Purpose: The aim of the study was to measure the effects of long-term extended wear of hydrogel lenses.
Methods: Nine subjects wearing disposable hydrogel lenses and age- and sex-matched non-lens-wearing control subjects were enrolled. Using confocal microscopy, stromal keratocyte cell densities were measured.
Results: Anterior stromal keratocyte density was reduced in the lens-wearing group (544+/-206 cells/mm2) compared to the non-lens-wearing group (804+/-145 cells/mm2) (P < 0.01). Posterior stromal keratocyte density was lower in the lens-wearing group (514+/-111 cells/mm2) than in the control group (628+/-101 cells/mm2) (P < 0.05).
Conclusions: These preliminary findings indicate that extended wear of hydrogel lenses reduces stromal keratocyte density. The mechanisms for this alteration may include hypoxic, cytokine-mediated or mechanical effects.