Donor Corneas Research Articles

Real-time monitoring of riboflavin concentration using different clinically available ophthalmic formulations for epi-off and epi-on corneal cross-linking.

To assess the feasibility of theranostics to determine the riboflavin concentration in the cornea using clinically available ophthalmic formulations during epithelium-off (epi-off) and transepithelial (epi-on) corneal cross-linking procedures. Thirty-two eye bank human donor corneas were equally randomized in eight groups; groups 1 to 3 and groups 4 to 8 underwent epi-off and epi-on delivery of riboflavin respectively. Riboflavin ophthalmic solutions were applied onto the cornea according to the manufacturers' instructions. The amount of riboflavin into the cornea was estimated, at preset time intervals during imbibition time, using theranostic UV-A device (C4V CHROMO4VIS, Regensight srl, Italy) and expressed as riboflavin score (d.u.). Measurements of corneal riboflavin concentration (expressed as µg/cm3) were also performed by spectroscopy absorbance technique (AvaLight-DH-S-BAL, Avantes) for external validation of theranostic measurements. At the end of imbibition time in epi-off delivery protocols, the average riboflavin score ranged from 0.77 ± 0.38 (the average corneal riboflavin concentration was 213 ± 190µg/cm3) to 1.79 ± 0.07 (554 ± 103µg/cm3). In epi-on delivery protocols, the average riboflavin score ranged from 0.17 ± 0.01 to 0.67 ± 0.19 (corneal riboflavin concentration ranged from 6 ± 5µg/cm3 to 122 ± 39µg/cm3) at the end of imbibition time. A statistically significant linear correlation (P ≤ 0.05) was found between the theranostic and spectrophotometry measurements in all groups. Real-time theranostic imaging provided an accurate strategy for assessing permeation of riboflavin into the human cornea during the imbibition phase of corneal cross-linking, regardless of delivery protocol. A large variability in corneal riboflavin concentration exists between clinically available ophthalmic formulations both in epi-off and epi-on delivery protocols.

The expanding roles of eye banks in India: Past, present, and future.

This review highlights the evolution in the scope of eye banking activities in India. The roles and responsibilities of the eye banks have expanded to match the requirements and necessities that arose because of advancements in keratoplasty techniques and the need for corneal surgeons. Adoption of different types of corneal preservation solutions and methods of donor cornea preservation was a consequence of the changing and unprecedented times. The growth of eye banking in India has been a commendable journey and has placed the country in an "almost sufficient" category in eye banking and corneal transplantation. There exists a potential to reach the status of cornea surplus country in the future. The rules and laws governing eye banking operations need dynamic amendments based on the trends in keratoplasty, surgical practice patterns, and status of self-sufficiency. Newer technological advances and quality measures must be adopted in donor cornea evaluation and tissue preparation. Research should be integrated as an important component of eye banking, especially in developing novel methods of donor preservation, and evaluating and validating the existing and changing practices of eye banking.

Use of discarded corneo-scleral rims to create cornea-like tissue.

Corneal disease is a major cause of blindness. Transplantation of cadaver-derived corneas (keratoplasty) is still the current therapy of choice; however, the global shortage of donor corneas continues to drive a search for alternatives. To this end, biosynthetic corneal substitutes have recently begun to gain importance. Here, we present a novel method for the generation of a cornea-like tissue (CLT), using corneo-scleral rims discarded after keratoplasty. Type I collagen was polymerized within the corneo-scleral rim, which functioned as a 'host' mould, directing the 'guest' collagen to polymerize into disc-shaped cornea-like material (CLM), displaying the shape, curvature, thickness, and transparency of normal cornea. This polymerization of collagen appears to derive from some morphogenetic influence exerted by the corneo-scleral rim. Once the CLM had formed naturally, we used collagen crosslinking to fortify it, and then introduced cells to generate a stratified epithelial layer to create cornea-like tissue (CLT) displaying characteristics of native cornea. Through the excision and reuse of rims, each rim turned out to be useful for the generation of multiple cornea-shaped CLTs. The approach effectively helps to shorten the gap between demand and supply of CLMs/CLTs for transplantation. We are exploring the surgical transplantation of this CLT into animal eyes, as keratoprostheses, as a precursor to future applications involving human eyes. It is possible to use either the CLM or CLT, for patients with varying corneal blinding diseases.

Femtosecond Laser Cutting of Human Crystalline Lens Capsule and Decellularization for Corneal Endothelial Bioengineering.

The bioengineering of corneal endothelial grafts consists of seeding in vitro cultured corneal endothelial cells onto a thin, transparent, biocompatible, and sufficiently robust carrier which can withstand surgical manipulations. This is one of the most realistic alternatives to donor corneas, which are in chronic global shortage. The anterior capsule of the crystalline lens has already been identified as one of the best possible carriers, but its challenging manual preparation has limited its use. In this study, we describe a femtosecond laser cutting process of the anterior capsule of whole lenses in order to obtain capsule discs of 8 mm diameter, similar to conventional endothelial grafts. Circular marks made on the periphery of the disc indicate its orientation. Immersion in water for 3 days is sufficient to completely remove the lens epithelial cells and to enable the seeding of corneal endothelial cells, which remain viable after 27 days of culture. Therefore, this method provides a transparent, decellularized disc ready to form viable tissue engineered endothelial grafts.

Qualitative Blade Topology in Donor Cornea Punches and Corresponding Endothelial Cell Loss in PK and DMEK Grafts

Purpose: Two commonly used donor cornea punches were assessed using quantification of peripheral endothelial cell loss (ECL) and scanning electron microscopy (SEM) of blade topology and associated features on donor grafts. Methods: Penetrating keratoplasty (PK) (n = 8 pairs) and Descemet membrane endothelial keratoplasty (DMEK) (n = 8 pairs) grafts were prepared from mate donor corneas using Moria Busin or Corza Barron donor cornea punches (all punches were 7.5 mm) and analyzed for global and peripheral ECL. Punches were examined by SEM and subsequently used to prepare PK grafts from mate donor corneas (n = 3 pairs) that were also assessed by SEM. Results: For PK grafts, peripheral ECL caused by Busin and Barron punches was 4.2% ± 0.6% and 4.0% ± 0.9% (P = 0.62), respectively. For DMEK grafts, peripheral ECL caused by Busin and Barron punches was 3.6% ± 1.9% and 3.0% ± 1.3% (P = 0.48), respectively. SEM analysis of the Busin punch identified a rolled blade with a seam; the Barron punch is created from full rod stock and is seamless. Busin punch PK grafts have a ridge of stromal tissue that was not observed in the Barron PK grafts. Both punches exhibit anomalies along the blade edge, and the stroma of both grafts exhibited “drag lines.” Conclusions: Both punches caused similar and minimal ECL. In PK grafts, the seam of the Busin punch may be the source of the observed uneven stromal surface. Striations and debris on the cutting surfaces of both punches may produce drag lines in cut stroma. These topological features may contribute to uneven donor–recipient tissue apposition, leading to astigmatism after PK.

Donor Cornea Storage Temperature: Investigation of the Time Period Immediately Before Cornea Transplantation Surgery

Purpose: Donor cornea storage temperature seems to affect tissue viability; however, the time period between removal from storage and transplant surgery has not been explored. We investigated the possible impact time at room temperature in the operating room may have on endothelial cell density (ECD) and corneal thickness (CT). Methods: In our simulation, transplant-ineligible corneas underwent 1 of 4 room temperature protocols. ECD (by specular microscopy) and CT (by anterior segment optical coherence tomography [OCT]), measured before and after protocols, were used to explore possible effects of time at room temperature. Control group tissue resided at room temperature only long enough for warming and subsequent ECD and CT measurements. Results: Corneas underwent one of the following protocols: 1) 17 (±1) minutes at room temperature (for baseline OCT measurements; n = 13) followed by 23 minutes at 35°C (to facilitate specular imaging, conducted for all 4 protocols), 2) 60 (±1) minutes (1 hour; n = 8) at room temperature, 3) 187 (±1) minutes (approximately 3 hours; n = 7) at room temperature, and 4) 416 (±1) minutes (approximately 7 hours; n = 7). Statistical analysis showed no significant difference in ECD change (P = 0.353) or CT change (P = 0.415) between protocol groups. Controlling for donor age and death-to-preservation time rendered no statistical significance. Conclusions: Time at room temperature did not seem to significantly influence ECD or CT measured soon after warming. Studies exploring ECD postoperatively and long-term graft survival are needed to assess the possible clinical impact of preoperative time at room temperature.

Safety and efficacy of McCarey-Kaufman medium supplemented with colistin (polymyxin E) and amphotericin B in inhibiting the multidrug-resistant Pseudomonas aeruginosa using an ex vivo donor corneal infection model.

This study aimed to evaluate the efficacy and safety of McCarey-Kaufman (MK) medium supplemented with colistin and amphotericin B in inhibiting the growth of multidrug-resistant Pseudomonas (P.) aeruginosa , using an ex vivo experimental model with human donor corneas. Cadaveric human corneas deemed unsuitable for corneal transplantation were obtained, and MK media were supplemented with colistin and amphotericin B. Multidrug-resistant P. aeruginosa was cultured and used to infect the human donor corneas ex vivo . Infected corneas were placed in the MK media with additional antibiotics (colistin and amphotericin B) and the standard MK media, which served as the control arm for comparison. Corneal opacity due to infiltration and quantitative analysis of colony-forming units (CFUs) were assessed. The viability of the corneal endothelium was assessed using trypan blue staining. Corneas incubated in MK media supplemented with additional antibiotics showed less corneal opacification compared with those in standard MK media at both 48- and 96-hour (hr) time points. Quantitative analysis revealed a lower bacterial load and a significant reduction in CFU in the corneas incubated in MK media with additional antibiotics compared with the control group. At 48 hrs, there was 84% ( P value = 0.024) reduction in bacterial load, and at 96 hr, a 53% ( P value = 0.016) reduction was observed in comparison with those placed in standard MK media. The trypan blue staining tests revealed that the extent of endothelial cell loss in corneas incubated in supplemented MK media was comparable to the ones in standard MK media. The addition of colistin and amphotericin B to MK media demonstrated efficacy in inhibiting the growth of multidrug-resistant P. aeruginosa in an ex vivo cornea infection model. The supplemented media had no detrimental effect on the corneal endothelium. The findings suggest that supplementing the MK media with these broad-spectrum antimicrobial agents may help mitigate the risk of postoperative donor-related infection in the recipients by reducing and containing the load of microbial contamination in donor corneas.

Development of an Instrument for Slit-lamp Examination of Donor Corneas in Preservation Medium

Purpose: To evaluate the effectiveness of an instrument devised for slit-lamp examination of donor corneas suspended in preservation medium.Methods: The study examined two donor corneas received at Yeouido St. Mary's Hospital in February 2023 and March 2023. The instrument has three main components: a plastic holder to hold the preservation medium bottle, a cube with a mirror for reflecting the slit beam, and a stand to attach the device to the slit-lamp. Using the instrument, the donor corneas were examined via slit-lamp: microscopy with the endothelium facing upward and downward. Specular microscopy and anterior segment optical coherence tomography (OCT) were also performed on the preserved donor corneas.Results: Slit-lamp examination of donor corneas in preservation medium using the instrument showed overall corneal buttoning and optical sections of the donor cornea. Using specular reflection and retroillumination, the endothelial layer was partially visible. However, specular microscopy and anterior segment OCT could not examine the donor cornea in preservation medium using the instrument.Conclusions: The devised instrument facilitates slit-lamp examination of donor corneas in preservation medium, enabling a qualitative assessment of donor corneas before corneal transplantation surgery.

Outcome analysis of brain-death referral to NOD-Lb: A retrospective chart review of a single hospital experience over 3 years.

Organ donation shortage and in particular organ procurement is an international concern as the gap between the number of donors and recipients is steadily growing. Organ procurement is a chain of steps with donor identification and referral (ID&R) as the very first link in this chain. Failure of this step hinders the progress in the organ transplantation program. Our study was conducted to evaluate and highlight the gap between the national system and the practice at the identification and referral (ID&R) step of the organ procurement chain in a single tertiary-care academic health center in Beirut: the Lebanese American University Medical Center-Rizk Hospital (LAUMC-RH), and to appraise the literature for challenges at this step and for possible interventions for improvement based on the international experience. This retrospective study was a descriptive case series of ICU and ED deceased patients at a single tertiary-care university hospital in Beirut. Patients' characteristics were collected from medical records for all patients who died between 2017 and 2019 while in the ICU or the ED and shared with the National Organization for Organ and Tissue Donation and Transplantation (NOD-Lb), for each subject separately, to decide on the donor status. All data collected from the patient cohort was analyzed using R version 3.6.1. Wilcoxon signed-rank test, chi-squared, and fisher-exact tests were used to compare differences in clinical characteristics in terms of donor status when appropriate. This study served as 3 years audit of a single hospital experience, and it demonstrates failure to make any referrals to NOD-Lb and zero actual organ and tissue donations over the study period. The review of 295 deceased subjects' charts demonstrates 295 missed alerts to NOD-Lb and the overall missing of 5 organ and tissue donors and 24 cornea donors assuming the organ procurement chain of steps will continue uninterrupted after ID&R. The data gathered suggests the presence of an inefficient identification and referral system that is translated into a complete failure of reporting to NOD-Lb from LAUMC-RH. A systematic evidence-based approach to evaluate for the most cost-effective intervention to increase identification and referral rates is needed with a serious effort to examine and account for any inefficient implantation.

FAMILY’S VIEW REGARDING THE DECISION TO BE A CORNEA DONOR: A PHENOMENOLOGICAL STUDY

Introduction and Objective: Family has an important role in the corneal donor process. Corneal extraction can be done when a potential donor dies, so it requires family involvement and support. The purpose of this study is to explore the family's view on the decision to be a cornea donor so that we can obtain a deep understanding on this issue.
 Methods: Phenomenological studies were conducted in Yogyakarta, Indonesia on families of prospective cornea donors (n=6) and registered cornea donor candidates (n=6). Data were collected using in-depth interviews and study documents. Data were analyzed using the Colaizzi’s method.
 Results: Family participants' knowledge and understanding of the urgency and procedure of corneal donors is the main point that constructs their view of corneal donors. Most family participants consider being corneal donors a good thing to do. All participants expressed their willingness to carry out the will of prospective donors, but there was no guarantee they would do so. Fifty percent of participants’ families are also interested in becoming corneal donors in consideration of religious organizations, educational background, and experience participating in activities with the Eye Bank and the donors.
 Conclusion: Families have an important role in the corneal donor process because they will carry out the will of prospective donors and serve as liaisons for the Eye Bank. Family involvement in the promotion of the cornea donor program is needed.

Efficacy of Emergency Penetrating Keratoplasty with Cryopreserved Human Donor Corneas.

To investigate the long-term outcomes of emergency penetrating keratoplasty using cryopreserved human donor corneas in the management of actual or imminent corneal perforation. A retrospective analysis was performed of the treatment efficacy of emergency penetrating keratoplasty using a cryopreserved human donor cornea, in 14 eyes of 14 patients with corneal ulcers of different etiology. For comparison, the medical histories of 14 patients who had undergone penetrating keratoplasty with the same indication, but received a regularly processed human corneal graft, were retrospectively analyzed. In both groups, the primary endpoint for graft failure was repeat surgery, defined as the necessity for amniotic membrane transplantation, conjunctival flap, or repeat penetrating keratoplasty, during a follow-up time of maximally 12 months. The difference in the need for repeated surgeries between the cryopreserved human donor cornea group and cultivated tissue graft group was not statistically significant (p = 0.835). Specifically, repeat complex surgery of any kind within 6 months was necessary in 50% of the cryopreserved cornea group and in 57.1% of the control group, with no further surgical interventions during the remainder of the follow-up period. However, repeat penetrating keratoplasty occurred more frequently in the cryopreserved cornea group (n = 5) than in the control group (n = 1) during the first 12 months after treatment (p = 0.048). Cryopreserved corneas appear to be a viable option for promptly addressing emergencies and stabilizing the corneal situation, providing a faster solution compared to waiting for fresh tissue availability. However, repeat penetrating keratoplasty is more frequent when cryopreserved human donor corneas are used. Cryopreserved human donor corneas may be useful if surgical treatment is urgent and alternative options, such as tissue use, a conjunctival flap, or multilayer amniotic membrane transplantation, are not available.

Treatment of Corneal Perforation Using Periosteal Graft Technique With the Continuation of Penetrating Keratoplasty

Introduction : Corneal perforation occurs due to various conditions and management are based on the underlying cause. Modalities to treat corneal leaks is dependent on the size of corneal defect and include tissue adhesive, conjunctival flap, grafts and transplants. Penetrating Keratoplasty (PK) is effective to treat large corneal defect and to improve visual acuity (VA), but unfortunately PK is usually delayed due to availability.
 Case Illustration : A 17-years-old teenager was diagnosed with corneal perforation on his left eye, VA at initial visit was 1/300, positive seidel test, and shallow anterior chamber. Patient immediately underwent periosteal graft with subsequent PK surgery one month later. First until eight days postoperatively, VA improved from 3/60 to 6/30. Ten days after PK, a mechanical trauma caused the transplant to be detached, and VA greatly decreased to 1/300. Patient underwent immediate repair surgery. First day after surgery, VA was light perception. Eight days later, VA increased to 1/60 with concurrent iris prolapse. Iris repair was done immediately and eight days later VA increased to 6/60. At day sixteen, the final VA is 6/30.
 Discussion : Periosteal graft was performed to maintain ocular integrity. After waiting for a month, PK was performed to improve vision. This combination therapy was successful proven by VA improvement from 1/300 to 6/30.
 Conclusion : Periosteal graft is necessary to maintain ocular integrity while waiting for availability of donor cornea. Penetrating keratoplasty is an appropriate procedure for patients with large corneal leaks. It replaces all corneal structures, and it also improve visual function.

Treatment of Corneal Perforation Using Periosteal Graft Technique With the Continuation of Penetrating Keratoplasty

Introduction : Corneal perforation occurs due to various conditions and management are based on the underlying cause. Modalities to treat corneal leaks is dependent on the size of corneal defect and include tissue adhesive, conjunctival flap, grafts and transplants. Penetrating Keratoplasty (PK) is effective to treat large corneal defect and to improve visual acuity (VA), but unfortunately PK is usually delayed due to availability.
 Case Illustration : A 17-years-old teenager was diagnosed with corneal perforation on his left eye, VA at initial visit was 1/300, positive seidel test, and shallow anterior chamber. Patient immediately underwent periosteal graft with subsequent PK surgery one month later. First until eight days postoperatively, VA improved from 3/60 to 6/30. Ten days after PK, a mechanical trauma caused the transplant to be detached, and VA greatly decreased to 1/300. Patient underwent immediate repair surgery. First day after surgery, VA was light perception. Eight days later, VA increased to 1/60 with concurrent iris prolapse. Iris repair was done immediately and eight days later VA increased to 6/60. At day sixteen, the final VA is 6/30.
 Discussion : Periosteal graft was performed to maintain ocular integrity. After waiting for a month, PK was performed to improve vision. This combination therapy was successful proven by VA improvement from 1/300 to 6/30.
 Conclusion : Periosteal graft is necessary to maintain ocular integrity while waiting for availability of donor cornea. Penetrating keratoplasty is an appropriate procedure for patients with large corneal leaks. It replaces all corneal structures, and it also improve visual function.

Pearls And Pitfalls of Keratoplasty to Achieve and Optimal Visual Function: A Case Report

Introduction : Keratoplasty, also known as corneal transplant, is a surgical procedure in which a damaged or diseased cornea is replaced with a healthy donor cornea. One of the common reasons for performing this procedure is to restore vision in people with a leukoma eye. Leukoma, also known as corneal opacification, is a condition in which the cornea becomes cloudy or opaque, leading to impaired vision or even blindness. This case will explain keratoplasty procedures for treating leukoma, the benefits and risks of the surgery, and the postoperative care required for a successful recovery.
 Case Illustration : A 49 years old Female diagnosed with Leukoma due to her symptoms, signs, and examination with VOD: 1/60 ph (-) and VOS : 6/7.5. The patient then underwent keratoplasty surgery. 7th day post operation, Corneal Graft had 16 interrupted sutures with minimal edema. VOD 6/60 and Intra ocular pressure on the right eye was 13.1 mmHg. Oral and topical corticosteroids Continued and planned to taper off gradually.
 Discussion : The success of the procedure depends on several factors, including the cell count of donor, determining high/low risk patients, Intraoperative, and the postoperative care provided. Topical corticosteroids remain the mainstay to prevent immunological graft reactions. Regular evaluation of the graft is important as the risk of rejection occur up to years.
 Conclusion : Keratoplasty has proven to be an effective treatment option for individuals with a leukoma eye. The procedure can significantly improve visual acuity and quality of life for these individuals.

Donor Corneal Endothelial Cell Maturity and Its Impact on Graft Survival in Glaucoma Patients Undergoing Corneal Transplantation

To examine corneal graft survival via corneal endothelial cell density (ECD) and corneal endothelial cell loss (ECL) at 5 years post-transplantation in the eyes of patients with and without a history of undergoing glaucoma surgery according to the maturity of the donor corneal endothelial cells. Prospective cohort study. This prospective cohort study included 17 patients with glaucoma and 51 patients without glaucoma who underwent Descemet's stripping automated endothelial keratoplasty or penetrating keratoplasty at the Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. Human corneal endothelial cells were cultured from residual peripheral donor cornea tissue, and the maturity of the cells was evaluated by cell surface markers (ie, CD166+, CD44-/dull, CD24-, and CD105-) using fluorescence-activated cell sorting. Kaplan-Meier analysis or the chi-square test was used to assess the rate of successful corneal graft survival post-transplantation. At 36 months postoperatively, the mean ECD and ECL in the glaucoma-bleb eyes were 1197 ± 352 cells/mm2 and 55.5% ± 13.9% in the high-maturity group and 853 ± 430 cells/mm2 and 67.7% ± 18.1% in the low-maturity group, respectively. Kaplan-Meier analysis revealed that at 5 years postoperatively, the overall rate of survival was 45%, that is, 100% in the high-maturity group and 25% in the low-maturity group (P < .05). The findings in this prospective cohort study revealed that the use of donor corneal grafts containing mature-differentiated corneal endothelial cells could maintain the survival of the transplanted graft for a long-term period, even in patients with a history of undergoing glaucoma surgery.

Assessment of performance and safety of Corneal Chamber hypothermic storage medium and PSS-L corneal rinsing solution in human and porcine corneas

PurposeTo prove the safety and performance of the hypothermic corneal storage medium "Corneal Chamber" and the rinsing solution "PSS-L" in support of the new Conformité Européenne (CE) certification process in...

Challenges of obtaining cultured corneal endothelial cells for regenerative purposes

Human posterior corneal epithelium (corneal endothelium) has limited proliferative activity both in vivo and in vitro. Disease or dysfunction in these cells leads to impaired corneal transparency of varying degrees of severity, up to blindness. Currently, the only effective standard treatment for corneal endothelial dysfunction is transplantation of donor cornea that contains a pool of healthy and functionally active cells. However, there is a global shortage of donor corneas, which has led to an unmet clinical need and the fact that only 1 patient out of 10 in need receives surgical treatment. Therefore, creation of cellular constructs and artificial human corneas containing healthy endothelium is a very urgent challenge facing modern ophthalmic transplantology. This review presents the current state of affairs, challenges and prospects for obtaining cultured corneal endothelial cells (CECs) in vitro for transplantation purposes.

Retrospective Analysis of a New Intrastromal Dissection Technique Using the Retinal Reflex for Deep Anterior Lamellar Keratoplasty.

The purpose of this study was to describe a new surgical technique for deep anterior lamellar keratoplasty. All pupils in the recipient eyes were dilated preoperatively. Vertical grooving was performed using a crescent blade with a width of 5 mm and a depth of one-third to half corneal thickness on the temporal side of the limbus. Stromal dissection was performed as close as possible to Descemet membrane by observing the gap between the gold line by retinal reflex and the front edge of the crescent blade. Lamellar dissection was performed along the lamellar plane using corneal dissectors. The ophthalmic viscoelastic device was injected into the intrastromal pocket to separate the anterior and posterior stroma and an anterior corneal lamella was excised. A donor cornea was sutured into the recipient bed. In 18 eyes, none of the patients had Descemet membrane rupture during surgery. The mean postoperative residual stromal thickness was 80 ± 31 μm. The mean central corneal thickness after surgery was 660 ± 69 μm. At the last follow-up, the cornea was cleared in all 18 eyes on slit-lamp examination. We estimated the residual stromal thickness based on the gap between the gold line by the retinal reflex and crescent blade, and intrastromal lamellar dissection was performed using a smooth corneal dissector. Consequently, the surface of stromal dissection was smooth, and the residual stromal thickness was even.

U-Net Convolutional Neural Network for Real-Time Prediction of the Number of Cultured Corneal Endothelial Cells for Cellular Therapy.

Corneal endothelial decompensation is treated by the corneal transplantation of donor corneas, but donor shortages and other problems associated with corneal transplantation have prompted investigations into tissue engineering therapies. For clinical use, cells used in tissue engineering must undergo strict quality control to ensure their safety and efficacy. In addition, efficient cell manufacturing processes are needed to make cell therapy a sustainable standard procedure with an acceptable economic burden. In this study, we obtained 3098 phase contrast images of cultured human corneal endothelial cells (HCECs). We labeled the images using semi-supervised learning and then trained a model that predicted the cell centers with a precision of 95.1%, a recall of 92.3%, and an F-value of 93.4%. The cell density calculated by the model showed a very strong correlation with the ground truth (Pearson's correlation coefficient = 0.97, p value = 8.10 × 10-52). The total cell numbers calculated by our model based on phase contrast images were close to the numbers calculated using a hemocytometer through passages 1 to 4. Our findings confirm the feasibility of using artificial intelligence-assisted quality control assessments in the field of regenerative medicine.

Quality assurance in corneal transplants: Donor cornea assessment and oversight

The cornea is the most frequently transplanted human tissue, and corneal transplantation represents the most successful allogeneic transplant worldwide. In order to obtain good surgical outcome and visual rehabilitation and to ensure the safety of the recipient, accurate screening of donors and donor tissues is necessary throughout the process. This mitigates the risks of transmission to the recipient, including infectious diseases and environmental contaminants, and ensures high optical and functional quality of the tissues. The process can be divided into 3 stages: (1) donor evaluation and selection before tissue harvest performed by the retrieval team, (2) tissue analysis during the storage phase conducted by the eye bank technicians after the retrieval, and, (3) tissue quality checks undertaken by the surgeons in the operating room before transplantation. Although process improvements over the years have greatly enhanced safety, quality, and outcome of the corneal transplants, a lack of standardization between centers during certain phases of the process still remains, and may impact on the quality and number of transplanted corneas. Here we detail the donor screening process for the retrieval teams, eye bank operators. and ophthalmic surgeons and examine the limitations associated with each of these stages.