Purchase this article with an account.
Jianhua Wang, Lili Ge, Meixiao Shen, Dexi Zhu, Yufeng Ye; Ocular Surface Optical Coherence Tomography For Imaging Tear Exchange Underneath Soft Contact Lenses. Invest. Ophthalmol. Vis. Sci. 2012;53(14):3628.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To demonstrate the feasibility for in vivo imaging tear exchange underneath soft contact lenses using newly developed ocular surface optical coherence tomography (OS-OCT).
The OS-OCT system has a custom designed spectrometer and a very board light source with 188 nm bandwidth at the center wavelength of 870 nm (T870, Superlum, Moscow, Russia). The measured depth resolution is 2.2 µm in tissue. The scan depth was set to 1.42 mm and speed was 24K A-line per-second determined. A telecentric light delivery system and video viewing system were co-axial aligned and mounted with a standard slit-lamp. Nine eyes of 5 normal subjects were imaged while wearing contact lenses (PureVision, Bausch & Lomb). The peripheral region of the cornea were imaged before and after instillation (0.5, 1, 2, 3, 5, 7, 10 min) of OCT scattering media (Soothe XP, Bausch & Lomb) on the top of the lens. The lens was placed inside out for creating posterior lens tear film gaps for facilitating OCT imaging. The light scattering from 50 x 50 pixels within the gap was quantified and normalized by the background noise.
The tear film gap underneath the lens on the peripheral cornea was clearly visualized on all eyes. Apparently, there were two categories of the intensity patterns. In 5 eyes (Figure 1A), two phases were evident with the increase of scattering underneath the lens within 3 minutes then the decrease up to 10 minutes. The 95% decay time was about 10 minutes. In the other category (4 eyes, Figure 1B), only one phase was captured with the decrease phase and the 95% decay time was about 20 minutes.
This is a pilot study demonstrating our ocular surface optical coherence tomography could be used to image tear film gap underneath software contact lenses and track tear mixing underneath the lens edge. Further studies will focus on a large scale of sample size with multiple lenses. Image processing algorithms and mathematic modeling will be further developed for precise quantification of the tear mixing.
This PDF is available to Subscribers Only