant visual acuity (UDVA) and wavefront data were evaluated.ResultsOne to 3 years after surgery, the group with PTA < 40 % (PTA ≥ 40 %) had a loss of two Snellen lines in 1.1 % (0.0 %) of the cases. Loss of one line occurred in 1.1 % (3.6 %) of the eyes, whereas 97.7 % (96.4 %) remained unchanged or gained lines. With respect to predictability of the spherical equivalent, 92.0 % (78.6 %) of the eyes were within ± 0.5D and 97.7 % (92.9 %) were within ± 1.0D. The group with high PTA values displayed a slightly but significantly greater undercorrection of about 0,25D. 74.4 % (71.8 %) achieved UDVA of at least 20/20 and 96.5 % (87.1 %) achieved at least 20/25. The mean UDVA was - 0.03 ± 0.10logMAR (0.01 ± 0.12logMAR) and its mean difference to the preoperative CDVA was 0.00 ± 0.09logMAR (0.03 ± 0.12logMAR).ConclusionReLEx SMILE is a safe and effective corneal refractive treatment, even for PTA values of 40 % and more. Eyes with high PTA values did not display any evidence of keratectasia development within the 3-year follow-up of this study.
authors.affiliation: Breyer, Kaymak & Klabe Augenchirurgie, Düsseldorf.
authors.forename: D R H
authors.initials: DR
authors.lastname: Breyer
authors.affiliation: Breyer, Kaymak & Klabe Augenchirurgie, Düsseldorf.
authors.forename: P
authors.initials: P
authors.lastname: Hagen
authors.affiliation: Breyer, Kaymak & Klabe Augenchirurgie, Düsseldorf.
authors.forename: H
authors.initials: H
authors.lastname: Kaymak
authors.affiliation: Breyer, Kaymak & Klabe Augenchirurgie, Düsseldorf.
authors.forename: K
authors.initials: K
authors.lastname: Klabe
authors.affiliation: Augenheilkunde, International Vision Correction Research Centre Network (IVCRC.net), Universität Heidelberg.
authors.forename: G U
authors.initials: GU
authors.lastname: Auffarth
authors.affiliation: Augenheilkunde, International Vision Correction Research Centre Network (IVCRC.net), Universität Heidelberg.
authors.forename: F T A
authors.initials: FT
authors.lastname: Kretz
mesh_terms: D000328:Adult; D000368:Aged; D015984:Causality; D015897:Comorbidity; D003315:Cornea / Q000473:pathology*; D003316:Corneal Diseases / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control; D048988:Corneal Surgery, Laser / Q000706:statistics & numerical data*; D004108:Dilatation, Pathologic; D019317:Evidence-Based Medicine; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control; D015995:Prevalence; D012030:Refractive Errors / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014792:Visual Acuity