title: [Riboflavin photoprotection with cross-linking effect in photorefractive ablation of the cornea].
abstract: Photorefractive ablation is inevitably accompanied by oxidative stress of the cornea and weakening of its biomechanical and photoprotective properties.
  
  
  OBJECTIVE
  To validate the expediency of riboflavin use in photorefractive ablation for photoprotection of the cornea and cross-linking.
  
  
  METHODS
  The effects of riboflavin use in photorefractive ablation was first studied in a series of in vitro and in vivo experiments performed on 56 eyes of 28 rabbits, and then on 232 eyes of 142 patients with different degrees of myopia. Biomechanical testing of corneal samples was performed with Zwick/RoellВZ 2.5/TN1S tensile-testing machine. Transepithelial photorefractive keratectomy (TransPRK) and femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) were performed on Wavelight-Allegretto200, MEL-80, and WaveLight-EX500 excimer laser systems and also VisuMax and WaveLight-FS200 femtosecond lasers. For preliminary examinations, an appropriate set of diagnostic tools was used.
  
  
  RESULTS
  In vivo experiments have proved that, in the absence of conservative therapy, riboflavin is able to produce both photoprotective and cross-linking effects to the cornea. Corneal syndrome was thus reduced and re-epithelialization after TransPRK accelerated. Biomechanical testing of corneal samples revealed an increase in tolerated load from 12.9±1.4 N to 18.3±1.2 N (p=0.0002) and tensile strength from 8.6±1.7 MPa to 12.4±1.7 MPa (p=0.007). Clinical studies conducted in a group of patients with mild to moderate myopia have also confirmed the photoprotective effect of riboflavin at months 1-12 after TransPRK. There were no significant differences in uncorrected visual acuity (ranged from 0.80±0.16 to 0.85±0.15) and corrected visual acuity at baseline (0.83±0.14). Evaluation of the optical and refractive effect achieved after Femto-LASIK with riboflavin photoprotection in the fellow eye has shown that this technique is not inferior to the traditional one as to its refractive accuracy, but provides better maintenance of biomechanical and photoprotective properties of the cornea.
  
  
  CONCLUSIONS
  Photorefractive ablation of the cornea with preliminary saturation of the stroma with riboflavin solution ensures its photoprotection and provides an additional cross-linking effect.
authors.affiliation: National Pirogov Medical Surgical Centre, Ministry of Health of the Russian Federation, 70 Nizhnyaya Pervomayskaya St., Moscow, Russian Federation, 105203.
authors.forename: I M
authors.initials: IM
authors.lastname: Kornilovskiy
authors.affiliation: National Centre of Ophthalmology named after acad. Zarifa Aliyeva, 32/15 Javadkhan St., Baku, Azerbaijan, AZ 1114.
authors.forename: A I
authors.initials: AI
authors.lastname: Sultanova
authors.affiliation: National Pirogov Medical Surgical Centre, Ministry of Health of the Russian Federation, 70 Nizhnyaya Pervomayskaya St., Moscow, Russian Federation, 105203.
authors.forename: A A
authors.initials: AA
authors.lastname: Burtsev
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D003315:Cornea / Q000378:metabolism / Q000503:physiopathology / Q000528:radiation effects / Q000601:surgery; D003432:Cross-Linking Reagents / Q000008:administration & dosage; D005260:Female; D006801:Humans; D054018:Lasers, Excimer / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D009216:Myopia / Q000378:metabolism / Q000503:physiopathology / Q000532:radiotherapy*; D018384:Oxidative Stress / Q000187:drug effects; D018903:Photorefractive Keratectomy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D011817:Rabbits; D011837:Radiation-Protective Agents / Q000008:administration & dosage; D012256:Riboflavin / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D003432:Cross-Linking Reagents; D011837:Radiation-Protective Agents; D012256:Riboflavin