title: Early Changes in Corneal Epithelial Thickness after Cataract Surgery--Pilot Study.
abstract: OBJECTIVE
  To assess early variations in central and paracentral corneal epithelial and non-epithelial thicknesses after uneventful clear corneal incision phacoemulsification.
  
  
  METHODS
  Twenty patients with a senile cataract underwent coaxial phacoemulsification through a 2.75-mm-wide corneal incision created at 180° in a prospective cohort pilot study. Corneal sublayer thickness measurements were obtained with Fourier-domain optical coherence tomography (FD-OCT, Cirrus HD-OCT, Carl Zeiss Meditec, Inc., Dublin, CA) before and after 1 week and 1 month postoperatively. Central measurements were performed in the middle of the FD-OCT scan and in the 3-mm corneal diameter (paracentral 180° and 0° locations). Epithelial, non-epithelial and total corneal pachymetry were measured at the central and paracentral locations.
  
  
  RESULTS
  No significant changes in epithelial thickness were seen 1 week postoperatively. However, 1 month postoperatively, the central, 180°, and 0° paracentral epithelial thicknesses (52.7 ± 3.8, 53.1 ± 5.4, and 52.7 ± 5.3 µm, respectively) decreased significantly (p < 0.01) compared to preoperatively (57.2 ± 4.8, 58.0 ± 5.7, 56.6 ± 5.3 µm, respectively). The 1-week central, 180°, and 0° paracentral non-epithelial corneal thicknesses (515.5 ± 39.6, 534.3 ± 45.6, and 521.3 ± 36.9 µm) were significantly (p < 0.01) higher than preoperatively (486.2 ± 34.7, 498.2 ± 33.8, 497.5 ± 32.3 µm, respectively). The non-epithelial corneal thickness increase was significantly (p = 0.02) greater after 1 week in the central (29.3 ± 17.2 µm) and the 180° paracentral (36.1 ± 28.7 µm) locations than at the 0° paracentral location (23.8 ± 16.5 µm).
  
  
  CONCLUSIONS
  Immediate postoperative corneal edema following phacoemulsification irregularly affects the cornea at the sublayer level. The initial central and paracentral non-epithelial thickening is compensated by subsequent central and paracentral epithelial thinning. These initial changes occurred more markedly closest to the main incision over the entrance pupil, which may have visual implications.
authors: a IOBA, Universidad de Valladolid , Valladolid , Spain and.|b Departamento de Oftalmología , Hospital Universitario Rio Hortega , Valladolid , Spain.
authors: María
authors: M
authors: Calabuig-Goena
authors: a IOBA, Universidad de Valladolid , Valladolid , Spain and.
authors: Alberto
authors: A
authors: López-Miguel
authors: b Departamento de Oftalmología , Hospital Universitario Rio Hortega , Valladolid , Spain.
authors: Victoria
authors: V
authors: Marqués-Fernández
authors: a IOBA, Universidad de Valladolid , Valladolid , Spain and.
authors: María B
authors: MB
authors: Coco-Martín
authors: b Departamento de Oftalmología , Hospital Universitario Rio Hortega , Valladolid , Spain.
authors: Darío
authors: D
authors: Iglesias-Cortiñas
authors: a IOBA, Universidad de Valladolid , Valladolid , Spain and.
authors: Miguel J
authors: MJ
authors: Maldonado
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015715:Corneal Edema / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D063171:Corneal Pachymetry; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D018918:Phacoemulsification; D010865:Pilot Projects; D011183:Postoperative Complications; D011446:Prospective Studies; D019591:Pseudophakia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology
keywords: Corneal edema; Fourier-domain optical coherence tomography; epithelial thickness; phacoemulsification; senile cataract