Abstract
Purpose: :
To determine the feasibility of imaging the tears on the ocular surface and contact lens in vivo with an ultra-high resolution optical coherence tomography (SD-OCT).
Methods: :
A slit-lamp based ultra-high resolution SD-OCT was developed with advanced optical delivery system. The system has a 3 micrometer depth resolution with a scan width up to 15 mm. The system was used to image the human eyes before and after wearing both soft and hard contact lenses. OCT imaging was also conducted immediately after instillation of one drop of artificial tears (Refresh Liquigel, Allergan). Two dimensional images of the central cornea and contact lens edge were obtained.
Results: :
The natural tear film immediately after blinking was directly visualized for the first time in normal and dry eye patients. The course of tear thinning over time after blinking was also imaged. Histology-like images of various layers of the cornea such as the epithelium (including the basal cell layer) and Bowman’s layer were obtained. Immediately after wearing soft contact lenses and instillation of one drop of artificial tears, pre- and post- tear films were clearly visualized on the central cornea. The tear menisci around both upper and lower eyelids were shown clearly. The edge configurations of the lens and tear meniscus around the lens edge and the pre- and post-lens tear films at the lens edge area were seen.
Conclusions: :
We have demonstrated the feasibility using ultra-high resolution spectral domain OCT for imaging the tears on the ocular surface and contact lens. It appears that ultra-high resolution OCT is a powerful tool for studying the tear system.This study was supported by research grants from NEI (R03 EY016420), NEI core center grant P30 EY014801, UM Scientific Award Committee, Allergan, Bausch & Lomb, and Research to Prevent Blindness (RPB).
Keywords: cornea: epithelium • cornea: tears/tear film/dry eye • contact lens