Predicting Long-Term Endothelial Cell Loss after Preloaded Descemet Membrane Endothelial Keratoplasty in Fuchs' Endothelial Corneal Dystrophy: A Mathematical Model.

(1) Background: This study offers a biexponential model to estimate corneal endothelial cell decay (ECD) following preloaded "endothelium-in" Descemet membrane endothelial keratoplasty (DMEK) in Fuchs' endothelial corneal dystrophy (FECD) patients; (2) Methods: A total of 65 eyes undergoing DMEK alone or combined with cataract surgery were evaluated. The follow-up period was divided into an early phase (first 6 months) and a late phase (up to 36 months). Endothelial cell count (ECC) and endothelial cell loss (ECL) were analyzed; (3) Results: The half time of the ECD was 3.03 months for the early phase and 131.50 months for the late phase. The predicted time-lapse interval to reach 500 cells/mm2 was 218 months (18.17 years), while the time-lapse interval to reach 250 cells/mm2 was 349 months (29.08 years). There was no statistically significant difference between the ECL in DMEK combined with cataract extraction and DMEK alone at 24 months (p ≥ 0.20). At the late phase, long-term ECL prediction revealed a lower ECC half time in patients undergoing DMEK combined with cataract surgery (98.05 months) than DMEK alone (250.32 months); (4) Conclusions: Based on the mathematical modeling, a predicted average half-life of a DMEK graft could reach 18 years in FECD. Moreover, combining cataract extraction with DMEK could result in excessive ECL in the long term.

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.

Ocular Manifestations in Patients Affected by p63-Associated Disorders: Ectrodactyly-Ectodermal Dysplasia-Clefting (EEC) and Ankyloblepharon-Ectodermal Defects-Cleft Lip Palate (AEC) Syndromes.

BACKGROUND/AIMS: The Ectrodactyly-Ectodermal dysplasia-Clefting (EEC) and Ankyloblepharon-ectodermal defect-cleft lip/palate (AEC) syndromes are rare autosomal dominant diseases caused by heterozygous mutations in the p63 gene. Patients are characterized by abnormalities of the skin, teeth, and hair and have limb defects, orofacial clefting and ectodermal dysplasia. In addition, they often show ocular surface alterations, leading to progressive corneal clouding and eventually blindness. Here, we present 8 cases describing patients affected by EEC (n = 6, with 5 sporadic and 1 familial cases) and AEC (n = 2, both sporadic cases) syndromes. We attempt to provide a description of the ocular disease progression over the years. METHODS: Clinical examinations and monitoring of ocular parameters for the assessment of limbal stem cell deficiency were constantly performed on patients between 2009 and 2023. Quantitative data and comparison with existing cases described in the literature are reported. RESULTS: The therapies supplied to patients were essential for the management of the symptoms, but unfortunately did not halt the progression of the pathology. CONCLUSIONS: A constant monitoring of the patients would help avoid the sudden worsening of symptoms. If the progression of the disease slows down, it would allow for the development of newer therapeutic strategies aimed at correcting the genetic defect.

Preloaded DMEK with endo-in technique: Standardizing and minimizing the learning curve over 5 years using 599 corneal tissues.

PURPOSE: To report the outcomes of standardizing pre-loaded DMEK with endothelium-inwards and its associated learning curve. METHODS: Between 2017 and 2021, a total of 599 tissues were stripped using 'trephine and strip' method and loaded by folding the tissue as a taco-fold with endothelium-inwards. The folded tissues were pulled inside the funnel of a 2.2 mm IOL cartridge and stored for the desired number of days in organ culture media supplemented with dextran. Donor characteristics, endothelial cell loss (ECL) and mortality assessed by trypan blue positivity before and after stripping, and eventful cases during stripping/loading were recorded. RESULTS: The tissues found unsuitable for transplant after stripping (6.7%) were significantly higher compared with loading (0.67%). Central or peripheral tears, fragility of the tissues, and insufficient endothelial cell density mainly attributed towards the discard rate. Mean ECL from pre-stripping to post-stripping was 0.27% with endothelial cell mortality of 0.64% at the end of stripping. Cumulative endothelial mortality fold change (pre-strip to post-strip) was high in the first two years of operation (18.9%), which reduced to 5.1% in the following three years with significant difference (p = 0.0352). Average tissue wastage (3 operators) from first 1-150 tissues was 3%, which significantly reduced to 0.9% after achieving the learning curve (151-250) (p = 0.0492). CONCLUSION: DMEK graft preparation requires a learning curve. However, an operator with DMEK stripping skills can easily adapt to pre-loading a DMEK graft in endothelium-inwards fashion with minimal learning curve.

Deep Anterior Lamellar Keratoplasty Using Dehydrated versus Standard Organ Culture-Stored Donor Corneas: Prospective Randomized Trial.

PURPOSE: To compare the outcomes of deep anterior lamellar keratoplasty (DALK) using dehydrated versus standard organ culture-stored donor corneas for eyes with keratoconus. DESIGN: Prospective, randomized, single-center trial conducted in Italy. PARTICIPANTS: Adult patients (age ≥ 18 years) with keratoconus scheduled for elective DALK. METHODS: Patients undergoing successful type 1 bubble pneumatic dissection using a standard DALK technique were randomized during surgery to receive either dehydrated (n = 30) or standard organ culture-stored (n = 30) donor corneas. MAIN OUTCOME MEASURES: The primary study outcome was best spectacle-corrected visual acuity (BSCVA) 12 months after surgery. Secondary outcomes were refractive astigmatism (RA), endothelial cell density (ECD), and complication rates. RESULTS: Postoperative BSCVA did not significantly differ between groups at both time points: mean difference at 6 months was 0.030 logarithm of the minimum angle of resolution (logMAR; 95% confidence interval [CI], -0.53 to 0.10 logMAR; P = 0.471) and at 12 months was -0.013 logMAR (95% CI, -0.10 to 0.08 logMAR; P = 0.764). No significant differences between groups were observed in terms of postoperative RA and ECD at all time points. In the first 3 days after DALK, an epithelial defect was present in 10 patients (33%) in the organ culture cornea group and in 29 patients (97%) in the dehydrated cornea group. Complete re-epithelialization was achieved by day 7 in all patients (100%) in both groups. CONCLUSIONS: The study provides evidence that the use of dehydrated corneas is noninferior to the use of standard organ culture donor corneas for DALK. Corneal tissue dehydration represents a viable solution that can allow long-term cornea preservation and avoid wastage of unused corneas. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

EBEI: A new index of eye bank efficiency.

PURPOSE: To describe a new proxy of the Eye Bank (EB) activity named "Eye Bank Efficiency Index" (EBEI), calculated as the ratio between the number of corneal tissues distributed by an EB within a certain time period, and the difference between the number of procured and discarded tissues. METHODS: To demonstrate the effectiveness of the new metric as compared to traditional statistics, an analysis was conducted using data from the largest Italian Eye Bank (Fondazione Banca degli Occhi del Veneto Venice, Italy). Collected data included: the number of corneas retrieved, the number of discarded grafts, and the number of distributed tissues. The analysis focused on three defined timeframes: January to December, March to May (the "Italian Lockdown period"), and June to December (the "Italian post-lockdown period"). RESULTS: In 2020, the annual variation of the EBEI showed a significant increase of up to 3.4% compared to the previous year (0.986 in 2019; 1.020 in 2020), but then gradually decreased to 0.993 in 2022. However, during the months of lockdown in 2020, there was a significant decline of -13.8% in the EBEI compared to the same period in the previous year. The variation in the EBEI during the post-lockdown months was minimal in 2020 and 2021, with the lowest EBEI value of 0.976 being reached in 2022 (-7.8% compared to 2019). CONCLUSION: The EBEI is a simple and reliable new measure of the EB activity. Its widespread adoption could ensure a more accurate and reliable analysis of EB data for academic, political, and economic purposes.

Hemi-Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (Hemi-UT-DSAEK) Using Pediatric Donor Corneas: A Case Series.

OBJECTIVE: We sought to evaluate the clinical outcomes of hemi-UT-DSAEK grafts from the pediatric donor corneas of patients affected by Fuchs Endothelial Corneal Dystrophy (FECD). METHODS: A prospective, interventional case series was conducted at the Ophthalmology Department of Venice Civil Hospital and the Veneto Eye Bank Foundation (Venice, Italy). Six eyes of six patients affected by FECD received large-diameter, semicircular hemi-UT-DSAEK grafts obtained from three pediatric donor corneas using the standard pull-through method. Endothelial cell density (ECD), central corneal thickness (CCT), best-corrected visual acuity (BCVA) and intraoperative and postoperative complications were recorded at different time intervals up to 12 months. RESULTS: The average donor age was 64.6 ± 8.6 years, and the pre-operative ECD was 3266 ± 225 cells/mm2. At 12 months postoperatively, the average ECD was 1376 ± 509 cells/mm2 with a mean decrease of 56.8 ± 19.1% from the preoperative donor count. At 12 months, four out of six eyes had significantly improved and reached a BCVA of ≥20/25 (Snellen equivalent). The mean CCT significantly decreased from 788 ± 138 µm before surgery to 576 ± 30 µm at 12 months postoperatively (p < 0.01). CONCLUSIONS: Hemi-UT-DSAEK grafts using pediatric donor corneas are surgically feasible and can provide similar clinical outcomes compared to conventional UT-DSAEK. Transplanting pediatric donor tissues with high ECD into two patients could potentially increase the donor tissue pool to treat endothelial disease.

Preoperative surgeon evaluation of corneal endothelial status: the Viability Control of Human Endothelial Cells before Keratoplasty (V-CHECK) study protocol.

INTRODUCTION: The success of keratoplasty strongly depends on the health status of the transplanted endothelial cells. Donor corneal tissues are routinely screened for endothelial damage before shipment; however, surgical teams have currently no means of assessing the overall viability of corneal endothelium immediately prior to transplantation. The aim of this study is to validate a preoperative method of evaluating the endothelial health of donor corneal tissues, to assess the proportion of tissues deemed suitable for transplantation by the surgeons and to prospectively record the clinical outcomes of a cohort of patients undergoing keratoplasty in relation to preoperatively defined endothelial viability. METHODS AND ANALYSIS: In this multicentre cohort study, consecutive patients undergoing keratoplasty (perforating keratoplasty, Descemet stripping automated endothelial keratoplasty (DSAEK), ultra-thin DSAEK (UT-DSAEK) or Descemet membrane endothelial keratoplasty) will be enrolled and followed-up for 1 year. Before transplantation, the endothelial viability of the donor corneal tissue will be evaluated preoperatively through trypan blue staining and custom image analysis to estimate the overall percentage of trypan blue-positive areas (TBPAs), a proxy of endothelial damage. Functional and structural outcomes at the end of the follow-up will be correlated with preoperatively assessed TBPA values. ETHICS AND DISSEMINATION: The protocol will be reviewed by the ethical committees of participating centres, with the sponsor centre issuing the final definitive approval. The results will be disseminated on ClinicalTrials.gov, at national and international conferences, by partner patient groups and in open access, peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05847387.

P12-A107†Porcine cornea ex vivo model as an alternative to human donor tissues for investigating new preservation conditions.

PURPOSE: Considering the growing shortage of corneal tissues for research, the present study aimed to develop and optimize a porcine cornea model with qualitative features comparable to those of human tissues. METHODS: A new decontamination procedure of porcine eye bulbs was set up and its efficacy as well as endothelial mortality were evaluated. Human corneas unsuitable for transplant and porcine corneas were then compared after storage under hypothermic (4-8°C, Eusol-C, AL.CHI.MI.A. S.R.L) or organ-culture (31-35°C, Tissue-C, AL.CHI.MI.A. S.R.L) storage conditions for 14 days. A new method, based on the semi-automatic analysis of Trypan-blue stained endothelial areas by Fiji software, was developed to quantify the whole endothelium viability. Corneas were assessed for central corneal thickness (CCT), corneal transparency, endothelial morphology, and endothelial cell density (ECD) at days 0, 7, and 14 of storage. Portions of lamellar tissues consisting of Descemet's membrane and endothelial cells were prepared for histological investigations. RESULTS: The new decontamination procedure of porcine eye bulbs resulted in 18% versus 89% ('no decontamination' control) of corneas still contaminated after 28 days of storage at 31°C. The decontamination protocol did not affect endothelium viability, as assessed by the new Fiji-based method. ECD (porcine: 3156 ± 144 cells/mm2; human: 2287 ± 152 cells/mm2), CCT (porcine: 1073 ± 151 µm; human: 581 ± 39 µm), transparency (porcine: 88.6 ± 11.0%; human: 76.3 ± 5.4%), and morphology score (porcine: 4.0 ± 0.0; human: 3.2 ± 0.4) measured in the porcine cornea at day 0 were significantly higher than in human corneas. Nonetheless, the qualitative parameters of porcine and human corneas showed comparable trends during the storage under hypothermic (4-8°C) and organ-culture (31-35°C) conditions for 14 days. CONCLUSION: The presented porcine cornea model represents a reliable and alternative model to human donor tissues for preliminary investigations and can be used for testing new media, substances, drugs, or preservation conditions and their impact on corneal tissue quality and safety. Furthermore, the quantitative method to assess whole endothelium mortality can be implemented at eye banks for the evaluation of corneas intended for transplantation.

P26-A125†Donation medicine: a change of paradigm in procuring ocular tissues for transplantation.

PURPOSE: To reflect on the implementation of the concept of 'Donation Medicine' as a substitute for 'Procurement' to describe the Foundation's activities in the procurement of ocular tissue and donor selection, considering that the prevailing connotation of procurement (the action of obtaining materials, goods and services necessary to the functioning of a productive activity) did not express satisfactorily all the social, human and medical implications of a programme aimed at promoting ocular tissue donation and recovery. Moreover, in medicine the term 'Procurement' is generally associated with the worst therapeutic outcome, which is the end of a human life. METHODS: A retrospective evaluation of the main indicators pertaining to activities in 2021 was performed, with particular regard to donor screening ,tissue recovery, and the human and professional relations with donor families and hospital staff. The results were assessed by an interdisciplinary team, composed of eye bank and healthcare personnel, regulators and experts in medical humanities. RESULTS: In 2021, in light of 2944 non-oppositions to donation (opting out system), 891 consultations of the national SIT donor registry were performed (Sistema Informativo Trapianti), with 2551 clinical charts reviewed, 4332 related phone consultations performed, and 2032 nasopharyngeal swabs for SARS-CoV-2 nucleic acid tested; as a consequence, 2213 condolence and gratitude letters were sent to donor families, of which 57%(1269) conveyed the outcome of donation, along with 115 gratitude letters sent in instances of the non-recovery. 24 families requested, and were granted, the opportunity to visit the eye bank. CONCLUSION: A consensus was reached on the evidence that the term 'Procurement' has obvious limitations in the long term nurturing and maintenance of the motivation of the eye bank and healthcare personnel. As a consequence, the concept of 'Donation Medicine' was implemented to define and develop the activities related to the promotion of donation, the recovery of ocular tissues for transplantation, and internal/external relations with healthcare personnel, thus changing the meaning of 'Procurement', from a process at the end of a life to the realization of a new pathway of care that takes into account both donor families and recipients. Donation medicine begins with the re-opening of the donor clinical chart, the interaction with donor relatives and the recovery of a precious gift for use in the restoration of sight of patients.

P16-A111†Factors affecting the density of corneal endothelial cell cultures obtained from donor corneas.

PURPOSE: The shortage of donor corneas represents a worldwide problem, and corneal endothelial cell (CEC) therapy might be a promising alternative approach. CEC can be implanted alone, which has shown limited efficacy, or with a scaffold that holds the cells together as a monolayer tissue, thus imitating Descemet membrane endothelial keratoplasty. We believe that endothelial cell density (ECD) >2000 cells/mm2, a cut-off value that eye banks use to provide quality tissues for transplantation to surgeons, should also be adopted as a parameter to define the quality of CECs as a new Advanced Therapy Medicinal Product for clinical applications in patients with endothelial dystrophies. METHODS: We isolated and cultured CECs from one or more corneas of elderly age donors with ECDs higher than or below 2000 cells/mm2. CEC cultures were carried out on coated plates and on hydrogels with a preformed basement membrane (from TissueGUARD, Germany). Immunofluorescence with antibodies against ZO-1 was performed to evaluate the ECDs of the CEC graft obtained. RESULTS: Our results suggest that primary cultures with ECDs>2000 cells/mm2 can be obtained on coated plated only when (1) CECs are isolated from one or more corneas of young donors; (2) CECs are isolated and pooled together from at least 2 elderly age donor corneas (if ECD>2000 cells/mm2) or 3 elderly age donor corneas (if ECD<2000 cells/mm2). Secondary cultures are all characterized by low ECDs. Hydrogels have been shown to be able to lead to increased ECDs after their release. CONCLUSION: Our protocol highlights the difficulties in obtaining cultures with ECDs>2000 cells/mm2. Despite being achievable with corneas from young donors, this becomes challenging when corneas from elderly donors are used, i.e., the overall majority of those collected by eye banks, particularly when corneas from elderly age donors with ECD<2000 cells/mm2 are considered as a source. One alternative would be to isolate CECs from more corneas, but this might raise the issue of antigenic stimulation, which could eventually lead to transplantation failure. Our strategy to overcome these challenges is the use of a preformed basement membrane as a scaffold for CECs. However, this challenging approach should be investigated more before proceeding to clinical application.

DMEK surgical training: An instructional guide on various wet-lab methods.

Descemet membrane endothelial keratoplasty (DMEK) is a partial-thickness corneal transplantation procedure that involves selective transplantation of the Descemet membrane and endothelium. DMEK offers significant advantages over other keratoplasty techniques, such as faster visual rehabilitation, better final visual acuity due to minimal optical interface effects, lower risk of allograft rejection, and less long-term dependence on topical steroids. Despite all its advantages, DMEK has been found to be more challenging than other corneal transplantation techniques, and its steep learning curve appears to be an obstacle to its widespread use and adoption by corneal surgeons worldwide. DMEK surgical training laboratories (wet labs) provide a window of opportunity for surgeons to learn, prepare, manipulate, and deliver these grafts in a risk-free environment. Wet labs are a significant learning tool, especially for those institutions that have limited tissue availability in their local centers. We provide a step-by-step guide for preparing DMEK grafts using different techniques on human and nonhuman models with instructional videos. This article should eventually help the trainees and the educators understand the requirements for performing DMEK and conducting a DMEK wet lab and develop their skills and interests from a wide variety of available techniques.

Porcine Cornea Storage Ex Vivo Model as an Alternative to Human Donor Tissues for Investigations of Endothelial Layer Preservation.

Purpose: Due to the growing shortage of human corneas for research, we developed a porcine cornea storage model with qualitative features comparable to human tissues. Methods: We established a decontamination procedure for porcine eye bulbs to ensure corneal storage at 31°C to 35°C for up to 28 days without contamination. We compared human and porcine corneas under hypothermic (2-8°C) or culture (31-35°C) conditions for central corneal thickness (CCT), corneal transparency, endothelial morphology, endothelial cell density (ECD), and a novel method to quantify whole endothelial mortality. We also examined portions of lamellar tissues consisting of Descemet's membrane and endothelial cells under the microscope after Alizarin red staining. Results: Our decontamination procedure reduced corneal contamination from 94% (control corneas without decontamination) to 18% after 28 days of storage at 31°C to 35°C. ECD, CCT, transparency, and morphology were significantly higher in porcine corneas than in human corneas at day 0. Nevertheless, the qualitative parameters of porcine and human corneas showed comparable trends under both investigated storage conditions for up to 14 days. Conclusions: The presented corneal storage model provides a reliable alternative to human tissues for preliminary corneal investigations. Translational Relevance: The porcine cornea storage model can be used to investigate the efficacy and safety of new media, substances, or storage conditions. Furthermore, the method developed to assess the percentage of endothelial mortality is tissue conservative and can be used in eye banks to monitor endothelial mortality during storage of tissues intended for transplantation.

Denuded Descemet's membrane supports human embryonic stem cell-derived retinal pigment epithelial cell culture.

Recent clinical studies suggest that retinal pigment epithelial (RPE) cell replacement therapy may preserve vision in retinal degenerative diseases. Scaffold-based methods are being tested in ongoing clinical trials for delivering pluripotent-derived RPE cells to the back of the eye. The aim of this study was to investigate human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells survival and behaviour on a decellularized Descemet's Membrane (DM), which may be of clinical relevance in retinal transplantation. DMs were isolated from human donor corneas and treated with thermolysin. The DM surface topology and the efficiency of the denudation method were evaluated by atomic force microscope, scanning electron microscopy and histology. hESC-RPE cells were seeded onto the endothelial-side surface of decellularized DM in order to determine the potential of the membrane to support hESC-RPE cell culture, alongside maintaining their viability. Integrity of the hESC-RPE monolayer was assessed by measuring transepithelial resistance. RPE-specific gene expression and growth factors secretion were assessed to confirm maturation and functionality of the cells over the new substrate. Thermolysin treatment did not affect the integrity of the tissue, thus ensuring a reliable method to standardize the preparation of decellularized DM. 24 hours post-seeding, hESC-RPE cell attachment and initial proliferation rate over the denuded DM were higher than hESC-RPE cells cultured on tissue culture inserts. On the new matrix, hESC-RPE cells succeeded in forming an intact monolayer with mature tight junctions. The resulting cell culture showed characteristic RPE cell morphology and proper protein localization. Gene expression analysis and VEGF secretion demonstrate DM provides supportive scaffolding and inductive properties to enhance hESC-RPE cells maturation. Decellularized DM was shown to be capable of sustaining hESC-RPE cells culture, thus confirming to be potentially a suitable candidate for retinal cell therapy.

Effect of Low-Temperature Preservation in Optisol-GS on Preloaded, Endothelium-Out DMEK Grafts.

The aim of the study was to assess different temperature ranges for the preservation of pre-loaded Descemet Membrane Endothelial Keratoplasty (DMEK) grafts in the DMEK RAPID Mini device. METHODS: Three groups of 15 DMEK grafts (five per group) were pre-loaded in the DMEK RAPID Mini and preserved in Optisol-GS for 72 h at different temperatures: group A at >8 °C, group B between 2-8 °C and group C at <2 °C. After stripping and preservation, the viability of the endothelium, cell loss and morphology were assessed through light microscopy following trypan blue and alizarin red staining. RESULTS: Overall mortality was 4.07%, 3.97% and 7.66%, in groups A, B and C, respectively, with percentages of uncovered areas of 0.31%, 1.36% and 0.20% (all p > 0.05). Endothelial cell density variation was 5.51%, 3.06% and 2.82% in groups A, B and C, respectively (p = 0.19). Total Endothelial Cell Loss (ECL) was 4.37%, 5.32% and 7.84% in groups A, B and C, respectively (p = 0.39). Endothelial cell morphology was comparable in all three groups. CONCLUSIONS: In the DMEK RAPID Mini, low temperatures (<2 °C) may affect the quality of pre-loaded grafts, inducing a higher ECL after 72 h of preservation, although no significant differences among groups could be proved. Our data would suggest maintaining grafts loaded in the DMEK RAPID Mini at temperatures between 2-8 °C for appropriate preservation.

Effect of Liposomal-Lactoferrin-Based Eye Drops on the Conjunctival Microflora of Patients Undergoing Cataract Surgery.

INTRODUCTION: Postoperative endophthalmitis is typically caused by the patient's conjunctival bacterial flora. Povidone iodine solution (5%) is used perioperatively to obtain periocular and ocular antisepsis. However, an adjunctive prophylaxis procedure could further help control the conjunctival microbial load. Considering the increase in antibiotic resistance, a progressive shift toward alternative methods would be desirable. Somilux® eye drops (Alfa Intes, lactoferrin-based eye drops) are medical devices containing liposomal lactoferrin (LF). This study evaluates the effects on conjunctival microflora of LF-based eye drops used in the preoperative phase in patients scheduled for cataract surgery. METHODS: LF-based eye drops or a vehicle solution (water solution) were instilled 4 times a day starting 3 days before cataract surgery. Before the therapy (T0) and at the time of surgery (T1), a conjunctival swab was performed in both eyes and processed to detect microbial growth, microbiological isolation, and species identification. The outcome was the quantification and characterization of the local microbial flora before and after using LF-based or vehicle-based eye drops. Safety of the treatments was also evaluated. RESULTS: 88 eyes of 44 patients (mean [± SD] age 75 [± 12.6] years) were enrolled. At baseline, 54 conjunctival swabs showed only saprophytic flora, 27 showed only potential pathogenic flora, and seven showed both of them. LF-based eye drops reduced the proportion of potentially pathogenic bacteria (36% at T0 vs. 9% at T1, p = 0.008) compared with the vehicle (41% at T0 vs. 55% at T1, p = 0.302) without altering the physiological ocular microbial composition. No adverse events have been reported. CONCLUSION: Our findings provide a novel contribution to the scientific knowledge on the role of LF in the ophthalmic field, supporting the use of LF-based eye drops as a safe and selective treatment to improve the ocular surface physiological defenses and control the bacterial ocular surface contamination prior to cataract surgery.

Stromal peeling for deep anterior lamellar keratoplasty in a post-penetrating keratoplasty eye with hematocornea.

Purpose: To present a case of hematocornea occurring in a post-penetrating keratoplasty (PK) eye and to report the outcomes of deep anterior lamellar keratoplasty (DALK) performed by simple stromal peeling. Observations: A 45-year-old female presented with hematocornea in the left eye that previously underwent PK 26 months prior for keratoconus. Clinical examination revealed a dense reddish-brown opacity within the PK graft which was associated with deep corneal neovascularization. Over 6 months, intracorneal hemorrhage developed a rust-colored appearance with minimal clearing. DALK was performed using the stromal peeling technique for post-PK eyes. Briefly, a dense partially organized hemorrhage was identified at the natural plane of separation, as confirmed by ex vivo histologic examination; after peeling of the deep corneal stroma and evacuation of the intracorneal hemorrhage, the residual bed appeared akin to pre-Descemet's layer-Descemet membrane-endothelium complex. One year after DALK, the graft remained clear with ECD of 1034 cells/mm2. Conclusions and Importance: Intracorneal hemorrhage is a rare but potentially sight-threatening complication following PK. Using the stromal peeling technique, DALK can be attempted to preserve functional endothelium in post-PK eyes. In the presence of a dense intracorneal hemorrhage, the spread of erythrocytic debris within the stroma can guide deep lamellar cleavage.

Microscopic corneal epithelial changes and clinical outcomes in simple limbal epithelial transplantation surgery after treatment with amniotic membrane eye drops (AMED): A case report.

Purpose: To describe the microscopic epithelial changes and the clinical outcomes of a patient treated with amniotic membrane eye drops (AMED) because of a persistent epithelial defect (PED) and a partial limbal stem cell deficiency (LSCD) after simple limbal epithelial transplantation (SLET) and deep anterior lamellar keratoplasty (DALK). Observations: A 72-year-old patient, who had previously undergone SLET and DALK due to a total LSCD, presented with a PED related to a partial LSCD, and was treated with AMED for one month. We evaluated the patient's visual acuity, the Oxford grading scale, the Wong-Baker Pain Rating Scale, and in vivo confocal microscopy, both at baseline and 3 months after the end of treatment. Visual acuity improved from 0.5 to 0.4 LogMAR, the Oxford grading scale changed from grade III to grade I and the Wong-Baker Pain Rating Scale from grade 4 to grade 1. The corneal surface, which initially showed conjunctival characteristics over approximately 50% of the whole area, consisted mainly (75%) of mature corneal epithelium 3 months after the end of treatment. Conclusions and importance: While improving symptoms and clinical characteristics, AMED was also able to restore the normal corneal epithelium's morphology in a case of partial LSCD after SLET and DALK.

Results of ultrathin Descemet stripping automated endothelial keratoplasty with donor corneas preserved in synthetic organ culture media.

PURPOSE: To evaluate outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) with donor corneas preserved at 31°C in Cornea Syn®, a medium formulated with recombinant human serum albumin (rHSA) to replace foetal calf serum, and deswelled-transported in the xeno-free medium Cornea Trans®. METHODS: Prospective, multicentre, open-label study. We evaluated the endothelial cell loss (ECL) as the percentage variation of the endothelial cell density (ECD, cells/mm2) between 6 and 12 months after surgery, corneal transparency and thickness at 12 months, and adverse events within 12 months. Endothelial lenticules of mean 89 µm, ECD ≥ 2300 cells/mm2, minimum signs of cell mortality or morphology alterations, were dissected by microkeratome in the eye bank, and grafted in patients ≥ 18 years without corneal neovascularisation, conjunctivalization, or blinking impairment. RESULTS: Thirty-five patients underwent UT-DSAEK, 3 showed primary failure, 1 late failure, and 2 skipped the 6-month visit. We analysed data from 29 patients, 27 with Fuchs endothelial corneal dystrophy (FECD) and 2 with pseudophakic bullous keratopathy (PBK). The median ECL between 6 and 12 months was 2.6% (p = .054, CI 0 to 12.5) and the absolute mean (SD) was 158.4 (364.1) cells/mm2. After 12 months, 96.5% of corneas were clear, with mean pachymetry of 585.9 (50.4) µm. CONCLUSIONS: The ECL rate after UT-DSAEK match overall that observed in DSAEK or UT-DSAEK models of endothelial survival and the overall safety compared that reported for similar follow-up. Corneas maintained in Cornea Syn® and Cornea Trans® did not affect the ECD and functional outcomes of UT-DSAEK up to 12 months.