 We're going to get started on two, because we have two more speakers and it's 8.35. So I'm Katherine, one of the second year residents, sorry, second year PGY2's first year ophthalmology resident. So just to jump into it, I'm going to tell a personal story, kind of keep my main topic, quite somewhat of a mystery first. So my story starts in the 1990s. This is me. I was one years old sitting in grandpa's lap. If there's three things that you need to know about my family. Number one, we love Thanksgiving. Number two, we love national parks. And number three, above all else, we love watching the Olympics. And we love watching the Winter Olympics. So my story starts in 1998. And I do remember that the specific year was 1998, because it was the Nagano Winter Olympics. And I, like myself, and other Asian American females across the country were glued to the television screens watching our idol, our champion, Michelle Kwan. So my family and I would crowd around our 1985 12 inch Zenith screen analog TV, you know, adjusting the antennas to watch NBC every night. And I remember one particular night we had watched all the ladies figure skating long program and watch Michelle place Silver next to Tara Lipinski. So that night I remember going back to my bedroom and I thought that my vision looked a little bit more grainy. It was kind of everywhere that I looked. It wasn't that I had any visual distortions or any changes in how objects looked, but it looked like I was just looking through this clear kind of staticky fog, almost like the analog TV that still sits in my parents house with these pixelated kind of staticky vision. So of course, the next day I told my mom and I told her, you know, I'm seeing this grainy vision. I'm seeing through it. It's not like my vision has really changed, but I'm not really sure what's going on. And of course, my mom, being a no nonsense traditional Chinese mother, came up with a perfect explanation for my symptoms and she said, Catherine, you've been watching too much TV and that is a result of the pixels on our TV burning themselves into the back of your red nut and you can never watch TV again. And so I was, unfortunately, not allowed to watch the closing ceremony of the Winter Olympics. And I actually have a memory of me being eight years old and my parents had me face away from the TV in the living room so that I could listen to the closing ceremonies. And then they would tell me whenever Michelle Kwan was on the screen so I could quickly turn, sneak a peek and then avert my gaze to further prevent damage of these pixels burning onto the back of my red nut, like looking at the sun too long. Being a very observant eight-year-old, I also asked my mom, you know, if you think this is due to me watching too much TV, why is it that the static is everywhere in my vision, including my peripheral vision? Why isn't it just, you know, a square, the shape of a TV? Like when I look in the sun for too long, I see a circle. Why isn't it that these symptoms are, why is it that they're everywhere and not just kind of in a box? And of course, my mom again had the perfect explanation and she said, well, Catherine, it's because you're sitting too close to the TV and you can never watch TV again, which of course did not really fly well with me. Our short move on to when I was in middle school, this is actually a picture of the community college that I learned how to swim in this pool. And my favorite stroke was backstroke. And so while I was facing on my back, looking up at the sky, I started noticing these very, very kind of faint floaters that slowly drifted across the sky. And as I looked more and kind of concentrated on the more, I started noticing that there were lots of floaters in my vision. Again, not really bothersome, but seemed like the more I concentrated on them, the more I noticed them. Just thousands and thousands of kind of white spots almost looking like bacteria under a microscope. So then in college at UC Berkeley, I was sitting in a lecture hall learning organic chemistry. And I remember looking at my professor with a well lit podium kind of like this one. And I remember looking at him and then as I looked around the room, I would kind of see this ghost-like image almost trailing after him. And it was especially apparent when I was taking notes on a blank sheet of note paper. I would just see these kind of ghost-like images following everywhere that I looked. And again, these symptoms weren't really bothersome to me. I never found them very distressing or disturbing. But I just actually thought that they were symptoms that everybody felt. So then fast forward to residency being at the beautiful Moran Eye Center. I was studying neuro-ophthalmology with Rachel Patel one evening. And I described these symptoms to her. And she thought that I might have visual snow. And that is the topic for today. So visual snow was first described at the clear description of literature was in 1995 by Dr. Liu and his colleagues when they were studying migraine patients with persistent positive visual phenomenon. They also suitly noted that these symptoms seem to be more constant and not really episodic and associated with headaches like traditional migraine with aura. And they describe this as a snow and flickering similar to what was between TV channels. About 10 years later, Dr. Yeager and other colleagues also, those was the first description and use of the term visual snow phenomenon. And then about another nine years later, Dr. Schankin and colleagues, including our own Dr. Kathleen DeGree, were the first to systematically characterize visual snow as a syndrome with proposed criteria for diagnosis using retrospective chart review, retrospective identification of visual symptoms, as well as prospective clinical characterization. So getting into the proposed and diagnostic criteria. So visual snow usually, it presents as this grainy pixelated vision. It's constant and usually present for at least three months on presentation. The presence of two additional symptoms, including palinopsia that includes after images, as well as trailing images and enhanced and topic phenomenon, which can include floaters, as well as seeing those thousands of white dots and lines on a bright blue background or blank, bright white background, as well as photophobia and Nicolopia. And sometimes are you not consistent with typical migraine aura and also by definition, these symptoms cannot be explained by another disorder. So these are some photos that I really, really liked from this paper. The first one shows kind of this grainy vision in dim light at night and then also at room light. There's also these floaters that can be associated with the part of the associated symptoms, palinopsias, including trailing images as well as after images. And then finally, the blue and topic phenomenon with the thousands of kind of light white lines or dots and vision. So if we take myself as an example, I have had these symptoms since childhood, circa the 1998 Olympics, which is when I first remember having those symptoms. Palinopsias, I've seen more as after images and then the floaters and the blue field and topic phenomenon that I described during my backstroke swim lessons. And then I fortunately have never had a history of migraines or headaches and have had normal eye exams. And for me, my visual symptoms have never been distressing. I've never really, I don't really notice them unless I concentrate on them. But just seeing patients in clinic, this can definitely be a wide spectrum for people who find these symptoms very, very distressing just because of their constant unremitting character. And I'm also fortunate that my symptoms have pretty much almost resolved or improved over time. So from the same paper, demographics, men and women were equally affected by visual snow symptoms. 87% of patients also had a headache with 59% also having migraine. About a fifth of patients had anxiety and depression in this comorbid, anxiety and depression in this study. The lifetime occurrence of these comorbidities have been cited as up to as high as 40 to 50% in other papers. And then 25, sorry, 24% of patients had experienced these symptoms since childhood and they were constant from presentation in 40% of patients. In a similar amount, 40% had also noted that their symptoms had progressively worsened. So pathophysiology is still somewhat of a mystery, still unclear, but there are a lot of new hypotheses and very exciting studies that have come out just over the last one to two years. Clinically, a pan-field, positive visual field, phenomenon and the associated symptoms that I had mentioned prior, suggests that there is some kind of a higher cortical hyper excitability. So one of the first papers that I wanted to go over was by Dr. Schencken and it showed a hyper metabolism in the right-lingual gyrus as well as the left anterior cerebellar lobe which was close to the left-lingual gyrus and this was done in 17 patients with visual snow using FDG PET scans and this was matched to controls of healthy patients and this is actually against convention but this is the left side. So this would be the lingual gyrus on the right side and then the left anterior cerebellar lobe and again this was the first kind of, there haven't been any structural abnormalities seen in visual snow but this was more of a functional and the first cited paper of an anatomic foci that could be different in patients with visual snow. Another paper by Dr. Aaron showed in 18 patients compared to age-matched patients with migraine and healthy controls that VP showed in visual snow patients increased latency as well as reduced P100 amplitudes and they localized this to the visual association cortex suggesting that there might be some dysfunction in the visual association cortex in patients with visual snow and just moving along and then the last study that I picked out that I thought was very interesting is that there was Dr. McKendrick did some behavioral studies with visual stimuli in different tests and they saw that in visual snow patients had reduced contrast suppression with certain testing and elevated luminance increment detection and noise and they related that to some kind of again hyper excitability of the occipital or occipital cortex or cortical hyper excitability. So for evaluation in diagnoses of these patients visual snow is a clinical diagnosis and somewhat one of exclusion these patients would benefit from a thorough neuro ophthalmology evaluation but things to keep in mind other things like migraine with visual aura can be overlapping or at least be contributing to some of these associated visual symptoms with palenopsias that can be a side of medication side effects such as topomax or diamox and any patient that comes in with flashes and floaters of course should be retinal attachment and PVDs should be ruled out. Other patients with photopsias in the right clinical history and clinical setting it could be beneficial to test them for perineoplastic retinal degeneration such as car and mar and then any patient with nyctalopia again with the right clinical context could be evaluated for other retinal degenerations in hypovitaminosis A. So treatment mostly in clinic we've seen that reassurance is very powerful and just telling these patients that you have a benign condition you don't have a progressive neurologic or ophthalmic disease can be very very powerful for them and just knowing that this is not something that will progress and worsen has I think most patients cope very well knowing that also if they have associated migraines or overlapping migraines symptoms beneficial to treat those as well as comorbidities such as depression and anxiety and there aren't studies showing evidence-based studies showing that treatment of these comorbidities will decrease visual snow symptoms but just talking to some of our patients getting in with a psychologist and working through their depression and anxiety can also kind of dampen the overall distress they feel from these symptoms and have helped them notice them less. FL 41 tint glasses we recommend to our patients to again dampen that background static and also treat photophobia if that is associated and then medications, pharmacological, pharmacologic options have been more empiric in treatment based on case series and expert opinion but Dr. Vindangan and colleagues recently published a retrospective kind of the first systematic retrospective chart review on treatment effects in 58 patients with visual snow. Lomotrogene was 50 milligrams PO BID was the one that was recommended most often and about one-fifth of patients at least achieved partial remission but a lot of patients discontinued the medication due to side effects same with to a pyramid however Valproate acidosolamide and flunarazine did not show any benefit and if you can see here all patients no patients no patients had complete resolution of their symptoms but just speaking to patients even dampening or reducing some of their symptoms can make this a lot more tolerable. So in summary visual snow is a panfield flickering pixelated positive visual phenomenon it can be associated with migraine anxiety and depression and pathophysiology is still a mystery but there's more to come the current hypothesis that it's kind of an over-excited ability of occipital cortex and visual processing and that one blink and also I just wanted to I was very excited to tell my mom that this was not a result of me watching too much TV. A special thank you of course to Dr. Kathleen DeGree and then also Dr. Ragunta and Dr. Patel and my sources and I will gladly take any questions with the time we have.