Bessel-gauss beam light sheet assisted fluorescence imaging of Trabecular meshwork in the Iridocorneal region using long working distance objectives

Glaucoma is one of the leading cause of blindness characterized by increased intra ocular pressure (IOP), visual field defects and irreversible loss of vision. Remedial intervention of glaucoma primarily aims at the reduction of IOP and subsequent examination concerning the related anomalies in the aqueous outflow system (AOS) especially with newer angle procedures. Thus, high resolution imaging of the iridocorneal angle (ICA) region comprising trabecular meshwork (TM) is extremely valuable to clinicians and vision analysts in comprehending the disease state for the efficacious analysis and treatment of glaucoma. Imaging of the AOS inside the eye using the digitally scanned Bessel-Gauss beam light sheet microscopy has been used in this study to obtain high resolution optical sections with minimal phototoxicity and photobleaching. This paper investigates the effect of long working distance objectives in obtaining high resolution TM images while offering non-contact and non-invasive approach in imaging. A series of experiments were conducted to optimize various imaging parameters using porcine eyes as test samples. Investigations carried out by illuminating both the anterior segment region and limbal region resulted in promising results. A delineated network of collagen fibers in a meshwork fashion can be clearly seen in the obtained images of the TM. The optical sectioning capability of this technique is demonstrated and the structural features match well with previous literature reports.