Lecture: Improved Perioperative Management of Cataract Surgery Using OCT Technology

During this live webinar, we will describe the principles and functionality of OCT technology in perioperative management of cataract surgery. Case demonstrations will highlight the use of OCT before and after cataract surgery. Additionally, the use of the latest anterior segment OCT technology will be discussed for biometry and evaluation of phacomorphic glaucoma. (Level: Beginner and Intermediate)

Lecturer: Dr. Christian Mardin, Ophthalmologist, FAU, Germany

Transcript

DR. MARDIN: Dear colleagues all over the world, good afternoon, good morning, good evening. Thank you for listening to this lecture of today’s afternoon of today from Orbis. It’s on the topic: Improved Perioperative Management of Cataract Surgery Using OCT Technology.
So, a rough description of if I outline of today’s talk. First of all, why do we use OCT for cataract surgery? And I will explain the OCT technique just in a nutshell. I will show you examples of application on the posterior segment in the perioperative management of cataract surgery. We can apply OCT on the anterior segment. I will show you some cases. And then, of course, finally, the conclusion. In the end, I will be happy to take your questions for the last 15 minutes of this hour in order to discuss important issues. Cataract is still a burden. And the main cause of blindness all over the world in all continents. And it’s also a burden on economy, causing millions of Euros or dollars of spending money to heal the patient and to help the patients.
When we look at this world map in the former — in another perspective of the relationship to prevalence of blindness, we see that there are continents which are stricken by blindness and continents which are not so much affected by blindness. And when we look at this same map, if the relationship of ophthalmology to care, we see that ophthalmology care, most of the areas where blindness is most prominent. And the main cause, as I mentioned, is still cataract. Cataract is a problem of patients’ access to healthcare. I had to experience in Nepal in the CBM Project several times with the colleagues that cataract blindness is avoidable blindness. And if you have the technique and the skill, it can easily be done. And it helps patients from childhood to old age equally.
The cataract surgery that’s performed nowadays and in all parts of the world, phaco, has become the standard, is a safe surgery. It has no complications in 95%. 91% of the patients achieve a vision more than 6/12. And 50% even more than 100%.
But some patients, as we have experienced all in our everyday practice fail a revision, and there is the question why this happens. And sometimes even ophthalmoscopy doesn’t give us the information. We talked today about using the OCT to talk about reasons for an unfavorable outcome or to explain an unfavorable outcome after cataract surgery after this happens. The main obstacles to a detailed fundus examination, that’s the key to the good outcome, retina, is most of lack of time for our patients. We are all very busy. Media opacities like dense cataracts, the disease you want to treat. Asteroid hyalosis as we see in the syndrome. So, here OCT examination can help a lot if you are — become able to examine the fundus more in detail.
Helmholtz in 1881 gave us the ophthalmoscope and the ability to have the sight of the human fundus. But with optical tomography and all the three people who helped to develop this technique a lot gives us the insight into the tissue of retina and optic nerve head to understand in vivo better subtle changes. Most often invisible to us during ophthalmoscopy. Roughly, the OCT techniques have developed a lot in the last 20 years. We all remember the time domain which was a pioneer of use of OCT. And the spectral domain technique. Now swept source technique is available. And roughly laser light like iconography is synced on to the tissue of the eye and it’s slowed down by the tissue. And the slow down or laser light or laser light change in the spectrum, as we do with the spectrum domain OCT, is then computed. And like in iconography, the two disenfranchisements are compared by the computer and then translated into a picture which reminds us of the histology of the eye. With high resolution.
Spectral domain OCT has not improved a lot in axillary resolution, up to 5 to 3 microns. But also become a very fast technique with more than 100,000 A-scans a second. We are available to examine our patients even if patients are difficult in cooperation in a very short time. And it’s a non-invasive examination. So, when we do that on the posterior pole, we are able to visualize the optic nerve head. The retina. We are able with fast OCTs to create volumes of the retina and measure different tissues important us to in everyday use.
One achievement is the development of broader wavelengths for the laser source. Broader wavelengths have been very expensive in the past, but now it’s commercially available. And the broader laser wavelength helps us to improve the axillary resolution on the fundus and give us a better and more detailed image of the fundus. Thanks to the modern techniques of laser light.
Another very important achievement is a kind of eye tracking. And I will show you in the following most often examples from the Spectralis fundus OCT because we use it every day in work. And the Spectralis has a special feature. It has two laser beams scanning the fundus. And one serves as a reference. And the other is the examining scan. So, you are averaging on a single safe spot and by averaging the scans on the spot, you increase the resolution of your B-scan image. On the upper right-hand corner, you see the example. The patient moves his eyes, but the picture doesn’t move and is average. And becomes sharper and sharper by averaging.
And this is not only easy for patients with — who can’t cooperate easily, like children, elderly, or mentally disabled patients, but it helps also to find the same spot in the following examination — follow-up examination. And then to compare two time points. And this helps a lot to even find very subtle changes of the retina and optic nerve head.
Different scan patterns, line scans, and volume scans, are offered by this very fast technique and very high-resolution technique. And in the setting of cataract surgery, most of the-line scans, circle scans, fast star scans, or volume scans are used in order to detect the pathology of the fundus of the retina and the optic nerve head. The nice thing that in most available OCT devices, you don’t only have an OCT scan, but you can compare the OCT — combine the OCT modality with infrared pictures with fluorescein angiography, OCT, pictures, or even multi-color images and get a very good idea of the fundus not only by scanning a certain area, but getting an on view on the fundus with false colors which helps you a lot to detect pathologies. Sometimes hidden from our eyes doing ophthalmoscopy.
This is an example of a 75-year-old lady. You see the brunescent cataract at the edge, and the fundus just gives you an idea, the optic nerve could be situated here, the nerves, and this could be the macula. But you don’t get any details. And you can see that the patient that is drusen changes, perhaps not permitting full after cataract surgery. And you get the laser imaging of the fundus, which is more detailed when our white light fundus image due to the inward and outward scatter of the light due to the opaque lens. One thing helping us in the OCT device is the confocal principle, improving the sharpness of our images, even the SLO scan, a lot.
With the high resolution up to 3 microns, we get an image very much similar to the histology we all know from our medical school. And here’s an example of a patient where the eye had to be enucleated due to a choroidal melanoma. And we tried to compare the OCT scan before, with histology, after removal of the eye. And you see that the layering of the retina is very similar to the histology of cause. You have the artifacts of histology for preparation. But the exudates under the retina are nicely depicted in the in vivo picture prior to surgery. Also gives with the structure of the OCT a very good image and very comparable to histology. Even the slight epithelial membrane found in the histology is found also in the in vivo picture.
The main problem after cataract surgery, and this happens in about 2% of our patients, even if their cataract surgery was uncomplicated and it will result in 90% after one year is cystic macular edema or CME. What you do after even with dilated pupils, it’s sometimes very subtle and can’t be appreciated. But when you do OCT scan, you immediately see the basis in the inner nuclear and the outer plexiform layer and very much resembling the nice electron images from the atlas of Spartan.
What is the preoperative risk for cystic macular edema? It’s most often diabetic retinopathy, it’s uveitis, it’s retinal vein occlusion. Use of prostaglandins in glaucoma patients. Epiretinal membranes and the history of the partner eye. If the partner eye also developed CME, then the second eye we do surgery on is liable to get the same problem. So, here’s an example of a female who two months after uneventful bilateral phaco with P CIO L still did not gain full vision back. On the fundus picture we see more on the left-hand than the right-hand side, the patient has a hyalosis, blocking the fundus image and blocking our eyes from reality. When we look at infrared spectrum of our OCT, and then afterwards using an FLA, the fluid angiograph, we nicely depicted macular edema. And with the OCT, we can measure even the central figures and appreciate the cystic macular edema. So, in the time of OCT, we can stop doing the fluid angiography to mind other cystic macular edema because I have the OCT. After the treatment with the anti-inflammatory eye drops and anhydrase inhibitors, the cystic macular edema resolved in this patient and visual acuity increased again. And again, you see the beauty of scanning the same spot as in the first picture. You can directly say what has changed or has not changed if you are not successful.
This is a patient with diabetes. After cataract surgery, developed the cystic macular edema. Anti-VEGF therapy was done, but was not successful. And the main reason in this patient was an uncontrolled blood sugar. And the second thing is the patient not only has diabetic retinopathy, nicely visible in the picture, much better than ophthalmoscopy, but has the membrane. This is one reason cystic macular edema may develop after cataract surgery is uncontrolled blood sugar. And the patient should be advised to improve his situation prior to cataract surgery. This also secondary edema after branch occlusion when the hemorrhage has disappeared. Then you have to do a very detailed ophthalmoscope to find this hard, subtle hemorrhages. These have resolved and the fluid angiography, you can see the vessels between the perfused and non-perfused area causing exudates and cystic edema. Nicely depicted here in the OCT scan. And this problem should be addressed prior to cataract surgery. Because after cataract surgery, this exudate, and especially cystic macular edema may get more.
Here’s a patient — a male patient — 77 years old. This is the fundus picture. A little bit of paleness, nothing special. Got cataract surgery and did not improve three weeks after phaco. And the scans were done and it becomes that the patient has a subretinal edema under the retina. And very much hinting towards CMD and AMD. And this patient was lucky enough not to get a hemorrhage after the cataract surgery. In this case, if we would have a good OCT image prior to surgery, we would have treated the MNV first before doing the cataract surgery or then doing a combination of both.
The same is true for this patient. The fundus picture doesn’t reveal any sign of MNV. No hemorrhages, no exudates. But in the OCT scan, you see the giant interior detachment in the subretinal fluid.
So, this is a question to you. This is also an old male with uneventful cataract surgery. But after surgery, vision was not improving and the patient was very not much satisfied. So, you see the fundus picture here on the left-hand side, the infrared picture on the right-hand side. And now I would ask you: What do you think? What is the reason for the vision loss? Soft drusen, arterial retinal branch occlusion, macular pucker formation, or macular hole formation. You may then vote and see what your opinion is. I think this makes the whole lecture a little bit more vivid. You have 30 seconds and then we will look how you decide. It might be obvious. So, the polling is in favor of soft drusen. That’s the majority. And thank you very much for voting. Now we will have a look. The OCT in this case help us. And what do we find both the minority already hinting towards — yes. It was a full thickness macular hole, stage four calling to guess. And when you look closer, you might see the slight ring in the center showing you an ophthalmoscopy that might be a macular hole. Very difficult to see, but it’s just one click with OCT. And if this would have been appreciated prior to surgery, the whole cause of the surgery would have been different.
So, this is another male after cataract surgery. Still not satisfied with a very long length of 32 millimeter. And you can see the pigmented epithelium and the choroid and the disc. Also in this situation where you look very closely and test the fixation. The fixation seems to be at the place where it should be. But again, this patient had this small macular hole. And this was the reason why cataract surgery didn’t help him much. And the next question is to do vitrectomy and peeling on him. But this, again, would have been appreciated if OCT scan would have been done prior to surgery.
Epiretinal gliosis is very often a reason for reduced vision after surgery and even causes cystic macular edema to a lower extent after surgery and should be appreciated before surgery and discussed with the patient. This is an example where in a pseudophakic eye, the patient didn’t gain much vision. The membrane and the thickening of the central retinal thickness. On the other eye with a slight cataract, vision was not too bad. He had a visual macular traction and vision was much better or the same than on the other eye. But the patient has not only a cataract, but a vitreoretinal problem. And in this case, could have been advised differently prior to surgery.
This is a very rare but a very sad case of a 15-year-old girl which showed to her doctor a bilateral decreased vision to two years. And on the right-hand side, a phaco was done with P CIO L four months before. Vision did not improve. And the patients — the patient was shown to us because the parents asked for second opinion. So, of course, you think of something urologic to do. This was quite okay. You look at the fundus. These are the fundus pictures of the girl, healthy optic disc. Not very — not much changed on the fundus, perhaps. A little bit this light spots on the left-hand side, the right fundus looks on the image quite nice. When we do the infrared imaging, or new infrared imaging, we see that the patient has the typical — or atypical in this case drusen. And when you do OCT scan, you realize that the photoreceptor also segments are normally present in the center of this patient. This was the reason why visual acuity dropped down and cataract surgery did not help. The picture on the right-hand side and on the left-hand side you see this atypical drusen. And I think everybody here has an idea. The fluorescence, it’s a typical example of Stargardt’s disease. The patient was suffering from Stargardt’s and it didn’t help a lot. But they lost the ability, and also you see the changes typical for the central vision changes in Stargardt’s disease.
In a nice publication from Brazil, dos Santos and colleagues did scans prior to macular surgery and found in eyes which clinically looked okay in 13.3% macular pathologies and changes. And I think that’s a high percentage which would advise to do us OCT on patients where we are not fully okay with the vision and correlation paths to the cataract.
This is the second case. And this is a 66-year-old person. And since 5 months, decreased vision and phaco/P CIO L was done three days before. Vision did not improve. And it was a suspected macular hole in this patient. So, I show you the OCT scan of the left eye. And I would ask you, again, the vision loss of this patient, when you look at the OCT of our patient, is due to soft drusen, arterial branch occlusion and the other cause is epiretinal gliosis. What do you think? You may work now again. You have 30 seconds time.
Again on the left-hand side of the vision, the high resolution scan. The scan is a little bit blurred. But all the structures can be seen easily.
Yes. And this polling fits quite well to the case. It’s nearly for all four — for all options. And the majority may ask for other cause. And in this case, the majority, as always, is right. And we have a look at that patient. So, when you look at the optic nerve a little bit more nasally, you will realize if you have OCT that on the left-hand side more than on the right-hand side, you have an atrophy of the retinal nerve fiber layers. Of course you do a visual field and you see on the right-hand side slight defects of the visual field. On the nasal side. But on the left-hand side, you have a nearly circular loss of visual field with a preserved center. And with us here, we have to ask the question why the patient has optic atrophy. The most common cause, of course, is glaucoma. And often glaucoma prior to cataract surgery is not known or overseen. But in this patient, it was unfortunately, a midline meningioma. And this was the reason why the patient had bad vision. And therefore, cataract surgery did not help the person much.
So, disc atrophy either to glaucoma or to any other cause, causing simple optic atrophy and pain less optic disc leads to vision loss. We will discuss that in July in another talk. But this causes loss of vision not related to cataract. But can easily be found out with the OCT scan. So, two take home messages for you. The preoperative consideration for an OCT of the fundus, you can’t do it in all the patients because the workflow does not always allow it. But if you have a disc opacity between lens opacity and vision, especially when you consider age as in our 15-year-old girl, then you have to ask yourself a question whether the reason is not at another place, fundus, macular, or optic nerve head. Pre-existing retinal desists, AMD, occlusion of retinal vessels, uveitis, diabetes, should give you an idea that OCT scan would be helpful. Especially when you think about anti-VEGF or steroid therapy prior to cataract surgery. Use of prostaglandins in cataract patients may cause it. And retinal holes, of course, this can easily be depicted with the OCT. And, of course, if you have post operative complications in the fellow eye, then it’s always good to get the time and to have the time to do a good work-up of the eye prior to cataract surgery. And look whether the patient has also another disease.
So, what can you do? Of course, a retinal examination with dilate the pupils, if possible. But if you are still? Doubt, performance of the OCT examination. It’s very fast and safe for the patient. You can do a fast macular scan horizontal, vertical, or star scan. You do the nerve fiber scan in a circle scan around the optic nerve. And also without even intruding if possible, very fast. It gives a lot of information. Very helpful. Avoid all the scenarios I have shown you in the cases before.
Now we have discussed in detail patients with fundus problems in the preoperative phase of our cataract surgery. But we can also apply modern OCT devices on the anterior segment. And, of course, also in the anterior segment, it can be very helpful to get high resolution images. This is still a montage and not the reality. But perhaps someday we will be able with the OCT scan to get with one scan such a nice image of the eye with the detailed posterior and a detailed anterior segment. And about this scanning of the anterior segment and the implications that we discussed in the next 15 minutes.
The anterior segment OCTs have developed a lot. And nowadays, the swept source technique is a lot. And is it allows a very deep imaging of the anterior segment behind the lens. And if you realize here, we have a longer wavelength with the spectral domain devices from the past. And the longer wavelength allows us to go deeper into the tissue and get more detailed images from the depth of the tissues. This is a very impressive example of a mature cataract where the whole lens could be imaged. And in its beauty and in its horror for the surgery prior to surgery. This is a very nice image from a colleague here from Germany. And this indicates that the longer wavelength of the lazier is able to image even this wide, opaque lens in total.
So, anterior segment OCT is not always available when to think of. Especially if the media are not allowing a standard biometry, for example. If you have phacomorphic glaucomas. If you want to enhance your biometry. And if there’s a discrepancy between vision, refraction, and slit-lamp finding. Posterior polar cataract can be useful. Post operative corneal edema, and anatomy if you happen to encounter unusual cataracts. This is an example of a capsular biometry where we couldn’t find the right peak and dot the right measurement. With ultrasound sonography, a scan immersion technique, of course, you are able to perform in these patients biometry, axillary length measurement or the other measurements you need. But you have to take the patient away from your workflow and lie him down and do the immersion by biometry with A-scan. But when you compare these measurements, or IOL master and A-scan with the interior from the engineering where you get an interior segment, and a long laser wavelength, you get a quite nice axial length measurement which is more precise than the A-scan measurement. And then you can go ahead and calculating your intraocular lens.
Another example again where our IOM master 500 is not able to find the right baby in the laser measurement is due to asteroid hyalosis, a real pain. And this may also cause problem when is you do the A-scan. If you look at the anterior again with the longer wavelength, you get quite a nice measurement of the axial length, rather precise. And then you can perform a normal standard of biometry and lens calculation as you wish. In this patient, after cataract surgery, we measured with our IOL master again, the axial length of our eye. And you see the measurement after surgery and prior to surgery very close together. This is a very nice GIF from Alex Wang from the United States showing a patient who is accommodating site dioptases. You can see the lens becomes thicker during accommodation, the lens wall, and the anterior depth changes. The pupil changes by 30%. That’s quite impressive. And gives us a nice idea about the high detailed imaging we can do in the anterior segment. But it also shows the drawbacks of the laser. It can’t penetrate the pigmented periphery of the ciliary body and the iris. Here a posterior polar cataract. Two patients I had to do surgery on. Both patients had on the lens a posterior polar cataract. So, we went to anterior imaging. Here in this patient, I expected and had the capsular defect during surgery. Here I did not expect the capsular defect and I had no capsular defect during surgery. And in this fashion, I was prepared what to expect to do the surgery and could adapt my technique during surgery to avoid a major complications due to the rupture of the posterior capsule.
Here a patient with 60-year-old with a mystery loss of vision. And he presented with a suspect optic neuritis with color deficiency and a reduced vision. He showed the myopisation, dioptase. Even an MRI scan was done before, it was normal. Here is a look at the OCT segment pictures and we realized that in the right-hand eye with the complaints we have a slight opacification and a densification of the nucleus causing my opacification and vision loss. This is compared to the left eye where the opacity is not as dense as in the right eye. but it’s similar in both patients and can be easily explained with the right OCT information. And here we have an uneventful cataract surgery in a 65-year-old female. But with spectacles after surgery, vision could not be improved. I show you this picture and ask you showing this OCT picture, why is vision loss present? Vitreous complication? Incomplete visco removal? Remained lens material? Or upside down implantation of the IOL capsule in the back? What do you think? I think this is the easiest of the questions. Because the anterior segment OCT gives us such a detailed image. Yes, majority is for upside down implantation. But 21% for remained lens material. This is not too bad. Let’s have another look at the patient. The patient has after the uneventful surgery perhaps a very — a small rhexis. A residual Hyland in the capsule back. And they’re not able to regain full vision until you do a YAG capsulotomy of the capsule. And this is released in the vitreous space and then the optics are restored again and the patient is able to see with full vision. Sometimes, and often you’ll appreciate that this during the examination. Oftentimes you’re not able to see it, but the OCT is able to see it. This is a patient after a phaco with posterior capsule IOL. And this patient was done in another place. When he at the time of presentation, vision was rather down with the movements. There was an air bubble in the anterior chamber. And they’re very opaque and decompensated cornea. When we look at the OCT scan in the anterior segment, we see that there is a loosening of the decimate, nearly total, causing edema of the cornea. And this is the 12:00 position where the surgeon entered the eye. And you see that you have here the beginning of the Descemet liasis. We tried air bubble several times and didn’t help much. And then after DMEK everything was fine, a nice technique. Clear cornea again, attached this new Descemet. And the difficulty after cataract surgery with Descemet lysis, off small area for the air to escape under the cornea. This may not happen with injection. It’s easier after DMEK when you have an implantation to attach with an air bubble. And here you have a patient with Marfan’s syndrome, beautifully depicted here with the zonule fibers. In phacomorphic glaucoma, it’s important to measure the anterior segment. And here you have all the modalities with anterior segment OCT giving you the right measurements to describe your chamber angle. And key is to detect the scleral spur here. And this is a patient where we thought the scleral spur would be. Because it was not quite easy from the image quality to detect it. But with AI and the anterior, the machine showed us the right place of the scleral spur and then we were able to do the right measurements.
One of my favorite measurements to estimate whether angle block may be imminent or not is here the lens fold. So, it’s the line between the scleral spurs and the distance to the surface of the lens. This is a patient with an anti-glaucomaous Phako + P CIO L. And you can see the large lens and the flat anterior chamber. These are the measures of the chamber prior to surgery. And delivered with the OCT device. And after the surgery, the chamber angle is open again. IOL is in place. The chamber is much deeper and the polar diagram shows change values hinting towards an open chamber angle again. This was a curious patient. Rather young. Wearing no spectacles, no refractive error. But the IOP was a 50 millimeter with a acute angle block. And this was recurrent since several months. And the patient already did disc cupping. The patient was not hyperopic. But the anterior lens was rather shallow, the lens was rather thick. And showed with the anterior segment scan, showing the depth of the anterior chamber in both eyes are and the lens thickness. And no relation to the space and the anterior chamber. So, it’s a relative anterior non-ophthalmos. And the axial length was measured also by the same device 21.8 millimeters. A little bit shorter. But the hole was a little bit disguised by a little bit steeper corneal measurements. So, all this information can be done in one scan with the anterior segment OCT.
This is a patient with an angle-block in pseudophakia. 85 years old, how could this happen? You see a very shallow anterior chamber, IOL in place. By IOP was rather high before acetazolamide was given. We suspected cycloplegia, and saw the block. And we were able to deepen the anterior chamber just by cycloplegia, and the IOP afterwards fell also down and to a very low pressure without any other medication. The patient was elderly and was not disturbed by a little bit wider pupil. Therefore, we decided to continue with the eye drops. The second option would be to go via pass and do a core vitrectomy, and then the anterior chamber can be deepened also. The reason for this was pseudo-syndrome with a weak zonular and anterior displacement. So, in conclusion, in the fundus and anterior segment, OCT is a fast and non-invasive technique. It can easily be integrated because it’s so past in the perioperative workflow. You can do it. OCT helps as you have seen in preoperative surgery planning. And OCT may parentheses patient from unexpected outcome and, of course, increase our service quality for the patients.
With this last slide, I would like to say thank you very much for listening. And I would send my kindest regards from Eriangen in Germany where our small university hospital is. And now I’m looking forward to questions from the discussion. Thank you very much.
So, I would read the first question to you. Can we opt out of cataract surgery merely on OCT features in a patient with dry AMD? If you look on your OCT — high resolution OCT scan at the formation of the outer polar — outer photo receptor segments, or ellipse on its own, if they are present, then it gives you a good idea that the vision will not be too bad after surgery. The second question is: With the current and future advances with SS OCT and more infrared laser imaging, will A-scans still remain relevant? Yes. Especially in very dense vitreous hemorrhages where you want to combine vitreous surgery with cataract surgery whether you need a good measurement. And then A-scan is still the best thing to do. Yes. I think we might use more A scans than in the past, but I think it will not be obsolete in the future. Other questions?
I go back. How much does OCT add to the cost borne by the patient? This depends on the healthcare system. In our place when the patient comes in outpatient, you get the same amount of money. Irrelevant how many examinations you do. In the private practice, in the private sector when you have to charge money for your OCT scans. But I think if you explain to the patients the advantages to do the OCT scan, they are willing to pay. And I think it depends on your healthcare system and on reimbursement. The next question: In OCT posterior capsular opacity — okay. Doesn’t continue. The next question would be: Would you suggest having anterior segment OCT image for routine cataract surgery in all patients? No. I wouldn’t. Because the availability of anterior segment OCT is not as common as posterior segment OCT. And posterior segment OCT for first OCT, we do in our hospital. We do routinely a scan of the posterior. Especially when ophthalmoscopy is very blurred of the fundus. How do we avoid the development of cataract? I think I don’t have other ocular pathologies and don’t get old. That would be my answer at the moment. Is it logical to do fundus OCT for every cataract patient pre-op? I think if you offer premium service, then I would do it, yes. The next question is: In OCT, any different kind of eye condition can show or not? I think you see most of the conditions if they are imminent in the central retina or optic nerve head. Of course, central changes like brain changes can’t be estimated. So, easily can measure ganglion cell layer. But that’s very complicated. But eye conditions of the fundus can easily be appreciated, yes. Also you have the infrared image which I like very much and appreciate the use of fundus if I have a blurred ophthalmoscopic picture. PCO, do you use YAG on the table or with needle after IOL insertion? When I have posterior capsular opacity and I can’t deal with it during the surgery, I avoid opening up my capsular back. Recall the patient after a few weeks and do the YAG in a sitting position for him. I think that’s the most — the less dangerous way. How much signal strength of OCT is considered to be reportable? That depends on the producer of the device. There are for each device a signal-to-noise ratios. And producer or manufacturer tells you where the boarder is. OCT in animals, can it be replicated across other animals, not just humans? Yeah, I think it depends on the anatomy of the animal you want to examine. I have done OCT already on some dogs presented to me. It works. If you have the dog under the right condition not to bite you. But it’s possible. And even OCTs are done on rats, on very small eyes or mice with special optics applied to the commercially-available devices. Would you recommend posterior segment OCT for all elderly patients due for cataract surgery? If you are able to manage that and the cataract is rather dense, I would recommend it, yes. Is it sufficient for surgery merely done by anterior segment OCT? This question I don’t understand. But anterior segment OCT I would only apply in special cases like imminent angular closure glaucoma or any pathologies of the anterior segment prior to surgery. Can we only relay on OCT — or rely on OCT of the patient for cataract surgery? Of course not. I still prefer to see the patient with my own eyes and do my ophthalmoscopy. It’s a very important additive examination. But you can’t replace all our skills we do when we do ophthalmoscopy when we do OCT.
Another question from the chat. Is anterior segment OCT indicated in post operative refractive surgery eyes? If the patients are not satisfied, it’s worth to look. Whether anterior chamber depth is in the range you calculated or if the lens position is okay, yes. Yes, anterior segment OCT is not addressed so often. Therefore I used the last 15 minutes to address this point. Because there are indications where you can make patients happy or yourself happy. I answered that last question already. I would — I would do OCT in the routine for all the cases where the ophthalmoscopy may be different. I’ve showed the slide where to think of. If it is a discrepancy with lens opacity and vision. If the patient has a history on the fundus, then I would always perform OCT. In all diabetics, of course. Because they may have CME. And after cataract surgery, it may turn larger and then it’s very difficult to teat these patients. They need steroids, anti-VEGF for a long time. Can OCT be done in intumescent cataracts? If you have the right wavelength in the infrared picture spectrum, then it may be possible. But not always. Is OCT the best option surgery for cataracts. At the moment, optimal tomography I think is still the best option to image anterior and posterior segment. Higher resolution in the iconography at the moment. But if you want to look at the body for tumors, for example, for solid masses, then you have to use biometricscopy, it goes into the pigmented epithelium. And the pigmented epithelium on the other hand, blocks the laser light. It was my pleasure to have so many listeners. We are right now 221 from all offer the world. And I thank Orbis, yes, for giving me that lecture. It was really fun for me.
We are still four minutes. I would take questions. If there are more detailed questions you can’t ask at the moment, of course, Orbis I think will feel happy to pass the questions to me to be solved by email. That’s no problem at all.
Who of you has at the moment the latest data? I think Eastern in my position, 9:00 in the evening, 10:00 in the evening. Therefore, I thank you very much for all attending the lecture even if it’s very late for you. Or for some people, rather early when you still have to work. And I have to thank the guys from Orbis, Andy and Hunter, which made it so easy from the technical side to reach you and pick the polling possible. They’re really professionals. And I am really looking forward to the next lecture in July. So, at the moment all questions are answered. We’ve still got two more minutes for questions. I will stay online for the next 2 minutes to take perhaps a late comer question. Otherwise, I want — would like to thank you again for listening from all over the world. And I hope you got perhaps a little small ideas to change your everyday process. The cases I’ve shown were all patients really to do with cataract surgery and no invented cases. And if you do it for a long time, now and then you will realize that OCT becomes very useful. Oh, my kind regards to Nepal. I have been to CBM project I think 11 times. And always, I think, learned more myself than I taught at the hospital. It was great fun. Oh, Peru is very far. But it’s early in the morning. 4:00. In the afternoon. Okay. Ah, good question. Any age above which you will always do OCT in cataract patients? No. No. I wouldn’t think so. Because you saw that give you that in young patient surprises. And if had very old patients off higher chance to meet AMD, diabetes, changes from arterial hypertension or epithelial membranes, of course. But I would not name here a certain age without trying to discriminate anyone. The lens sickness influenced cataract operating procedure? Yeah, you might need more phaco energy, of course. And I think the density of the lens is the bigger problem. But the space you have in the capsular back may cause problems for the posterior effect — post-operative refraction. You might end up in a hyper or myopia side. And that’s — that may cause an unhappy patient. That’s right. And, of course, the lens thickness. If the lens thickness is double as thick as the anterior chamber depth, then you have to keep in mind that by dilating the pupil for surgery, you might end up in an angle block before you can remove your lens.
OCT in premature, you can do. But we still don’t because we don’t have the device. But there are hand held devices to do that. And there are nice publications on this topic, yes. Thank you very much. I think now we have one past 4:00. I will close with session and say thank you very much for listening. I really enjoyed it. And have a nice working day or evening and a nice weekend. Bye, bye!

Last Updated: April 12, 2024

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