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Published on: May 12, 2020
Multipurpose care solution-induced corneal surface disruption and Pseudomonas aeruginosa internalization in the
Leila C Posch1, Meifang Zhu1, Danielle M Robertson1
1Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
Purpose:
To evaluate the effects of a chemically preserved multipurpose contact lens care solution (MPS) on the corneal epithelial surface and Pseudomonas aeruginosa (PA) internalization in the rabbit corneal epithelium.
Methods:
Rabbits were fit in one eye with a silicone hydrogel lens (balafilcon A) soaked overnight in a borate-buffered MPS (BioTrue). The contralateral eye was fit with a lens removed directly from the blister pack containing borate-buffered saline (control). Lenses were worn for 2 hours. Upon lens removal, corneas were challenged ex vivo with invasive PA strain 6487 and assessed for PA internalization. Ultrastructural changes were assessed using scanning electron (SEM) and transmission electron microscopy (TEM).
Results:
Scanning electron microscopy showed frank loss of surface epithelium in MPS-exposed eyes, while control eyes exhibited occasional loss of surface membranes but retention of intact junctional borders. Transmission electron microscopy data supported and extended SEM findings, demonstrating the presence of epithelial edema in MPS-treated eyes. There was a 12-fold increase in PA uptake into the corneal epithelium following wear of the MPS-treated lens compared to control (P = 0.008).
Conclusions:
These data demonstrate that corneal exposure to MPS during lens wear damages the surface epithelium and are consistent with our previous clinical data showing an increase in bacterial binding to exfoliated epithelial cells following MPS use with resultant increased risk for lens-mediated infection. These findings also demonstrate that the PA invasion assay may provide a highly sensitive quantitative metric for assessing the physiological impact of lens-solution biocompatibility on the corneal epithelium.
Insights
Multipurpose contact lens solutions (MPS) damage the corneal epithelium, increasing Pseudomonas aeruginosa (PA) invasion. This study highlights the risks associated with MPS use and contact lens wear.
Area of Science:
- Ophthalmology
- Microbiology
- Materials Science
Background:
- Contact lens care solutions are essential for maintaining lens hygiene.
- Multipurpose solutions (MPS) are widely used but their biocompatibility with the ocular surface requires thorough evaluation.
- Preservatives in MPS can potentially affect corneal health.
Purpose of the Study:
- To assess the impact of a specific chemically preserved MPS on the rabbit corneal epithelial surface.
- To investigate the effect of MPS exposure on Pseudomonas aeruginosa (PA) internalization into the corneal epithelium.
- To evaluate the potential risks associated with MPS use during contact lens wear.
Main Methods:
- Silicone hydrogel contact lenses were soaked in MPS or saline (control) and worn by rabbits for 2 hours.
- Corneas were challenged ex vivo with PA strain 6487 after lens removal.
- Ultrastructural analysis of corneal epithelium was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Main Results:
- SEM revealed significant loss of corneal surface epithelium in MPS-exposed eyes compared to controls.
- TEM indicated epithelial edema in corneas exposed to the MPS.
- A 12-fold increase in PA uptake into the corneal epithelium was observed following wear of MPS-treated lenses.
Conclusions:
- Corneal exposure to MPS during contact lens wear causes epithelial damage.
- The observed damage is linked to increased bacterial internalization, raising the risk of lens-mediated infections.
- The PA invasion assay is a sensitive tool for assessing the biocompatibility of contact lens solutions with the corneal epithelium.
