title: Evaluation of contact lens-induced changes in keratoconic corneas using in vivo confocal microscopy.
abstract: OBJECTIVE
  To quantitatively analyze laser scanning in vivo confocal microscopy (IVCM) images of all corneal layers in contact lens-wearing and noncontact lens-wearing keratoconus patients.
  
  
  METHODS
  The study population included rigid gas permeable (RGP) contact lens-wearing keratoconus patients (group 1; N = 29), keratoconus patients who did not wear contact lenses (group 2; N = 30), and subjects who neither had keratoconus nor wore contact lenses (group 3; N = 30), with groups 2 and 3 matched to group 1 by age and sex. The central cornea was examined with IVCM in all subjects. The mean duration of contact lens wear was 5.50 ± 3.68 years (range, 2-15 years).
  
  
  RESULTS
  Eyes with keratoconus showed significantly lower basal epithelial cell and anterior and posterior stromal keratocyte densities, as well as subbasal nerve fiber density, nerve branch density, and nerve fiber length compared with healthy control subjects. Furthermore, compared with group 2, group 1 had significantly lower basal epithelial cell density (4920 ± 476 cells/mm(2) vs. 4503 ± 461 cells/mm(2), P = 0.001) and anterior stromal keratocyte density (561 ± 91 cells/mm(2) vs. 464 ± 55 cells/mm(2), P < 0.001), but there was no significant difference for posterior stromal keratocyte density (P = 0.808), endothelial cell density (P = 0.699), or subbasal nerve fiber density (P = 0.142), nerve branch density (P = 0.614), and nerve fiber length (P = 0.850).
  
  
  CONCLUSIONS
  Significant corneal microstructural abnormalities were observed in eyes with keratoconus. RGP contact lens wear was associated with a further reduction in the basal epithelial cell and anterior stromal keratocyte densities, but with no effect on posterior stromal keratocyte density, endothelial cell density, or corneal nerve morphology.
authors.affiliation: Department of Ophthalmology, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey. gbitirgen@yahoo.com
authors.forename: Gulfidan
authors.initials: G
authors.lastname: Bitirgen
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ozkagnici
authors.forename: Rayaz A
authors.initials: RA
authors.lastname: Malik
authors.forename: Refik
authors.initials: R
authors.lastname: Oltulu
mesh_terms: D000293:Adolescent; D000328:Adult; D002452:Cell Count; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000473:pathology* / Q000534:rehabilitation; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D012720:Severity of Illness Index; D055815:Young Adult
keywords: confocal microscopy; contact lens; cornea; keratoconus