title: Tear Function and Ocular Surface Alterations After Accelerated Corneal Collagen Cross-Linking in Progressive Keratoconus.
abstract: OBJECTIVE
  To investigate the alterations in the ocular surface and tear film parameters 3 months after accelerated corneal collagen cross-linking (A-CXL) in progressive keratoconus (KC) patients.
  
  
  METHODS
  Twenty-six patients (33 eyes total) with progressive KC were enrolled in this study. All patients were subjected to ophthalmic surface examination, such as OSDI (ocular surface disease index) scoring, the osmolarity tear test, Schirmer test, tear film breakup time (TBUT) analysis, rose bengal (RB) and fluorescein (Fl) ocular surface staining, and conjunctival impression cytology (IC) analysis, respectively. These tests were performed at baseline and 3 months after A-CXL. Nelson's grading system was used to evaluate the cell morphology and goblet cell density.
  
  
  RESULTS
  No statistically significant differences in the levels of tear osmolarity, TBUT, Schirmer test, OSDI scoring, and Fl and RB staining between pretreatment and 3 months postoperatively were observed (all P values >0.05). A statistically significant increase in superior (P=0.005) and temporal (P=0.006) IC grading was seen at the postoperative third month compared to pretreatment.
  
  
  CONCLUSIONS
  Only metaplastic changes and a reduction in the density of the goblet cells were seen in conjunctival IC, which is probably because of the toxicity of ultraviolet-A 3 months after A-CXL. However, these results do not lead to deterioration in TBUT. In this study, A-CXL has no adverse effect on ocular surface and tear function, which are important for visual quality.
authors.affiliation: Department of Ophthalmology (E.K.A., A.K., B.S.U., H.A., N.C.), Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, Ankara, Turkey; and Department of Ophthalmology (G.H., P.K.), Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
authors.forename: Emine
authors.initials: E
authors.lastname: Kalkan Akçay
authors.forename: Aydan
authors.initials: A
authors.lastname: Kilicarslan
authors.forename: Betul Seher
authors.initials: BS
authors.lastname: Uysal
authors.forename: Gozde
authors.initials: G
authors.lastname: Hondur
authors.forename: Pinar
authors.initials: P
authors.lastname: Kosekahya
authors.forename: Hasan
authors.initials: H
authors.lastname: Altinkaynak
authors.forename: Nurullah
authors.initials: N
authors.lastname: Cagil
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003228:Conjunctiva / Q000473:pathology*; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D003432:Cross-Linking Reagents; D005260:Female; D020397:Goblet Cells / Q000473:pathology*; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009994:Osmolar Concentration; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012256:Riboflavin / Q000627:therapeutic use; D013666:Tears / Q000737:chemistry / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin