17†Cell viability after DMEK preparation.

PURPOSE: To evaluate the effect of graft preparation and organ-culture storage on endothelial cell density (ECD) and viability of Descemet membrane endothelial keratoplasty (DMEK) grafts. METHODS: DMEK grafts (n=27) were prepared at Amnitrans EyeBank Rotterdam from 27 corneas (15 donors) that were eligible for transplantation but could not be allocated due to the COVID-19-related cancellation of elective surgeries. Cell viability (by Calcein-AM staining) and ECD of 5 grafts originally scheduled for transplantation, were evaluated on the originally planned surgery day, whereas 22 grafts from paired donor corneas were evaluated either directly post-preparation or after 3-7 days of storage. ECD was analyzed by light microscopy (LM ECD) and Calcein-AM staining (Calcein-ECD) RESULTS: Light microscopy (LM) evaluation of all grafts showed an unremarkable endothelial cell monolayer directly after preparation. However, median Calcein-ECD for the 5 grafts initially allocated for transplantation was 18% (range 9-73%) lower than median LM ECD. For the paired DMEK grafts, Calcein-ECD determined by Calcein-AM staining on the day of graft preparation and after 3-7 days of graft storage showed a median decrease of 1% and 2%, respectively. Median percentage of central graft area populated by viable cells after preparation and after 3-7 days of graft storage was 88% and 92%, respectively. CONCLUSIONS: Cell viability of most of the grafts will not be affected by preparation and storage. Endothelial cell damage may be observed for some grafts within hours after preparation with insignificant additional ECD changes during 3-7 days of graft storage. Implementing an additional post-preparation step in the eye bank to evaluate cell density before graft release for transplantation may help to reduce postoperative DMEK complications.

9†Supply of non-clinical ocular tissue from a tissue and eye services research tissue bank.

INTRODUCTION: NHS Blood and Transplant Tissue and Eye Services (TES) is a human multi-tissue, tissue bank supplying tissue for transplant to surgeons throughout the UK. In addition, TES provides a service to scientists, clinicians and tissue bankers by providing a range of non-clinical tissue for research, training and education purposes. A large proportion of the non-clinical tissues supplied is ocular tissue ranging from whole eyes, to corneas, conjunctiva, lens and posterior segments remaining after the cornea is excised. The TES Research Tissue Bank (RTB) is based within the TES Tissue Bank in Speke, Liverpool and is staffed by two full-time staff. Non-clinical tissue is retrieved by Tissue and Organ Donation teams across United Kingdom. The RTB works very closely with two eye banks within TES, the David Lucas Eye Bank in Liverpool and the Filton Eye Bank in Bristol. Non-clinical ocular tissues are primarily consented by TES National Referral Centre Nurses. METHODS AND RESULTS: The RTB receives tissue via two pathways. The first pathway is tissue specifically consented and retrieved for non-clinical use and the second pathway is tissue that becomes available when tissue is found to be unsuitable for clinical use. The majority of the tissue that the RTB receives from the eye banks comes via the second pathway. In 2021, the RTB issued more than 1000 samples of non-clinical ocular tissue. The majority of the tissue, ~64% was issued for research purposes (including research into glaucoma, COVID-19, paediatrics and transplant research), ~31% was issued for clinical training purposes (DMEK and DSAEK preparation, especially after COVID-19 cessation of transplant operations, training for new eye bank staff) and ~5% was issued for in-house and validation purposes. One of the findings was that corneas are still suitable for training purposes up to 6-months after removal from the eye.In 2021, the RTB received 43 applications for ocular projects from new customers and supplied to 36 different projects, meeting 95% of all orders placed this year. DISCUSSION: The RTB works to a partial cost-recovery system and in 2021 became self-sufficient. The supply of non-clinical tissue is crucial for advancement in patient care and has contributed to several peer-reviewed publications.

Bilateral EK Rejection After COVID-19 Vaccine.

ABSTRACT: Owing to its rapid development, short-term and long-term effects of the COVID-19 vaccine are still not well understood. This case report highlights bilateral corneal endothelial graft rejection after administration of the Pfizer COVID-19 vaccine. A 73-year-old woman with bilateral Descemet stripping endothelial keratoplasty presented with bilateral decreased visual acuity, ocular pain, and photophobia after her second dose of the Pfizer-BioNTech COVID-19 vaccine. Two weeks after vaccine administration, the uncorrected visual acuity was 20/70 and 20/40. Central corneal thickness as measured by ultrasound was 809 and 825 µm and by Scheimfplug imaging was 788 and 751 µm at the pupil center. Slit-lamp biomicroscopy revealed quiet conjunctiva and sclera but was significant for thickened corneas with Descemet folds in both eyes. The patient was instructed to use prednisolone acetate 1% every 1 to 2 hours with Muro ointment at bedtime.

Eye banking and keratoplasty trend analysis during the COVID-19 pandemic: A South Indian observational study.

Purpose: To analyze the impact on eye donation and corneal transplantation during the COVID-19 pandemic in a tertiary eye hospital in south India. Methods: A retrospective analysis of the donor and recipient records during the study period from January 2020 to May 2021 was conducted and tabulated in Microsoft Excel 2013. Demographic details of the donor, utility rate, cause of death, culture characteristics, storage methods, wet lab usage, and the surgical donor outcomes were evaluated. Additionally, the postoperative workup of the recipients, diagnosis, graft infection and rejection episodes, development of COVID-19 postoperatively, and outcome in terms of visual acuity at one, three, and six months were also noted. Results: A total of 466 eyes from 249 donors were received during the study period. The mean age of the donor population was 62.43 years (20.9). The corneal transplantation utility rate was 36.4% (n = 170). Fifty-one percent of the total transplant surgeries were for therapeutic purposes. This was followed by penetrating optical keratoplasty (34%), Descemet's stripping endothelial keratoplasty (9%), and patch grafts (3%). Seventeen (10%) graft rejection episodes were noted and nine (53%) had complete resolution after medical treatment. Conclusion: Proper preventive measures are key to carrying out safe and efficient eye banking activities even during a deadly pandemic, as COVID-19 transmission via transplantation is rare.

OP-7†Our experience of DMEK wet lab-training course as a precursor to starting DMEK service at NHS Trusts during COVID-19 pandemic in UK.

*Correspondence - Tina Khanam: t.khanam1@nhs.net OBJECTIVE: The benefits of simulation model and wet lab training courses have been well publicised. We were keen to introduce DMEK service in our NHS trust and put simulation and wet-lab training courses to the test for corneal consultants. METHODS: We designed and held DMEK wet lab courses using human donors and the simulation model and wet lab training for consultants. We collected surveys pre- and post- wet lab course attendance. We also recorded their performance times. We used human research grade corneas and Phillip DMEK, Kitaro model eye, artificial anterior chambers for consultants. RESULTS: All participants had practiced all the steps of DMEK and improved performance times. All reported to have increased confidence level as a direct result of the wet lab courses. All steps of DMEK surgery except graft manipulation were closely simulated to real-life surgery on patients. Out of the six consultants participating, two started DMEK services in their respective NHS trusts in the following month, with others planning to start DMEK services in the coming months. CONCLUSIONS: The benefits of simulation and wet lab training is particularly valuable during the COVID-19 pandemic, which drastically reduced the availability of donor cornea, thus grinding to a halt corneal graft surgery nationally for many months. Surgeons, regardless of grade (beginner to advanced) can keep their skills up using wet lab and simulation. This setting also improves safety for patients.

Five Cases of Corneal Graft Rejection After Recent COVID-19 Vaccinations and a Review of the Literature.

PURPOSE: The purpose of this study was to report 5 cases of acute corneal graft rejection after COVID-19 vaccination and perform a review of the literature. METHODS: This was a case series and review of literature dated on the October 10, 2021. RESULTS: We describe 5 cases-2 patients with Descemet stripping automated endothelial keratoplasty (for Fuchs endothelial dystrophy) who presented with acute corneal graft rejection after their first dose of mRNA (BNT162) vaccine. The other 3 patients who had penetrating keratoplasty performed more than 10 years ago for keratoconus presented with acute graft rejection-2 patients after their second dose of adenovirus vector (AZD1222) vaccine and 1 patient after first dose of mRNA (BNT162) vaccine. Three patients were not using any topical steroid treatment at the time of diagnosis of graft rejection. The mean duration between vaccination and onset of symptoms was 16.86 ± 6.96 days for the mRNA vaccine and 17 ± 11.89 days for the adenovirus vector vaccine. CONCLUSIONS: Corneal graft rejection has recently been reported after COVID-19 vaccination. Patients with keratoplasty need to be advised regarding the risk of corneal graft rejection and warning symptoms of rejection after COVID-19 vaccination. Seeking early referral to the emergency department and increasing topical steroids pre-COVID-19 and post-COVID-19 vaccination may reduce the risk of rejection.

Reverse graft suturing to avoid Descemet's membrane detachment of glycerol-preserved donor cornea used for therapeutic penetrating keratoplasty during COVID-19 to overcome the tissue shortage - A novel surgical technique.

To overcome tissue shortage during pandemic, we switched to 100% glycerol preservation of the donor cornea, which is economical and provides longer duration of storage than the short and intermediate storage mediums we normally use like McCAREY Kaufman (MK) or cornisol. During our initial few cases of therapeutic penetrating keratoplasty using glycerol preserved donor cornea, we faced spontaneous Descemet's detachments resistant to air tamponade. We tried reverse graft suturing and successfully reinforced Descemet's attachment along with air tamponade, in one of the cases after multiple failed air injections. In the subsequent two cases of infective keratitis needing therapeutic penetrating Keratoplasty, we took eight reverse sutures in between the eight cardinals, to anchor the Descemet's membrane of the graft. Both the grafts showed attached Descemet's and maintained good graft clarity. The reverse corneal suturing technique has not been described to the best of our knowledge and hope this helps our corneal fraternity.

Resource maximization during COVID-19 crunch - A novel graft marking technique to use one cornea for two recipients for either Descemet membrane endothelial keratoplasty or deep anterior lamellar keratoplasty.

During pandemic, eye banks worldwide faced drastic reduction of corneal retrieval. Since precut tissues are uncommon in India, the onus is on corneal surgeons to maximize the donor corneal usage. The stumbling block making the stromal part unusable in the graft preparation of the Descemet membrane endothelial Keratoplasty is the stromal window creation to place the orientation mark on the stromal side of the folded graft. To overcome this, we simply marked directly on the folded Descemet graft, after partly stripping it from the donor cornea. Then, we unfolded, punched, and created two grafts after completely stripping it, retaining the Descemet part for the endothelial Keratoplasty and the stromal part for lamellar Keratoplasty. Initially, we used a special F marker, and later we marked an L using just a spatula. This simple technique needing no extra donor tissue or instrumentation maximizes the tissue utility with proper patient selection.

Year one of COVID-19 pandemic in India: Effect of lockdown and unlock on trends in keratoplasty at a tertiary eye centre.

PURPOSE: To describe the impact of lockdown and unlock phases of the COVID-19 pandemic on keratoplasty trends at a tertiary eye care center in India. METHODS: This cross-sectional hospital-based study included 6,277 patients presenting between March 25, 2017 and March 31, 2021. The data of the patients who underwent keratoplasty during the lockdown and unlock phases were compared with the respective periods in the previous three years before COVID-19. RESULTS: During the year one of pandemic, there was a 29.46% decline in the total number of keratoplasty performed at the institute compared to previous year's annual numbers. The patients undergoing keratoplasty decreased by 90.28% (28/288) of pre-COVID-19 volumes during the lockdown phase. This was mainly because of a 40.6% reduction in the proportion of patients requiring interstate travel. There was complete recovery in the number of patients undergoing keratoplasty to 129.27% (184/142) of pre-COVID-19 volumes by March 2021. This gradual incremental trend was seen across all types of keratoplasty in Descemet stripping endothelial keratoplasty (135.29%), penetrating keratoplasty (117.6%), therapeutic keratoplasty (122.22%), anterior lamellar keratoplasty (150%), and Descemet membrane endothelial keratoplasty (141.18%) by March 2021 with the gradual ease of lockdown regulations. The eye bank affiliated to the institute saw a 55.44% decline in donor cornea collection and an increase in utilization rate from 58.12% in previous years to 83.78% in year one of the pandemic. The overall eye bank donor cornea collection recovered to 86.96% (627/721) and tissue utilization increased by 109.99% (455/414) by March 2021. CONCLUSION: The first year of the COVID-19 pandemic saw an overall reduction of 29.46% of the patients undergoing keratoplasty at the institute. There was a gradual and incremental increase in all types of keratoplasty in the unlock phase, which surpassed the preceding years' monthly numbers in February and March.

Descemet Membrane Endothelial Keratoplasty in Eyes With Chronic Ocular Hypotony Following Glaucoma Surgery.

PURPOSE: To assess the outcomes of Descemet membrane endothelial keratoplasty (DMEK) in patients with ocular hypotony after glaucoma surgery. DESIGN: retrospective case series. METHODS: Setting: Multicenter retrospective case series. PATIENTS/INTERVENTION: Hypotonic eyes with prior glaucoma surgery that underwent DMEK between January 2013 and July 2019 in Israel (2 centers) and Canada (1 center). MAIN OUTCOME MEASURES: Pre/postoperative corrected distance visual acuity, complications, 3- to 6-month endothelial cell loss, and intraocular pressure (IOP). RESULTS: The study included 11 DMEK procedures performed in 10 eyes of 4 males and 6 females aged 65-84 years. Indications for DMEK included 7 cases of pseudophakic bullous keratopathy, 2 cases of failed DMEK, and 1 case of failed Descemet stripping automated endothelial keratoplasty. All patients had at least 1 previous trabeculectomy operation. One patient had 2 trabeculectomy procedures and 1 tube placement procedure. Two patients had 1 previous trabeculectomy and 1 tube placement procedure. The corrected distance visual acuity improved significantly from 1.52 ± 0.68 logarithm of minimal angle of resolution preoperatively to 0.49 ± 0.32 logarithm of minimal angle of resolution 3 months postoperatively (P < .001). Rebubbling occurred in 3 of 11 procedures (27%). Endothelial cell loss 6-12 months postoperatively was 60% ± 16% (range, 41%-89%). At the last follow-up visit, 6 of 11 (54%) of the grafts were clear. The remaining 5 grafts failed at 1-4 years postoperatively. The preoperative IOP was 5.1 ± 1.6 mm Hg (range, 1-7 mm Hg). In all but one patient, the postoperative IOP did not increase to more than 13 mm Hg. In 2 cases, the IOP decreased from 5 and 7 mm Hg preoperatively to 1 mm Hg 1 year postoperatively. CONCLUSION: DMEK is a valid procedure for the treatment of corneal edema in hypotonic eyes after glaucoma procedures. These eyes benefit from improvement in vision after DMEK.

Acute Corneal Transplant Rejection After COVID-19 Vaccination.

PURPOSE: The purpose of this report was to describe 4 cases of acute corneal transplant rejection occurring in association with coronavirus disease 2019 (COVID-19) mRNA vaccination. METHODS: Four patients with prior keratoplasty developed presumed immunologic rejection after the mRNA-1273 vaccination for coronavirus 2 (SARS-CoV-2). Case 1 had received Descemet membrane endothelial keratoplasty 6 months ago and presented with endothelial graft rejection 3 weeks after the first vaccine dose. Case 2 had undergone penetrating keratoplasty 3 years previously and presented with acute endothelial rejection 9 days after the second vaccine dose. Case 3 had prior Descemet stripping automated endothelial keratoplasty (DSAEK) and began experiencing symptoms of endothelial graft rejection 2 weeks after the second vaccine dose. Case 4 presented with endothelial rejection of the penetrating keratoplasty graft 2 weeks after the second vaccine dose. RESULTS: Frequent topical corticosteroids alone were initiated in all 4 cases. In case 1, the endothelial rejection line appeared fainter with improvement in visual acuity and corneal edema 5 weeks after diagnosis. Case 2 experienced complete resolution of corneal stromal edema and rejection line 6 weeks after diagnosis. Cases 3 and 4 have both experienced initial improvement with steroid treatment as well. CONCLUSIONS: These cases suggest acute corneal endothelial rejection may occur soon after either dose of the COVID-19 mRNA vaccine. Prompt initiation of aggressive topical steroid therapy may result in complete resolution of clinical signs and symptoms. Further studies are needed to elucidate the causal mechanism of corneal graft rejection after COVID-19 vaccination.

A Novel Virtual Wet Lab-Using a Smartphone Camera Adapter and a Video Conference Platform to Provide Real-Time Surgical Instruction.

PURPOSE: Proctored surgical instruction has traditionally been taught through in-person interactions in either the operating room or an improvised wet lab. Because of the COVID-19 pandemic, live in-person instruction was not feasible owing to social distancing protocols, so a virtual wet lab (VWL) was proposed and implemented. The purpose of this article is to describe our experience with a VWL as a Descemet membrane endothelial keratoplasty (DMEK) skills-transfer course. This is the first time that a VWL environment has been described for the instruction of ophthalmic surgery. METHODS: Thirteen participant surgeons took part in VWLs designed for DMEK skills transfer in September and October 2020. A smartphone camera adapter and a video conference software platform were the unique media for the VWL. After a didactic session, participants were divided into breakout rooms where their surgical scope view was broadcast live, allowing instructors to virtually proctor their participants in real time. Participants were surveyed to assess their satisfaction with the course. RESULTS: All (100%) participants successfully injected and unfolded their DMEK grafts. Ten of the 13 participants completed the survey. Respondents rated the experience highly favorably. CONCLUSIONS: With the use of readily available technology, VWLs can be successfully implemented in lieu of in-person skills-transfer courses. Further development catering to the needs of the participant might allow VWLs to serve as a viable option of surgical education, currently limited by geographical and social distancing boundaries.

Characteristics of endothelial corneal transplant rejection following immunisation with SARS-CoV-2 messenger RNA vaccine.

AIM: We report two cases of endothelial corneal allograft rejection following immunisation with SARS-CoV-2 messenger RNA (mRNA) vaccine BNT162b2 and describe the implications for management of transplant recipients postvaccination for COVID-19. METHODS: A 66-year-old woman with Fuchs endothelial corneal dystrophy (FECD) and a unilateral Descemet's membrane endothelial keratoplasty (DMEK) transplant received COVID-19 mRNA vaccine BNT162b2 14 days post-transplant. Seven days later, she presented with symptoms and signs of endothelial graft rejection. An 83-year-old woman with bilateral DMEK transplants for FECD 3 and 6 years earlier developed simultaneous acute endothelial rejection in both eyes, 3 weeks post second dose of COVID-19 mRNA vaccine BNT162b2. Rejection in both cases was treated successfully with topical corticosteroids. CONCLUSIONS: We believe this is the first report of temporal association between corneal transplant rejection following immunisation against COVID-19 and the first report of DMEK rejection following any immunisation. We hypothesise that the allogeneic response may have been initiated by the host antibody response following vaccination. Clinicians and patients should be aware of the potential of corneal graft rejection associated with vaccine administration and may wish to consider vaccination in advance of planned non-urgent keratoplasties. Patients should be counselled on the symptoms and signs that require urgent review to allow early treatment of any confirmed rejection episode.

Rebubbling of detached descemet membrane endothelial grafts at the slit lamp with 50% air fill after PI-less DMEK during COVID-19 era.

PURPOSE: To describe the effective use of only 50% air fill of the anterior chamber for rebubbling partially detached Descemet Membrane Endothelial Keratoplasty (DMEK) grafts at the slit lamp at a time of restricted operating theatre access during the COVID-19 pandemic. METHODS: We present two cases of patients who underwent rebubbling of a partially detached DMEK grafts at the slit lamp following DMEK surgery without peripheral iridotomy. The rebubbling was performed with a 27-gauge needle attached to a 1ml syringe and the patients seated at the slit lamp. Air was injected into the anterior chamber until a 50% air fill was achieved. The patients were instructed to lie supine for 30 min in clinic and the remainder of the day at home. RESULTS: We performed two rebubbling procedures at the slit lamp using the standard needle and syringe. Both cases achieved 50% air fills without any complications. At 3 days post-procedure the air bubble had resolved and the graft appeared attached centrally and at day 14 post-procedure the two patients had a clear and attached corneal graft with corrected visual acuity of 6/7.5 and 6/9, respectively. CONCLUSION: Rebubbling of detached DMEK grafts at the slit lamp with 50% air fill in the anterior chamber is a relatively simple and effective procedure. This provides an alternative approach for managing the complication of partially detached DMEK grafts in the era of COVID-19 with limited operating theatre access and avoids the risk of complications such as pupillary block in 'PI-less' DMEK.

Four in one: Four recepients with a single donor tissue - A novel concept for eye transplantation surgery post-COVID-19.

A donor corneo-scleral button was dissected into four parts using a simple manual technique. The anterior corneal lamellae was stripped from the Descemet's Membrane (DM) and Deep Anterior Lamellar Keratoplasty (DALK) was performed in a patient with advanced keratoconus after removing the recipient's stroma using the big bubble technique. Descemet's Membrane Endothelial Keratoplasty (DMEK) was done with the stripped donor DM in a patient with Fuch's endothelial dystroph (FECD). The cadaveric limbal stem cells from the tissue were used for simple limbal epithelial transplantation (SLET) in a Steven- Johnson Syndrome (SJS) with localized limbal stem deficiency and symblepharon. The sclera was used to revise a leaking hypotonus bleb in an advanced single-eyed glaucoma patient. No intraoperative or postoperative complications were observed. At 1 year, all the 4 cases retained healthy transplanted tissues with good visual outcomes. Shortage of donor eyes is a global problem and with the present COVID-19 scenario the situation is bound to worsen. The advent of customized component corneal transplantation using simple cost-effective techniques will be the future trend in the years to come.

Eye Banking: One Cornea for Multiple Recipients.

PURPOSE: Corneal transplantation is the most frequently performed transplant procedure. In much of the world, the demand for donor tissue heavily outstrips supply. With developments within lamellar corneal graft surgery, the use of split corneal donor tissue to increase donor tissue supply seems a pragmatic solution to reduce the supply and demand mismatch. This is especially important with tissue supply expected to be affected by the COVID-19 pandemic. METHODS: A literature review of techniques was performed, enabling multiple transplants to be derived from a single donor and simulation of a model to quantify the number of corneas potentially saved. RESULTS: Studies on splitting corneal donor tissue have demonstrated that up to 5 recipients may benefit from 1 donor scleral button. The impact of splitting donor tissue may provide a saving of up to 25.3% of donor graft tissue. CONCLUSIONS: Splitting and preparing the donor tissue within an eye bank will improve tissue validation and donor tissue availability and may increase surgeon efficiency.