Lecture: Corneal Infection in Post-COVID Convalescence

In summary, post-COVID immune changes in the body are less well understood. During this live webinar, we will cover concomitant keratitis in the setting of post-COVID vaccination and/or recovery from COVID.

Lecturer: Dr. Aravind Roy, LV Prasad Eye Institute, India


DR ROY: Hello, everyone. Today we shall be discussing a very unique entity of keratitis that we note during the post-COVID convalescence. I am Aravind Roy, I’m a cornea faculty at LV Prasad Eye Institute in India. And welcome to this webinar. Here I would encourage all of you to share your questions, your queries, and any difficulties that you face when you are dealing with COVID patients with ocular manifestations in your clinical work. And with this, we’ll start our discussion for the session. We do not have any financial disclosures or conflicts of interest. So the novel coronavirus disease, or COVID-19, is responsible for the current global pandemic that we find ourselves in. The first case of ocular transmission was reported from China, but there was limited evidence that the eye as an organ was effective for transmission of the coronavirus. In this report, that was published from Wuhan, in a series of 535 patients of COVID-19, chronic eye disease, especially conjunctivitis and keratitis, were the commonest conditions that were noted. And this was seen more in patients who had red eye than those who did not have red eye. There are other entities, such as diabetic retinopathy, glaucoma, or macular disease, which were relatively lower. Xerophthalmia was higher than the other. Such as the retinal pathologies. So our understanding of coronavirus disease and the ocular manifestations have been mostly on strategies to limit spread, what are the personal protective guidelines we should follow, whether conjunctivitis is the most common symptom, et cetera. The coronavirus belongs to the genus beta coronavirus lineage. So our understanding of it now is that the coronavirus internalizes into the host cell, using two key receptors. One is the ACE2 receptor and the other is the TMPRSS2 receptor. And once the spike proteins of the coronavirus bind to these receptors, it is internalized by endocytosis, following which the virus replicates and gets released. The release of the viral antigens by the viral RNA replication leads to infection, proliferation, inflammation, coagulopathy, and multiorgan dysfunctions. So as we can see from this cartoon, the nasal lower and upper airway have variable expression of the serum ACE2. And this is responsible for the lungs as the primary pathway through which this virus enters into the body. Now, we understand that only these two receptors are key to the internalization of the virus, but there are other receptors that are also coming into the fore. This includes the DCSIGN and the DCSIGN-related. So how do we understand COVID infection? We know it starts typically peaking by one week, and by the second week, the viremia starts slowly decreasing. However, there are long-term effects of COVID infection. Typically called by long COVID. The long COVID sequelae are something we are able to understand now, and they’re not very well characterized. We understand there are generalized body symptoms, such as fatigue, decline in quality of life, muscular weakness, joint pain, whereas the lung parenchyma can have current scarification, persistent cough, dyspnea, or oxygen requirement. It may result in neuropsychiatric manifestations, thromboembolism, chronic kidney disease, hair loss, et cetera. Similarly, in the eye, multiple manifestations have been described. Keratitis, neuropathy, uveitis, a flare-up of previous chronic eye disorders, inflammatory eye disease, but the long-term ocular manifestations are not well described. They’re limited mostly to case reports. Because our understanding is evolving now. And we are very much interested to understand that what happens to the eye in the long COVID sequelae… With this background, we are reviewing cases that we have examined, to understand how keratitis presents in the post-COVID convalescence. We study the clinical and demographic profile of such patients who presented within three months of acute post-COVID-19 infection in our clinic. We searched our electronic medical record database, and found that we had 18 eyes of 16 patients with microbial keratitis during post-COVID convalescence. This was conducted during the time period September 2020 to September 2021. We had 14 patients with highly unilateral involvement, and the remaining had bilateral involvement. The presentation was typically one to 93 days post-COVID. There are multiple systemic risk factors. The most prominent of those were diabetes and hypertension. And there are other risk factors, such as patients who had been hospitalized in the previous months, prior to developing microbial keratitis, or those in whom oxygen was administered, or those who needed systemic steroids. When we analyzed the kind of microbes which caused these microbiological manifestations, we found that there was an even distribution of fungi and microsporidia, which contributed to 7 cases each. What was remaining was herpes zoster and pythium. So we shall be describing the clinical features of each of these lesions as we see them, and try to understand how these cases presented in the post-COVID convalescence phase. The cases resolve with one to six weeks of follow-up. Most of them resolve with medical management alone, but therapeutic keratoplasty was required in five patients, and bandage contact lens was required in two patients. We will go with the scenario of the microsporidia keratitis. The patient was a 14-year-old female, who presented with a one week history of redness and blurring of vision in both of her eyes. She was not tested for COVID. But her mother and sister were COVID positive, and they were all quarantined together at home. For the entire duration of the illness. One month prior to this presentation. What was unusual about this case was that microsporidial keratoconjunctivitis typically presents as a self-limiting conjunctivitis with punctate keratopathy on the cornea. And as we can see, the right eye has some punctate dust-like speckles, which are there on the anterior ocular surface and the cornea. And they typically take up the stain, which is the fluorescein stain, and they appear as stuck-on lesions on the surface of the cornea. Often they have a mild discharge, redness, and discomfort. Typically the vision is not affected in such cases. And the left eye largely had redness of the conjunctivitis, but there were no corneal lesions. When we scraped the lesions and placed them on the slide and put a cough slip with 10% KOH, we’re typically able to see rice grain-like tiny spores of microsporidia at 40x magnification. So that was noted in this patient’s right eye scraping. However, we wanted to make sure that we are dealing only with microsporidia and not any other organism. So we also sent a PCR for adenovirus as well, and the PCR came positive for pan-microsporidial. What was also intriguing in this case is that the patient also had an anterior uveitis. Now, anterior uveitis is not very common in the scenario of microsporidia keratoconjunctivitis. Nevertheless, we started treating her with topical lubricants, which is what is required for microsporidia keratoconjunctivitis. But in view of the anterior uveitis, as you can see in this clip section, there are keratic precipitates, and also you can appreciate the indirect illumination from the iris — you can see that there is a variegated appearance. Which is basically the keratic precipitates on the corneal epithelium, responsible for the drop in vision. We prescribed this patient chloramphenicol. We examined the cornea and found a low corneal endothelial cell density. The left eye was essentially normal. So this patient was treated for one week and after one to two weeks, she slowly started getting better, based on her symptomatology. And her vision also started getting clearer. And naturally with that, the specular microscopy findings were also better, and we can see that now it has almost reached normal levels of endothelial cell density and a normal morphology has also been retained. So this was the understanding that the microsporidia keratoconjunctivitis may not follow the typical self-limited course with only involvement of the ocular surface, but rather there could be a heightened reaction in the anterior chamber. In a patient who is in the post-COVID convalescence. Another case scenario was that the patient who had a microsporidial stromal keratitis — there was an elderly gentleman who hailed from Nashik, Maharashtra, in India. This patient had decreased vision for 9 months in the right eye and in the left eye, 3 months’ duration. He had multiple consultations at several hospitals and institutes. And he was on multiple medications to start with. So he was using topical antivirals, antibiotics, steroids, and his current treatment was right eye chloramphenicol eye drops and left eye, betaxolol. He had undergone cataract surgery in his left eye in November of the previous year. He was diabetic and hypertensive and had an angioplasty performed. His right eye had hand motions and he had a large central epithelial defect. There were multiple deep stromal infiltrates, and there were fuzzy, ill-defined borders, and some endothelial plaque-like appearances of those infiltrates as well. There was a top anterior chamber reaction also in this patient. The left eye had finger-counting vision, and there were central stromal whitish infiltrates with minimal cellularity and stromal edema. There was anterior chamber activity and keratic precipitates. So we made the diagnosis of stromal keratitis with uveitis, a scraping was negative, an AC tap was negative. The patient had a corneal biopsy and the confocal microscopy showed a linearly arranged small hyperreflective dots along the keratocytes. And this was a stromal microsporidial keratitis. And when we did the corneal biopsy, there was widened intrastromal clefts, and they had debris and granularity. And when the acid fast stain was performed, we noted that there was short, stout organisms, which are suggestive of microsporidia. This confirmed the diagnosis of the microsporidia stromal keratitis. And we revisited the history with this diagnosis. And we found that this patient had a history of herbal eye drop usage. And he also had a dip in river water. And he hailed from a region which was a COVID hot spot of the country. And he also had COVID-like illness about two to four weeks prior to symptoms. Which could be a possible temporal association, if not a causal association, for his symptoms. So he was advised for therapeutic keratoplasty, and a shield keratoplasty was performed for the right eye, followed by the left eye. Which resolved his condition, following which the patient was on steroids and lubricants. The corneal button shows this. This was similar to what we got in the corneal biopsy earlier. Widened intralamellar clefts with debris in between them, and the acid fast stain showed short, stout rod-like organisms. Consistent with microsporidia. The patient was doing well, but two months post-procedure in the right eye, he had epithelial recurrence of microsporidiosis. So we started topical treatment for this patient. The next patient is of a herpes zoster presentation. He was 71, hailed from Karnataka, India, and he had redness, swelling, watering, and discharge in the left eye for the past 6 days. No systemic history. Treated for COVID-19 three weeks prior to the ocular symptoms, had moderate disease, and was on IV steroids and remdesivir and hospitalized for treatment of COVID. The clinical picture was unavailable at the first visit. But the vision was 20/100 with exterior excoriation of the lower lids, the conjunctiva was congested and the anterior segment was quiet. He had a conjunctival swab and suspected to have a lid margin lesion. So I’m going to pause here and take a question about one of our viewers, who asked about that 50% keratitis from microsporidia and 50% from fungus. Basically how did this compare to the non-COVID patients? Very interesting question, David. Typically, in the Indian context, primarily we see either bacterial or the second most common organism is fungus. Because we are a hot, humid, and tropical climate. And both bacteria and fungi are very common in our part of the world. Microsporidia typically has a seasonal variation. But it’s not as common as we would see fungal keratitis. And I’m going to discuss — as the talk proceeds, about very typical unusual fungal keratitis that we noted in this series of patients. So thank you. So coming back to this patient, this patient had the clinical picture that was unavailable at this visit. And there are severe limits to the vision, with 20/100 vision. The conjunctival was congested and the anterior segment was quiet. So he was a central conjunctival swab — but that was deferred as the conjunctivitis was suspected to the secondary to the lid margin lesions that were there. So the patient was treated with the differential diagnosis of the herpes zoster, and was treated with antibiotics and lubricants. And was put on chloramphenicol ointment with amoxicillin clavulanic acid. So when he came in one week for the follow-up visit, there was a pseudodendrite lesion on the cornea, diagnosed as ophthalmic zoster sine herpes, and he was treated with HZO and given a full course of acyclovir, 800 milligrams 5 times a day, and medications for pain relief. At three weeks of treatment, the patient’s lid lesions have resolved but there was ectropion with punctal scarring and the corneal lesions had resolved with faint scarring. The next are a series of fungal keratitis that we noted in this patient. We need to understand that in the context of patients seen in the Indian scenario, the fungal keratitis is typically a lesion that is seen in agricultural workers. Typically following history of trauma with vegetative matter, which is perhaps the number one risk factor for development of fungal keratitis. It can occur in all age groups, but typically the 20 to 40 year age group. Now, what we have seen in these cases are not really all of them belonging to either an agricultural occupation or those who are day laborers. And the history of fungal keratitis with vegetative trauma is typically missing in these patients. So this was a patient of a 24-year-old male patient, who presented with a ten day history of redness, watering, and pain. Ten days history, and prior to that, he had COVID positive, and he was subsequently cured from COVID. But he did not have any systemic illness, and he was initially treated as conjunctivitis elsewhere. He came essentially as a patient of red eye. When we noted this patient’s vision it was pretty good. A lesion next to the interpalpebral fissure of the cornea. And there was a plaque by the corneal limbus. That was all we could see. There were infiltrates with feathery borders which were localized. At a scraping, the entire plaque came off, with plenty of fungal filaments. This patient typically responded very well with natamycin, and at one week, we can see the lesion is almost healed, except for the mild congestion we see in his eyes. He resolved after one month, and we continued for three weeks the antifungals. The is second case was the 56-year-old male who had both eye redness, pain, and headache for ten days. He was COVID positive a month prior to presentation, hospitalized, treated for COVID, and consulted elsewhere. This patient was diagnosed with a bilateral herpes keratitis elsewhere with a possible secondary bacterial infection. The left eye had a bandage contact lens applied. He was on antivirals with antibiotics and cycloplegics at presentation. This was the clinical picture at presentation. We can see in the right eye, there was a stromal infiltrate with epithelial defect. And an unhealthy appearing epithelial — raised epithelial margins. The region was restricted to the lower one third of the cornea. There were infiltrates that were restricted to the mid-to-deep stroma of the cornea. Vascularizations, which were seen more prominently in the inferior and superior limbus, and a convex appearing hypopyon. The left eye had a bandage contact lens placed, but nevertheless, a lot of congestion of the eyes, and a lot of vascularization elsewhere. So we performed the scraping, which was negative, but then two days later, there was significant growth in culture of aspergillus niger. Following which we started treating this patient with a line of antifungals. As we see, the right eye started to resolve. But the clinical picture we see is very typical of ocular surface disorder. And gradually we stopped the antifungals and treated the patient only with lubricants. However, the ocular surface was persistently poor. Following which there was a lot of scarring and pitting of 40% to 50%. The hypopyon had resolved with lubricants. So this was possibly an underlying neurotrophic etiology. So what we did was we entirely weaned the patient from the antifungals and actually started promoting the healing of the surface and amniotic membrane was also placed in this patient. In both eyes, we also considered for tarsorrhaphy, bilateral punctal cautery, and we had to redo the TCL. So after a follow-up of four month, the patient healed with scarring, status posttarsorrhaphy, and amniotic membrane transplantation. So there is a question. If a contact lens wearer increases the risk for post-COVID corneal infection? We’re not sure what may happen. In our part of the world, contact lens wear is not very common. But there are altered immune responses on the ocular surface in the immediate post-COVID convalescence, which may make the cornea possibly less sensitive to minor trauma. And thereby predispose such corneas to infections. So suddenly everything which is a foreign body or the source of a persistent irritation to the cornea might be entirely altogether avoided. So the next question is: Why COVID patients are vulnerable to fungal keratitis? We don’t really know the answer to this question. But what we suspect is that when the corneal surface is compromised, any organism can potentially infect it. In our part of the world, fungal infections are fairly common. Which is why in most of the patients that we saw, 7 of those were actually having fungal keratitis. Though it’s also possible that the other kind of organisms might also concomitantly affect and then cause a microbial keratitis in such a scenario. So the next case was that of a 44-year-old gentleman who was a welder. He presented on 10 June with a 15 day history of decrease in vision, redness, and watering in the left eye. This patient had a fall with some foreign body in his work. But he was not sure what it was. His COVID history is displayed. He had COVID before and was treated at home. He was still on the treatment when he presented to us. He had a previous hospital admission. He was on oxygen therapy. He was on steroid treatment. But the records were not available. He had a pneumonitis and hypertension and was on treatment for that. So his left eye showed a visual acuity of finger counting. There was a ring shaped infiltrate and central thinning. So scrapings were very gently taken and tissues applied, but we could not get enough material for culture. So in this scenario, the patient was treated with antifungals, because the scrapings revealed plenty of septate hyaline branched fungal filaments. And the patient was treated with topical natamycin, with oral ketoconazole and atropine. The patient progressed and was considered for a therapeutic penetrating keratoplasty. But in view of his clinical condition, we thought we should stabilize his eye and performed a Tenon’s patch graft with central tarsorrhaphy to promote healing and allowed the eye to heal. Subsequently, when we saw the patient three months later, the patient had resolved well. There was no evidence of infection. The globe was tectonically stable, the B scan was normal, and the patient had the eye healed. We planned for penetrating keratoplasty with cataract surgery for restoration of vision. The next case is of a 48-year-old gentleman who was a farmer from Nashik, Maharashtra, in India. He presented on 17th June with painful decrease in vision, redness, and watering in the left eye. He had some history of injury. And on treatment with natamycin, moxifloxacin, oral ketoconazole. He was COVID positive two months prior, and there were no records of hospital administration or treatment with steroids or oxygen. He was a one-eyed patient. He had a vision of hand motions. And this patient had an advanced keratitis. Advanced because as you can see, it’s almost more than 8 millimeters in diameter. There were mostly deep infiltrates. There was the dense hypopyon, some lesions involving the corneal periphery. And of course, he’s a one-eyed patient. So therefore we need to take more care for such patients. So as to treat their condition. And these scrapings also yielded Gram positive and Gram negative bacteria. And we started him with broad spectrum antibiotics. So as is our regime that we follow, we gave a course of fortified vancomycin and ciprofloxacin with atropine in such cases. So this patient started worsening, and there was some involvement of the 11:30 to 12:00 limbus. There was culture positivity of staphylococcus hominis and fusarium solani. So he was started on topical natamycin. In view of the large size of the ulcer and worsening, he was planned for a therapeutic keratoplasty, and a suture was done. In view of his one-eyed status, we planned to perform an early penetrating keratoplasty, and the graft was doing well with 20/400 vision one week post. There was a 39-year-old gentleman from Madhya Pradesh, who had sudden loss of vision, watering, and redness in the right eye since 1.5 months. History of fall of some dust particle in the right eye. Using natamycin and timolol. He was COVID positive in April, negative up to two weeks. Hospital admission, oxygen therapy, steroid treatment records not available. He was also a diabetic. As we can see, there was a large 8*8 central corneal infiltrate with corneal melting, unhealthy appearing corneal epithelial margins and a lot of melt. Flattening of the anterior chamber with the possible occult melt somewhere, and the B scan showed choroidals. The patient was planned for therapeutic PK and back button scraping, which yielded septate hyaline filaments. This grew aspergillus flavus. So one was niger, one was flavus. It could be a possible coincidence as well. And all these patients were taken up for therapeutic PK for treatment. If we summarize the cases two, three, and four, we see a melt, a history of injury in the previous cases, but the past two did not have history of injury. No relationship to agricultural work or any trauma. And in the cases of previous surgical intervention, these patients had a very severe manifestation. They all had a systemic history, also had hospitalization for COVID, and they were looking to be a bit of a neurotrophic ulcer to start with. This was seen in the previous case we were discussing a while ago. Typically it was a neurotrophic kind of ulcer, which was possibly secondarily contaminated with the fungal infection. So we’ll take a few questions. The cornea is highly vascular. Perhaps… We would not consider a PKP. I agree to your point. That maybe we can wait. But it’s always a difficult question of providing care to the patient who is one-eyed. But the chances of success are better if we wait for the visual rehabilitation. But yes, in an emergency setting, irrespective of the vascularity of the cornea, one can consider doing a therapeutic PK. Because the objective there will be to eradicate the infection. So we would have seen close to about 300 to 400 patients of microbial keratitis in the same period. But then this would have been something that we would need to look into the records. Thank you. So another case that we saw was that of a patient who was an agricultural worker, and he had left eye redness and watering and pain for one week. He was COVID positive but was under home quarantine. Otherwise he was healthy. There was no systemic illness. And this patient was initially treated elsewhere, with antibiotics. And antifungals as a combination. This patient had a very atypical ring-like infiltrate, with dot-like infiltrates, which were suggestive of pythium. But we performed the first scraping, which was negative. The vision was paracentral, restricted to the inferior portion of the cornea. And the vision was 20/60. The other eye was within normal limits. The patient was started on broad spectrum antibiotics. When he came again, we reviewed the history. And we started him on anti-pythium. After the repeat scraping showed that this patient had multiple broad aseptate or sparsely septate filaments. Which are suggestive of pythium. So we started the anti-pythium treatment and reviewed the patient. Within one week of anti-pythium treatment, as we can see, the margins have become grossly blunted and the lesion was also slowly healing. So this was the 10% KOH CFW 40x, which shows that there are broad aseptate filaments that are very scanty septa that are there. And mostly they are — the broad aseptate filaments. These are very strongly suggestive of pythium insidiosum. So this patient was reviewed and gradually this patient healed with the anti-pythium treatment that we followed. Which includes linezolid 0.2% hourly, azithromycin 1% TID, and oral azithromycin twice daily for two weeks. This patient had two weeks of redness and pain in his only seeing eye. He was COVID positive in April, admitted for 8 days, treated with oxygen and steroids. He presented with mild decrease of vision, and when we examined this patient, he had a side port infection with endophthalmitis. So this was the presenting clinical picture that we saw. Gradually, this patient started worsening. Because you can see there’s a bit of a coagulum in front of the lens. And this started getting worse and worse. He went through multiple vitreous biopsies, and corneal scraping was of course also performed from the side port. In this patient, however, it red to rapid clinical worsening. And he was required to undergo a therapeutic penetrating keratoplasty. But unfortunately the eye could not be saved. The therapeutic keratoplasty failed. And PK with a tarsorrhaphy — we were not able to save this eye. So the organism that we got was again aseptate or sparsely septate filaments. But these are branched. This is how we distinguish pythium from mucor. The colonies of mucor species from the corneal scraping. What was unusual is that mucor keratitis is extremely rare. Perhaps the last five years, of 20,000 or so microbial keratitis, mucor has been noted in perhaps 5 cases or so. So that’s something which is very rare. And this was a very chance finding that we saw in a post-COVID fungal case. Which led to very severe clinical implications. As in this case. So yes, I agree to the question that we did not note bacterial keratitis in the post-COVID sense. We are not sure why we did not see this pattern. But unfortunately, we did not note any such bacterial keratitis. It’s possible that these patients in the post-COVID convalescence do have bacterial keratitis, but especially community acquired bacterial keratitis might get resolved with treatment at the community level. And therefore they may not present to a cornea referral service or a tertiary care service, as is our practice. So it’s possible that such associations may exist. Which perhaps we do not see them. But if you do see them, it’s possible that one sees them in the community. I would like to show this case — you can say as a comparison of how these keratitis might evolve in the post-COVID convalescence. This was a 52-year-old male, farmer by profession. He had a history of decreased vision, and inability to move the eye to the lateral aspect for three months. He was treated for mucormycosis. This patient did not have a definitive history of COVID. But if we look at his medical history, that is very, very suggestive of possible COVID infection. Because he was referred to the institute for a large non-healing ulcer of the left eye. His medical history is seemingly very interesting. He had a history of pneumonia three months ago. And had treatment with steroids and with oxygen supplementation. He had also uncontrolled blood sugars. Then he was continuing on oral hypoglycemic agents. He had bilateral partial maxillectomy done and nasal debridement done three times, but the reports were negative. So he had pneumonia in May. He had been hospitalized. And then he had uncontrolled blood sugars on oral hypoglycemic agents. There was history of administration of steroids and oxygen. After 15 days of admission, he had decreased vision and inability to move the left eye outwards. There was sinus debridement done twice, partial maxillectomy, treated with transcutaneous retrobulbar amphotericin B, TRAMB, and posaconazole. So this was reported to the hospital on 20th of August, 2021. So we’ll take some of the questions here. So in the case of the pythiosis, the patient resolved on anti-Pythium treatment. The corneal disease occurs — perhaps it occurs when there is a neurotrophic element with damage to the corneal epithelium. The healing response is slower. And that leads to — it prepares the ground for a possible keratitis. We have one question of: COVID-19 was prevalent and keratitis… So we do not know that this is an association. But this is why this case that I’m discussing now is interesting. Because there is no association, but perhaps the anterior surface is compromised in a manner that leads to a possible predisposing factor for development of keratitis. And especially in a part of the country where — or rather, in the Indian context, where keratitis is extremely, extremely common, this might lead to some particular bizarre associations. And also, as we saw in the series of microsporidia, there are some abnormal pictures, such as uveitis, the keratoconjunctivitis, that’s what we see. And this is purely an effort to understand together how colleagues elsewhere in the world also see keratitis. And how they treat them and what the outcomes are. So we come back to this patient who was possibly a COVID positive patient. And he presented with inability to move his eye with corneal ulcer. Here the ulcer is typically a neurotrophic ulcer. The sensations were grossly reduced. There was a large ulcer on the inferior portion of the cornea, restricted to interpalpebral area. The epithelium was unhealthy. Heaped up. And this patient did not have a lot of cellularity. But there was a fair bit of cellularity, restricted to the anterior stroma, three month history, so there was a lot of scarring, corneal edema, and this patient doesn’t seem to have a secondary infection. But this was very typical of a neurotrophic keratitis. And he was advised lubricants and tarsorrhaphy. So he was diagnosed with neurotrophic keratitis with 6th nerve palsy. So this patient… In this context, we came across a very interesting paper in BJO which suggested based on a confocal study that the nerve density of COVID eyes is very different from that of healthy eyes. So the figure A represents nerve density of patients who have normal… This is the nerve density of the acute COVID patient. This is the nerve picture, the corneal nerve imaging, of confocal microscopy of a patient recovered from COVID with long COVID symptoms. So here, compared to the normal, we see there is a decrease in the nerve density. The nerve fiber length. And increase in the glial cells. So it could be quite possible as more literature emerges that COVID, in a way, not only alters the immune system, heightens the immune reaction when there is a cytokine storm — it also has a neuropathic effect. And that neuropathic effect is possibly responsible for the abnormal corneal sensation, which predisposes such corneas in the post-COVID convalescence to secondary infection. And this is how we see varied manifestations with different organisms. Or different clinical course. Sometimes the chronic clinical course with sometimes a very poor outcome. And this is what we understood from our experience. That not only COVID can lead to significant impact on the activities of daily living, but they might also have an altered host immune response. They may cause a decreased corneal sensation. Neurological alterations. They may affect the clinical course of keratitis. Keratitis in the post-COVID convalescence is not really very well understood. And as reports emerge, as experiences are shared amongst colleagues, we understand that the course of the keratitis, the type of organisms, may be possibly very different from what we see in non-COVID patients. We cannot clearly ascribe a causal association, but the temporal association is certainly noteworthy. So thank you so much for attending this webinar. And I would like to take this opportunity to thank my colleagues. And fellows with whose contribution — we could take care of this very special and unique cohort of patients. And thank you once again for joining the lecture. And we can take a few questions now. Before we end the session. So thank you very much. So thank you so much for joining. We have been taking the questions live. During the discussion. So if there are no further questions, perhaps we can wait for a few moments and then we can close the session. Yes, perhaps. There are many manifestations in the eye. So yes, perhaps COVID may not cause keratitis as a primary feature. But yes, these associations are something that we are beginning to understand. That’s a very interesting question. What topics would make a review article? I think practically this is all new knowledge. All of it is interesting. Preventative measures? Perhaps if we can see the patient early, maybe we can promote the epithelial healing. And prevent it from having a secondary infection by just having a regular observation. And promoting the surface healing. Treatment of choice for microsporidia stromal keratitis? We prefer a surgical modality. But keratoconjunctivitis is self-limiting. And only lubricants should be enough. Steroid use… Might predispose because it generally lowers the body immunity. So it’s possible that it can lower the immunity, predisposing the individual for an infection. So thank you very much.

>> I think that’s a very good please to leave it for today, Dr. Roy. Thank you for sharing your expertise and thank you to our audience for joining today. Have a great weekend, everyone, and thank you again, Dr. Roy.

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November 26, 2021

Last Updated: October 31, 2022

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