Purpose: 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.
*Clinical and Experimental Optometry Research Lab, Center of Physics (Optometry), University of Minho, Braga, Portugal
†Iberian Contact Lens Research Group
‡Optometry Research Group, University of Valencia, Valencia, Spain
§Optica Queiros Lda, Povoa de Lanhoso, Portugal
Reprints: Jose M. Gonzalez-Meijome, Department of Physics (Optometry), School of Science, University of Minho, 4710-057 Gualtar, Braga, Portugal (e-mail: firstname.lastname@example.org).
Supported in part by research grants to A. Cerviño from the Universitat de Valencia (UV-AE-20070225), the “Jose Castillejo” Research Grant from the Spanish Ministry of Science and Technology (JC2008-00078) and the Spanish Network for Research in Optometry (SAF2008-01114-E).
The authors have no proprietary interest in any of the instruments or materials mentioned in this article.
Received September 27, 2010
Accepted October 14, 2011