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EW GLAUCOMA 76 byline goes here plus fade February 2017 Charting continued from page 75 " With structural and functional assessment using OCT and aqueous angiography, respectively, in addition to a relationship between the two, we hope to improve MIGS surgical outcomes in the future. " –Alex Huang, MD to translate structure to function makes sole OCT structural outcomes confusing at times. A common clinical question is whether trabecular MIGS should be targeted to regions of greater flow to take advantage of known aqueous outflow pathways. The downside is that if flow is good, potential improvement there may be limit- ed. Pre-clinical experiments by Dr. Huang imply that using aqueous an- giography for functional assessment to guide trabecular bypass to regions of initially poor flow can recruit additional and increased aqueous humor outflow. 6 Now, in unpublished data, Dr. Huang has been able to perform aqueous angiography in the eyes of living, healthy cataract patients. Pre- liminarily, patients have had good surgical outcomes with no sequelae from the angiographic investiga- tion. He said, "The thought process was to start with a cataract patient, since the tracers we use for aqueous angiography can double as capsu- lar stains to make cataract surgery easier. Our purpose was to visualize aqueous flow patterns of the eye and prove the feasibility of the procedure in live patients. The procedure, done during cataract surgery, was just a couple of extra steps, completed in a few short minutes. We are currently planning to gather more data. In the future, this modality will allow us to determine the outflow pattern and hopefully customize the placement and location of MIGS devices, to high flow or low flow areas." Dr. Huang's work took him from bedside to bench and back to bedside, starting with FDA-ap- proved, clinically applicable tools and dyes, reengineering them in the lab, and bringing them back for use in the operating room. "My aim was to make this clinically applicable, not just a laboratory skill set. With structural and functional assessment using OCT and aqueous angiogra- phy, respectively, in addition to a relationship between the two, we hope to improve MIGS surgical outcomes in the future," Dr. Huang said. EW References 1. Kagemann L, et al. Identification and as- sessment of Schlemm's canal by spectral-do- main optical coherence tomography. Invest Ophthalmol Vis Sci. 2010;51:4054–4059. 2. Kagemann L, et al. 3D visualization of aqueous humor outflow structures in-situ in humans. Exp Eye Res. 2011;93:308–315. 3. Kagemann L, et al. Visualization of the con- ventional outflow pathway in the living human eye. Ophthalmology. 2012;119:1563–1568. 4. Saraswathy S, et al. Aqueous angiog- raphy: Real-time and physiologic aque- ous humor outflow imaging. PLoS One. 2016;11:e0147176. 5. Lestak J, et al. Schlemm's canal in OCT images in glaucoma patients and healthy subjects. J Clin Exp Ophthalmol. 2013;4:292. 6. Huang AS, et al. Aqueous angiography- mediated guidance of trabecular bypass improves angiographic outflow in human enucleated eyes. Invest Ophthalmol Vis Sci. 2016;57:4558–4565. Editors' note: Dr. Huang has finan- cial interests with Allergan (Dublin, Ireland) and Heidelberg Engineering (Heidelberg, Germany). Dr. Kagemann's comments do not reflect the opinions of the FDA. He has no financial interests related to this article. Contact information Huang: AAHuang@mednet.ucla.edu Kagemann: lekagemann@gmail.com

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