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Corneal endothelium cells (CECs) regulate corneal hydration between the leaky barrier of the corneal endothelium and the ionic pumps on the surface of CECs. As CECs do not regenerate, loss of CECs leads to poor vision and corneal blindness. Corneal transplant is the only treatment option; however, there is a severe shortage of donor corneas globally. Cell therapy using propagated primary human CECs is an alternative approach to corneal transplantations, and proof of functionality is crucial for validating such CECs. Expression markers like Na-K-ATPase and ZO-1 are typical but not specific to CECs. Assessing the barrier function of the expanded CECs via electrical resistance (i.e., TEER and Ussing's chamber) involves difficult techniques and is thus impractical for clinical application. Calcium has been demonstrated to affect the paracellular permeability of the corneal endothelium. Its absence alters morphology and disrupts apical junctions in bovine CECs, underscoring its importance. Calcium signaling patterns such as calcium waves affect the rate of wound healing in bovine CECs. Therefore, observing calcium waves in expanded CECs could provide valuable insights into their health and functional integrity. Mechanical or chemical stimulations, combined with Ca2+-sensitive fluorescent dyes and time-lapse imaging, can be used to visualize these waves, which could potentially be used to qualify expanded CECs. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate indications, clinic characteristics, and outcomes in a series of patients who underwent explantation of phakic intraocular lens (pIOL). Methods: Retrospective case series of patients who underwent iris-claw pIOL explantation in our institution from 2018 to 2022. Indications for explantation and visual and refractive outcomes were analyzed. Results: Twenty-three eyes of 14 patients underwent pIOL explantation with a mean time to explantation of 11.7 ± 3.4 years. The mean age at explantation was 46.0 ± 3.9 years. Sixteen Artisan and seven Artiflex IOL were explanted. The main indication for explantation was endothelial cell loss (n = 14) and morphometric significant alterations of endothelial cells other than endothelial cell count decline (n = 5). The mean corrected vision after explantation was 0.4 ± 0.4 logMAR, and around 70% of intervened patients achieved visual acuity of at least 0.3 logMAR (0.5 in decimal scale). Conclusions: In our group series, the main reason for the removal of pIOL was endothelial cell loss. This complication should be monitored and followed, so that early actions, namely IOL explantation, can be performed to avoid the development of deterioration requiring corneal transplantation. In fact, loss of follow-up, found in several cases for many years, continues to be a serious problem.

Abstract Fuchs endothelial corneal dystrophy is a heterogenous disease with multifactorial etiology, and genetic, epigenetic, and exogenous factors contributing to its pathogenesis. DNA damage plays a significant role, with ultraviolet-A (UV-A) emerging as a key contributing factor. We investigate the potential application of neuropeptide α-melanocyte stimulating hormone (α-MSH) in mitigating oxidative stress induced endothelial damage. First, we examined the effects of α-MSH on a cultured human corneal endothelial cell line (HCEnC-21T) exposed to hydrogen peroxide (H2O2) induced oxidative DNA damage. We performed immunofluorescence and flow cytometry to assess DNA damage and cell death in the cultured cells. Additionally, we used an established mouse model that utilizes ultraviolet light to induce corneal endothelial cell damage resulting in decreased CEnC number, increased cell size variability, and decreased percentage of hexagonal cells. This endothelial decompensation leads to an increase in corneal thickness. Following UV-A exposure, the mice were systemically treated with α-MSH, either immediately after exposure (early treatment) or beginning two weeks post-exposure (delayed treatment). To evaluate treatment efficacy, we analyzed CEnC density and morphology using in vivo confocal microscopy, and central corneal thickness using anterior segment optical coherence tomography. Our findings demonstrated that α-MSH treatment effectively protects HCEnC-21T from free-radical induced oxidative DNA damage and subsequent cell death. In vivo, α-MSH treatment, mitigated the loss of CEnC density, deterioration of cell morphology and suppression of the resultant corneal swelling. These results underline the potential application of α-MSH as a therapeutic agent for mitigating corneal endothelial damage.

Introduction: Complex corneal conditions present surgical challenges and necessitate innovation. Here, we present two cases where we performed intraocular lens trans-scleral fixation using the double-needle Yamane technique, followed by penetrating keratoplasty and vitrectomy using a temporary Landers wide-field keratoprosthesis. Case Presentation: Case 1 involved a 70-year-old man with an aphakic eye of bullous keratopathy and corneal opacity owing to multiple penetrating and endothelial keratoplasty, endophthalmitis, and herpetic keratitis. His visual acuity was counting fingers at 20 cm before surgery. Penetrating keratoplasty with vitrectomy and intraocular lens scleral fixation was performed using the double-needle Yamane technique, and 10 months postoperatively, his best-corrected visual acuity improved to 0.6, presenting a clear cornea. Case 2 involved a 62-year-old man who underwent penetrating keratoplasty twice for corneal perforation and therapeutic penetrating keratoplasty with vitrectomy for traumatic globe rupture, resulting in the loss of the intraocular lens. The patient exhibited graft failure, and his best-corrected visual acuity was 0.03. Utilizing a temporary Landers wide-field keratoprosthesis, we performed penetrating keratoplasty and intraocular lens trans-scleral fixation without complications. His final best-corrected visual acuity improved to 0.15 with a clear cornea. Conclusions: Trans-scleral fixation of intraocular lens with penetrating keratoplasty, using temporary Landers wide-field keratoprosthesis, yielded positive clinical outcomes without serious complications.

The corneal endothelium is responsible for pumping fluid out of the stroma in order to maintain corneal transparency, which depends in part on the expression and activity of sodium–potassium pumps. In this study, we evaluated how physiologic pressure and flow influence transcription, protein expression, and activity of Na+/K+-ATPase. Native and engineered corneal endothelia were cultured in a bioreactor in the presence of pressure and flow (hydrodynamic culture condition) or in a Petri dish (static culture condition). Transcription of ATP1A1 was assessed using qPCR, the expression of the α1 subunit of Na+/K+-ATPase was measured using Western blots and ELISA assays, and Na+/K+-ATPase activity was evaluated using an ATPase assay in the presence of ouabain. Results show that physiologic pressure and flow increase the transcription and the protein expression of Na+/K+-ATPase α1 in engineered corneal endothelia, while they remain stable in native corneal endothelia. Interestingly, the activity of Na+/K+-ATPase was increased in the presence of physiologic pressure and flow in both native and engineered corneal endothelia. These findings highlight the role of the in vivo environment on the functionality of the corneal endothelium. [ABSTRACT FROM AUTHOR]

Fuchs endothelial corneal dystrophy is a heterogenous disease with multifactorial etiology, and genetic, epigenetic, and exogenous factors contributing to its pathogenesis. DNA damage plays a significant role, with ultraviolet-A (UV-A) emerging as a key contributing factor. We investigate the potential application of neuropeptide α-melanocyte stimulating hormone (α-MSH) in mitigating oxidative stress induced endothelial damage. First, we examined the effects of α-MSH on a cultured human corneal endothelial cell line (HCEnC-21T) exposed to hydrogen peroxide (H2O2) induced oxidative DNA damage. We performed immunofluorescence and flow cytometry to assess DNA damage and cell death in the cultured cells. Additionally, we used an established mouse model that utilizes ultraviolet light to induce corneal endothelial cell damage resulting in decreased CEnC number, increased cell size variability, and decreased percentage of hexagonal cells. This endothelial decompensation leads to an increase in corneal thickness. Following UV-A exposure, the mice were systemically treated with α-MSH, either immediately after exposure (early treatment) or beginning two weeks post-exposure (delayed treatment). To evaluate treatment efficacy, we analyzed CEnC density and morphology using in vivo confocal microscopy, and central corneal thickness using anterior segment optical coherence tomography. Our findings demonstrated that α-MSH treatment effectively protects HCEnC-21T from free-radical induced oxidative DNA damage and subsequent cell death. In vivo, α-MSH treatment, mitigated the loss of CEnC density, deterioration of cell morphology and suppression of the resultant corneal swelling. These results underline the potential application of α-MSH as a therapeutic agent for mitigating corneal endothelial damage. [ABSTRACT FROM AUTHOR]

Descemet's Stripping Only (DSO) is a surgical technique that utilizes the peripheral corneal endothelial cell (CEnC) migration for wound closure. Ripasudil, a Rho-associated protein kinase (ROCK) inhibitor, has shown potential in DSO treatment; however, its mechanism in promoting CEnC migration remains unclear. We observed that ripasudil-treated immortalized normal and Fuchs endothelial corneal dystrophy (FECD) cells exhibited significantly enhanced migration and wound healing, particularly effective in FECD cells. Ripasudil upregulated mRNA expression of Snail Family Transcriptional Repressor (SNAI1/2) and Vimentin (VIM) while decreasing Cadherin (CDH1), indicating endothelial-to-mesenchymal transition (EMT) activation. Ripasudil activated Rac1, driving the actin-related protein complex (ARPC2) to the leading edge, facilitating enhanced migration. Ex vivo studies on cadaveric and FECD Descemet's membrane (DM) showed increased migration and proliferation of CEnCs after ripasudil treatment. An ex vivo DSO model demonstrated enhanced migration from the DM to the stroma with ripasudil. Coating small incision lenticule extraction (SMILE) tissues with an FNC coating mix and treating the cells in conjunction with ripasudil further improved migration and resulted in a monolayer formation, as detected by the ZO-1 junctional marker, thereby leading to the reduction in EMT. In conclusion, ripasudil effectively enhanced cellular migration, particularly in a novel ex vivo DSO model, when the stromal microenvironment was modulated. This suggests ripasudil as a promising adjuvant for DSO treatment, highlighting its potential clinical significance. [ABSTRACT FROM AUTHOR]

Purpose: To determine if smoking has an effect on corneal endothelium. Study Design: Descriptive observational. Place and Duration of Study: Lamar eye center in Kerbala city in Iraq during December, 2023 and January, 2024. Methods: A total of 108 eyes were selected, 54 eyes of smokers and 54 eyes of non-smokers. The smokers included in this study had history of smoking for more than twenty years and they smoke more than 40 cigarettes per day. All the participants were male. Specular microscopy was used to determine four corneal parameters; cell density, hexagonality, coefficient of variation and central corneal thickness. Results: Patients age ranged from 50 to 60 years. Central Corneal Thickness was 515.29±40.62 and 522.37±36.68 in smokers and non-smokers respectively with p=0.32. Coefficient of variation and, Cell Density and Hexagonal shape parameters were also not statistically different between the two groups (p>0.05). Conclusion: Smoking does not have a statistically significant effect on the corneal endothelium in terms of cell density, hexagonality, coefficient of variation, and central corneal thickness. However, more studies are needed to provide further evidence. [ABSTRACT FROM AUTHOR]

Background and Objectives: The purpose of this study was to compare two commercially available specular microscopes (Tomey EM-4000 and Nidek CEM-530) in a real-life clinical setting in terms of intra- and interdevice variability. The study was conducted on all patients seen in a clinical practice specializing in anterior segment pathologies, regardless of the purpose of their visit. Materials and Methods: In total, 112 eyes of 56 patients (age 23–85 years old) were included in the study. Each eye was measured three times with each device (for a total of six measurements), and results for central corneal thickness (CCT) and corneal endothelial cell density (ECD) were recorded. The results were then evaluated with the D'Agostino–Pearson normality test and compared with a Wilcoxon signed-rank test, t-test, ANOVA or Mann–Whitney test for intra- and interdevice variability. Results: Both specular microscopes produced very reliable reproducible intradevice results: The Tomey EM-4000 measured an ECD of 2390 ± 49.57 cells/mm2 (mean ± standard error of mean); the range was 799–3010 cells/mm2. The determined CCT was 546 ± 5.104 µm (mean ± standard error of mean [SEM]); the range was 425–615 µm. The measurements with the Nidek CEM-530 revealed an ECD of 2417 ± 0.09 cells/mm2 (mean ± SEM); the range was 505–3461 cells/mm2 (mean ± SEM). The mean CCT detected was 546.3 ± 4.937 µm (mean ± SEM); the range was 431–621 µm. The interdevice differences were statistically significant for both parameters, ECD (p = 0.0175) and CCT (p = 0.0125) (p < 0.05). Conclusions: The Nidek CEM-530 and the Tomey EM-4000 both produced reliable and reproducible results in terms of ECD and CCT. The absolute measurements were statistically significantly different for CCT and ECD for both devices; the Nidek produces slightly higher values. [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.

Introduction: Corneal graft detachment is a major postoperative complication of Descemet’s stripping automated endothelial keratoplasty (DSAEK). When a corneal graft becomes detached, corneal endothelial function generally fails, and repeat corneal transplantation is required. Herein, we report a rare case in which a transparent cornea was maintained after the removal of a dislocated DSAEK graft. Case Presentation: A 79-year-old woman with a residual lens cortex who had undergone cataract surgery was referred to our hospital. The cortex was removed, and bullous keratopathy progressed. Six months after the initial surgery, DSAEK was performed under topical anesthesia without any complications. Although the corneal graft had attached fairly well, it detached from the host cornea 3 weeks later. Two months after DSAEK, an air tamponade was used to treat the anterior chamber with single interrupted suturing; however, the graft detached again, except for the suture site. Because the detached cornea became cloudy in the anterior chamber, it was surgically removed 8 months after DSAEK. Accordingly, the host cornea transparency improved to a best-corrected visual acuity of 0.8 with a rigid gas permeable lens and a central corneal thickness of 580 μm. The corneal endothelial cell density was 995 cells/mm2. Conclusion: Removal of the corneal graft from the dislocated cloudy graft improved the visual acuity of this patient after DSAEK. The condition of the cornea should be carefully monitored after corneal endothelial transplantation, even after the graft has been dislocated.

Abstract Background Sleep deprivation (SD) is a common public health problem that contributes to various physiological disorders and increases the risk of ocular diseases. However, whether sleep loss can damage corneal endothelial function remains unclear. This study aimed to determine the effect and possible mechanism of SD on the corneal endothelium. Methods Male C57BL/6J mice were subjected to establish SD models. After 10 days, quantitative RT-PCR (qRT-PCR) and western blot or immunostaining for the expression levels of zonula occludens-1 (ZO-1), ATPase Na+/K + transporting subunit alpha 1 (Atp1a1), and core clock genes in the corneal endothelium were evaluated. Reactive oxygen species staining and mitochondrial abundance characterized the mitochondrial function. The regulatory role of Bmal1 was confirmed by specifically knocking down or overexpressing basic helix-loop-helix ARNT like 1 protein (Bmal1) in vivo. In vitro, a mitochondrial stress test was conducted on cultured human corneal endothelial cells upon Bmal1 knockdown. Results SD damaged the barrier and pump functions of mouse corneal endothelium, accompanied by mitochondrial dysfunction. Interestingly, SD dramatically downregulated the core clock gene Bmal1 expression level. Bmal1 knockdown disrupted corneal endothelial function, while overexpression of Bmal1 ameliorated the dysfunction induced by SD. Mitochondrial bioenergetic deficiency mediated by Bmal1 was an underlying mechanism for SD induced corneal endothelial dysfunction. Conclusion The downregulation of Bmal1 expression caused by SD led to corneal endothelial dysfunction via impairing mitochondrial bioenergetics. Our findings offered insight into how SD impairs the physiological function of the corneal endothelium and expanded the understanding of sleep loss leading to ocular diseases.

AIM: To study the effect of mitomycin C (MMC) applied during transepithelial photorefractive keratectomy (TPRK) on the corneal endothelium one week (W1) and three months (M3) after surgery and its determinants. METHODS: In this two-armed cohort study conducted in 2022, eyes treated with MMC during TPRK (group 1) were compared with eyes not treated with MMC (group 2). The corneal endothelial cell (EC) count, EC density (ECD; cells/mm2), average (μm2), standard deviation (μm2), coefficient of variation (CV%), ECmax, ECmin, and EC percentage of hexagonality were estimated at W1 and M3. The postoperative changes in the EC count in the two groups were compared and correlated with the other independent variables. RESULTS: Group 1 had 26 eyes, and group 2 had 78 eyes. All TPRK indices were significantly higher for the eyes in group 1 than for those in group 2. The MMC usage was not a significant predictor of the change in ECD (P=0.644), change in CV (P=0.374), and change in the percentage of hexagonality of EC (P=0.164) at W1. However, the use of MMC was a significant predictor of changes in CV (P=0.014) and the change in the percentage of hexagonality of EC (P=0.039) at M3. The duration of laser exposure and the size of the optical zone influenced the correlation of MMC use with the changes in EC indices, postoperatively. CONCLUSION: The use of MMC doesn't affect ECD, CV, and percentage of hexagonality at W1 if other surgical indices are considered. At M3 after operating myopic eyes by TPRK, MMC significantly influence the CV and percentage of hexagonality. The duration of the laser application and the size of the optical zone should be considered when determining the effect of MMC on the EC indices.

Introduction: Corneal graft detachment is a major postoperative complication of Descemet’s stripping automated endothelial keratoplasty (DSAEK). When a corneal graft becomes detached, corneal endothelial function generally fails, and repeat corneal transplantation is required. Herein, we report a rare case in which a transparent cornea was maintained after the removal of a dislocated DSAEK graft. Case Presentation: A 79-year-old woman with a residual lens cortex who had undergone cataract surgery was referred to our hospital. The cortex was removed, and bullous keratopathy progressed. Six months after the initial surgery, DSAEK was performed under topical anesthesia without any complications. Although the corneal graft had attached fairly well, it detached from the host cornea 3 weeks later. Two months after DSAEK, an air tamponade was used to treat the anterior chamber with single interrupted suturing; however, the graft detached again, except for the suture site. Because the detached cornea became cloudy in the anterior chamber, it was surgically removed 8 months after DSAEK. Accordingly, the host cornea transparency improved to a best-corrected visual acuity of 0.8 with a rigid gas permeable lens and a central corneal thickness of 580 μm. The corneal endothelial cell density was 995 cells/mm2. Conclusion: Removal of the corneal graft from the dislocated cloudy graft improved the visual acuity of this patient after DSAEK. The condition of the cornea should be carefully monitored after corneal endothelial transplantation, even after the graft has been dislocated. [ABSTRACT FROM AUTHOR]

Background: Sleep deprivation (SD) is a common public health problem that contributes to various physiological disorders and increases the risk of ocular diseases. However, whether sleep loss can damage corneal endothelial function remains unclear. This study aimed to determine the effect and possible mechanism of SD on the corneal endothelium. Methods: Male C57BL/6J mice were subjected to establish SD models. After 10 days, quantitative RT-PCR (qRT-PCR) and western blot or immunostaining for the expression levels of zonula occludens-1 (ZO-1), ATPase Na+/K + transporting subunit alpha 1 (Atp1a1), and core clock genes in the corneal endothelium were evaluated. Reactive oxygen species staining and mitochondrial abundance characterized the mitochondrial function. The regulatory role of Bmal1 was confirmed by specifically knocking down or overexpressing basic helix-loop-helix ARNT like 1 protein (Bmal1) in vivo. In vitro, a mitochondrial stress test was conducted on cultured human corneal endothelial cells upon Bmal1 knockdown. Results: SD damaged the barrier and pump functions of mouse corneal endothelium, accompanied by mitochondrial dysfunction. Interestingly, SD dramatically downregulated the core clock gene Bmal1 expression level. Bmal1 knockdown disrupted corneal endothelial function, while overexpression of Bmal1 ameliorated the dysfunction induced by SD. Mitochondrial bioenergetic deficiency mediated by Bmal1 was an underlying mechanism for SD induced corneal endothelial dysfunction. Conclusion: The downregulation of Bmal1 expression caused by SD led to corneal endothelial dysfunction via impairing mitochondrial bioenergetics. Our findings offered insight into how SD impairs the physiological function of the corneal endothelium and expanded the understanding of sleep loss leading to ocular diseases. [ABSTRACT FROM AUTHOR]

Among the different layers of the cornea, the corneal endothelium, which is composed of corneal endothelial cells (CEC), plays a key role in the maintenance of cornea transparency. Based on the donor shortages and the limitations associated with transplantation, in this work we have developed collagen hydrogels with different patterned structures on the surface to provide topographies in ranges similar to the natural environment that CEC sense. This aimed at stimulating cells to maintain a typical CEC phenotype and provide alternatives to corneal transplantation. In this sense, we have elaborated curved collagen hydrogels (concave and convex) with three different topographies (50, 200 and 300 µm grooves), with the help of 3D printed mold and replicating the mold with the collagen hydrogel, onto which CEC were cultured in order to analyze its behavior. Flat hydrogels were used as controls. Cell morphology, cell circularity and gene expression of ATP1A1 and ZO-1 genes were analyzed after 3 and 6 days. Results showed an effect of the curvature and the topography compared to flat collagen hydrogels, showing higher expression of ZO-1 and ATP1A1 in curved non-patterned hydrogels at day 3. The patterned hydrogels did not have such a significant effect on gene expression compared to flat hydrogels, showing stronger effect of the curvature compared to the topography. The effect was opposite at day 6, showing higher gene expression at days 6 on the patterned hydrogels, especially for the ZO-1 gene. The gene expression results were in accordance with the cell morphology observed at the different time points, showing circularities closer to hexagon like morphology at shorter time points. Overall, this platform can serve as a system to culture cell under proper environment to further be able to transplant a CEC monolayer or to allow transplantation of thin collagen layers with cultured CEC.

Background/aimsCorneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL).MethodsPilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions.ResultsThirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p = 0.02, and 44% vs. 33%, p = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points (p = 0.03 and p = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month (p = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group (p

PURPOSE: The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss. MATERIALS AND METHODS: This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified. RESULTS: This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery. CONCLUSION: The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information.

Background Loss of endothelial cells is inevitable after cataract surgery. Therefore, it is critical to protect the corneal endothelium during cataract surgery to reach good visual outcomes afterward. Maintenance of corneal clarity depends on the good function of healthy endothelial cells in addition to an intact pumping system intended to remove fluid from the corneal stoma. Purpose Our study aimed to assess changes in the corneal endothelium using specular microscopy, after intracameral injection of ceftazidime in uncomplicated phacoemulsification and compared with a placebo. The changes were measured preoperatively and 1 month postoperatively. Patients and methods Our prospective cohort study comprised 40 eyes from 35 patients diagnosed with cataract, all of whom underwent uncomplicated phacoemulsification for cataract extraction. Results Endothelial cell density significantly decreased postoperatively compared with preoperative values in both groups. Central thickness of the cornea, coefficient of variation, and visual acuity significantly increased postoperatively compared to preoperative values in both groups. Endothelial cell density showed a significant decrease postoperatively with a P value equal to 0.01 for group A (placebo group) and 0.02 for group B (ceftazidime group). Central thickness of the cornea, coefficient of variation, and visual acuity showed significant increases postoperatively with a P value equal to 0.026, 0.005, and 0.001 for group A and 0.001, 0.034, and 0.001 for group B, respectively. Conclusion Ceftazidime can be considered safe for corneal endothelium when used intracamerally during phacoemulsification cataract surgery for prophylaxis of postoperative endophthalmitis.

Corneal endothelium cells (CECs) regulate corneal hydration between the leaky barrier of the corneal endothelium and the ionic pumps on the surface of CECs. As CECs do not regenerate, loss of CECs leads to poor vision and corneal blindness. Corneal transplant is the only treatment option; however, there is a severe shortage of donor corneas globally. Cell therapy using propagated primary human CECs is an alternative approach to corneal transplantations, and proof of functionality is crucial for validating such CECs. Expression markers like Na-K-ATPase and ZO-1 are typical but not specific to CECs. Assessing the barrier function of the expanded CECs via electrical resistance (i.e., TEER and Ussing’s chamber) involves difficult techniques and is thus impractical for clinical application. Calcium has been demonstrated to affect the paracellular permeability of the corneal endothelium. Its absence alters morphology and disrupts apical junctions in bovine CECs, underscoring its importance. Calcium signaling patterns such as calcium waves affect the rate of wound healing in bovine CECs. Therefore, observing calcium waves in expanded CECs could provide valuable insights into their health and functional integrity. Mechanical or chemical stimulations, combined with Ca2+-sensitive fluorescent dyes and time-lapse imaging, can be used to visualize these waves, which could potentially be used to qualify expanded CECs.

PurposeThe purpose of this study was to evaluate the tolerability and efficacy of topical rho-kinase inhibitor ripasudil in the treatment of primary corneal endothelial degeneration (PCED) in dogs.MethodsTwenty-one eyes of 12 client-owned, PCED-affected dogs received topical ripasudil 4 times daily. Ophthalmic examination, ultrasonic pachymetry (USP), Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal microscopy were performed at baseline and 1, 3, 6, and 12 months. Effects of treatment on corneal thickness, corneal edema extent, and endothelial cell density (ECD) were evaluated by repeated-measures ANOVA or Friedman test. Individual eyes were classified as improved, progressed, or stable at 12 months using clinical response criteria. Kaplan-Meier curves and log-rank test were used to compare ripasudil-treated eyes to age-, breed/size-, and disease stage-matched historical controls.ResultsDuring treatment, 12 dogs developed conjunctival hyperemia, 4 demonstrated reticular bullous epithelial edema, and 2 developed corneal stromal hemorrhage. No adverse event necessitated permanent cessation of ripasudil. Central corneal thickness measured by USP significantly progressed from baseline to 12 months. Corneal thickness by FD-OCT, ECD, and edema extent did not differ over time. Considered individually, 5 eyes improved, 8 remained stable, and 8 progressed. The log-rank test found less edema progression in ripasudil-treated eyes compared to historical controls.ConclusionsRipasudil was well-tolerated in PCED-affected dogs. Response to therapy varied; 62% of eyes showed improved or stable disease whereas 38% progressed. Ripasudil-treated eyes progressed more slowly than historical controls.Translational relevanceTopical ripasudil offered a therapeutic benefit in a subset of patients using a canine model of endothelial degeneration, which may guide future trials in humans.

Background: The aim of this review was to investigate the influence of various laser refractive surgery methods on the corneal endothelium in myopic patients. The role of the corneal endothelium in laser refractive surgery (LRS) is currently being addressed in the assessment of postoperative corneal edema risk. Methods: Changes in corneal endothelial cell density and morphology after LRS were evaluated based on a systematic review of current studies. The results of a literature search in the PubMed, Science Direct, Google Scholar, and the Web of Science databases, as well as a manual search, were selected for the final review according to the PRISMA 2020 flow diagram. Results: We included 24 prospective clinical trials in the review: surface ablation (twelve), LASIK and FemtoLASIK (two), femtosecond lenticule extraction (two), and comparable studies (eight). Endothelial cell density was determined by specular or in vivo confocal microscopy. In most studies, no statistically significant differences were found between preoperative and postoperative endothelial parameters. In nine studies, the changes were statistically significant, but no vision-threatening complications occurred, and no serious corneal complications developed in any eyes during the follow-up period. Conclusions: Based on collected data, laser keratorefractive surgery appears not to exert a significant effect on the corneal endothelium. [ABSTRACT FROM AUTHOR]

Background: Traumatic injuries in eyes previously treated with Deep Anterior Lamellar Keratoplasty (DALK) can lead to ruptures in the Descemet Membrane (DM) and damage to the corneal endothelium, a crucial layer for maintaining corneal clarity. Due to cell cycle constraints, the human corneal endothelium cannot proliferate; instead, it compensates for injury through cell enlargement and migration from adjacent areas. Methods: This study examines a notable case of corneal endothelial cell migration following a penetrating eye injury in a patient previously treated with DALK for keratoconus, supplemented by a review of relevant literature to contextualize the regenerative response. Results: A 39-year-old male with a history of DALK suffered a traumatic eye injury, resulting in damage to the Descemet Membrane and loss of the crystalline lens. After primary repair and considerations for further surgery, the patient's cornea cleared remarkably, with an improved visual acuity. This demonstrates the DM's potential for self-repair through endothelial cell migration. Conclusions: The outcomes suggest that delaying corneal transplant surgery for up to 3 months following Descemet Membrane injury due to ocular trauma could be advantageous. Allowing time for natural healing processes might eliminate the need for further invasive surgeries, thereby improving patient recovery outcomes. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to compare early clinical results regarding the safety and efficacy of dual-linear vs. conventional foot-pedal control in cataract surgery. Methods: This was a paired-eye contralateral, retrospective, observational study. Each patient underwent cataract surgery in both eyes: one eye with dual-linear foot-pedal control (study group) and the other eye with conventional foot-pedal control (control group). Absolute phaco time (APT), average phaco power, effective phaco time (EPT), and surgical complications were analyzed and compared. Corneal endothelial cell count, corneal thickness, corneal volume, and best-corrected distance visual acuity (BCDVA) were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively. Results: A total of 94 patients (188 eyes) were enrolled. The respective APT, average phaco power, and EPT values were 7.05 ± 5.31 s, 28.4 ± 1.00, and 2.05 ± 1.56 s in the study group and 6.82 ± 6.48 s, 18.9 ± 1.74, and 1.35 ± 1.35 s in the control group. Conclusions: The average phaco power and EPT values were significantly higher in the study group. The safety of the dual-linear foot pedal was comparable to that of a conventional pedal in terms of endothelial cell loss, central corneal thickness, and surgical complications. [ABSTRACT FROM AUTHOR]

Macular corneal dystrophy (MCD) is a progressive, bilateral stromal dystrophic disease that arises from mutations in carbohydrate sulfotransferase 6 (CHST6). Corneal transplantation is the ultimate therapeutic solution for MCD patients. Unfortunately, postoperative recurrence remains a significant challenge. We conducted a retrospective review of a clinical cohort comprising 102 MCD patients with 124 eyes that underwent either penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK). Our results revealed that the recurrence rate was nearly three times higher in the DALK group (39.13%, 9/23 eyes) compared with the PKP group (10.89%, 11/101 eyes), suggesting that surgical replacement of the corneal endothelium for treating MCD is advisable to prevent postoperative recurrence. Our experimental data confirmed the robust mRNA and protein expression of CHST6 in human corneal endothelium and the rodent homolog CHST5 in mouse endothelium. Selective knockdown of wild-type Chst5 in mouse corneal endothelium (ACsiChst5), but not in the corneal stroma, induced experimental MCD with similar extracellular matrix synthesis impairments and corneal thinning as observed in MCD patients. Mice carrying Chst5 point mutation also recapitulated clinical phenotypes of MCD, along with corneal endothelial abnormalities. Intracameral injection of wild-type Chst5 rescued the corneal impairments in ACsiChst5 mice and retarded the disease progression in Chst5 mutant mice. Overall, our study provides new mechanistic insights and therapeutic approaches for MCD treatment by high-lighting the role of corneal endothelium in MCD development. [ABSTRACT FROM AUTHOR]

Background Loss of endothelial cells is inevitable after cataract surgery. Therefore, it is critical to protect the corneal endothelium during cataract surgery to reach good visual outcomes afterward. Maintenance of corneal clarity depends on the good function of healthy endothelial cells in addition to an intact pumping system intended to remove fluid from the corneal stoma. Purpose Our study aimed to assess changes in the corneal endothelium using specular microscopy, after intracameral injection of ceftazidime in uncomplicated phacoemulsification and compared with a placebo. The changes were measured preoperatively and 1 month postoperatively. Patients and methods Our prospective cohort study comprised 40 eyes from 35 patients diagnosed with cataract, all of whom underwent uncomplicated phacoemulsification for cataract extraction. Results Endothelial cell density significantly decreased postoperatively compared with preoperative values in both groups. Central thickness of the cornea, coefficient of variation, and visual acuity significantly increased postoperatively compared to preoperative values in both groups. Endothelial cell density showed a significant decrease postoperatively with a P value equal to 0.01 for group A (placebo group) and 0.02 for group B (ceftazidime group). Central thickness of the cornea, coefficient of variation, and visual acuity showed significant increases postoperatively with a P value equal to 0.026, 0.005, and 0.001 for group A and 0.001, 0.034, and 0.001 for group B, respectively. Conclusion Ceftazidime can be considered safe for corneal endothelium when used intracamerally during phacoemulsification cataract surgery for prophylaxis of postoperative endophthalmitis. [ABSTRACT FROM AUTHOR]

PURPOSE: The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss. MATERIALS AND METHODS: This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified. RESULTS: This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery. CONCLUSION: The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus [DM] is a systemic metabolic disease. It is characterized by increase blood glucose level over a prolonged period of time. Diabetes is due to either the pancreas is not producing enough insulin, or the cells of the body are not responding properly to the insulin produced.The Aim of the work: To measure the effect of diabetes type-II on corneal endothelial cells using specular microscopy versus normal individuals.Patients and Methods: This is a case-control study including 96-eye of 48-diabetic patients’ type-II from those attending the outpatient clinics of memorial institute of ophthalmology and Helwan University.Results: The results of the current study revealed that the diabetes mellitus may have some adverse effects on corneal endothelial cell parameters. We have found that Specular microscopy is the only investigative tool that measures all corneal endothelial parameters together [CCT, CD, CV, HEX].Conclusion: The current study revealed that diabetes mellitus may have an adverse effect on different corneal endothelial cell parameters especially on cell density.

AIM: To investigate the effects of small incision extracapsular excision and phacoemulsification on the number of corneal endothelial cells, macular thickness and surgically induced corneal astigmatism in cataract patients.METHODS: Retrospective research. A total of 296 age-related cataract patients(296 eyes)admitted to our hospital from May 2019 to February 2023 were selected. They were divided into a small incision extracapsular excision group(144 eyes)and a phacoemulsification group(152 eyes)according to surgical method. The uncorrected visual acuity, best corrected visual acuity, numbers of corneal endothelial cells, macular thickness, surgically induced corneal astigmatism and postoperative complications between the two groups of patients at 7d, 1 and 3mo after surgery were compared.RESULTS: The uncorrected visual acuity and best corrected visual acuity of patients in the small incision extracapsular excision group after 7d of surgery were better than those of the phacoemulsification group, the number of corneal endothelial cells after 7d and 1, 3mo of surgery were higher than that of the phacoemulsification group, the macular thickness after 7d and 1mo of surgery was lower than that of the phacoemulsification group, and the incidence rate of postoperative corneal edema and incidence rate of total complications were lower than those of the phacoemulsification group(all P0.05).CONCLUSION: Compared with phacoemulsification, the changes in the number of corneal endothelial cells and thickness of the macular area after small incision extracapsular excision are relatively small, visual recovery is faster, and the complications reduced.

Background and Objectives: The purpose of this study was to compare two commercially available specular microscopes (Tomey EM-4000 and Nidek CEM-530) in a real-life clinical setting in terms of intra- and interdevice variability. The study was conducted on all patients seen in a clinical practice specializing in anterior segment pathologies, regardless of the purpose of their visit. Materials and Methods: In total, 112 eyes of 56 patients (age 23–85 years old) were included in the study. Each eye was measured three times with each device (for a total of six measurements), and results for central corneal thickness (CCT) and corneal endothelial cell density (ECD) were recorded. The results were then evaluated with the D’Agostino–Pearson normality test and compared with a Wilcoxon signed-rank test, t-test, ANOVA or Mann–Whitney test for intra- and interdevice variability. Results: Both specular microscopes produced very reliable reproducible intradevice results: The Tomey EM-4000 measured an ECD of 2390 ± 49.57 cells/mm2 (mean ± standard error of mean); the range was 799–3010 cells/mm2. The determined CCT was 546 ± 5.104 µm (mean ± standard error of mean [SEM]); the range was 425–615 µm. The measurements with the Nidek CEM-530 revealed an ECD of 2417 ± 0.09 cells/mm2 (mean ± SEM); the range was 505–3461 cells/mm2 (mean ± SEM). The mean CCT detected was 546.3 ± 4.937 µm (mean ± SEM); the range was 431–621 µm. The interdevice differences were statistically significant for both parameters, ECD (p = 0.0175) and CCT (p = 0.0125) (p < 0.05). Conclusions: The Nidek CEM-530 and the Tomey EM-4000 both produced reliable and reproducible results in terms of ECD and CCT. The absolute measurements were statistically significantly different for CCT and ECD for both devices; the Nidek produces slightly higher values.

Descemet’s Stripping Only (DSO) is a surgical technique that utilizes the peripheral corneal endothelial cell (CEnC) migration for wound closure. Ripasudil, a Rho-associated protein kinase (ROCK) inhibitor, has shown potential in DSO treatment; however, its mechanism in promoting CEnC migration remains unclear. We observed that ripasudil-treated immortalized normal and Fuchs endothelial corneal dystrophy (FECD) cells exhibited significantly enhanced migration and wound healing, particularly effective in FECD cells. Ripasudil upregulated mRNA expression of Snail Family Transcriptional Repressor (SNAI1/2) and Vimentin (VIM) while decreasing Cadherin (CDH1), indicating endothelial-to-mesenchymal transition (EMT) activation. Ripasudil activated Rac1, driving the actin-related protein complex (ARPC2) to the leading edge, facilitating enhanced migration. Ex vivo studies on cadaveric and FECD Descemet’s membrane (DM) showed increased migration and proliferation of CEnCs after ripasudil treatment. An ex vivo DSO model demonstrated enhanced migration from the DM to the stroma with ripasudil. Coating small incision lenticule extraction (SMILE) tissues with an FNC coating mix and treating the cells in conjunction with ripasudil further improved migration and resulted in a monolayer formation, as detected by the ZO-1 junctional marker, thereby leading to the reduction in EMT. In conclusion, ripasudil effectively enhanced cellular migration, particularly in a novel ex vivo DSO model, when the stromal microenvironment was modulated. This suggests ripasudil as a promising adjuvant for DSO treatment, highlighting its potential clinical significance.

Abstract Objective Stem cell therapy is a promising strategy for the treatment of corneal endothelial dysfunction, and the need to find functional alternative seed cells of corneal endothelial cells (CECs) is urgent. Here, we determined the feasibility of using the retinal pigment epithelium (RPE) as an equivalent substitute for the treatment of corneal endothelial dysfunction. Methods RPE cells and CECs in situ were obtained from healthy New Zealand male rabbits, and the similarities and differences between them were analyzed by electron microscopy, immunofluorescent staining, and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Rabbit primary RPE cells and CECs were isolated and cultivated ex vivo, and Na+/K+-ATPase activity and cellular permeability were detected at passage 2. The injection of cultivated rabbit primary RPE cells, CECs and human embryonic stem cell (hESC)-derived RPE cells was performed on rabbits with corneal endothelial dysfunction. Then, the therapeutic effects were evaluated by corneal transparency, central corneal thickness, enzyme linked immunosorbent assay (ELISA), qRT-PCR and immunofluorescent staining. Results The rabbit RPE cells were similar in form to CECs in situ and ex vivo, showing a larger regular hexagonal shape and a lower cell density, with numerous tightly formed cell junctions and hemidesmosomes. Moreover, RPE cells presented a stronger barrier and ionic pumping capacity than CECs. When intracamerally injected into the rabbits, the transplanted primary RPE cells could dissolve corneal edema and decrease corneal thickness, with effects similar to those of CECs. In addition, the transplantation of hESC-derived RPE cells exhibited a similar therapeutic effect and restored corneal transparency and thickness within seven days. qRT-PCR results showed that the expressions of CEC markers, like CD200 and S100A4, increased, and the RPE markers OTX2, BEST1 and MITF significantly decreased in the transplanted RPE cells. Furthermore, we have demonstrated that rabbits transplanted with hESC-derived RPE cells maintained normal corneal thickness and exhibited slight pigmentation in the central cornea one month after surgery. Immunostaining results showed that the HuNu-positive transplanted cells survived and expressed ZO1, ATP1A1 and MITF. Conclusion RPE cells and CECs showed high structural and functional similarities in barrier and pump characteristics. Intracameral injection of primary RPE cells and hESC-derived RPE cells can effectively restore rabbit corneal clarity and thickness and maintain normal corneal function. This study is the first to report the effectiveness of RPE cells for corneal endothelial dysfunction, suggesting the feasibility of hESC-derived RPE cells as an equivalent substitute for CECs.

Purpose: To investigate subclinical corneal changes using corneal topography in the evaluation of corneal curvature and specular microscopy in the evaluation of the endothelial layer after mild coronavirus disease 2019 (COVID-19). Methods: In this prospective study, 112 eyes of 56 individuals with mild COVID-19 who recovered were investigated. Mean cell density (CD), mean coefficient of variation (CV), mean percentage of hexagonal cells, mean cell area (AVG), and central corneal thickness (CCT) were recorded from specular microscopy. K readings, including simulated keratometry flat (K1), simulated keratometry steep (K2), average keratometry (Kmean) and maximum keratometry (Kmax), pachymetric measurement and central corneal thickness (CCT), corneal volume (CV), topographic astigmatism (TA), curvature asymmetry front (CAf) and curvature asymmetry back (CAb) were recorded from corneal topography. Best corrected visual acuity (BCVA), spherical equivalant and biometric measurements were recorded. Results: The mean time interval between examinations before and after COVID-19 infection was approximately one year. Analysis of specular microscopy data showed a statistically significant change in all endothelial cell parameters (p

Progressive corneal endothelial disease eventually leads to corneal edema and vision loss due to the limited regenerative capacity of the corneal endothelium in vivo and is a major indication for corneal transplantation. Despite the relatively high success rate of corneal transplantation, there remains a pressing global clinical need to identify improved therapeutic strategies to address this debilitating condition. To evaluate the safety and efficacy of novel therapeutics, there is a growing demand for pre-clinical animal models of corneal endothelial dysfunction. In this review, experimentally induced, spontaneously occurring and genetically modified animal models of corneal endothelial dysfunction are described to assist researchers in making informed decisions regarding the selection of the most appropriate animal models to meet their research goals.

PurposeTo retrospectively evaluate the clinical data, diagnostic tests, treatments, and outcomes for dogs with corneal endothelial dystrophy (CED) and determine risk factors for CED when compared with a canine reference population.MethodsMedical records of 99 dogs (1991-2014) diagnosed with CED at the University of California Davis Veterinary Medical Teaching Hospital were reviewed and compared with 458,680 dogs comprising the general hospital population during the study period. Retrieved data included signalment, examination findings, diagnoses, treatments, and outcomes associated with CED. The exact Pearson χ2 test or exact Kruskal-Wallis test was used to compare parameters between the groups. Progression of corneal edema was assessed using 3 independent Kaplan-Meier curves, identifying clinically significant changes in corneal opacity.ResultsBoston terriers, German wirehaired pointers, and Dachshunds were overrepresented in the CED-affected group, whereas Labradors were underrepresented. Dogs older than 11 years were overrepresented in the CED-affected group, whereas intact dogs were underrepresented. Surgical intervention was performed (n = 11) based on the severity of disease and secondary complications from CED. Median time to progression of corneal edema was 1) 368 days when an at-risk eye initially without edema developed edema at a subsequent visit, 2) 701 days when there was progression from mild to marked corneal edema, and 3) 340 days when there was progression from focal to diffuse corneal edema.ConclusionsMany CED-affected dogs progress over months to years without surgical intervention, making dogs with CED a useful model for studying genetic predispositions and development of novel therapeutics for Fuchs endothelial corneal dystrophy.

Mark C Vital,1 Kevin Y Jong,1 Clarise E Trinh,1 Tomy Starck,2 David Sretavan3 1Houston Eye Associates, Houston, TX, USA; 2UltraVision, San Antonio, TX, USA; 3Centricity Vision Inc., Carlsbad, CA, USACorrespondence: Mark C Vital, Houston Eye Associates, 2855 Gramercy Street, Houston, TX, 77025, USA, Tel +1 713 668 6828, Fax +1 832 553-7154, Email MVital@HoustonEye.comPurpose: To compare endothelial cell density (ECD), percentage of hexagonal cells (%Hex) and coefficient of variation (CV) in cell size following lens cataract surgery with phacoemulsification performed using Continuous Curvilinear Capsulorhexis (CCC) or Precision Pulse Capsulotomy (PPC).Patients and Methods: Sixty-seven subjects were randomly assigned to undergo lens cataract removal with the capsulotomy step performed using either CCC or PPC. Specular microscopy images were obtained pre-operatively, 1 month and 3 months after surgery. ECD, %Hex and CV were analyzed in a masked fashion by an independent reading center.Results: The mean percentage ECD loss at 1 month was 11.5% in the CCC group and 12.3% in the PPC group (P = 0.818; t-test). At 3 months, the mean percentage ECD loss was 11.7% in the CCC group and 12.4% in the PPC group (P = 0.815; t-test). The mean %Hex at 1 month was 54.3% in the CCC group and 54.7% in the PPC group (P = 0.695; t-test). At 3 months, the mean %Hex was 56.2% in the CCC group and 54.7% in the PPC group (P = 0.278; t-test). The CV at 1 month was 34.4% in the CCC group and 34.3% in the PPC group (P = 0.927; t-test). At 3 months, the CV was 32.7% in the CCC group and 33.4% in the PPC group (P = 0.864; t-test).Conclusion: No differences in ECD loss, %Hex and CV were observed between patients who received CCC or PPC. PPC use during cataract surgery does not result in any increased endothelial cell loss beyond that normally associated with this surgery.Keywords: automated capsulotomy, zepto, corneal endothelium

Abstract Background To accurately measure ultrathin Descemet stripping automated endothelial keratoplasty (DSAEK) donor lamella thickness during the first postoperative year and to correlate this with pre-operative and other postoperative measurements. Methods Donor lamella thickness in 41 eyes undergoing DSAEK for Fuchs endothelial dystrophy (FED) was measured using the Tomey Casia OCT directly after graft preparation and at 1 week and 1, 3, 6 and 12 months postoperatively. Visual acuity and endothelial cell density were measured as the secondary parameters. Results Individual graft thickness profiles were shown to be fairly regular within the optically relevant area. There was a strong and highly significant correlation between the pre- and postoperative lamellar thicknesses at all time points (p

Abstract Background Cataract surgery induces corneal endothelial cell loss (ECL). This study investigates the relationship between bottle height (BH) and ECL induced due to irrigation and aspiration (I/A) in cataract surgery and quantifies protective effects of intraoperatively used ophthalmic viscoelastic substances. Methods Intermittent I/A without phacoemulsification was performed in porcine eyes for 10 min with varying BHs of 100 cm (BH100), 125 cm (BH125), 150 cm (BH150) or no treatment (control, no I/A). Additionally, in one group a dispersive ophthalmic viscoelastic substance was injected into the anterior eye chamber before treatment with I/A at a BH of 150 cm (BH150 + V). After exposure of the corneal endothelium to I/A, the corneas were prepared to split corneal buttons on day 0 and cultivated for 15 days. Endothelial cell density (ECD) was analyzed blinded on days 1, 8 and 15. Results Relative ECL significantly correlated with irrigation BH (control (n = 13): -9.69 ± 6.03% (average ± standard deviation); BH100 (n = 12): -9.69 ± 4.81%—p = 1.000; BH125 (n = 14): -19.44 ± 7.30% – p

Abstract Purpose This study aims to comparatively evaluate the morphological changes of the cornea after phacoemulsification (PHACO) and femtosecond laser-assisted cataract surgery (FLACS) without intercurrences in patients with type 2 diabetes mellitus. Methods A total of 95 diabetic patients with moderate cataracts (N2 + and N3+), 47 undergoing PHACO and 48 undergoing FLACS, were selected randomly for the study. Surgeries were performed by a single surgeon between July 2021 and December 2021. Cumulative dissipated energy (CDE) and total balanced saline solution (BSS) data were obtained at the end of each surgery. Changes in corneal endothelial cell density (ECD) and central corneal thickness (CCT) at three months postoperatively were investigated. Results After three months, evidence is lacking between groups in the CCT measures; the difference was neither statistically nor clinically relevant. However, for ECD, a significant and clinically significant difference was found; if all patients were treated with laser, the mean ECD would be 423.55 greater (RSE: 86.09; p-value

Nowadays, treating corneal diseases arising from injury to the corneal endothelium necessitates donor tissue, but these corneas are extremely scarce. As a result, researchers are dedicating significant efforts to exploring alternative approaches that do not rely on donor tissues. Among these, creating a tissue-engineered scaffold on which corneal endothelial cells can be transplanted holds particular fascination. Numerous functional materials, encompassing natural, semi-synthetic, and synthetic polymers, have already been studied in this regard. In this review, we present a comprehensive overview of recent advancements in using polymer biomaterials as scaffolds for corneal endothelium tissue engineering. Initially, we analyze and present the key properties necessary for an effective corneal endothelial implant utilizing polymer biomaterials. Subsequently, we focus on various emerging biomaterials as scaffolds for corneal endothelium tissue engineering. We discuss their modifications (including natural and synthetic composites) and analyze the effect of micro- and nano-topological morphology on corneal endothelial scaffolds. Lastly, we highlight the challenges and prospects of these materials in corneal endothelium tissue engineering. [ABSTRACT FROM AUTHOR]

PurposeTo elucidate the molecular events in solute carrier family 4 member 11 (SLC4A11)-deficient corneal endothelium that lead to the endothelial dysfunction that characterizes the dystrophies associated with SLC4A11 mutations, congenital hereditary endothelial dystrophy (CHED) and Fuchs endothelial corneal dystrophy 4.MethodsComparative transcriptomic analysis (CTA) was performed in primary human corneal endothelial cells (pHCEnC) and murine corneal endothelial cells (MCEnC) with normal and reduced levels of SLC4A11 (SLC4A11 KD pHCEnC) and Slc4a11 (Slc4a11-/- MCEnC), respectively. Validation of differentially expressed genes was performed using immunofluorescence staining of CHED corneal endothelium, as well as western blot and quantitative PCR analysis of SLC4A11 KD pHCEnC and Slc4a11-/- MCEnC. Functional analyses were performed to investigate potential functional changes associated with the observed transcriptomic alterations.ResultsCTA revealed inhibition of cell metabolism and ion transport function as well as mitochondrial dysfunction, leading to reduced adenosine triphosphate (ATP) production, in SLC4A11 KD pHCEnC and Slc4a11-/- MCEnC. Co-localization of SNARE protein STX17 with mitochondria marker COX4 was observed in CHED corneal endothelium, as was activation of AMPK-p53/ULK1 in both SLC4A11 KD pHCEnC and Slc4a11-/- MCEnC, providing additional evidence of mitochondrial dysfunction and mitophagy. Reduced Na+-dependent HCO3- transport activity and altered NH4Cl-induced membrane potential changes were observed in Slc4a11-/- MCEnC.ConclusionsReduced steady-state ATP levels and subsequent activation of the AMPK-p53 pathway provide a link between the metabolic functional deficit and transcriptome alterations, as well as evidence of insufficient ATP to maintain the Na+/K+-ATPase corneal endothelial pump as the cause of the edema that characterizes SLC4A11-associated corneal endothelial dystrophies.

Abstract Corneal endothelium is a single cell layer that is mainly responsible for maintaining corneal clarity. Endothelial damage secondary to toxicity, stress, or genetic predisposition are common and in conjunction with the low regenerative ability of the cells, making their preservation critical for maintaining visual acuity. Patients with glaucoma, who are estimated to be close to 80 million worldwide, have a plethora of reasons for developing endothelial damage, being exposed to a spectrum that extends from various medical and surgical interventions to the disease itself. The wide spectrum of glaucoma pharmacotherapy that has been recently extended by addition of newer classes of medications has been the focus of extensive research on its effects on corneal endothelium. Both basic and clinical research have attempted to shine a light on the complex mechanisms associated with the effects of glaucoma medication on corneal endothelium and to answer the important question as to whether these findings are clinically significant. The aim of this review is to summarize and present current literature of the various findings, both from in vivo and in vitro studies that have focused on the complex relationship between different classes of glaucoma medication and their effect on corneal endothelium.

Here, we report the case of a patient with multiple parallel-line endotheliitis with myopic shift, which has not been previously reported. A 36-year-old man visited our clinic with blurred vision in his left eye. A slit lamp examination revealed an interesting pattern of multiple parallel lines of keratic precipitates, along with subtle corneal edema. The spherical equivalents measured in the right and left eyes were −9.25 and −11.875 diopter, respectively, with the left eye showing more myopic progression. On specular microscopy, endothelial cell loss was found in the left eye. After administration of a weak topical steroid, keratic precipitates and corneal edema resolved completely within 2 days. The myopic shift in his left eye recovered to −10.0 diopters. Multiple parallel-line endotheliitis can be easily treated with a weak topical steroid in a short period. A temporary myopic shift may occur, which in this case resolved upon disease recovery. However, corneal endothelial cell loss is inevitable; therefore, careful monitoring is needed.

PURPOSE: The inducible Cre-ERT2 recombinase system allows for temporal control of gene targeting, and it is useful to studying adult function of genes that have critical developmental roles. The Zeb1flox/flox: UBC-CreERT2 mouse was generated to conditionally target Zeb1 to investigate its role in mesenchymal transition in the mouse corneal endothelium in vivo. MATERIALS AND METHODS: Hemizygous UBC-CreERT2 mice were crossed with homozygous mice harboring loxP-flanked Zeb1 alleles (Zeb1flox/flox) to generate the Zeb1flox/flox: UBC-CreERT2 mouse. 4-hydroxytamoxifen (4-OHT) exposure leads to excision of exon 6 of Zeb1, resulting in a loss function allele in the Zeb1flox/flox: UBC-CreERT2 mouse. Intracameral 4-OHT injection further isolates Zeb1 targeting to the anterior chamber. Mesenchymal transition and induction of Zeb1 expression in the corneal endothelium was achieved using FGF2 in ex vivo organ culture. Gene expression was analyzed by semi-quantitative reverse transcription-polymerase chain reaction and by immunoblotting in the mouse corneal endothelium in vivo. RESULTS: Following Cre-mediated targeting of Zeb1 by intracameral 4-OHT injection in Zeb1flox/flox: UBC-CreERT2 mice, FGF2 treatment in ex vivo organ culture resulted in abrogation of Zeb1 mRNA and protein expression in the corneal endothelium. CONCLUSION: The data show Zeb1, a critical mediator of fibrosis in corneal endothelial mesenchymal transition, can be targeted by intracameral injection of 4-OHT in the mouse corneal endothelium in vivo. These results suggest that genes with critical developmental roles can be targeted at a specific time in the corneal endothelium to study its role in adult disease using an inducible Cre-Lox strategy.

Objectives:To evaluate the effects of intracameral drugs and dyes on rat corneal endothelial apoptosis and cell morphology.Materials and Methods:The right eyes of 72 rats were injected intracamerally with 1% lidocaine, 0.01% adrenaline, triamcinolone acetonide (TA) 4 mg/mL, 1% trypan blue (TB), 0.5% indocyanine green (ICG), and fortified balanced salt solution as control. Corneal samples were taken 1 day and 1 week post-injection. Corneal endothelial apoptosis was assessed by the TUNEL technique, and the ratio of apoptotic cells in each group was compared with the control. Corneal endothelial cell morphology was evaluated in each specimen by transmission electron microscopy.Results:The mean apoptotic endothelial cell ratio was significantly higher at 1 day and 1 week after intracameral adrenaline injection when compared to controls (p=0.03 and 0.021, respectively). TB caused a significantly higher apoptotic cell ratio when compared to controls at 1 week after injection (p=0.043). Lidocaine caused a higher apoptotic cell ratio compared to TA and ICG at 1 week, although not statistically significant (p=0.058, 0.09, 0.69, respectively). In all experimental specimens, transmission electron microscopy showed morphological changes associated with apoptosis.Conclusion:This study showed that intracameral adrenaline, TB, and lidocaine injections may have toxic effects on corneal tissue, as indicated by ultrastructural and histopathological alterations. Therefore, these agents should be used with caution in intraocular surgery.

Abstract Background The purpose of this study was: [1] to evaluate the infectivity of two SARS-CoV-2 lineage A variants on human ocular tissues in vitro, and [2] to evaluate the stability of SARS-CoV-2 lineage A variants in corneal preservation medium. Methods Primary cultures of donor corneal, conjunctival, and limbal epithelium were inoculated with two lineage A, GISAID clade S isolates of SARS-CoV-2 (Hong Kong/VM20001061/2020, USA-WA1/2020), to evaluate the susceptibility of the ocular tissue to infection. Flat-mounted Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK) grafts were inoculated with SARS-CoV-2 to evaluate the susceptibility of the endothelium to infection. All inoculated samples were immunostained for SARS-CoV-2 nucleocapsid (N)-protein expression to confirm positive infection. SARS-CoV-2 Hong Kong was then inoculated into cornea preservation media (Life4°C, Numedis, Inc.). Inoculated media was stored at 4oC for 14 days and assayed over time for changes in infectious viral titers. Results Corneal, conjunctival, and limbal epithelial cells all demonstrated susceptibility to infection by SARS-CoV-2 lineage A variants. Conjunctiva demonstrated the highest infection rate (78% of samples infected [14/18]); however, infection rates did not differ statistically between cell types and viral isolates. After inoculation, 40% (4/10) of DSAEK grafts had active infection in the endothelium. SARS-CoV-2 lineage A demonstrated

Abstract Background To investigate the possible association of different pattern of diabetic retinopathy (DR) on corneal endothelium cells in type 2 diabetes mellitus patients. Methods In this descriptive-analytical cross-sectional study, corneal endothelium parameters including endothelial cell density (ECD), average cell size (AVG), coefficient of variation in cell size (CV), and hexagonality (Hex) were evaluated by non-contact specular microscopy. Results One hundred and thirty-four eyes of 134 diabetic patients including 77 females (57.5%) with a mean age of 61.03 ± 8.08 years were enrolled. The overall corneal parameters in diabetic patients with and without retinopathy were not significantly different (P > 0.05). There is a significant relationship between CV and the duration of the disease with age variable control (B = 0.369, p-value

AIM: To analyze the effects of dual viscoelastic agents DisCoVisc and sodium hyaluronate on corneal endothelium of patients after phacoemulsification and foldable intraocular lens(IOL)implantation.METHODS: A total of 247 patients(285 eyes)with cataract treated in Jingmen Aier Eye Hospital between June 2017 and December 2019 were selected, and they were divided into DisCoVisc group(123 cases, 141 eyes)and sodium hyaluronate group(124 cases, 144 eyes)by random number table method. Both groups were treated with phacoemulsification and foldable IOL implantation. DisCoVisc and 1.7% sodium hyaluronate were used as viscoelastic agents in DisCoVisc group and sodium hyaluronate group, respectively. The two groups were compared in terms of intraoperative ultrasound time(UST), cumulative dissipated energy(CDE), time for aspiration of viscoelastic agents after IOL implantation, corneal edema at 1d, 1wk, 1 and 3mo after operation, corneal endothelial cell density(ECD)and ECD loss rates before operation and at 3mo after operation, coefficient variation of corneal endothelial cell size(CV), percentage of corneal hexagonal endothelial cells(6A), intraocular pressure, the proportions of patients with uncorrected visual acuity ≥0.5 and central corneal thickness(CCT)values before and after operation at 1d, 1wk and 1mo.RESULTS:There was no statistically significant difference between the two groups in UST, CDE, aspiration time of viscoelastic agents(P >0.05)or corneal edema both rate on day 1 after operation(P>0.05). Corneal edema disappeared at 1 wk after operation. The ECD loss rate in DisCoVisc group was significantly lower than that in sodium hyaluronate group at 3mo after operation(P0.05).CONCLUSION: DisCoVisc, as the viscoelastic agent in phacoemulsification and foldable IOL implantation for patients with Emery-Little grade Ⅱ-Ⅲ lens nucleus hardness, can better protect the patients' corneal endothelium.

Background: To accurately measure ultrathin Descemet stripping automated endothelial keratoplasty (DSAEK) donor lamella thickness during the first postoperative year and to correlate this with pre-operative and other postoperative measurements. Methods: Donor lamella thickness in 41 eyes undergoing DSAEK for Fuchs endothelial dystrophy (FED) was measured using the Tomey Casia OCT directly after graft preparation and at 1 week and 1, 3, 6 and 12 months postoperatively. Visual acuity and endothelial cell density were measured as the secondary parameters. Results: Individual graft thickness profiles were shown to be fairly regular within the optically relevant area. There was a strong and highly significant correlation between the pre- and postoperative lamellar thicknesses at all time points (p < 0.0001). Compared with the measurements directly after preparation at the cornea bank, the lamella thickness decreased by 12% after 12 months. Between 1 and 12 months postoperatively, the lamella thickness (mean ± SD) changed from 112 ± 27 μm to 101 ± 21 μm. Best spectacle-corrected visual acuity (BSCVA) changed from 0.46 ± 0.30 logMAR pre-operatively through 0.36 ± 0.33 at 1 month to 0.13 ± 0.16 at 1 year postoperatively. The endothelial cell counts were comparable to those reported in previous studies. Conclusions: Thickness profiles of individual grafts were fairly regular within the optically relevant area. A strong relationship between pre- and postoperative graft thicknesses was detected, and ultrathin DSAEK grafts prepared using methods similar to that applied in this study are expected to show a deswelling of around 12% during the first postoperative year. No correlation was detected between graft thickness and BSCVA. [ABSTRACT FROM AUTHOR]