title: Long-term results of combined transepithelial phototherapeutic keratectomy and corneal collagen crosslinking for keratoconus: Cretan protocol.
abstract: OBJECTIVE
  To present the long-term results of combined transepithelial phototherapeutic keratectomy (PTK) and corneal collagen crosslinking (CXL) for keratoconus.
  
  
  METHODS
  Vardinoyiannion Eye Institute of Crete, University of Crete, Heraklion, Crete, Greece.
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  Patients with progressive keratoconus had combined transepithelial PTK and CXL (Cretan protocol). Visual and refractive outcomes and the endothelial cell density (ECD) were evaluated preoperatively and postoperatively.
  
  
  RESULTS
  Twenty patients (23 eyes) were enrolled; postoperatively 23 eyes were evaluated at 1 and 2 years, 11 at 3 years, and 7 at 4 years. The mean follow-up was 33.83 months±10.82 (SD) (range 24 to 56 months). No intraoperative or postoperative complications occurred. The mean uncorrected distance visual acuity improved significantly from 0.99±0.57 logMAR preoperatively to 0.61±0.36 logMAR at the last follow-up (P<.001) and the mean corrected distance visual acuity, from 0.27±0.24 logMAR to 0.17±0.14 logMAR (P=.018), respectively. The mean steep and mean flat keratometry readings decreased significantly from 53.39±7.14 diopters (D) and 47.17±4.87 D, respectively, preoperatively to 49.99±4.36 D (P<.001) and 45.47±2.95 D (P=.002), respectively, at the last follow-up. The mean corneal astigmatism improved significantly from -6.27±4.19 D preoperatively to -4.52±2.80 D (P<.001) at the last follow-up. No significant ECD alterations occurred (P>.05).
  
  
  CONCLUSIONS
  Combined transepithelial PTK and CXL was effective and safe in keratoconic patients over a long-term follow-up.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA. Electronic address: kymionis@med.uoc.gr.
authors.forename: George D
authors.initials: GD
authors.lastname: Kymionis
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Grentzelos
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Vardhaman P
authors.initials: VP
authors.lastname: Kankariya
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Liakopoulos
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Karavitaki
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Dimitra M
authors.initials: DM
authors.lastname: Portaliou
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Konstantinos I
authors.initials: KI
authors.lastname: Tsoulnaras
authors.affiliation: From the Vardinoyiannion Eye Institute of Crete (Kymionis, Grentzelos, Kankariya, Liakopoulos, Karavitaki, Portaliou, Tsoulnaras, Pallikaris), Faculty of Medicine, University of Crete, Heraklion, Crete, Greece and the Bascom Palmer Eye Institute (Kymionis, Portaliou), Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Pallikaris
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism*; D003131:Combined Modality Therapy; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents; D019573:Epithelium, Corneal / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000378:metabolism / Q000601:surgery / Q000628:therapy*; D054018:Lasers, Excimer / Q000627:therapeutic use; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D018903:Photorefractive Keratectomy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin