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Purpose: Corneal transplantation is the most commonly performed transplant surgery. Medical students, doctors of the future, will educate the public about organ transplantation and raise public awareness on this issue. The first aim of this study is to evaluate the initial awareness of medical students about corneal transplantation, then to provide training to these students and finally to evaluate the change in their knowledge on this subject. Method: 310 medical students from Ege University were asked to participate in a 20-question survey. Later, they were given education by a corneal transplant specialist. Immediately after the lessons, the survey was reapplied. Results: The number of students who said they had knowledge about corneal transplantation before the training was 25.5% (n = 79). The knowledge level of 1st grades was lower than the 5th and 6th grades. Final-test scores were significantly higher than pre-test scores in each year group (p < 0.001). The final-test scores were significantly higher than the pre-test scores in both groups, who said they had knowledge about corneal transplantation and who said they did not. Conclusion: Physicians' attitudes toward organ transplantation play a crucial role in influencing the public interest in organ donation. In addition, the physicians' level of knowledge about organ and tissue transplantation is the main determinant of their attitudes via answering the questions and clarifying the worries of the society. This article showed the level of knowledge about corneal transplantation does not increase linearly as the medical school year progresses. In addition, regardless of the initial level of knowledge, the education on corneal transplantation will increase the knowledge level of every student from the 1st grade to the 6th grade. [ABSTRACT FROM AUTHOR]

PurposeMethodsResultsConclusionWe aim to report the frequency and distribution of corneal transplantation, by age, sex, and state/territory, in Australia over a > 25-year period from 1994 to 2022, including during COVID-19 lockdowns.Using data from Medicare, Australia’s Government-funded health insurance scheme, we retrospectively analysed corneal transplants performed from January 1994 to December 2022.From 1994 to 2022, there were 27,536 corneal transplantation services processed by Medicare. Transplants tended to be more common in males in younger age groups (67.7% male in 15–24-year-olds), and in females in older age groups (59.2% female in 75–84-year-olds). Most transplants were performed in New South Wales (9,438 services, 34.3%), Queensland (7,722, 28.0%), and Victoria (5,209, 18.9%). Annual corneal transplantation rates in Australia tended to decrease from 1994 to 2006 (lowest rate during study period), falling by 31%, and then increased by 81%, from 2006 to 2022 (end of study period). Annual repeat corneal transplantation rates (i.e. second and subsequent transplants) increased from 2004 to 2022, rising 301%. During Australia’s nationwide 2020 COVID-19 lockdown (from March to April), monthly transplantation rates decreased by 31%.We performed a longitudinal analysis of corneal transplantation in Australia using a comprehensive, routinely collected, population-based data source. Prior studies examining corneal transplantation have interrogated data from the Australian Corneal Graft Registry, which relies on voluntary reporting. Corneal transplantation rates have increased during the last 15 years, likely as new corneal transplant techniques have evolved, with increasing demand for corneal donation and eye banking services. [ABSTRACT FROM AUTHOR]

Zuheer Meeraalam,1 Shaker O Alreshidi,2 Hani B ALBalawi,3 Naif M Alali,3 Faris Hashem,3 Omar M Kirat4 1Ophthalmology Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia; 2Ophthalmology Division, Department of Surgical Specialties, College of Medicine, Majmaah University, Majmaah, Saudi Arabia; 3Division of Ophthalmology, Department of Surgery, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia; 4Anterior Segment Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi ArabiaCorrespondence: Hani B ALBalawi, Division of Ophthalmology, Department of Surgery, Faculty of Medicine, University of Tabuk, Tabuk, 71491, Saudi Arabia, Email hb.albalawi@ut.edu.saBackground: Corneal transplantation is a critical procedure for restoring vision affected by different corneal pathologies. However, postoperative infections threaten graft survival, particularly microbial keratitis and endophthalmitis.Objective: This study aims to evaluate the incidence of culture-positive corneoscleral rims (CPCR) among transplanted corneas at a tertiary eye hospital and explore its association with death-preservation and preservation-surgery times.Methods: A retrospective analysis of keratoplasty surgeries performed in 2015 was conducted, involving 603 cases meeting the study criteria.Results: The incidence of CPCR was found to be 4.6%, predominantly bacterial (68%), with Methicillin-resistant Staphylococcus epidermidis (MRSE) being the most common isolate, followed by fungal (32%) species, notably Candida. However, none of the cases developed subsequent keratitis or endophthalmitis post-transplantation. Statistical analysis revealed no significant association between CPCR occurrence and death-preservation or preservation-surgery times.Conclusion: The study underscores the reduced impact of contaminated CPCR on graft outcomes, advocating for targeted fungal culturing, intraoperative practices to mitigate post-transplant infections, and maintaining current prophylactic antibiotic regimens, such as optisolGS ™, which contains streptomycin and gentamicin.Keywords: corneal transplant, keratitis, endophthalmitis, infection, bacterial keratitis

Purpose: To report on the clinical characteristics, and outcomes of patients who developed infectious keratitis associated with contact lens (CL) wear following penetrating keratoplasty (PK). Methods: A retrospective chart review was performed to identify all patients who underwent PK between November 2012 and January 2023 at a single tertiary referral practice, and subsequently developed CL related infectious keratitis. 74 patients using CL following PK were identified. Charts were reviewed to obtain data about demographics, ocular history, CL usage, microbial culture reports, visual acuity, treatment, and clinical outcomes. Results: CL-associated infectious keratitis occurred in 9 patients, more frequently in males (66%), and patients had a mean age of 54.5 ± 11.8 years old. The identified causative organisms included: Stenotrophomonas maltophilia (N = 3), Candida parapsilosis (N = 2), Moraxella nonliquefaciens (N = 1), Pseudomonas aeruginosa (N = 1), Staphylococcus epidermidis (N = 1), Streptococcus mitis (N = 1), Candida albicans (N = 1), and Acanthamoeba (N = 1). Contact lenses were used following PK for an average of 9.1 ± 10.8 months before development of keratitis. Patients were followed for 31.8 ± 30.2 months after infection. The mean best corrected visual acuity without CL prior to infection was 20/150 and decreased to 20/260 post-infection. Complications following the contact-lens-associated infectious keratitis included: central corneal haze (N = 8), chronic corneal epithelial defects (N = 3), perforation (N = 3), endophthalmitis (N = 1), and enucleation (N = 1). Three grafts required repeat PK. Conclusions: CL-associated infectious keratitis following PK have high rates of complication. Patients should be monitored closely for signs of infection. [ABSTRACT FROM AUTHOR]

Background/Objectives: To describe the pseudochamber-protected keratoplasty (PPK) procedure with the new Endo-K Pro® implant technique and report the clinical outcomes in patients at high risk for penetrating keratoplasty (PKP). Methods: This case series study included patients who required a PKP and had a high risk for corneal transplant failure. All cases underwent the PPK procedure with simultaneous Endo-K Pro® implantation and had a minimum follow-up of 12 months. Graft survival was the primary outcome (defined as a clear graft with an endothelial cell density >500 cells/mm2). Central corneal thickness (CCT), corrected distance visual acuity (CDVA), intraocular pressure (IOP), and complication rate were the secondary outcomes. Results: Twenty-five eyes (twenty-five patients) were included. The mean follow-up was 23.64 ± 8.2 months (range: 12–36 months). Graft survival was achieved in 23 of the 25 cases (92%). One eye had to be re-transplanted due to persistent oedema secondary to uncontrolled IOP. In two cases (8%), the graft failed three months after surgery when an anterior pseudochamber collapsed due to direct contact of donor endothelium and host tissue. Six eyes experienced host tissue protrusion that was successfully managed using an Nd: YAG laser (two eyes) or injecting a cohesive viscoelastic into the pseudochamber (four eyes). CDVA increased significantly during the follow-up period. No significant changes were found in IOP. No intra- or postoperative complications were reported. Conclusions: PPK with the Endo-K Pro® implant seems to be an effective and safe surgical approach as an alternative in high-risk patients for PKP, allowing full-thickness corneal transplantation without performing an open-sky procedure. [ABSTRACT FROM AUTHOR]

AimTo analyze the clinical outcomes of repeat keratoplasties following a failed primary optical keratoplasty in an Asian population.MethodsIn this prospective cohort study, clinical data of consecutive patients who had repeat keratoplasty at Singapore National Eye Centre from 2007 to 2020 were recorded from our ongoing Singapore Corneal Transplant Registry.ResultsA total of 284 first regrafts (181 Descemet stripping automated endothelial keratoplasty (EK), 63 penetrating keratoplasty (PK), 21 Descemet membrane endothelial keratoplasty, and 19 deep anterior lamellar keratoplasty (DALK)) were analyzed. Graft rejection (38.4%) and late endothelial failure (15.8%) were the main causes of initial graft failure. PK/EK and EK/EK had better one-year postoperative best corrected visual acuity compared to PK/PK (p = 0.006 and p

Purpose To highlight the rarity of the endothelial rejection line, also known as the Khodadoust line, as a manifestation following Descemet’s stripping automated endothelial keratoplasty (DSAEK). The objective is to present a meticulously detailed case, including imaging and anterior optical coherence tomography (OCT), to enhance understanding and recognition of this phenomenon. Methods A detailed case presentation involving a 50-year-old male, 3 years post-DSAEK transplantation for endothelial damage resulting from intraocular surgeries. The patient urgently sought consultation due to vision loss while under daily fluorometholone use. Clinical examination revealed acute graft rejection characterized by corneal edema, anterior chamber reaction, and the presence of keratic precipitates forming a Khodadoust line. The management approach included the initiation of a tapered dexamethasone regimen. Results The identified acute graft rejection, marked by the presence of a Khodadoust line, demonstrated favorable responsiveness to the initiated tapered dexamethasone regimen. Corneal OCT and imaging played crucial roles in providing detailed insights into the manifestation. Conclusions While the endothelial rejection line (Khodadoust line) is a rare occurrence following DSAEK, this case underscores its potential association with graft rejection. The successful management outlined in this report suggests the importance of prompt recognition and appropriate anti-inflammatory intervention in such cases to achieve positive outcomes.

Abstract Background The purpose of the study was to assess visual outcomes, complications, intraocular lens (IOL) stability, and corneal status after sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty (PKP). Methods This retrospective single-arm cohort study included patients who underwent PKP and sutured scleral-fixated intraocular lens implantation between 2013 and 2018 at the Dhahran Eye Specialty Hospital. The eyes were examined postoperatively at 1, 3, 6, 12, and 24 months. Corneal status, complications, and IOL status were also evaluated periodically, and the number of eyes with a BCVA of > 20/200 was recorded. Results Twenty-two eyes from 22 patients were included. The median duration of follow-up was 3 (IQR 1.8; 4.4) years. Reasons for surgery were traumatic globe rupture (six eyes, 27.3%), bullous keratopathy (nine eyes, 40.1%), failed previous graft (five eyes, 22.7%), and corneal scarring (two eyes, 9.1%). Twelve (54.5%) eyes showed a BCVA of > 20/200 (non-blind) at 12 months after surgery and only five (22.7%) before surgery. Twelve months after surgery, 13 patients showed an improvement in BCVA in two lines (59.1%), seven remained the same (31.8%), and 2 deteriorated (9.1%). The indication for surgery (p = 0.2) and the stability of the sutured-scleral fixated IOL (p = 0.8) were not associated with an improvement in BCVA at the final follow-up. The corneal graft remained clear in nine eyes (40.9%) at a median duration of 3 years. The overall average survival period for all corneal grafts was 42.9 months. Conclusions The combination of sutured scleral-fixated intraocular lens implants and PKP is an effective intervention for preserving visual acuity in patients with complex cases. However, the risk of graft failure and then need for repeat transplantation should be taken into consideration.

Purpose: To describe a case of well-documented corneal stroma transparency improvement following the intrastromal implantation of autologous adipose-derived mesenchymal stem cells (ADASC) in a keratoconic patient with established stromal scars. Observations: ADASC were isolated by elective liposuction, and a solution composed of 3x106 ADASC contained in 1mL saline was used to soak a corneal intrastromal pocket created with femtosecond laser at mid-depth. No signs of inflammation or rejection were observed. One year after surgery, we observed a complete restoration of the pre-existing corneal stroma scars, observed both clinically and by anterior segment OCT. The rest of the visual and topographic parameters did not show relevant changes except for the patient's refractive sphere. OCT showed a thin new layer of neocollagen deposited at the surgical plane. Total stroma optical density (OD) improved from 51.5 to 41.2 GSU, anterior stroma OD improved from 55.9 to 42.8 GSU, and posterior stroma OD improved from 46.9 to 39.6 GSU. Conclusions and importance: This clinical case provides new clinical evidence supporting the use of intrastromal mesenchymal stem cell implantation to solve or alleviate established corneal scars.

Background: The purpose of the study was to assess visual outcomes, complications, intraocular lens (IOL) stability, and corneal status after sutured scleral-fixated intraocular lens implantation combined with penetrating keratoplasty (PKP). Methods: This retrospective single-arm cohort study included patients who underwent PKP and sutured scleral-fixated intraocular lens implantation between 2013 and 2018 at the Dhahran Eye Specialty Hospital. The eyes were examined postoperatively at 1, 3, 6, 12, and 24 months. Corneal status, complications, and IOL status were also evaluated periodically, and the number of eyes with a BCVA of > 20/200 was recorded. Results: Twenty-two eyes from 22 patients were included. The median duration of follow-up was 3 (IQR 1.8; 4.4) years. Reasons for surgery were traumatic globe rupture (six eyes, 27.3%), bullous keratopathy (nine eyes, 40.1%), failed previous graft (five eyes, 22.7%), and corneal scarring (two eyes, 9.1%). Twelve (54.5%) eyes showed a BCVA of > 20/200 (non-blind) at 12 months after surgery and only five (22.7%) before surgery. Twelve months after surgery, 13 patients showed an improvement in BCVA in two lines (59.1%), seven remained the same (31.8%), and 2 deteriorated (9.1%). The indication for surgery (p = 0.2) and the stability of the sutured-scleral fixated IOL (p = 0.8) were not associated with an improvement in BCVA at the final follow-up. The corneal graft remained clear in nine eyes (40.9%) at a median duration of 3 years. The overall average survival period for all corneal grafts was 42.9 months. Conclusions: The combination of sutured scleral-fixated intraocular lens implants and PKP is an effective intervention for preserving visual acuity in patients with complex cases. However, the risk of graft failure and then need for repeat transplantation should be taken into consideration. [ABSTRACT FROM AUTHOR]

Background: To study and make a comparative analysis on knowledge, attitude, and practice pattern regarding eye donation amongst MBBS, BDS, Homeopathy and Nursing students in a tertiary care medical college hospital in Central India. Materials and Methods: It is a population based cross sectional study involving 369 MBBS & Paramedical students. A structured questionnaire including 21 questions divided in three sections assessing knowledge, attitude and practice pattern is noted. Chi square test is done for dependent and independent variables. Test performed at 95% confidence interval with p value <0.05 considered statistically significant. Results: Mean knowledge score was 3.875±2.185. MBBS students had a mean score of 5.150 (SD = 1.400, range 1-9) indicating a higher level of knowledge than other medical courses. Knowledge score among nursing students was the least 2.180 (SD = 2.222, range 0-7). Willingness to donate eyes also showed a significant association with knowledge (χ2=371.471, p<0.001). Conclusion: MBBS students had better knowledge than paramedic students. Higher knowledge is linked to positive attitude towards eye donation. The practice pattern regarding pledging is poor in all the students. Thus, structured eye donation awareness programmes targeting medical and paramedical students are recommended. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate ophthalmologists' interest and opinions regarding corneal transplantation and donation in Türkiye. Material and methods: An online questionnaire was prepared using Google Forms, and the electronic link to this questionnaire was sent via WhatsApp to ophthalmologists working in Türkiye. Eighteen open-ended/multiple-choice questions were asked about ophthalmologists' demographic information and their opinions regarding corneal transplantation and donation. The answers were analyzed by transferring the data to Excel. Results: A total of 195 ophthalmologists participated in the survey. While 68.6% of them stated that they wanted to donate their corneas, 21.1% stated that they were undecided, and 10.3% did not want to donate their corneas. While 93.8% of the participants agreed to have a cornea transplant in case of need, 5.7% of them stated that they were undecided, and 0.5% said that they would not accept a cornea transplant. The most frequent (90.5%) reason for being willing to donate one's cornea was to give hope to patients with low vision. The most frequent (46.2%) reason for not wanting to donate one's cornea was the unwillingness to have one's body/eye integrity impaired. The vast majority (80.8%) of the participants thought that there was not enough corneal donation in Türkiye and that this was mostly (85.9%) due to cultural and/or religious reasons. Conclusions: Even in a sample with a high level of education and the most knowledge about corneal transplantation, the willingness to donate corneas may remain below the expected rates. Therefore, it is necessary to alleviate unrealistic concerns and prejudices about corneal donation and transplantation. [ABSTRACT FROM AUTHOR]

Background: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. Objectives: The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. Search Methods and Selection Criteria: A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record's reference list. Data Extraction: Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. Data Statistical Analyses: The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for p-values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I2, chi-square (χ2), and tau-squared. Main Results: We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK. [ABSTRACT FROM AUTHOR]

Fuchs endothelial corneal dystrophy (FECD), the leading indication for corneal transplantation in the U.S., causes loss of corneal endothelial cells (CECs) and corneal edema leading to vision loss. FECD pathogenesis is linked to impaired response to oxidative stress and environmental ultraviolet A (UVA) exposure. Although UVA is known to cause nonapoptotic oxidative cell death resulting from iron-mediated lipid peroxidation, ferroptosis has not been characterized in FECD. We investigated the roles of genetic background and UVA exposure in causing CEC degeneration in FECD. Using ungenotyped FECD patient surgical samples, we found increased levels of cytosolic ferrous iron (Fe2+) and lipid peroxidation in end-stage diseased tissues compared with healthy controls. Using primary and immortalized cell cultures modeling the TCF4 intronic trinucleotide repeat expansion genotype, we found altered gene and protein expression involved in ferroptosis compared to controls including elevated levels of Fe2+, basal lipid peroxidation, and the ferroptosis-specific marker transferrin receptor 1. Increased cytosolic Fe2+ levels were detected after physiologically relevant doses of UVA exposure, indicating a role for ferroptosis in FECD disease progression. Cultured cells were more prone to ferroptosis induced by RSL3 and UVA than controls, indicating ferroptosis susceptibility is increased by both FECD genetic background and UVA. Finally, cell death was preventable after RSL3 induced ferroptosis using solubilized ubiquinol, indicating a role for anti-ferroptosis therapies in FECD. This investigation demonstrates that genetic background and UVA exposure contribute to iron-mediated lipid peroxidation and cell death in FECD, and provides the basis for future investigations of ferroptosis-mediated disease progression in FECD.

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. [ABSTRACT FROM AUTHOR]

Microbial keratitis in a post-transplant cornea should be considered a distinct entity from microbial keratitis in a non-transplant cornea. Firstly, the use of immunosuppressive treatments and sutures in corneal transplants changes the etiology of keratitis. Secondly, corneal transplant has an impact on corneal biomechanics and structure, which facilitates the spread of infection. Finally, the emergence of lamellar transplants has introduced a new form of keratitis known as interface keratitis. Given these factors, there is a clear need to update our understanding of and management strategies for microbial keratitis following corneal transplantation, especially in the era of lamellar transplants. To address this, a comprehensive review is provided, covering the incidence, risk factors, causes, and timing of microbial keratitis, as well as both clinical and surgical management approaches for its treatment in cases of penetrating and lamellar corneal transplants. [ABSTRACT FROM AUTHOR]

Michael Christensen,1 Jeffrey Kartchner,1– 3 Matthew Giegengack,1,2,&ast; Atalie C Thompson1,2,4,&ast; 1Wake Forest University School of Medicine, Winston Salem, NC, USA; 2Department of Surgical Ophthalmology, Atrium Health Wake Forest Baptist Medical Center, Winston Salem, NC, USA; 3Arizona Eye Consultants, Tucson, AZ, USA; 4Department of Gerontology and Geriatric Medicine, Atrium Health Wake Forest Baptist Medical Center, Winston Salem, NC, USA&ast;These authors contributed equally to this workCorrespondence: Michael Christensen, Wake Forest University School of Medicine, 475 Vine St, Winston Salem, NC, 27101, USA, Tel +1-707-880-7802, Email mchriste@wakehealth.eduPurpose: Patients with advanced keratoconus (KCN) are less likely to benefit from corneal cross-linking and may require a partial or full thickness keratoplasty. This study aimed to determine whether racial disparities exist in the clinical presentation and initial treatment recommendations for patients evaluated for KCN.Methods: A single-center retrospective review was conducted on all patients who presented to the cornea department for initial evaluation of KCN between 2018 and 2020. Patients who had undergone prior corneal procedures or surgeries were excluded. Baseline sociodemographic and clinical information was collected and stratified according to black versus non-black race. Generalized estimating equations were used to examine the association between black race and presenting corrected distance visual acuity (CDVA), presence of corneal scarring, keratometry values, Belin ABCD score, and treatment recommendations. Multivariate models were adjusted for patient demographics.Results: A total of 128 patients (251 eyes) were included in this study. In fully adjusted models, black individuals presented with significantly worse CDVA (p < 0.0001) and worse tomographic KCN staging according to the Belin ABCD criteria (p = 0.002) compared to non-blacks. Blacks were also more than four times as likely to present with a thinnest pachymetry < 400 μm (p < 0.0001) and more than three times as likely to have corneal scarring (p = 0.001). Blacks were more than seven times more likely to have keratoplasty recommended as treatment than conservative management such as corneal cross-linking or contact lenses (p = 0.004).Conclusion: Compared with their non-black counterparts, blacks presented with significantly more advanced KCN, which placed them at risk of requiring more invasive treatment plans. Future studies should investigate reasons for such late presentations and aim to mitigate disparities in the presentation and management of KCN.Keywords: corneal cross-linking, corneal transplant, racism in ophthalmology, Cornea

PurposeMethodsResultsConclusionPatients with sight-threatening inflammatory eye disease (IED) are maintained on systemic immunosuppression whilst in long-term clinical remission. There are no clear guidelines on the duration of remission before implementing treatment withdrawal. We present a real-world analysis on the use of immunosuppression in IED in long-term remission and consider strategies for withdrawal.Adult IED patients on systemic immunosuppression were categorised into four disease groups: Corneal Transplant Survival Strategies (CTSS), Ocular Surface Disease (OSD), Non-infectious Uveitis (NIU) and Scleritis. Patients with Behçet’s disease were excluded. Data on systemic immunosuppressants and biologics used; duration of treatment; reasons for drug discontinuation; disease activity/remission status; duration of clinical remission with an emphasis on patients who had been in remission for a minimum of 24 months were captured.Out of a total of 303 IED patients, 128 were on systemic immunosuppression with a clinical remission of their ocular disease for ≥24 months. The median duration of remission was 4–5 years with the longest duration of remission 22 years, and some patients on immunosuppression for up to 23 years. Sixty patients stopped at least one immunosuppressive agent without prior discussion with a health-care practitioner.Progressive conditions, such as cicatrising conjunctivitis may require lifelong immunosuppression, but patients with NIU and Scleritis and those on CTSS, immunosuppression withdrawal should be considered if they remain in remission for 2 years. Any patient stopping a medication should be contacted immediately for counselling. These data will better inform patients, encourage adherence and aide formal guideline development. [ABSTRACT FROM AUTHOR]

Objective: To identify the characteristics of cornea transplant after transplantation. Methods: Cross-sectional, retrospective study with quantitative approach. Research was conducted at Banco de Olhos do Ceará and at three other private transplant centers in Fortaleza. Medical records of transplant patients from October 2020 to September 2022 were analyzed within one year of the procedure. Results: 300 medical records of patients undergoing corneal transplantation were collected, of which 289 (96.3%) corneas demonstrated good transparency. Regarding visual acuity, 62 transplants (20.7%) presented mild vision loss, with 129 (43%) presenting normal intraocular pressure. Conclusion: The characteristics of post-transplant corneas vary depending on the recovery phase and the success of graft integration. The tissue showed good transparency, with visual acuity with slight loss of vision. [ABSTRACT FROM AUTHOR]

Introduction and aim: In patients waiting for organ transplantation, increased waiting time can increase anxiety by creating negative automatic thoughts. The aim of this study is to examine the relationship between corneal transplant recipients' negative automatic thoughts and anxiety before organ transplantation. Material and methods: The population of this correlational descriptive study consisted of 108 patients waiting for cornea transplantation in the Eye Bank unit of a hospital in the south east region of Türkiye. The data were obtained from the patients presented to the ophthalmology clinic for transplantation between September and December 2022. A patient information form, the Negative Automatic Thoughts Scale, and the Trait Anxiety Scale were used to collect the data. Percentage distribution, arithmetic mean, logistic regression and correlation analysis were used in the data analysis. Results: It was determined that the mean score of the negative automatic thoughts of the transplant patients participating in the study was 100.69±47.83, and the trait anxiety mean score was 53.06±6.07. There was a positive relationship between negative automatic thoughts and trait anxiety at a moderate level, which was statistically significant (p<0.05, r=0.53). Concusion: It was determined in the study that the patients' negative automatic thoughts and trait anxiety were high, and their anxiety increased as the negative automatic thoughts increased. [ABSTRACT FROM AUTHOR]

In the last twenty years an impressive body of evidence in diverse inflammatory animal disease models and human tissues, has established polyunsaturated fatty acids (PUFA) derived specialized-pro-resolving mediators (SPM), as essential mediators for controlling acute inflammation, immune responses, wound healing and for resolving acute inflammation in many non-ocular tissues. SPM pathways and receptors are highly expressed in the ocular surface where they regulate wound healing, nerve regeneration, innate immunity and sex-specific regulation of auto-immune responses. Recent evidence indicates that in the eye these resident SPM networks are important for maintaining ocular surface health and immune homeostasis. Here, we will review and discuss evidence for SPMs and other PUFA-derived mediators as important endogenous regulators, biomarkers for ocular surface health and disease and their therapeutic potential.

Purpose: To provide a comprehensive review of the incidence, risk factors, and management of early complications after deep anterior lamellar keratoplasty (DALK), Descemet stripping automated keratoplasty (DSAEK), and Descemet membrane endothelial keratoplasty (DMEK). Methods: A literature review of complications, that can occur from the time of the transplant up to 1 month after the transplant procedure, was conducted. Case reports and case series were included in the review. Results: Complications in the earliest postoperative days following anterior and posterior lamellar keratoplasty have shown to affect graft survival. These complications include, but are not limited to, double anterior chamber, sclerokeratitis endothelial graft detachment, acute glaucoma, fluid misdirection syndrome, donor-transmitted and recurrent infection, and Uretts-Zavalia syndrome. Conclusion: It is essential for surgeons and clinicians to not only be aware of these complications but also know how to manage them to minimize their impact on long-term transplant survival and visual outcomes. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this work was to evaluate the in vitro growth capacity and functionality of human corneal endothelial cells (hCEC) expanded from corneas of elderly (>60 years) donors that were preserved using an organotypic culture method (>15 days, 31°C) and did not meet the clinical criteria for keratoplasty. Methods: Cell cultures were obtained from prior descemetorhexis (≥10 mm) and a controlled incubation with collagenase type I followed by recombinant trypsin. Cells were seeded on coated plates (fibronectin-albumin-collagen I) and cultures were expanded using the dual supplemented medium approach (maintenance medium and growth medium), in the presence of a 10 μm Rho-associated protein kinase inhibitor (Y-27632). Cell passages were obtained at culture confluency (∼2 weeks). A quantitative colorimetric WST-1 cell growth assay was performed at different time points of the culture. Morphometric analysis (area assessment and circularity), immunocytochemistry (ZO-1, Na+/K+-ATPase α, Ki67), and transendothelial electrical resistance (TEER) were performed on confluent monolayers. Results: There was no difference between the cell growth profiles of hCEC cultures obtained from corneas older than 60 years, whether preserved cold or cultivated organotypic corneas. Primary cultures were able to maintain a certain cell circularity index (around 0.8) and morphology (hexagonal) similar to corneal endothelial mosaic. The ZO-1 and Na+/K+-ATPase pump markers were highly positive in confluent cell monolayers at 21 days after isolation (passage 0; P0), but significantly decreased in confluent monolayers after the first passage (P1). A weak expression of Ki67 was observed in both P0 and P1 monolayers. The P0 monolayers showed a progressive increase in TEER values between days 6 and 11 and remained stable until day 18 of culture, indicating a state of controlled permeability in monolayers. The P1 monolayers also showed some functional ability but with decreased TEER values compared to monolayers at P0. Conclusions: Our results indicate that it is possible to obtain functional hCEC cultures in eye banks, using simplified and standardized protocols, from older donor corneas (>60 years of age), previously preserved under organotypic culture conditions. This tissue is more readily available in our setting, due to the profile of the donor population or due to the low endothelial count (<2,000 cells/mm2) of the donated cornea. [ABSTRACT FROM AUTHOR]

Background/objectives: Post-keratoplasty infectious keratitis (PKIK) is a unique sight-threatening clinical entity which often poses significant therapeutic challenges. This study aimed to examine the clinical presentation, risk factors, management, and clinical outcomes of PKIK. Methods: This was a retrospective study of all patientswho presented to the Queen's Medical Centre, Nottingham, with PKIK between September 2015 and August 2022 (a 7-year period). Relevant data on types of keratoplasty, clinical presentations, causative microorganisms, management, and outcome were analyzed. Results: Forty-nine PKIK cases, including four cases of interface infectious keratitis, were identified during the study period. The most common graft indications for PKP, DALK and EK were failed grafts (9, 37.5%), keratoconus (6, 54.5%) and Fuchs endothelial corneal dystrophy (FECD; 8, 57.1%), respectively. Staphylococcus spp. were the most commonly identified organisms (15, 50.0%). Bullous keratopathy (18, 36.7%), ocular surface disease (18, 36.7%), and broken/loose sutures (15, 30.6%) were the most common risk factors. Concurrent use of topical steroids was identified in 25 (51.0%) cases. Of 31 functioning grafts at presentation, 12 (38.7%) grafts failed at final follow-up with 15 (48.4%) patients retaining a CDVA of =1.0 logMAR. The overall estimated 5-year survival rate post-PKIK was 55.9% (95% CI, 35.9%-75.9%), with DALK having the highest survival rate [63.6% (95% CI, 28.9%-98.3%)], followed by EK [57.1% (95% CI, 20.4%-93.8%)] and PKP [52.7% (95% CI, 25.1%-80.3%)], though no statistical difference was observed (p=0.48). Conclusions: PKIK represents an important cause of IK and graft failure. Bullous keratopathy, OSD and suture-related complications are the commonest risk factors, highlighting the potential benefit of prophylactic topical antibiotics (for unhealthy ocular surface) and early suture removal (where possible) in reducing the risk of PKIK. Graft survival may be higher in lamellar keratoplasty following PKIK but larger studies are required to elucidate this observation. [ABSTRACT FROM AUTHOR]

Background: In the general population, 1 in 2000 people has keratoconus. Indians and other people from Southeast Asia have a higher incidence of keratoconus. Children with keratoconus typically present earlier in life and with a more severe disease. Rubbing the eyes has been identified as a risk factor. Children have a higher incidence and a faster rate of keratoconus progression. Visual rehabilitation in children with keratoconus is challenging. They have a low compliance with contact lens use. Many of these children require penetrating keratoplasty at an early age. Therefore, stopping the progression of keratoconus in children is of paramount importance. Main text: Compared to treatment, keratoconus progression prophylaxis is not only preferable, but also easier. Corneal collagen cross-linking has been shown to be safe and effective in stopping its progression in children. The Dresden protocol, which involves central corneal deepithelization (7–9 ​mm), saturation of the stroma with riboflavin (0.25%), and 30 ​min UV-A exposure, has proven to be the most successful. Two significant disadvantages of the typical Dresden regimen are the prolonged operating time and the significant post-operative pain. Accelerated-CXL (9 ​mW/cm2 x 10 ​min) has been studied to reduce operative time and has been shown to be equally effective in some studies. Compared to accelerated CXL or traditional CXL, epi-off procedures, transepithelial treatment without the need for de-epithelialization and without postoperative discomfort, have been shown to be safer but less effective. Corneal crosslinking should only be performed after treating children with active vernal keratoconjunctivitis. Corneal opacity, chronic corneal edema, sterile infiltrates, and microbial keratitis have been reported after cross-linking of corneal collagen. Conclusions: The ''Dresden protocol'', also known as the conventional corneal cross-linking approach, should be used to halt the progression of keratoconus in young patients. However, if the procedure needs to be completed more rapidly, accelerated corneal crosslinking may be considered. Transepithelial corneal cross-linking has been proven to be less effective at stabilizing keratoconus, although being more safer.

Paras P Shah,1 Aisha Hasan,2 Jules Winokur,1,2 Richard Braunstein,1,2 David C Ritterband,1,2 John A Seedor,1,2 Isha Cheela1,2 1Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA; 2Department of Ophthalmology, Northwell Health/Manhattan Eye, Ear & Throat Hospital, New York, NY, USACorrespondence: Paras P Shah, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 500 Hofstra Blvd, Hempstead, NY, 11549, USA, Email pshah27@northwell.eduPurpose: Although several donor, recipient, and graft characteristics have been studied in relation to corneal transplantation outcomes, no study to our knowledge has assessed the impact of donor cooling times on postoperative outcomes longitudinally. With only one corneal graft available for every 70 needed worldwide, this study seeks to identify any factors that could alleviate this shortage.Methods: Patients undergoing corneal transplantation at the Manhattan Eye, Ear & Throat Hospital over a 2-year period were retrospectively studied. Study metrics included age, diabetic history, hypertensive history, endothelial cell density, death-to-preservation time (DTP), death-to-cooling time (DTC), and time-in-preservation (TIP). Postoperative transplantation outcomes, including best corrected visual acuity (BCVA) at 6- and 12-month follow-up visits, need for re-bubbling, and need for re-grafting, were assessed. Unadjusted univariate and adjusted multivariate binary logistic regressions were performed to determine the association of cooling and preservation parameters with corneal transplantation outcomes.Results: Among 111 transplants, our adjusted model found that DTC ≥ 4 hours was associated with significantly worse BCVA, but only at 6-month postoperative follow-up (odds ratio [OR]: 0.234; 95% confidence interval [CI]: 0.073– 0.747; p = 0.014). By 12-month follow-up, DTC > 4 hours was no longer associated with BCVA in a statistically significant manner (OR: 0.472; 95% CI: 0.135– 1.653; p = 0.240). A similar trend was found at a DTC cutoff of ≥ 3 hours. None of the other studied parameters, including DTP, TIP, donor age, or medical history were significantly correlated with transplantation outcomes.Conclusion: Longer DTC or DTP did not have a statistically significant effect on corneal graft outcomes after one year, though short-term outcomes were improved in donor tissues with DTC below four hours. None of the other studied variables correlated with transplantation outcomes. Given the global shortage of corneal tissue, these findings should be considered when determining suitability for transplantation.Keywords: corneal transplant, donor, recipient, outcome, cooling, refrigeration

Objective: We reported a case of Descemet's membrane detachment (DMD) following ripcord removal of a Baerveldt shunt in a post-corneal transplant eye, and the interventions done. Method: This is a case report. Results: A 65-year-old male with multiple surgeries (phacoemulsification, two corneal transplants, and Baerveldt shunt implantation) in the right eye developed increased intraocular pressures, prompting removal of the intraluminal stent (ripcord) of the shunt. This was complicated by hypotony and DMD. Ripcord reinsertion and viscoelastic injection were performed to reattach the Descemet's membrane (DM) but failed. 0.1mL of 14% perfluoropropane (C3F8) gas was injected into the anterior chamber that successfully reattached the DM with return to pre-operative best-corrected visual acuity after 1 week. Conclusion: Injection of an expansive gas (C3F8) was effective in repairing a corneal graft DMD in an eye with a Baerveldt shunt.

IntroductionThe purpose of this review is to consolidate and examine the available literature on the coronavirus disease 2019 pandemic and its effect on corneal transplantation and eye banking.MethodsA primary literature search was conducted using the PubMed (Medline) database with keywords and MeSH terms such as “corneal transplantation,” “eye banks,” “keratoplasty” and then were combined with COVID-19. Relevant articles through September 2022 were assessed and 25 articles were included in this review.ResultsDonor tissue volumes declined globally during lockdown periods due to a lower number of referrals and tighter tissue screening guidelines. Rates of elective surgeries decreased in the lockdown period compared to respective periods in previous years. However, changes in rates of emergency procedures were not uniform across different regions. Moreover, rates of different elective corneal grafts [i.e., penetrating keratoplasty (PK), endothelial keratoplasty (EK), or anterior lamellar keratoplasty (ALK)] were affected differently with the pattern of change being dependent on region-specific factors.ConclusionBoth donor tissue volumes and rates of corneal transplant procedures were affected by lockdown restrictions. The underlying etiology of these changes differed by region. Examining the range of impact across many countries as well as the contributing factors involved will provide guidance for future global pandemics.

Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman’s layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.

Purpose: Descemet membrane endothelial keratoplasty (DMEK) accounts for >50% of all corneal transplants in Germany. So far, no data from such a large multicenter study have been published. Methods: This retrospective study included 3200 DMEKs at seven departments performed for Fuchs endothelial corneal dystrophy (FECD) or bullous keratopathy (BK). We evaluated best corrected visual acuity (BCVA, logMAR), endothelial cell density (ECD, cells/mm2), minimal corneal thickness (CT, μm), rebubbling‐, primary transplant failure‐ and immune reaction‐rate. Changes over time were evaluated by linear mixed models for repeated measures and correlation with case number by center by weighted linear regression. Results: For patients without vision‐limiting comorbidities (74% of all analysed eyes, n = 2270), mean BCVA improved from 0.6 ± 0.4 logMAR to 0.2 ± 0.2 logMAR 6 months (p < 0.001, n = 1441) and 0.1 ± 0.2 logMAR 12 months (p = 0.001, n = 1402) postoperatively. BK‐ had a worse BCVA compared to FECD‐patients (0.3 ± 0.5 vs. 0.1 ± 0.2 logMAR [p < 0.001] at 1 year). ECD declined from 2465 ± 259 cells/mm2 (n = 2876 preoperatively) to 1587 ± 433 cells/mm2 after 12 months (p < 0.001, n = 1237). Mean rebubbling rate was 0.4 ± 0.7/eye. 784 eyes (25%) received at least one rebubbling. More rebubblings correlated with a lower ECD, a worse BCVA, a higher CT, and higher transplant failure and rejection rates (p < 0.001, p = 0.013 for BCVA at 12 months). A single rebubbling did not influence the BCVA (p = 0.785). Graft failure rate was 3% (n = 67), rejection rate 1.5% (n = 48). Conclusion: Descemet membrane endothelial keratoplasty increases visual acuity with low transplant failure‐ and rejection‐rates. FECD has a better outcome than BK. Since a quarter of all patients need a rebubbling, this should be included in the informed consent. Remarkably, one rebubbling has no influence on the outcome. [ABSTRACT FROM AUTHOR]

Descemet membrane endothelial keratoplasty (DMEK) is a popular procedure for the treatment of corneal endothelial diseases mainly targeting Fuchs endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK). Although DMEK has multiple advantages, it is challenging in terms of graft preparation and delivery. One of the crucial factors of DMEK graft preparation is determining the size of the graft. Evaluating risks and benefits of transplanting larger or smaller grafts compared with the descemetorhexis performed following a standard DMEK procedure thus becomes important. Advanced techniques like pre‐loaded DMEK requires pre‐selection of graft diameter without physical examination of the eye making it more challenging. Therefore, recognizing the benefits of graft size and the number of transplanted endothelial cells becomes essential. Smaller DMEK grafts have been preferred and accepted for grafting. Larger diameter grafts have advantages but can be challenging due to higher detachment rates. We thus aim to review the challenges of preparing and delivering DMEK tissues with small or large diameter based on selected descemetorhexis area, discuss the outcomes based on different graft sizes, highlight related complications and suggest which cases may benefit from adopting smaller or larger graft size. [ABSTRACT FROM AUTHOR]

Cell injection therapy is emerging as an alternative to treat corneal endothelial dysfunction (CED) and to avoid corneal scarring due to bullous keratopathy. However, establishing a standardized culture procedure that provides appropriate cell yield while retaining functional features remains a challenge. Here, we describe a detailed framework obtained from in vitro culture of human corneal endothelial cells (HCECs) and comparative in vivo experimental models for CED treatment with a new cell tracking approach. Two digestion methods were compared regarding HCEC morphology and adhesion. The effect of Y-27632 (ROCKi) supplementation on final cell yield was also assessed. Cell adhesion efficacy with two cell delivery systems (superparamagnetic embedding and cell suspension) was evaluated in an ex vivo human cornea model and in an in vivo rabbit CED model. The injection of supplemented culture medium or balanced salt solution (BSS) was used for the positive and negative controls, respectively. HCEC isolation with collagenase resulted in better morphology and adhesion of cultured HCEC when compared to EDTA. Y-27632 supplementation resulted in a 2.6-fold increase in final cell yield compared to the control. Ex vivo and in vivo adhesion with both cell delivery systems was confirmed by cell tracker fluorescence detection. Corneal edema and opacity improved in both animal groups treated with cultured HCEC. The corneas in the control groups remained opaque. Both HCEC delivery systems seemed comparable as treatments for CED and for the prevention of corneal scarring. [ABSTRACT FROM AUTHOR]

Background and Objectives Corneal transplantation is one of the most common eye surgeries and the most common and successful tissue transplantation in the world. This study aims to determine the frequency and causes of different types of corneal transplantation surgeries in patients referred to the ophthalmology ward of Imam Khomeini Hospital in Ahvaz, Iran. Subjects and Methods This descriptive study was performed on the records of patients who underwent corneal transplantation in Ahvaz, Iran. The information including age, sex, cause of transplantation, sex and age of the donor, the need for re-transplantation, reason for re-transplantation, laterality of cornea, and the type of surgery were extracted. Results The mean age of recipients was 50.93 years and included 491(49.3%) males and 505(50.7%) females. It was reported that 51.7% of surgeries were related to the right eye and 47.9% to the left eye. Pseudophakic bullous keratopathy (PBK) was the most common cause of corneal transplantation. Most patients underwent corneal transplantation by penetrating keratoplasty (PK) and Descemet stripping automated endothelial keratoplasty (DSAEK) methods. Conclusion The prevalence of PBK, compared to previous studies in Iran, is high in Ahvaz, which may be due to significant increase in rate of phacoemulsification surgery. The PK and DSAEK methods are common surgeries for corneal transplantation diseases such as PBK. Further studies are recommended to evaluate underlying diseases and re-transplantation rates based on the surgical techniques in transplant recipients. [ABSTRACT FROM AUTHOR]

Introduction: Deep anterior lamellar keratoplasty is a surgical procedure for removing the corneal stroma down to Descemet's membrane. It is most useful for the treatment of corneal disease in the setting of a normally functioning endothelium. Materials and Methods: Patients attending Sarojini Devi Eye Hospital were screened. Twenty-eight eyes of 23 patients with anterior corneal pathologies and who had a best-corrected visual acuity of less than 6/60 and not improving beyond it were included in the study. Results: Conditions in which the pathology is limited to the anterior stroma and sparing the endothelium, lamellar keratoplasty as a procedure offers many advantages with fewer risks of complications. Conclusion: Corneal pathologies involving anterior stroma are better treated with DALK with fewer complications.

Abstract Keratoconus is the most common form of primary corneal thinning. Different methods have been suggested to deal with the condition, including glasses, contact lenses, and surgical interventions, like penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK), well-known methods of the latter. This study was conducted to compare the outcomes and side effects of the two mentioned keratoplasty techniques. First, we systematically reviewed all original articles studies on PubMed, Scopus, Web of Science, and Embase. Then, the extracted data were pooled and meta-analyzed on each of the intended outcomes. A total of 30 studies were included in which PKP was more commonly performed compared to DALK. We found that adverse outcomes consisting of cataracts, graft rejection, graft failure, High-IOP, and corneal infection, were all more common findings in the PKP groups compared to the DALK groups. However, only for the high-IOP, cataracts, and graft rejection, the analysis of the extracted results demonstrated statistical significance. Overall, the DALK groups demonstrated significantly better results when considering the improvement levels by measuring the Endothelial Cell Count (ECC) and Spherical Equivalent (SE). In addition, though statistically insignificant, the Central Corneal Thickness(CCT), Best Corrected Visual Acuity(BCVA), Topographic Cylinder(TC), Refractive Cylinder values were greater in the PKP groups. Based on our study and with its limitations in mind, we can conclude that DALK can be a relatively safer and more effective procedure. Though, a larger number of high-standard randomized clinical trials still need to be conveyed for more definite conclusions.

Introduction. Corneal transplantation is the most successful and commonly performed allotransplantation procedure as compared with other organs and tissues. Over 100,000 corneal transplantations are performed worldwide every year.Purpose. This study investigated whether in vivo confocal microscopy (IVCM) can aid in the diagnosis of a graft rejection reaction by detecting changes in cellular structures and density of immune cells after penetrating keratoplasty.Materials and methods. The study included thirty-four eyes of 34 patients who underwent penetrating keratoplasty (7 eyes with corneal graft rejection, 27 without rejection). The average age of patients is 51.1 ± 13.6 years (from 23 to 76 years). The follow-up period ranged from 12 to 36 months (24.5 ± 4.84 months). Follow-up was performed at 1, 3, 6, 12 months and annually after PKP. To study the morphology of the cornea all patients underwent IVCM to assess the basal epithelium, subbasal layer, stroma and endothelium. Immune cells were identified and evaluated for the shape, length of the processes and their density.Results. Patients with corneal graft rejection demonstrated significant accumulation of corneal dendritic-like immune cells compared to patients with non-rejected grafts. In addition, the cells acquired a more mature morphology (grade 2–3). The density of dendritic cells (DC) was 809.17 ± 342.19 (p < 0.001). A positive correlation was found between DC density and graft rejection (p < 0.001). As well the patients showed signs of endothelial failure with low endothelial cell density and pleomorphism, increased light scattering and hyperreflectivity of the stroma.Conclusions. In a complex of diagnostic measures, confocal microscopy may provide a valuable clinical adjunctive tool in diagnosis and management of early corneal graft rejection.

Keratoconus is a progressive bilateral corneal ectasia, accompanied by loss of vision due to high irregular astigmatism, which is the leading indication for corneal transplantation. The review presents a variety of surgical corneal transplantation techniques for keratoconus available today and discussed their advantages and disadvantages.