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Hypoxic Corneal Changes following Eight Hours of Scleral Contact Lens Wear

Vincent, Stephen J.; Alonso-Caneiro, David; Collins, Michael J.; Beanland, Alison; Lam, Linda; Lim, Ching Chong; Loke, Alyssa; Nguyen, Nhi

doi: 10.1097/OPX.0000000000000803
Original Articles

Purpose: To examine the change in corneal thickness and posterior curvature following 8 hours of miniscleral contact lens wear.

Methods: Scheimpflug imaging (Pentacam HR; Oculus) was captured before, and immediately following, 8 hours of miniscleral contact lens wear for 15 young (mean age 22 ± 3 years), healthy participants with normal corneae. Natural diurnal variations were considered by measuring baseline corneal changes obtained on a separate control day without contact lens wear.

Results: Over the central 6 mm of the cornea, a small but highly statistically significant amount of edema was observed following 8 hours of miniscleral lens wear, after accounting for normal diurnal fluctuations (mean ± standard deviation percentage swelling 1.70 ± 0.98%, p < 0.0001). Posterior corneal topography remained stable following lens wear (−0.01 ± 0.07 mm steepening over the central 6 mm, p = 0.60). The magnitude of posterior corneal topographical changes following lens wear did not correlate with the extent of lens-related corneal edema (r = −0.16, p = 0.57). Similarly, the initial central corneal vault (maximum post-lens tear layer depth) was not associated with corneal swelling following lens removal (r = 0.27, p = 0.33).

Conclusions: Although a small amount of corneal swelling was induced following 8 hours of miniscleral lens wear (on average <2%), modern high Dk miniscleral contact lenses that vault the cornea do not induce clinically significant corneal edema or hypoxic-related posterior corneal curvature changes during short-term wear. Longer-term studies of compromised eyes (e.g. corneal ectasia) are still required to inform the optimum lens and fitting characteristics for safe scleral lens wear to minimize corneal hypoxia.

*PhD, FAAO

PhD

BVisSc

Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia (all authors).

Stephen J. Vincent Contact Lens and Visual Optics Laboratory School of Optometry and Vision Science Queensland University of Technology Room D513, O Block, Victoria Park Road Kelvin Grove, 4059 Brisbane Queensland, Australia e-mail: sj.vincent@qut.edu.au

© 2016 American Academy of Optometry