Purpose:
We present optical coherence tomography (OCT) imaging, image-processing pipeline and visualization tool for investigation and evaluation of femtosecond laser-created, partial-thickness aqueous humor drainage channels in the sclera. We have shown that femtosecond laser pulses tuned to 1.7 µm can be used to create partial thickness channels that drain aqueous into the sub-conjunctival space, without damage to the overlaying episclera or conjunctiva [1]. A key requirement for clinical application of this tool is the accurate delivery of laser pulses through the sclera, but in contrast to femtosecond laser corneal surgery, detailed imaging and visualization of translucent scleral procedure cannot be accomplished with direct viewing using visible light microscopy.
Methods:
In this study we use time-domain (TD) & Fourier-domain (FD) OCT imaging, demonstrate image processing pipeline, and three dimensional visualization tool for femtosecond laser created scleral channels for glaucoma treatment. Three-dimensional (3D) OCT image stacks of the triangular anterior chamber angle were acquired for volume rendering and visualization.
Results:
A few results after the image processing pipeline are presented in Fig. 1. The volumetric cutting-plane approach allowed reconstruction of images at any cross-sectional position in the entire 3D volume of tissue, making it a valuable tool for exploring and evaluating the location, shape and dimension of the channel from all directions. Some measurement tools have also been implemented to quantify dimensions for verification and analysis of the laser created channels.
Conclusions:
In conclusion, image enhancement and visualization system for investigating and evaluating femtosecond laser-created aqueous humor drainage channels in the sclera is presented here.[1] Juhasz T., "The effect of femtosecond laser scleral treatments on the outflow of aqueous humor", In Investigative Ophthalmology & Visual Science (ARVO Meeting Abstract), 45: U392-U392 1052 Suppl. 1, APR 2004.
Keywords: image processing • imaging/image analysis: non-clinical • anterior segment