Lecture: The Fundamentals of Ophthalmic Fundus Photography

During this live, interactive webinar, we will focus on maximizing photographs in the posterior segment for documentation, tracking disease progression over time, and now artificial intelligence (AI). Retinal fundus photography is a key skill and service for ophthalmic practices globally. This session will answer major challenges or learning curves that many users experience. The objectives of this webinar will include the following: a brief review of camera fundamentals/optics, the key techniques for capturing images and how to help “coach” your patients, pure fundus photography focus, examples/classifications of good and bad photos, how photos are being used by AI, and camera care and maintenance. (Level: All)

Lecturer: Michelle Buck, COT, Retinal Photographer, Retina Associates of Kentucky, USA

Transcript

MICHELLE BUCK: Hello. Good morning, everyone. Welcome, happy International Women’s Day. Today we’re going to talk a little bit about fundus photography and how to capture some better images to be able to help your patient and your physicians as well. So let me get my video up here. All right. So this is fundamentals of fundus photography. We’re going to talk a little bit first about how the fundus camera actually works. Basically this first photo shows the pathway of light that goes through the camera. It goes through a series of mirrors and lenses, basically to focus the camera on the retina and to get the picture back to the capture station. This is the daily fundus camera that I use. So this kind of shows you the inside part of it and also the outside part. So light generated from a flash is projected through a set of filters onto a round mirror. The mirror reflects light through a series of lenses. The lenses focus the light. The lens at the very top shapes the light into a doughnut shape. That’s what you actually see when you’re lining the patient up in the camera. The light reflected onto the mirror with the central aperture. The light is projected through another lens and proceeds into the eye through the cornea. The retinal image is projected back to the camera through the hole in the doughnut. Then through a series of mirrors and lenses, to the camera capture station. I know everybody has different cameras, not everybody has the same system. This is sort of a basic overview of how that camera actually works. So basically light just goes through lenses, a set of lenses and mirrors, on both ends of it. So when you’re getting started, to be able to take photos, you want to make sure your camera is ready to go. You want to make sure headrest and chin rest have been cleaned and wiped, that you’re keeping that clean. You don’t want to spread germs. You want to make sure too that we don’t have any debris on the camera. Make sure that the lenses are free of dust and debris. You can use whatever approved method you have to clean that. I normally use lens paper here. I do have a little air brush. You can use lint-free cloths or any kind of approved lens cleaner. I do have some lens wipes, but you don’t want to ever clean those camera lenses with bleach or alcohol right on the lens or anything like that that would actually damage the lens. You’re going to focus your eye piece, if your camera has one. I know some of you all have cameras where you’re actually looking through an eye piece to focus on the patient. Some of you have cameras that you’re actually looking at the screen to line them up. So if you are looking through an eye piece, make sure you focus that eye piece. If you’re still using film cameras, I know some places are probably using film as well, make sure you have your film in there ready to go. So if you do have to set your eye piece on your camera, it should be done for each individual photographer. If you have more than one photographer using that camera, when each one switches out, they need to go in and set that eye piece for themselves. If you wear glasses or contact lenses, you can focus the lens with your corrective lenses or if it’s easier you can remove your glasses and focus the lens, it will accommodate for your correction. Some people like to leave their glasses on, some people feel like their glasses fog up if they leave them on so they take them out and set that correction. To focus the eye piece, you’re going to make sure your camera setting is turned on, you have your view lined up, that you’re able to visualize the crosshairs in there. I just take a white piece of paper, hold it where the patient’s eyes are going to be in the camera, turn the eye piece as far as it will go in the plus direction and blur it out. People tend to accommodate, you usually accommodate in the minus direction, that’s why I turn it to the plus. To do that, if you turn it to minus, you might accommodate for the distance. So I look through the eye piece. You’re going to turn it toward the plano or the zero setting. As soon as those crosshairs come in sharp and in focus for you, you want to stop. Like I said, you can accommodate for that distance especially if you’re a younger photographer, your eyes will tend to accommodate. If you keep going, it’s going to get out of focus for you. The eye piece should be adjusted for each individual photographer. I actually prefer to do it before each patient. You don’t necessarily have to do that if you’re the only photographer in there using it. But I feel like, you know, I start to accommodate some afterwards. So I will actually do it in between patients. Here is a picture of those crosshairs that are in the camera, what they look like when they’re sharp and if focus. And then you want to align the patient in the camera. So you want to make sure that they’re aligned comfortably. I always try to make sure their feet is touching the ground, if we can do that, they’re in a secure chair, they don’t feel like they’re going to roll backwards. If you have a chair that locks, or you can kind of secure their chair, usually if they feel comfortable in the machine, you’re going to get better photos on them because they’re not worried about falling out of the chair the whole time. Adjust the chin rest. So the hash marks on the camera line up with the patient’s outer canthus. On your setup for your camera there’s usually a bar or something on the side of the chin rest that has hash marks there. That’s going to put you in the best position to line them up. Patients should be able to touch the headrest comfortably with their forehead, you want to make sure they’re in the chin rest. A lot of patients, when you start taking the pictures, you’ll notice they start to back away from that headrest, that’s something you need to watch when you’re actually doing photos, if you notice your picture is if focus, then it starts to go out of focus, look up and make sure the patient actually has their head positioned correctly in the camera because that will affect your photos as well. If you have a patient who is a big person, sometimes we have to raise the chair up and actually have the patient lean forward. Otherwise the body is actually restricting movement of the camera. You can’t move it enough side to side or can’t move it in enough. So that is something to take into account as well. When you are getting the patient ready, you want to explain the procedure to them. And the results you’re trying to achieve. The patient knows what’s going on, you know, and why you’re trying to get these photos, it will lead to better diagnosis and treatment plan if you can get good photos. The more they know about the test and what you’re actually doing and what you’re trying to find, the better cooperation you’re going to get from your patient. If you’re using a traditional fundus camera, make sure the patient is dilated at least 6 millimeters or greater to get the best images. My retinal camera is not forgiving if the patient isn’t dilated, sometimes I can’t get images at all, I might have to give a second set of drops. If you have access to dilating drops, if you can dilate them, go ahead and do so. You’re always going to get better images on a dilated patient, even if you have that nonmydriatic camera. I have dim lights in the room that causes people to naturally dilate. It also allows a better view for the fixation lights for the patient. If you have external or internal fixation lights, the patient can focus on that easier. I try to have the patient look straight ahead. I like to take lens photos. We do it a lot for our research patients we have in the office, but it shows the doctor basically how dilated the patient was, if you’re shooting through any obstacles. So, you know, if the patient has a lot of cataract or they have any sort of corneal issue or anything that’s blocking your view when you look in there. Also it helps me just focus. So, you know, to do this you’re going to move the camera away from the patient as far as it will go back. Align the eye in your machine, just have them look straight ahead, canthus to canthus. I’m going to focus on the pupil and iris and try to get that into focus and capture the image there. For retinal images, I have them look straight ahead, try to focus on the small vessels in the back of the eye. Your camera should have a little doughnut, basically, a little round circle with a hole in the middle. You want it makes sure that that’s aligned properly on the eye for the best focus. When you get that in the position that it needs to be, you’ll actually see it just glow. I have a picture of that here in a minute so that you can actually see that. That is going to be your best focus and your best place to get a picture for the patient. To have them look where you need them to look, if they can’t, you’re — we have a lot of patients here who have no central vision, no fixation. So we do have external fixation lights. I know some of you have internal fixation lights. I try to use the fixation lights. We do have a stick in the camera where you can put that down inside there and have them try to focus on that stick, and to look in the right place. You do need to really pull that out before you take the picture so that it doesn’t show up in your picture. If those don’t work, I try to just use verbal directions, try to tell the patient to look up, down, left, or right. Sometimes it’s hard for patients when they’re looking at that light, they can’t really tell which way they’re actually looking. So you can always just tap on the patient, you know, sometimes I’ll have them look this direction or look at the shoulder. Sometimes that helps them to actually have those physical cues to be able to know where they’re trying to look. To get the posterior poll picture, we’re lining up the patient from the side. We’re still off a little bit. When you actually have that lined up where it needs to be, your whole iris here is glowing, that’s the correct position. That’s where you’re going to get the best photo of your patient. And I usually lean around the side of the camera to do that and actually watch it from the side to get in there. It’s a little bit harder to see when you’re looking straight ahead. If you can line them up from the edge, do that. I did tell you all I normally take external photos to see what we’re shooting through. So you want to focus on this little edge here between your pupil and your iris. As you can see, this patient has had cataract surgery and they’ve got — this is where the capsule was here. So that shows up in your picture. This one is a good picture. It also shows you, like I said, how dilated your patient was. If there’s any issues, like they don’t dilate well, another here, this external photo, showing how dilated the patient is and your view is clear to look through there. This is your posterior poll photo. Also another posterior poll photo, here is a picture that shows the anatomy of what you’re looking for. Here is your optic nerve right here, your optic disc. Macula is over here. Fovea. All these veins and arteries coming off your picture here. When you take the photo, like I was saying before, I usually will try to line it up as much as I can inside. Especially if I’m moving to a different field, I’ll lean around the side and look for that glow, because that’s going to be your best position to find that. Also if you have a patient who has a lot of cataract, sometimes you kind of have to find a hole in their cataract to shoot the images through. If you look around the side there, that’s an easy way to kind of find that area in the cataract that you can get through. If you’re taking multiple fields, I know some places, you’re probably taking four fields or seven fields for your diabetic patients. Use the fixation devices, verbal cues. If none of those work for me, like I say, we have a lot of patients here, I’m in a retina practice, so we have a lot of patients with just no central vision whatsoever. And sometimes they just can’t follow that fixation at all. I have to try to have the patient look straight ahead. Fortunately I do have a camera that will move side to side and crank up and down. A few times I have to have the patient try to look straight ahead or look a little bit to the side and then I’ll have to try to move the camera to get to the field I want to get to. You have to be careful because if you move too far to the side, you are going to lose some picture quality. Your camera was actually made to take pictures on a curved surface, the front of your eye. If you start getting over to the side, you’re away from that, you’re getting out of that curve and it’s not going to take as good a picture, you’ll lose some detail. Keep that in mind. You may have to have the patient look a little bit to the side and then try to get in there and move your camera to get those. If you have a patient who is blinking excessively or their eyes are watering, here we try to put in artificial tears or numbing drops. If those aren’t available to you, I would have the patient close their eyes for a few seconds, reopen them, blink three or four times really quick, and try to get a picture on them. A lot of times, even if, you know, those drops will actually have a placebo effect sometimes on the patient, if they think that, you know, they’re not going to blink as much if you put those drops in, it may work for them. If they have dry eyes and their eyes are watering a lot, it does help to put those artificial tears in there. You want to make sure your lids and lashes are out of the way. We try to hold the lids if we need to. It’s usually best to hold the top and bottom lids both. I find a lot of times, if you put the top lid up, the bottom lid goes up as well. You’ll get a better picture if you can hold both lids. If you’re not able to do that and hold the camera, you can get a second person to come in and hold the lids, that’s acceptable also. You may have some patients who can’t position in your camera. We have some patients here who either they have neck issues, they have their neck is fused or we’ll get patients who are just — have their, you know, their head is down like this, they have spinal issues. So you have to get kind of creative to be able to line them up in the camera. What I usually do for those is try to pad up the chin rest, especially if they can lean forward and touch their head on the headrest but they can’t get their chin in the machine, I try to put some padding underneath their chin, either tissues, paper towels. We have some foam here that we can use. I also have a patient who can get his chin in but can’t get his head in. So I tape a piece of foam to the top of the camera so he can actually lay his head against that. It does put his eye back too far for the machine. So for him I actually have to turn him to the side to be able to get those pictures like we were talking about earlier. If you can, try to get your photos as quickly as possible. But the longer it takes you to get the photos, the more tired the patient becomes. They’re going to be less cooperative. Their eyes are going to water more. So the quicker that you can get the pictures, the actual better it’s going to be. I find personally that 50 degree photos are easier to get good focus on. And you get a better view. So if you do have that option and your clinic lets you do that, I would do 50 degree photos. I think the program for Orbis artificial intelligence evaluates 50 degree photos. If you can take those, those are great. They give a little bit wider field, give a little bit more information to the doctor. So you also want to make sure there are some common issues that happen with your photos. So to try to troubleshoot those, a lot of times you can get artifact in your picture. So you may have spots that show up in there, dirt that shows up in there, dust. So you want to make sure your lens is clean. If you’re seeing anything like that, try to have the patient sit back, clean the lens. A lot of times the patient, if their eyes are watering a lot, they’ll get tears on the lens and that will show some spots on the back of your photos. So it helps if you can actually just clean the lenses off. You want to make sure their eye is well-dilated and their lids and lashes are out of the way. So a lot of times that can affect your picture. You’re going to get blockage where those lids are, you’ll see lashes in the photos, make sure those are out of the way. If you get a light arc in the picture, you want to move in the opposite direction to correct that. If you’re not on the people enough, you want the patient to keep both eyes open. You’ll have some patients who try to squeeze one eye shut to try to focus with that eye. Usually if they squeeze one eye shut, both eyes want to squeeze shut and that eye will tend to roll up, the one that’s still open. I know with me, I’m using their opposite eye for fixation, I’m having them look at a fixation device or light with their opposite eye to try to get them in the right spot. Really try to keep both eyes open for that. So here is a light arc defect right here. This picture, a little bit off here, this is where you have the light defect. A little bit out of focus. This other picture shows the corrected picture of it. So here is where the light arc is out of the picture. This here is lid interference on this patient. Basically lid’s not being held out of the way, so you’re getting this light area down here where it’s being blocked. Here is the corrected version of that. Same thing here, this is actually the same patient. This is just a different field. But just really showing how those lids kind of — lashes being in the way or really kind of blocking your picture here. Another one here, same issue here. And if you look, here is my external picture of the patient. So you can see, you know, they’re not able to get their eye open very wide. So it was one that we actually had to hold lids on. The other issue is focus. So you want to make sure you’re in the best focus that you can be to get the patient’s picture. So when I go in and focus, I want to focus on the small retinal vessels instead of the big ones. You want to try to get a focus on those. You want to make sure the color is consistent and saturated across the back part of the eye. If there’s light areas or dark areas, you know, try to move around a little bit. Try to get that best color that you can get across the eye for the back. Don’t try to constantly refocus the camera. I used to have a huge problem with this, especially when I was younger. Like I said, a lot of times you will start to accommodate for distance. So I would get the camera in focus, I would start to take pictures, then it didn’t look like it was in focus to me and I would try to refocus it again and then the pictures I was taking were actually out of focus. So try to leave it where it is when you initially get it in focus. If you for some reason move it and you can’t get it back into focus, you need to just stop, try to look off into the distance for a minute or so to try to get your eyes adjusted to distance, not accommodating for that near distance anymore. A lot of times what I will do too is just move the camera back again, focus on that lens photo again to get it in focus, then bring it back into the retina and try to get it focused at the retinal point. So much of your focus is actually distance. So if you’re having trouble with the focus or if it comes in focus and it’s out of focus again, try moving your camera a little in or a little out. A lot of times it’s just that distance that you have with the camera from the eye that’s causing your focus to be off. So here’s a patient with focus issues. Here’s the first picture here. You can tell it’s blurry. Here the focus has been corrected for that. Same thing here. Another picture where this is good, in focus. You can see the smaller vessels are all in focus here. Here is a blurry picture, same patient. And this one just shows the difference in distance. This is actually the same patient here. This is having the camera a little bit closer. This is having the camera a little bit further away. Technically this one is more in focus, actually, for this distance. If you notice, you can see those vessels much better, they’re much more in focus. So distance is a huge part of it. Another issue that we have is flash. So you want to make sure that your flash is set correctly for your patient. And with me, I just have to take pictures and see. You take a picture, if it looks too bright and washed-out, then I’ll turn the flash down. If it’s really dark or there’s not enough contrast, I’m going to turn the flash up to try to get a better picture. Generally people with darker pigmented skin tend to have a darker pigment at fundus. They may need brighter flash settings. Lighter skin tones usually have a blonder fundus. Sometimes I have to change that flash setting even while I’m taking photos. If I’m taking another field, I may have to change the flash a little bit to get that field in a little bit better focus for us. Here is an example of this. Here is a patient, here is the corrected one, here is a little bit too dark. So you just turn the flash up a little bit for this one. Much better picture. Same thing here. This, if you notice, is all dark up here, a little too dark for the picture. Here is a corrected version of it. So you just turn the flash up a little bit to get that. This one is actually a little bit too bright. If you can tell here, it’s really bright on here. The corrected version, we just turn the flash down a little bit here for this one and got a little bit better photo. Also here is another one, another example. This is a nerve photo. Too dark here. And just increase the flash a little bit, got a little bit better picture. Everyone, I know, has different cameras here, so it’s a little hard to be specific about how you do your camera maintenance. You just basically want to make sure that you keep your camera as clean as you can. Keep your lenses, eye pieces, mirror clean. Clean them with some sort of approved cleaner, lens cloths, lens paper, any kind of wipe that’s approved for your camera. Like I said again, you do not want to clean those with peroxide or bleach or alcohol straight on those lenses or mirrors, you’ll pit the mirrors, you’ll take the coating off the lenses. It’s going to mess up your camera. So make sure you are using some sort of approved method to actually clean those. You want to keep your chin rest and headrest free of makeup and oil and debris. So you want to clean that. Those you can clean with alcohol and other cleaners, just as long as you’re not cleaning the lens. But the external part of the camera, you can clean with those. You want to try to keep your camera as dust-free as possible. So try to keep your camera covered when it’s not in use, to keep some kind of cover over it, just to keep dust from getting in your camera. You want to clean your capture and viewing screens so those don’t get dusty, so you get a good view. You can clean those with your air or brush or approved wipe. Try to know how to change the bulbs and fuses and flash tubes in your camera and try to keep those supplies and tools on hand. Make sure your camera is backed up after use. You want to make sure you are archiving it or doing whatever sort of backup that you need. Just to make sure that we don’t lose any images. So Orbis is using artificial intelligence to grade most of their images. And it’s a big help, because the AI can help track disease progression over time for diabetes, macular degeneration, glaucoma. I know that macular degeneration is not as prevalent in other countries as it is here, it’s a huge problem here in the U.S. Diabetes is a huge problem everywhere, as is glaucoma. But it can compare it with the last photo and actually see if there’s a change in disease progression. It can be utilized from anywhere in the world. So as long as you have the Internet, you can send those images and AI is going to be able to grade those. AI also, you know, allows you to be able to capture photos maybe in areas where there is no specialist, no ophthalmologist to be able to grade those photos. It can go to AI and AI can be able to do that for you. It allows Orbis to evaluate which specialist would be needed in certain areas or maybe what type of surgeons need to go on an Orbis trip. So if you have a lot of diabetic patients needing surgery, you’ll know they need to send a retinal specialist to take care of the surgery. It will also identify patients who need to be referred to a specialist. If their diabetes is getting worse and it’s to the point where they need to see a retina person. It lets them know what the need is in that area. It’s important that you get the best quality photos for artificial intelligence to be able to grade those. And when you’re looking for photos for AI, if you’ve seen the patient before, go back and look at their past photos. Try to see if there’s any factors there that can make your set of photos today that you’re taking better. Look and see, was the flash not bright enough last time? Is there something I can do to get this in better focus? Try to get the same field position that you got in last time so that they have a good way to compare those. And for Orbis, they do want 50 degree images for that. So make sure that you’re capturing 50 degree. So in summary here, you want to use any kind of tips and tricks to obtain the best quality image. So whatever you have to do to get your patient positioned correctly, to get them to actually look in the right position, to guide them with that. You want to make sure that you do that, try to keep your equipment as clean as possible and as maintained as well as possible as you can. You know, we’re trying to get the best images there, so that your doctor can diagnose the patient and decide what kind of treatment they need and for artificial intelligence. You may have to be creative with the patient with positioning or instructions with them to get them to understand what you actually want them to do. So like I said, you may have to pad the chin rest, you may have to tap their face to be able to get them to look in the right direction. So whatever you need to do, you need to try to find creative ways to do that so you’re getting the best photo quality that you can. Also you want to be clear with your instructions. And why it’s important to get these images and to get good images. Patients tend to cooperate better when they’re more informed and they know why you’re doing something and why that’s important. So you want to make sure that you’re telling them exactly what you want them to do, you’re always going to get better pictures that way. This is my email here. If anybody has specific questions. I know with this, we needed to be broad because everybody has different camera systems. So we’re not getting into any sort of specific, necessarily, camera system. So if there are any questions, you can try to email me. If I don’t know the answer I’ll try to look it up and try to find out the answer for you. So that basically is our presentation for today. I am going to look at our questions here. I would imagine at some point, smartphone cameras — the question is, are traditional fundus cameras going to be replaced by newer smartphone cameras. That probably is going to — you know, in the future, that’s going to work for a lot of things. I don’t think it’s going to be as easy to get extra fields if you’re trying to get some sort of four fields or seven fields or anything like that. But I think eventually in the future, especially as technology gets better, I think that yes, that a lot of those will be replaced and it will be a lot more accessible for everybody to do that. So again, with artificial intelligence used in newer smartphone-based cameras, is it going to be reason for them to totally, entirely replace? I don’t think it is. I don’t think that phones are ever going to completely replace. There’s a lot of people who are using artificial intelligence to grade things, but there’s a lot of doctors’ offices where they still have physicians in there who are actually grading their own photos or looking at them. So when I take my photos, of course we’re all digital here, so as soon as I take them, the doctor actually has them and they can review them, they can show them to the patient. And I think, you know, that eventually — I don’t think it will completely replace it. It could. No idea. The next question, let’s see, can nurses use the fundus camera to do fundus screening in areas where there’s no ophthalmologist? Probably you can do the — you know, usually for retinopathy, prematurity, there are usually special cameras, pediatric cameras that we actually use. Honestly, I don’t know how accurate the phone camera is with that, I would imagine you could use something like that. So I do think that, as technology improves, everything is going to improve with smartphones and being able to capture good images with those. Babies are tricky anyway, they’re moving around, you have to put the lids back in. So, you know, it would be great if it would, because that would allow so much more access. Let’s see. I’ve seen one-minute video clips using smartphone-based fundus cameras, more beneficial than original uses of merely taking still photos especially in ROP screening and hazing media like cataracts. It probably is. I would imagine that you could be able to get those. Especially, you know, with cataracts, you’re going to have to try to get through that cataract to be able to get a good photo. Whether you’re using a smartphone or whether you’re using like an actual camera that you would normally use for pediatric. So I would think that, yeah, that could be beneficial for you. Let’s see. As regards contact fundus camera is like wet cam. Fundus cameras are the most [indiscernible] nonophthalmologist. Usually, you know, around here, it’s a photographer taking those photos anyway. It’s not the actual ophthalmologist who’s taking them. So I would think that it would be fine for those, for nonophthalmologists. So it’s kind of just dependent on what your clinic wants and what regulations allow you to do in your area. How effective are heat maps and 3D effect functionalities that some smartphone-based fundus cameras offer? So those, they’re getting better. They’re getting more effective. So I think that, you know, there are some benefits for those. Like I said, I don’t think at this point in time that smartphones are going to completely replace retinal cameras at this point. Maybe sometime in the future when technology gets a lot better. So I think that, you know, that is something for the future. Let’s see. In clinical practice, is fundus photography better charged as a separate investigation with a distinct cost instead of making it part of the routine consultation fees? So here, especially in the United States, the government basically sets what we can charge fees for. So they set what our prices are for Medicare and other insurances to be able to, you know, have those fees. I know that in our practice, you know, it is a separate fee. I don’t know of any practice here right off that charges that, that includes that in with their actual visit exam. Even with like open optometrists in our country, they’ll dilate the patient, they’ll give the patient the option, they’ll be, we can either dilate you or charge you 40 bucks. I don’t know of any place right off that includes that in the fee or that it actually is. It should be a separate billable test. So how do you do scleral indentation while fundus imaging capture most peripheral [indiscernible]? We actually in our practice here, we are fortunate enough to have an Optos wide angle 200-going camera. So I can get a lot of those peripheral lesions with it. Also we have steering on our camera, so we are able to, you know, have the patient to get superior temporal, you know, nasal, inferior photos. I can steer the patient to get up. We don’t actually use any sort of scleral depression here. Even with the regular fundus camera, it’s only a 50-degree. So you can still have them try to look in different areas. But here, we’re not actually trying to do that. I think it would be very, very difficult to try to actually scleral depress somebody while trying to take a picture and control the camera. Let’s see. Are there any portable smartphone based cameras that can also do OCT? Not that I’m aware of at this time. There are some portable OCT systems that they’re coming out with. We did a research study on a home-based OCT system. There are some regular retina cameras that will do OCT and fundus photos as well. Optos does that, Spectralis can do that. Those are two that I’m familiar with. At this time I’m not familiar with any sort of smartphone OCT at this point. How much time entering exam room to walking out does imaging take? That really is going to depend on your patient. So here, like I said, I’m in a retina practice, so we’re basically getting OCT scans on our patients. We’re getting photos. For the most part we get wide angle photos on our patients. You know, as long as the patient is cooperative, I can get OCT on them in a couple of minutes. For those fundus photos, I can get fundus photos on them in a couple of minutes with that machine. If I’m actually having to do it on this actual fundus camera, we use these mostly for research for our patients. And some of those patients have pictures on four different machines. It may take me an hour with those. I would think that you could knock out a set of fundus photos in five minutes or so, basically. If you’re just — especially if you’re just doing maybe like a nerve and a posterior poll photo, if you have to do multiple fields, ten or 15 minutes with your patient would be a good time, I think. Some fundus cameras focus better on nonmydriatic eyes. Here I know in our charting it does have a place where you dilated the patient. By the time that I get them in photo, unless the patient has some sort of condition where we don’t dilate the patient first, you know, uveitis or something where the doctor wants to take a look at that first. Everyone is dilated when I get them for the most part, unless — we have a lot of patients who come in who are just having injections in the eye, and those patients are not dilated, and we do get photos in there. But there is a place in our chart that lets you know whether the patient was dilated or not today. Optos is supposed to be nonmydriatic. I find I get much better pictures if the patient is dilated. If the patient has an a tear, retinal detachment, a nevus to look for, I get so much better photos if the patient is actually dilated for that. Let’s see. Some report retinal phototoxicity due to flashes by fundus cameras. How many maximum times can we expose the same patient to fundus flash, to limit the patient’s exposure to this risk? We have some patients who come in every month and have photos. I’m usually just taking, you know, a couple of photos in each eye. I wouldn’t think — I mean, unless you’re doing excessive photos in there, I wouldn’t think that it would be a problem if you’re just getting a couple of photos when they come in for their visit. Even if you’re having to get four fields or whatever, you know, even if you’re taking stereo photos, you’re talking, you know, maybe eight photos in each eye. Like I said, I wouldn’t think, unless you’re doing just repeated tons and tons of photos, that it would actually be a problem in the patient. Do you usually obtain written consent from patients before performing the procedure? Thank you. Oh, thank you. We have basically like a form when the patient comes in, when they check into the office, that it gives permission to treat them. We don’t have them necessarily sign a consent for photos. Basically it’s covered in that main consent. The only thing that we get a separate consent for photo-wise for the patient is if they’re going to have an angiogram or ICG testing, because we are injecting, you know, medicine into a vein that can cause side effects. So for those, we are getting separate consents for. But for photos, we are not. That’s included in our general treatment consent. Same thing for dilation, we’re not getting special consents for any of that. Somebody asked my opinion about pan optic. I don’t know that much about pan optic, I’m happy to look it up and give you my opinion, I’m sorry, I’m not that familiar with it. The Cybersight AI in comparison with other grading methods. One of my doctors actually did — he helped train AI, not necessarily for Orbis, he worked with a group in Africa and India, training AI how to grade fundus photos. And the photos that he was actually trying to grade them for was based like a Topcon film camera. So that’s not really going to — sorry, lost my train of thought there. But I think that — you know, they were made to grade sort of on a basis for the film camera. There’s a lot of — it’s good for grading diabetic patients until you get up to a proliferative diabetic stage, when the patient starts having a lot of bleeding and things like that in the eye, it’s harder for AI to read those than it would be for a doctor to read them just because it is blocked in certain areas. So I think that our doctor found when he did the study that it was fairly comparable, at least until it gets to a certain point. What advice can you give to make it easier to do fundus photos in a ped group? We fortunately don’t have a lot of kids that I have to take pictures on. We did have a pediatric ophthalmologist downstairs, he would send patients up. A lot of times they’re so little that their heads don’t fit in the camera so I have to do what I have to do for patients who can’t put their chin in the camera, I would have to pad up that chin rest, I would have their parents try to hold them and have them sit in their parents’ lap. Sometimes we would actually have the parent take their hand and make a fist and put it in the chin rest and have the patient put their chin on top of that, that seemed to help some. So that’s, you know, a good way to do that. Sometimes, you know, cooperation is not that easy. Fortunately with our Optos it’s pretty easy to snap a picture on a kid. It’s a little bit easier to keep their eye open, to get a quick image there. I’m not sure about this one. Please explain more about fundus camera method. I’m not sure exactly what you’re asking there. If you want to email me with a more specific question, I’ll be happy to do that. What’s the most valid model of fundus camera? There are a lot of great fundus cameras out there. You just — you know, it’s whatever basically works best for your practice. We — like I said, I’m in a retina practice. We actually have an Optos wide angle camera that works great for retinal stuff because we’re getting a lot of things out on the periphery. If you’re in a group that’s not worrying about retina stuff so much, there are so many brands of fundus cameras that work great. You know, most of the newer fundus cameras are all pretty good. A lot of places will let you demo the cameras. We have done that here in our office before, brought in cameras where they let us use them for two or three weeks and decide whether we want them or not. So that may be something that you would be able to do. Really, for that I think it really just depends on what type of practice you’re in and what type of camera best suits your needs. Also for us, our volume is so high. We see at least 150 patients a day in our main clinic most of the times. I can get a much quicker picture with that camera than I can with some of the other ones. So that’s something to keep in mind too, is your volume and how quickly you can obtain those. How can you eliminate reflections in pediatrics when taking fundus photos? Again, this is a lot about positioning. You can kind of try to go off center just a little bit, try to move it in and out a little bit, make sure you get that retina glow on there. Sometimes it is a refraction error on the patient’s part. You might want to try to dial that in to try to get a better photo there. How can we get the protocol policy and standards for performing fundus color and fundus auto fluoresce? It depends on where you’re actually asking that from. Here, you know, in the U.S., the government sort of sets those policies about who can do what. I mean, there’s policies about who can actually inject dye. That varies from state to state. So I would imagine that it just depends on where you are to actually be able to get those. So I’m not sure where you’re asking that from. I would think that there is some sort of guideline in place for that. Like I said, here it’s set state by state, about who can inject and who can do those type of things. And really in our office, we do have ophthalmologists here, and so we are basically working under them. So as long as we have an ophthalmologist here, you know, who is basically in charge and we’re billing under them and everything, we’re allowed to do most of the testing here. Let’s see. I’m working in an ROP center in Iran, in many cases we have to increase quality of ROP pictures by multiple method of image processing. Okay. I’m not sure what your question is there. You’re welcome to email me. Let’s see. I face great challenges in doing fundus images for post PPD patients especially if they’ve had silicon oil . How do we go about this? I know you’ll get a reflection a few times with that silicon oil try to get back there. Like I said, try to move the camera off-center. Normally you want it that way. If you do have a camera that swings to the side, try swinging it to the side a little bit, see if there’s somewhere you can get in there that it doesn’t. I’m usually taking pictures of those patients with an Optos, and if I can off-center that a little bit with Optos, it usually gets rid of that flash thing that you see on there, that light reflects. So that’s probably just going to be positioning and trying to move that camera around. What are possible risks related with use of the fundus camera? As far as I know, when you’re taking regular photographers, if you’re dilating the patient, there’s always a risk they can have a reaction to your dilating drops. If you have patients with epilepsy or any kind of seizure disease, flashing lights in the eyes can actually cause them to have seizures, so you want to make sure that, you know, your patient doesn’t have a problem like that. If you’re taking pictures of your patient and they tell you that they’re starting to feel, you know, dizzy or like they might pass out or whatever, stop, ask your doctor about it, see what they want to do. But just risk for actual regular fundus photos, I don’t feel like there’s really that great of a risk. For — you know, if you’re actually doing angiograms, that’s a different story because you’re actually injecting something into their vein that could cause them to have a reaction, anaphylactic reaction and actually kill them. That’s a bigger risk, that’s different than just regular photos. What medical-legal risks are there in fundus photography as a career, how do we limit — like I said, with just regular fundus photography, your risk is not that great. You know, if you’re doing fluoresceins and everything that is a different story. Just make sure that you know what the — you know, what’s required in your area. Do you have to have an ophthalmologist there? There are some places where you actually have to have a doctor on site to be able to dilate the patient or to perform certain testing. So you just need to try to find that out for your area and find out, you know, what the qualification are, do you need to have a doctor there onsite, are you able to — there are some places that they have the doctor in surgery for the day, and they’ll just have patients come in and do testing. And there’s certain testing here that’s okay to do if you don’t have somebody on premise, and there’s certain testing that isn’t. If I’m doing a dye test I do have to have a physician on the premise to be able to do that in case the patient has a reaction. Our photographers here do our own dye injections, so — but we do have to have a physician here in case there is any sort of reaction with the patient. Please suggest a wild field camera for clinics especially with diabetic patients. I think the Optos is great for that kind of thing, that’s what we have here in our clinic. Again, it is kind of up to you. I’m not — I have no financial interest in any camera brand. I can just tell you that I’ve used it, it’s pretty easy to get pictures. It’s easy to get wide field. Every picture is a 200-degree picture. It does have options to where it will actually set an internal fixation light so that I can have them look in different directions. If I have a patient that comes in with vitreous detachment or vitreous hemorrhage or maybe they have any kind of detachment, especially on their first visit when they come in, we are getting steering on them, so we’re having them look in every direction. You’re actually getting a much broader field because you’re getting a 200-degree field this way and that same sort of field up at the top and at the sides. So it’s a very good camera for that. It’s great for fluoresceins too, just because, you know, we do a lot of fluoresceins on our diabetic patients to see how good vision is on the periphery. Maybe the patient doesn’t look that bad in the center, they don’t have macular edema, but they have core perfusion in the peripheral area, they may start early PRP on that patient to avoid having problems in the future. But again, it’s doctor preference. You may see if there’s something — sometimes the camera companies, if you’re willing to purchase a camera, will let you actually try it out and see. Okay. Let’s see. Can one take up fundus photography as an entire career, what’s your advice for people living in sub-Saharan Africa where we don’t have a specific group specializing in fundus photography? This is my career, basically, I am a retinal photographer. I do fundus photography here. I do OCT scans, the back part of the eye. We do auto fluoresce photos, fluorescein, ICD. We are also heavily involved in research in our office. So I do a lot of research photography for different research groups who are trying to get different medicines. We have a court delivery system for injecting antiveg F that just got approved a couple of years ago. We’ve done vitamin studies for macular degeneration, we do a lot of studies here. I actually do research photography as well. And here in the U.S., definitely retinal photographer is a career. Especially if you’re in a retina practice. I know there’s some specialty groups that may not have that. But here we do have specific, specified, you know, photographers. We are trained to inject and we have to get research certified for our studies. So it can be a career here. If you don’t have specialists oriented toward that, I’m not sure what your best method, if you want to consider that as a career, is. You know, I don’t know if general ophthalmologists are doing a lot of fundus photography. They can do it in their clinic and that might be something, if you know a general ophthalmologist who would be interested, you think, in maybe having a photographer, that might be a way to approach that, talk to him and try to hype up why it’s good to have a photographer, and, you know, what you can do, and they may be open to doing that. So I know that a lot of places, that the job market is limited. Like I said, here that is an actual career here. Okay. Some patients with significant photo phobia are so difficult to place on the fundus camera despite instilling drops. What do you do in this case? I have a lot of really photophobic patients, especially our research patients. So, you know, sometimes you just have to do what you have to do. I try to hold their eyes open. I’ll try to — you know, we’ll try to put the drops in. I know sometimes that it doesn’t always work, and if you have somebody who’s just constantly — what I notice sometimes, when I’m trying to hold the eye open, if they are really photophobic, not only are they squeezing but they’re trying to look away from the actual flash in the camera. And it’s hard to get those. Sometimes you just kind of have to get what you can get. But, you know, unfortunately, if I have a second person who can help me maybe hold lids, that’s something that you can do, and try to see if that helps. I try to let them maybe close their eyes for a few seconds in between pictures, which is fine to do unless you’re trying to take stereo photos. If you’re trying to get the stereo ones and you need two quick ones right next to each other, that’s a little bit harder. But I do agree, it is very difficult with some of those patients who are just really, really photophobic. It happens a lot with diabetic patients I know. I wish I had a little bit, you know, better thing for you. But just try what you can try, try to get them to, you know — try to have them close their eyes and try to blink a few times and try to get it as quick as you can when they open it back up. I know it’s hard because sometimes you lose alignment that way. I have some patients who are really challenging for that. What’s the most risk-free source of light for fundus camera? Most of our fundus cameras have, you know — they have a flash, basically, or they have I guess a sort of a lamp that gives out the light. As far as I know, there shouldn’t be any risk with that for those. I really don’t know of any light source for fundus cameras that’s actually much of a risk. How do you best obtain fundus images in a patient with nystagmus? I have patients like that, fortunately, you know, like I said, I’m using a wide angle camera most of the time from Optos. It takes pictures very, very quickly, I can get a quick picture. I know they’re constantly moving back and forth. And a lot of times with nystagmus, you have to get what you can get. If they’re kind of moving, it depends on how fast their nystagmus is. You have people who are rotary and you have people who have different kinds of nystagmus. If you can start, if they’re kind of looking to the side, if you can flash the camera when they’re looking to the side a little bit, hopefully you’ll catch it when it goes through the middle. Sometimes you have to do that. And see if that works for you. Like I said, it is very difficult with nystagmus. I know it’s very challenging, and sometimes, like I said, we just have to kind of get what we can get and hope it’s something that the doctor can use. You know, if we’re having trouble getting the photo, the doctor is having trouble getting a good look at them too because they’re moving so much. So that would be good. Let’s see. Can a ret cam be used for adults who are comatose? I wouldn’t think so, only because normally if you’re comatose like that, the eyes a lot of times will roll back, if you have your eyes closed they tend to roll up toward the top. I would think it would be very hard necessarily to get those patients to position correctly for that. I don’t have any experience with that, I’m sorry. But I would think that that would be something that would be very, very difficult. Here’s another question about the nystagmus. Hopefully I answered that with the last one. Like I said, sometimes you just have to do your best and try to get what you can get. But, you know, try to see if you can catch it as it goes by. I know that’s kind of a hard thing to do, but I try to, if they’re out here at the side and you know their eye is going to move this way, I try to flash it and maybe catch it as it goes through. Who are recommended to take fundus photography, nonophthalmologist? Here in our office we have dedicated photographers that basically take our photos here in the office. A lot of practices, just their regular ophthalmic technicians in the office take photos. There is an ophthalmic photographer society here that you can get certified through to do fundus photos and OCT, also international joint commission of allied health and ophthalmology has programs to get you certified to be a certified technician. We have a lot of people who take photos who are not certified in any way but they’ve been trained on the job. We do a lot of on-the-job training for that. Here in the U.S., it doesn’t have to be an ophthalmologist that takes the pictures. Our ophthalmologists never take pictures. We do have doctors here doing their fellowship here who come in sometimes on the weekends and see patients and they may take pictures if they think they can when they’re here. But here it’s always going to be a technician or photographer that takes the photos. Doctors never take photos here. Does a black and white pic provided by all fundus cameras sort of mimic auto fluoresce? It does not. That black and white picture you’re taking with your fundus camera is a red-free photo. There’s a green filter that comes in, it gives you a black and white picture. The fundus photography actually, there are things that will fluoresce in the eye without dye. And it’s actually lipofusion, a product of cell degeneration. There is a special filter in there that’s different from what your regular black and white picture is that lets that auto fluoresce basically show up, more like a fluorescein filter than just a regular red-free filter. So it is not really the same there. So you actually have to have a camera that will do auto fluoresce and will pick up that. There are other things that fluoresce too, drusen auto fluoresces in the eye. A lot of times if somebody has retinal dystrophy where cells are breaking down, that will show up. Dry AMD, geographic atrophy from dry AMD shows up. There are things that do show up on auto fluoresce, we do quite a bit of it here. We have a doctor who is a uveitis specialist, we see patients with weird issues. Here we get auto fluoresce on our dry AMD patients. That is sort of a new thing. We used to not get them on everyone but in the last couple of years, there have been injections that have been approved for dry AMD. And the insurance companies are requiring now that we actually take those auto fluoresce photos to be able to show progression of the geographic atrophy. So we do take quite a few of them here. Usual field of view for retinal images. So the majority of retinal cameras have, they are 30 — usually 30 to 60-degree. So there are some cameras that have — my retinal camera back here has a 20-degree setting which is great if you’re trying to take a picture of the optic nerve, high def photo of someone’s optic nerve, 20 degrees works great. Most retinal images are taking it at 30 to 35 degrees, whenever setting is on your camera. The camera I’m sitting at right here is a little bit different camera, this is an Spectralis over here. It does 30 degrees, 55 degrees, and there is an external lens you can put on it that does 120-degree. Most of your wide angle cameras, the Claris, I think it’s 180-degree, I believe, but it takes two pictures to get that. The Optos does 200-degree photos. That’s done in one photo. Usual field is 30 to 60 degrees. If it’s not specified here, all of our research studies that we do have protocols, so they will tell us that, you know, we have to do 30-degree or we have to do 50-degree or whatever. If it’s not specified, I usually always do 50-degree, it gives them a wider angle, gives them more information. I feel like it’s easier to focus on 50-degree and get better pictures. Regular routine photos would be macular; is that correct? Yes. So normal retinal photos, you want the posterior poll. Usually what we do for those is you want the temporal edge of the macula on those crosshairs. So it’s not quite centered. It’s over just a little bit to the side. So you get some of the nerve in that picture too. Disc centered photos, I would be taking is if I was looking for any kind of optic nerve issue. So papilledema, swollen optic nerves, optic nerve drusen, if you’re trying to look at glaucoma progression and you want to take photos of the optic disc to see that progression in glaucoma, those would be that. Or any sort of, you know — sometimes you can get infections that cause swollen optic nerves. Anything that’s causing those optic nerves to swell, we would go ahead and get centered photos on those. And everything else is macula centered, unless — we get a lot of photos here of peripheral things just because we see retinal tears and detachments and different problems like that. And we have patients with retinoschisis and things on the periphery. Diabetic patients, there’s a lot of places that get four wide fields with a 50-degree lens on the camera or if they don’t have 50-degree lens they may get seven-field 30-degree photos. And those can be like montaged together to kind of give you a wide angle if you don’t have that wide angle camera to be able to get all that area in the back and see a little bit further back. Let’s see here. Can a narrow field fundus camera with panoramic functionality sort of reach close to the efficiency of a wide angle fundus camera if you use the panoramic views quite well? It’s still not going to give you that same degree. It just depends on — I mean, you have — you know, if you’re doing 30-degree photo compared to a 200-degree photo, even if you’re going in other directions, you’re only going to get that 30-degree every direction. So it’s not going to quite get out as far. So even if you panorama it, you know, I get it depends on, you know, what your view is. Probably better with 50-degree. But even with a — with the difference in a 50-degree and a 200-degree is a huge difference. So you’re not getting near close to what you would get with an actual wide angle camera. How did you cope with fundus photography during Covid? Okay. So when Covid hit here, like I said, I’m in a retinal practice so we did stay open. What we did is, all of our patients who were stable and could go out three to six months or longer than that, we rescheduled those patients. Anyone that had acute problems that we had to see, anybody getting monthly injections, retinal detachments, any sort of emergency patients, we did see during that time. We were masked, patients were masked. We tried to leave our room doors open during that time, which I know is not always the best thing. We close them now. But just to keep the air circulating so you weren’t shut up in a small room with the patient. A lot of our research studies where we have to do, you know, maybe the patient has, you know, 40 minutes’ worth of photos on all different cameras, you’re sitting right across from them, a lot of research studies deferred those — that photography during that period of time. And we actually did probably a lot more just wide angle photography on the patients during that time so that our doctors did not have to spend quite as much time looking in the patient’s eye and sitting right across, 12 inches away from them, looking at them. They were able to look at those wide angle photographs, see a lot of what they needed to see without having to go in and do so much of an exam. The one problem that we did have sometimes was people fogging up the lenses with their mask on. So that was an issue occasionally. But mostly we just, you know, had people keep their mask on and we disinfected everything well in between each patient, which we disinfect anyway, but normally I just wipe down the chin rest and headrest. We did our best precautions, we wiped down the chairs. We wore gloves with everybody. But we did continue to see patients during that time. How do you best take a fundus image of psychiatric patients and delirious patients? You know, you got to do what you got to do. We used to a patient here who — I’m not exactly sure what they had wrong with them, but every time you tried to take their pressure or you would try to take a photo and you would get close to them, she would tell you she was going to kill you. So I have kind of dealt with that. And you just have to be creative. Try to get what you can get. Sometimes, you know, being a good photographer is knowing when you have to give up. Sometimes you can only get what you can get. And if you think that you’re in danger in any way with patients like that, then you don’t want to proceed with that. And, you know, my doctors know, you know, if I tell them I can’t get a photo on somebody or if I — they know that there’s a reason for it. So, you know, that’s something that you’re just going to have to try to get what you can get. And like I said, part of being a good photographer to you is knowing when you have to quit. How effective is the Pax fundus camera? I don’t have any experience with that fundus camera, I’m sorry for that. Do you do auto fluoresce for ROP? We do not do any photography for ROP at this time. There are actually pediatric specialists here who take care of the ROP babies. We used to see quite a few of them. But we do not at this time. I wouldn’t think there would be a real big need for auto fluoresce for those. Or, you know, I guess — even for fluorescein, you know, I would think that just regular standard photos and an ophthalmic exam would be all that you would need on those. But that’s probably a doctor question. Can one use wide field fundus photography as a method for screening diabetic retinopathy? Absolutely. We — there are a lot of places here in the U.S., I don’t know where you’re exactly coming from here, but there are places who go out and do diabetic screenings at malls and at different festivals and different venues. And they’ll also do health screenings, places where they’ll check your blood pressure, blood sugar, take photos, do different things like that. They usually have somebody there who is not dilating the patients, taking a wide angle photo, and then that photo is graded either by AI or by, you know, someone who either an ophthalmologist or a photographer who is trained to grade those photos. And they will get in touch with the patient if they see any diabetic retinopathy. And they will be able to, you know, send them where they need to go. Hemorrhages are going to show up, microaneurysms are going to show up on those, any kind of bleeding, neo-vascularization of the disc is going to show up in the pictures. That’s a great way to screen diabetic patients. We take pictures of or diabetic patients every three to six months at least. Ret cam to replace ophthalmoscope? Honestly, I don’t know. I would think that would be more of a doctor question. You know, I don’t think that imaging is ever going to completely replace a doctor exam. That’s just my personal opinion. So I don’t know exactly what to tell you on that. I think that you will always have doctors doing screenings. You know, I think that there’s pressing, they’ve got the lids back in, babies are secured. So I think they may actually get a better view than you might get with your imaging. Specific advice in fundus photography for ROP screening. Again, you know, with babies, it’s very difficult to get pictures. You know, you’re going to have to try to get what you can get. A lot of times they don’t dilate well because they cry out their drops. When we did see ROP babies a lot, we would give them three sets of drops, dilating drops every five minutes, we would put those in, hopefully they wouldn’t cry all their drops out, so that was a good thing. And just make sure they’re swaddled and they’re secure, and if they are using, you know, any kind of lid spec to hold the eye open, that that is good as well. So I hope that helps you some. I’m sorry, we don’t see ROP babies as much as we used to. We used to see a whole lot of them. But at this point we really — we have specialists who take care of that. All right. That seems to be all of my questions that I have here. I hope that I was helpful and that you all learned some things about being able to get better photos for your patients and for your doctors and for AI to be able to grade them. If you do have any individual questions, feel free to email me. I will try to get back with you. And if I don’t know the answer, I will try to find out the answer for you. So thanks, everyone, for coming. Have a great weekend. And good luck.

Last Updated: March 8, 2024

3 thoughts on “Lecture: The Fundamentals of Ophthalmic Fundus Photography”

  1. i need cyber learn,i wish long time ago,i have no basic skill and most power full in cyber.can i have got this course to give me,with on my email plase

    Reply
    • Dear Tesfa Tatek,

      Thank you for your comment.

      Cybersight is an online training and mentorship service for eye health professionals in developing countries.

      You can create a free account here: https://consult.cybersight.org/en/web/guest/create-account

      With your Cybersight account, we offer two services: (A) Online courses only and (B) Online courses and expert advice (i.e., Consult).

      More information regarding Cybersight Consult can be found here: https://cybersight.org/consultation/

      Cybersight Consult is only available for ophthalmic clinicians in the countries that we serve (https://cybersight.org/where-we-work/) and requires you to submit a copy of your medical ID/registration. Please wait 48-72 hours for your application to be approved if you select this service.

      In addition to these services, we broadcast free, live webinars about once a week with ophthalmic topics that may interest you. More information can be found here: https://cybersight.org/lectures/

      Our free, online courses can be found here: https://cybersight.org/online-learning/

      Lastly, our Cybersight Library offers an extensive number of free, online resources where you can explore our recordings of previous Cybersight Live Webinars, surgical videos, Test Your Knowledge quizzes, textbooks and manuals, and simulation resources. More information can be found here: https://cybersight.org/library/

      Do alert us with any further questions at [email protected].

      Reply

Leave a Comment