Abstract
Purpose: :
We have established a rat model showing moderately dry eye using a novel treatment method: persistent strain by Jogging Board (JB) treatment in combination with exposure to an evaporative environment, which induces chronic dysfunction of tear dynamics and superficial punctate keratopathy. In this study, we investigated changes in the proliferation and differentiation rates of corneal epithelial cells.
Methods: :
A series of treatments were performed under continuous exposure to low–humidity airflow (25±5%, 2–4 m/s). For 10 days, SD rats were placed on JB made of plastic pipe for 7.5 h/d, then placed in individual cages without JB for 16.5 hours. BrdU incorporation assay was applied to corneal epithelia. To investigate proliferation capacity, the ratio of BrdU–labeled cells in the basement cell layer was calculated before and after the 10–day JB treatment. To investigate differentiation capacity, the rate of decrease in labeled cells over 5 days was compared with findings in non–treated cornea.
Results: :
There was a significant reduction in the ratio of BrdU–labeled cells in the corneal epithelia compared to that before treatment (5.88±1.64% vs. 9.39±2.37%, p<0.01). The rate of decrease from day 6 to day 10 was apparently suppressed compared to that in non–treated cornea (60.8± 17.4% vs. 39.6±7.8%, p<0.01).
Conclusions: :
These findings suggest that our dry eye treatment induced the suppression of proliferation and differentiation capacity of corneal epithelial cells, indicating that this alteration plays a role in the appearance of chronic dysfunctions of corneal epithelia in dry eye.
Keywords: cornea: tears/tear film/dry eye • cornea: epithelium • cornea: basic science