title: Comparison of keratocyte density between keratoconus, post-laser in situ keratomileusis keratectasia, and uncomplicated post-laser in situ keratomileusis cases. A confocal scan study.
abstract: OBJECTIVE
  To compare keratocyte density in corneal stromal layers in keratoconus, post-laser in situ keratomileusis (LASIK) keratectasia, uncomplicated post-LASIK cases, and normal unoperated corneas by confocal scan.
  
  
  METHODS
  Thirty-one unscarred corneas from 22 patients with keratoconus, 24 clear corneas from 17 cases with post-LASIK keratectasia, 12 corneas from 7 uncomplicated post-LASIK cases, and 26 corneas from 13 normal unoperated cases were evaluated by using confocal scan. None of the cases were contact lens wearers. Keratocyte densities were determined in 3 stromal layers in each cornea and compared with densities in the corresponding layers of normal unoperated corneas. Cell densities in different corneal layers were also compared in each group.
  
  
  RESULTS
  In overall, 93 eyes from 59 patients with mean age of 30 +/- 7.3 years were enrolled. There was no difference in mean keratocyte density at 3 stromal layers between keratoconic and normal unoperated corneas. In post-LASIK keratectasia, keratocyte density in the anterior and posterior stromal layers was significantly lower than that in normal unoperated group. In uncomplicated post-LASIK cases, the keratocyte density at 3 stromal layers was lower than that in normal unoperated group. No difference in keratocyte density was found between post-LASIK keratectasia and uncomplicated post-LASIK cases. Furthermore, in post-LASIK keratectasia, there was a meaningful difference in keratocyte density between the anterior and posterior and between the middle and posterior stromal layers; such a difference was not observed in the uncomplicated post-LASIK cases.
  
  
  CONCLUSIONS
  Mean keratocyte density in post-LASIK keratectasia and uncomplicated post-LASIK cases was lower than that in normal unoperated group. Given the different distribution of keratocytes between the stromal layers in the 2 LASIK groups, there was a nonhomogenous distribution of keratocytes in stromal layers in post-LASIK keratectasia. A homogenous distribution of keratocytes in uncomplicated post-LASIK cases may be a factor in prevention of corneal ectasia.
authors: Ophthalmic Research Center of Shahid Beheshti University (MC), Tehran 16666, Iran. ma_javadi@yahoo.com
authors: Mohammad
authors: M
authors: Ali Javadi
authors: Mozhgan Rezaei
authors: MR
authors: Kanavi
authors: Manijeh
authors: M
authors: Mahdavi
authors: Mehdi
authors: M
authors: Yaseri
authors: Hosein Mohammad
authors: HM
authors: Rabiei
authors: Atefeh
authors: A
authors: Javadi
authors: Seyed Hamid
authors: SH
authors: Sajjadi
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002452:Cell Count; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D003319:Corneal Stroma / Q000473:pathology*; D019781:Corneal Topography; D004108:Dilatation, Pathologic / Q000473:pathology / Q000601:surgery; D005260:Female; D005347:Fibroblasts / Q000473:pathology*; D006801:Humans; D007640:Keratoconus / Q000473:pathology* / Q000601:surgery; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D011184:Postoperative Period; D055815:Young Adult