HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ladage, P. M. Articles by Cavanagh, H. D. Search for Related Content PubMed PubMed Citation Articles by Ladage, P. M. Articles by Cavanagh, H. D.

Vertical Movement of Epithelial Basal Cells toward the Corneal Surface during Use of Extended-Wear Contact Lenses

¹From the Department of Ophthalmology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas; and the ²College of Optometry, University of Houston, Houston, Texas.

PURPOSE. To study the effects of extended contact lens wear (EW) on the movement of basal epithelial cells toward the corneal surface.

METHODS. Rabbits (n = 32) were injected with 5-bromo-2-deoxyuridine (BrdU) to label a group of proliferating basal epithelial cells, and, 24 hours later, one randomly chosen eye was fitted with a low- or medium-oxygen-transmissible (Dk/t) rigid gas permeable (RGP) contact lens, while the other eye served as the control (n = 28). Four rabbits were not fitted with any contact lens. Rabbits were euthanatized at different time points and the corneal epithelium was immunocytochemically stained for BrdU and/or Ki-67 and counterstained with propidium iodide or Syto 59. Corneal flatmount tissues were examined three dimensionally under a laser confocal microscope and the location of each BrdU-labeled cell in the corneal epithelium (basal or suprabasal) was determined.

RESULTS. Four days after injection of BrdU, both low- (P < 0.001) and medium-Dk/t RGP (P < 0.001) lens groups showed significantly more BrdU-labeled cells in the basal cell layer than in the control eyes. Six days after injection of BrdU, a small percentage of BrdU-labeled cells (<0.5%) were Ki-67 positive.

CONCLUSIONS. Within 6 days, the majority (80%) of BrdU-labeled basal cells became terminally differentiated and rarely divided secondarily in the central epithelium. Short-term use of low- and medium-Dk/t RGP EW contact lenses slows the normal movement of basal epithelial cells toward the surface in the central cornea. This is consistent with known EW-lens–induced decreases in corneal epithelial basal cell proliferation and surface cell exfoliation. Overall, the data suggest that EW lenses significantly inhibit the normal homeostatic turnover rate of the corneal epithelium.

This article has been cited by other articles:

				D. M. Robertson, W. M. Petroll, and H. D. Cavanagh The Effect of Nonpreserved Care Solutions on 12 Months of Daily and Extended Silicone Hydrogel Contact Lens Wear Invest. Ophthalmol. Vis. Sci., January 1, 2008; 49(1): 7 - 15. [Abstract] [Full Text] [PDF]

				G. Adhikary, J. F. Crish, R. Gopalakrishnan, F. Bone, and R. L. Eckert Involucrin Expression in the Corneal Epithelium: An Essential Role for Sp1 Transcription Factors Invest. Ophthalmol. Vis. Sci., September 1, 2005; 46(9): 3109 - 3120. [Abstract] [Full Text] [PDF]

				T. Zaidi, M. Mowrey-Mckee, and G. B. Pier Hypoxia Increases Corneal Cell Expression of CFTR Leading to Increased Pseudomonas aeruginosa Binding, Internalization, and Initiation of Inflammation Invest. Ophthalmol. Vis. Sci., November 1, 2004; 45(11): 4066 - 4074. [Abstract] [Full Text] [PDF]

				G. Adhikary, J. Crish, J. Lass, and R. L. Eckert Regulation of Involucrin Expression in Normal Human Corneal Epithelial Cells: A Role for Activator Protein One Invest. Ophthalmol. Vis. Sci., April 1, 2004; 45(4): 1080 - 1087. [Abstract] [Full Text] [PDF]