Submission
| Title: | Imaging fine structures of the human trabecular meshwork in vivo using a custom design goniolens and OCT gonioscopy |
| Presenter: | Alessandra Carmichael-Martins |
| Institution: | Indiana University Bloomington |
| Authors: | Alessandra Carmichael-Martins, IU Bloomington Thomas J. Gast, IU Bloomington Brett J. King, IU Bloomington Brittany R. Walker, IU Bloomington Marcelina Sobczak, IU Bloomington Stephen A. Burns, IU Bloomington |
Abstract
| Background/Significance/Rationale: | The trabecular meshwork (TM), located within the iridocorneal angle (ICA), is a target for many glaucoma treatments aimed at controlling intraocular pressure. Structural variations between individuals are poorly understood. We propose a newly designed gonioscopic lens optimized for high-resolution imaging for fine structures of the human TM in vivo. |
| Methods: | The body of the new lens is index-matched to the human cornea. The new design allows a diffraction-limited image plane at the ICA. The goniolens design was 3D printed and manufactured in house. The lens is then placed on the subjects´ eyes coupled to the cornea with goniogel. Images were obtained and analyzed using a commercially available Optical Coherence Tomography (OCT) device (Heidelberg™ Spectralis). |
| Results/Findings: | The optical resolution was measured in a model eye to be 11.05 µm. Dense OCT scans with minimum spacing oriented tangential to the iris and ICA were performed on 7 healthy subjects (23-73 yrs). The TM was successfully imaged in all subjects. The custom goniolens improved the contrast of the uveoscleral meshwork structures and corneoscleral meshwork revealing limbus parallel striations, not visible with previous goniolens designs. Transverse OCT images were constructed segmented along the anterior TM, providing an enface image of the TM structures including corneoscleral beams, previously only imaged in vivo using custom adaptive optics systems. |
| Conclusions/Discussion: | A new optimized goniolens design has successfully been used to image the human TM with sufficient resolution to depict fine structural features. This high-resolution gonioscopic OCT allows imaging of fine collagenous structures within the TM that are not resolvable with commercially available systems using a clinically feasible approach. |
| Translational/Human Health Impact: | The clinical feasibility and cost-efficient gonioscopic OCT imaging of the TM at high-resolution in vivo, allows us to study the structural changes with age and disease. This will increase insight into the development of high intraocular pressure and glaucoma by imaging such patients. |
