Abstract
Purpose: :
To characterize the tear dynamics on soft contact lenses in situ using optical coherence tomography (OCT).
Methods: :
An ultra-high resolution spectral domain optical coherence tomography was used to image the central cornea and limbus during contact lens wear (PureVision, -3.00D; BC 8.6 mm). Pre- and post lens tear film in the center and edge of the lens were examined visually. In one group of 20 subjects, one drop of artificial tears (Refresh Liquigel, Allergan) was instilled into the concave side of the lens before the lens was inserted on one eye of each subject. On the bilateral eye, one drop was instilled on the lens 3 minutes after lens insertion. OCT images were obtained every 2 minutes for total 10 minutes. In another group of 20 subjects, the lens edge was imaged at lens insertion and 30 minutes.
Results: :
The pre- and post-lens tear films were visualized immediately after lens insertion in some cases. When the drop was instilled on the lens before lens wear, more than 50% cases showed the post-lens tear films for more than 6 minutes (including 6 minutes). When the drop was instilled on the lens after lens insertion, post-lens tear film did not appear increased, while pre-lens tear film was visualized for more than 8 minutes (including 8 minutes) in 65% cases. At the lens edge, more than 50% of the cases showed that the conjunctiva sealed the lens edge about 50% 30 minutes after lens wear Post-lens tear film underneath the edge was visualized in 77% cases 30 minutes after lens wear.
Conclusions: :
We have demonstrated the feasibility using ultra-high resolution spectral domain OCT for characterizing the tear dynamics on contact lenses in situ. It appears that ultra-high resolution OCT is a powerful tool for studying the tear system. (This study was partially supported by a research grant from Vistakon).
Keywords: cornea: tears/tear film/dry eye • contact lens • anterior segment