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Show The Latest on Optical Coherence Tomography Robert C. Sergott, MD, Laura J. Balcer, MD, MSCE Beginning almost 25 years ago, optical coherence tomography (OCT) began its journey into the mainstream of ophthalmology. Initially developed commercially for retinal and vitreo-retinal interface diseases and glaucoma, this revolutionary technology has proved to ultimately have broader applications in neuro-ophthalmology and neurology, 2 specialties in which a better understanding of OCT has led to more widespread investigation and clinical use. This year at the annual meeting, the North American Neuro-Ophthalmology Society (NANOS) leadership designed a symposium in which several "early adapters" of OCT in neuro-ophthalmology presented data regarding the state-of-the-art of this technology. A series of case studies by this group complemented the 4 presentations and illustrated how real-world use of OCT could help us to solve otherwise difficult clinical diagnoses. In this special edition of the Journal of Neuro-Ophthalmology, readers can learn more from the energy and enthusiasm of that symposium. For those of us who remember neuro-ophthalmology in the pre-imaging era, the OCT symposium evoked memories of the Frank Walsh meetings in the 1970s and 1980s. It was during this time that the first computed tomographic and magnetic resonance (MRI) images were brought to our specialty. OCT now joins these imaging modalities as a technology that will change neuro-ophthalmology forever. A quantitative and qualitative ophthalmoscope, OCT represents the most significant advance toward in vivo visualization of the optic nerve and retina since Charles Scheppens literally used his head with the indirect ophthalmoscope to augment the power of Helmholtz's first device. However, despite the rich history of discovery within neuro-ophthalmology, OCT was not always embraced as a tool that would add to the direct ophthalmoscope, the 90-diopter lens and fundus photography with monochromatic light. Through a series of investigations, first in optic neuritis (ON) and multiple sclerosis (MS) and following in other neuro-ophthalmologic disorders, OCT began to take center stage as a way to correlate structure with visual function. These observations were not only useful to validate clinical visual outcome measures such as low-contrast letter acuity, but established the anterior visual pathway as a model for testing new therapies that involve neuroprotection and repair. With the advent of capabilities for computerized segmentation of the ganglion cell layer (neurons, "retinal gray matter") in addition to retinal nerve fiber layer (RNFL; axons), neuro-ophthalmologists can now examine the eye in a manner analogous to how MRI evolved to evaluate the brain in greater detail than ever before. Its ability to identify retinal disease and to document optic disc swelling that eludes even the most astute clinical eye has also brought OCT to the forefront as a clinical tool for neurologists. Although OCT will never replace the neuro-ophthalmologic examination, it does repre-sent a useful, and often revealing, extension of it. At the NANOS OCT symposium, both the didactic lectures and the case presentations provided a refreshing and positive vibe about OCT in neuro-ophthalmology. As Fiona Costello's paper com-prehensively reviews in this supplement, OCT devices are improving both in terms of hardware and software. We now have images with resolution down to within 5-6 mm; quantitative measurements have coefficients of variability of 2.5%. Although time-domain OCT had a single commercial platform, competition and the free market system have likely advanced the newer spectral-domain OCT tech-nologies even further. For these advances, we must thank the collaborating innovators from the fields of biomedical engineering, clinical ophthalmology, commercial imaging companies, and the United States Food and Drug Administration (FDA) device division. All of these groups have worked together to Department of Neuro-ophthalmology (RCS), Wills Eye Hospital, Philadelphia, Pennsylvania; Department of Ophthalmology and Neurology (RCS), Thomas Jefferson University, Philadelphia, Pennsylvania; and Department of Neurology (LJB), New York University School of Medicine, New York, New York. Address correspondence to Robert Sergott, MD, Wills Eye Hospital, 840 Walnut St, Philadelphia, PA 19107; E-mail: rcs220@comcast.net Sergott and Balcer: J Neuro-Ophthalmol 2014; 34(Suppl): S1-S2 S1 Editorial Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. produce a technology that has and will continue to improve the lives of thousands of patients. OCT enables safer, quick-er, and more accurate diagnosis and, in the care of patients, nothing is more rewarding. In the second article of this supplement, Randy Kardon comprehensively and elegantly provides the Journal of Neu-ro- Ophthalmology readers with a scientific summary of OCT, using papilledema as the clinical platform for discussion. His outstanding review should make all of us look at pap-illedema like we have never done in the past and should provide models of how we should always do so in the future. OCT technologies have also emerged to the forefront of considerations by the global regulatory community in the evaluation of visual outcomes in phase 2, 3, and 4 clinical trials. Laura Balcer's detailed and all-inclusive commentary should empower the neuro-ophthalmology community with the critical thinking required to properly evaluate clin-ical trials reporting efficacy and safety results in clinical trials and in peer-reviewed publications. Her team's work has led to collaborative efforts in MS culminating in the first-ever use of acute ON as the model for testing a new remyelinat-ing agent in a Phase 2 clinical trial. Within that ongoing study, OCT measures are key outcomes of the visual path-way axonal and neuronal loss that so invariably occur after even a single episode of ON. In clinical trials where pre-venting axonal and neuronal loss are the primary goal, OCT no doubt has a bright future. For clinical uses in which our goal is to improve on subjective observations, OCT will be even more helpful. Although we will always admire the beautiful anatomic drawings of Cajal, we will also continue to apply objective measurement techniques such as OCT for evaluation of the optic nerve and retina. Even more exciting will be the next dimension of OCT: MultiColor imaging. As described by Robert Sergott, this technology involves expertise of biomedical engineers and imaging physicists, yet will make us better clinicians. This will be possible by facilitating topographic imaging of the inner, mid, and deep retinal layers, giving neuro-ophthalmologists an even greater window on this relatively unexplored area of the nervous system. The currently untreatable neuro-degenerative diseases await the applica-tion of OCT and MultiColor imaging to localize damage and target new therapies. The fast-growing area of sports-related concussion and study of athletes exposed contact sports will also benefit from OCT to corroborate clinical signs of brain dysfunction in vivo. The next NANOS symposium on OCT will report on these findings, and likely offer us techniques molecular imaging, OCT angiog-raphy and total RNFL analysis. OCT puts into practice one of Fiona Costello's favor-ite sayings: "The retina is both the back of the eye and the front of the brain." In that spirit of innovation, we also should recall the words of Steven Jobs as we evaluate any new technologies, "It is really hard to design products by focus groups. A lot of times, people do not know what they want until you show it to them." These words should inspire us all to continue to think forward, artic-ulate new ideas, and thus create the future of neuro-ophthalmology. S2 Sergott and Balcer: J Neuro-Ophthalmol 2014; 34(Suppl): S1-S2 Editorial Copyright © North American Neuro-Ophthalmology Society. 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