title: "In situ" corneal and contact lens thickness changes with high-resolution optical coherence tomography.
abstract: OBJECTIVE
  To show the use of high-resolution spectral-domain optical coherence tomography (HR-SOCT) for the in situ evaluation of epithelial, stromal, and contact lens (CL) thickness changes under closed-eye conditions without lens removal.
  
  
  METHODS
  Eight young healthy patients wore a thick soft CL for 90 minutes under closed-eye conditions, and measures of epithelial and stromal corneal thickness were obtained at regular intervals using a HR-SOCT (Copernicus HR; Optopol Tech. SA, Zawiercie, Poland).
  
  
  RESULTS
  Minimal changes in epithelial thickness were detected with a transient statistically significant increase in epithelial thickness in the fellow control eye 30 minutes after insertion (P = 0.028). A significant and progressive increase in stromal thickness up to 8% after 90 minutes of lens wear was observed at a constant rate of 2.5% every 30 minutes, being statistically significant in all observations (P < 0.001). Fellow control eyes also showed a significant increase in stromal thickness at a much lower rate of 0.5% every 30 minutes. Lens thickness decreased significantly by 2% after 90 minutes of lens wear under closed-eye conditions (P < 0.001). Individual analysis showed that all eyes displayed stromal swelling, whereas only half of them showed epithelial swelling.
  
  
  CONCLUSIONS
  Increase in stromal thickness and a slight decrease in lens thickness were observed in response to a hypoxic stimulus under closed-eye conditions. HR-SOCT is a powerful tool to investigate in vivo the physiological interactions between cornea and CLs.
authors.affiliation: Clinical and Experimental Optometry Research Lab, Center of Physics (Optometry), University of Minho, Braga, Portugal. jgmeijome@fisica.uminho.pt
authors.forename: Jose M
authors.initials: JM
authors.lastname: González-Méijome
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cerviño
authors.forename: Sofia C
authors.initials: SC
authors.lastname: Peixoto-de-Matos
authors.forename: David
authors.initials: D
authors.lastname: Madrid-Costa
authors.forename: Jorge
authors.initials: J
authors.lastname: Jorge
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrer-Blasco
mesh_terms: D000328:Adult; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D015715:Corneal Edema / Q000175:diagnosis* / Q000209:etiology; D003319:Corneal Stroma / Q000473:pathology*; D019573:Epithelium, Corneal / Q000473:pathology*; D006801:Humans; D000860:Hypoxia / Q000150:complications; D009929:Organ Size; D017755:Prosthesis Fitting; D013997:Time Factors; D041623:Tomography, Optical Coherence; D055815:Young Adult