Abstract
Purpose: :
To compare osmotically regulated tear preparation (Optive) versus passive tear substitutes (Systane) in ex vivo porcine corneal dehydration model.
Methods: :
Porcine eye bulbs were obtained from local abattoir. The whole eye bulbs were heated and dried in a vented incubator at 37°C for one hour to dehydrate the ocular surface epithelium. The corneal surfaces were then instilled with Optive, Systane, or phosphate-buffered saline (PBS), covered with plastic food film, and incubated in 5% CO2 at 37°C for 15 minutes. At the end of the incubation, the corneas were immediately cut, fixed in 10% formalin and proceeded for paraffin preparation and Hematoxylin and Eosin (H&E) staining. Dried corneas or corneas without dehydration were used as controls. Each group, consisting of 3 corneas, was sectioned and H&E stained. Each cornea was photographed under the light microscope at six different areas of both full thickness of the corneas and the epithelium only. The areas expressed as pixels were quantified by Photoshop software. An epithelial/stromal ratio reflecting an overall rehydration status was calculated. One-way analysis of variance was used to assess the statistical significance.
Results: :
Optive treated corneas demonstrated a significant increase in the epithelial plumping in terms of epithelial/stromal ratio over dry only (p<0.05), and over the control (p<0.05). Systane treated corneas showed no significant increase in epithelial/stromal ratio over dry only. Thickness and morphology of the corneas treated with Optive was significantly better compared with dry only corneas.
Conclusions: :
Osmotically regulated tear preparations (Optive) may provide good epithelial rehydration following a desiccant stress.
Keywords: cornea: epithelium • cornea: tears/tear film/dry eye