Structure and vasculature of the human corneo-scleral limbus as imaged in-vivo with sub-micrometer axial resolution OCT

Abstract

Purpose : To visualize in-vivo the microstructure and vasculature of the human corneo-scleral limbus by use of a sub-micrometer axial resolution OCT technology.

Methods : A sub-micrometer axial resolution, fiberoptic SD-OCT was developed for in-vivo imaging of the morphology and blood / lymph perfusion of the human corneo-scleral limbus. The UHR-OCT system utilizes a commercial supercontinuum light source, a custom filter to select the necessary spectral bandwidth and a 4096 pixel CCD. All optical and fiberoptic components of the system were specifically selected to sustain a spectral bandwidth > 260 nm centered at ~785 nm. The OCT system provides 0.95 µm axial and < 3µm lateral resolution in biological tissue and SNR of ~95 dB for 650 µW incident power. By utilizing different imaging protocols, both morphological and Doppler / OMAG images of the corneo-scleral limbus were acquired from healthy subjects and subjects with limbal abnormalities. The UHR-OCT images were processed with novel algorithms, developed by our research group, to further image resolution and contrast.

Results : Volumetric images of the human corneo-scleral limbus, acquired in-vivo with the new sub-micrometer resolution OCT system, allowed for visualization of the corneal epithelium and Bowman membrane’s termination at the limbus, as well as the microstructure of the Vogt palisades. Overlapping Doppler OCT and IMAG images revealed the blood and lymph vasculature of the limbus. Both morphological and vascular changes were observed in cases of limbal abnormalities.

Conclusions : Sub-micrometer resolution OCT is capable of visualization and characterization of both the micro-structure and vasculature of the human corneo-scleral limbus.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.