Cornea Samples Research Articles

Pharmacokinetics and metabolism of ketoconazole after single ocular instillation in Sprague-Dawley rats

Background and purpose: Ketoconazole is limited to its conditioned oral use due to hepatic toxicity. Its ocular eye drop administration may be an option for mycotic keratitis treatment. Therefore, it is necessary to explore its pharmacokinetic and metabolic profile via topical ocular administration. Experimental approach: Nine rats were dosed at 300 µg/rat via topical ocular administration, and sacrificed at 5, 30, and 120 min with 3 rats/timepoint. Plasma, cornea, retina, and vitreous humour samples were collected, processed, and analysed. Key results: Ketoconazole was quantified with a mean peak plasma concentration of 445 ng/mL at 5 min post-dose. In the rat ocular tissue, the mean ketoconazole concentration at 5 min post-dose was 423 μg/g in the cornea, 4.96 μg/g in the retina, and 1.19 μg/g in the vitreous humour, respectively. The mean ketoconazole concentration in each matrix decreased from 5 to 120 min. The mean ketoconazole concentration at 120 min was 38.4 ng/mL in plasma, and 8.36, 0.0944, and 0.116 μg/g in the cornea, retina, and vitreous humour, respectively. Pooled plasma, cornea, retina, and vitreous humour homogenates were used for metabolite identification. Nine metabolites were identified in rat plasma, and O-dealkylated metabolite (M3) and dehydrogenated metabolite (M11) were the top two, accounting for 5.0 and 5.8 % of the relative mass abundance. The metabolic pathways were O-dealkylation, mono-oxygenation, and dehydrogenation. Eleven metabolites were identified in the rat cornea, and two metabolites were identified in the rat retina and vitreous humour, respectively. The O-dealkylated and hydrogenated metabolite (M2) was a dominant metabolite in the cornea, retina, and vitreous humour, while M3 and M11 were the dominant metabolites in plasma. Conclusion: Ketoconazole was a dominant component (≥ 98.5 %) in the cornea, retina, and vitreous humour, having higher concentrations in cornea than in plasma. M2 was identified as a dominant metabolite (1.1 - 1.2 %) in the cornea, retina, while M3 (5.0 %) and M11 (5.8 %) were identified as dominant metabolites in the plasma.

Effect of preservation on changes in the volume of corneal endothelial cells in an environment with a high concentration of potassium

The experimental study of preservation length on the effect of high potassium concentration in the medium on the volume of human corneal endothelial cells was done. The results of the study of individual samples of fragments of donor material and the values calculated using joined data after hypothermic preservation for 4 and 10 days are presented. The increase of the time when cornea samples are kept in preservation medium (Eusol-C) at 4℃ led to a decrease in the average value (M ± SEM) of cell swelling indicator (N) in a potassium medium from 1.055 ±0.001; n = 982 to 1.014±0.001; n = 338; after 4 and 10 days, respectively. Student’s-t test for independent samples showed a high degree of significance for the difference between these values (p = 2E-76). Identification of the proportion of cells capable to swell in a medium with a high content of potassium ions (N 1), reflecting the electrogenic activity in these cells, showed a decrease of this indicator in the studied groups with increasing duration of preservation (94.3% and 56.8% after 4 and 10 days, respectively). Based on the results of the study, it is suggested that the values of endothelial cells swelling in a potassium environment can serve as indicators of the cells’ ability to restore electrogenic transport. It is concluded that the study of cell swelling in a medium with a high content of potassium ions can provide information for predicting the functionality of the graft.

A case report of endophthalmitis caused by Streptococcus pneumoniae serotype 3

Background: Streptococcus pneumoniae is often the cause of infections, including eye infections such as endophthalmitis, keratitis, and conjunctivitis. Endophthalmitis is a severe infection and can cause blindness. This case report aims to investigate and report the incidence of endophthalmitis caused by S. pneumoniae. Case presentation: We report the case of a 67-year-old man with blurred vision in his right eye accompanied by red, watery eyes, discharge, swollen eyelids. The patient was assessed as having exogenous endophthalmitis ocular dextra et causa bacterial infection with a post-secondary implant for three years. From the result of the culture and sensitivity test of the cornea and vitreous sample, S. pneumoniae was found to have a 97% probability using VITEK 2 Compact. We continued to examine the serotype using Polymerase Chain Reaction (PCR), and the result was S. pneumoniae serotype 3. The patient was treated with ceftriaxone as definitive therapy, and the condition improved. Conclusion: S. pneumoniae is the known organism that causes one eye infection with risk factors such as previous cataract surgery. Prompt diagnosis and treatment are needed for good outcomes.

Circular RNA expression profile identifies potential circulating biomarkers for keratoconus

Early diagnosis is important for improving the outcomes of keratoconus (KC). Stable expression and a closed-loop structure of circular RNAs (circRNAs) make them ideal for the diagnosis and treatment of diseases. However, the expression pattern and potential function of circRNAs in KC is not studied yet. Hence, this study explored the circRNA expression profile of KC corneas through transcriptome sequencing and circRNA expression profile analysis. The diagnostic potential of blood circRNAs for KC was explored by analysing the circRNAs' expression levels of fifty paired blood samples from patients with KC and normal controls. The results showed that 107 significantly upregulated and 145 significantly downregulated circRNAs (|fold change| ≥ 2.0, p-value <0.05) were identified in KC tissues. Eight top differently expressed circRNAs were further validated in more cornea samples. Among them, five circRNAs expressed in peripheral blood, and four circRNAs (circ_0006156, circ_0006117, circ_0000284 and circ_0001801) showed significant downregulation in KC patients’ peripheral blood too. The blood circ_0000284 expression levels of early, moderate, and advanced KC patients both were significantly lower than the controls. The blood circ_0006117 expression levels present a positive correlation with corrected distance visual acuity values, and a negative correlation with back elevation values of KC eyes. Notably, the expression levels of these circRNAs distinguished KC patients from their healthy counterparts, with the area under the curve (AUC) of circ_0000284, circ_0001801, and circ_0006117 being 0.7306, 0.6871 and 0.6701, respectively. Further, the AUC value for five circRNAs under the logistic regression model was 0.8203, indicating that they can function as effective biomarkers for the KC diagnostics. In conclusion, the expression of circRNAs showed a relationship with KC, with four significantly differentially expressed circRNAs demonstrating potential as biomarkers for the disease.

Possible depth-resolved reconstruction of shear moduli in the cornea following collagen crosslinking (CXL) with optical coherence tomography and elastography.

Corneal collagen crosslinking (CXL) is commonly used to prevent or treat keratoconus. Although changes in corneal stiffness induced by CXL surgery can be monitored with non-contact dynamic optical coherence elastography (OCE) by tracking mechanical wave propagation, depth dependent changes are still unclear if the cornea is not crosslinked through the whole depth. Here, phase-decorrelation measurements on optical coherence tomography (OCT) structural images are combined with acoustic micro-tapping (AµT) OCE to explore possible reconstruction of depth-dependent stiffness within crosslinked corneas in an ex vivo human cornea sample. Experimental OCT images are analyzed to define the penetration depth of CXL into the cornea. In a representative ex vivo human cornea sample, crosslinking depth varied from ∼100 µm in the periphery to ∼150 µm in the cornea center and exhibited a sharp in-depth transition between crosslinked and untreated areas. This information was used in an analytical two-layer guided wave propagation model to quantify the stiffness of the treated layer. We also discuss how the elastic moduli of partially CXL-treated cornea layers reflect the effective engineering stiffness of the entire cornea to properly quantify corneal deformation.

Nonlinear fourth-order elastic characterization of the cornea using torsional wave elastography

Measuring the mechanical nonlinear properties of the cornea remains challenging due to the lack of consensus in the methodology and in the models that effectively predict its behaviour. This study proposed developing a procedure to reconstruct nonlinear fourth-order elastic properties of the cornea based on a mathematical model derived from the theory of Hamilton et al. and using the torsional wave elastography (TWE) technique. In order to validate its diagnostic capability of simulated pathological conditions, two different groups were studied, non-treated cornea samples (n=7), and ammonium hydroxide (NH4OH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$NH_4OH$$\\end{document}) treated samples (n=7). All the samples were measured in-plane by a torsional wave device by increasing IOP from 5 to 25 mmHg with 5 mmHg steps. The results show a nonlinear variation of the shear wave speed with the IOP, with higher values for higher IOPs. Moreover, the shear wave speed values of the control group were higher than those of the treated group. The study also revealed significant differences between the control and treated groups for the Lamé parameter μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document} (25.9–6.52 kPa), third-order elastic constant A (215.09–44.85 kPa), and fourth-order elastic constant D (523.5–129.63 kPa), with p-values of 0.010, 0.024, and 0.032, respectively. These findings demonstrate that the proposed procedure can distinguish between healthy and damaged corneas, making it a promising technique for detecting diseases associated with IOP alteration, such as corneal burns, glaucoma, or ocular hypertension.

Pharmacokinetics of Sirolimus Eye Drops Following Topical Ocular Administration in Rabbits.

Purpose: To evaluate the pharmacokinetics of sirolimus eye drops following topical instillation in rabbits. Methods: The study included 2 experiments. In single-dose pharmacokinetic study, rabbits received a single bilateral instillation of 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye). In repeat-dose pharmacokinetic study, 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye/time) were instilled into both eyes of rabbits four times a day for 6 consecutive days and one time on day 7. Whole blood, tears, aqueous humor, cornea, and conjunctiva samples were collected. Sirolimus concentration was determined by a validated liquid chromatography-tandem mass spectrometry. Results: Sirolimus was hardly detected in plasma or aqueous humor after either single or repeated dosing. The Cmax of sirolimus in tears, cornea, and conjunctiva after a single instillation was 163.34 ± 69.30 μg/g, 150.56 ± 84.98 ng/g, and 113.22 ± 49.82 ng/g, respectively. As the number of instillation elevated, the Cmax of sirolimus was increased to 486.18 ± 297.93 μg/g, 418.63 ± 41.07 ng/g, and 314.25 ± 63.74 ng/g, respectively. In repeat-dose administration, the steady state of sirolimus concentration was achieved on the third day. Ocular exposure to sirolimus after single and repeated dosing, based on AUC0-t, was highest in tears, followed by cornea and conjunctiva. Compared with single administration, a significant increase in sirolimus exposure as measured by AUC0-t was observed in tears, cornea, and conjunctiva following repeated administration. Conclusions: Topical administration of sirolimus eye drops results in extensive distribution of sirolimus in tears, cornea, and conjunctiva, while aqueous humor and systemic exposure were negligible. Repeat-dose administration increases sirolimus exposure in tears, cornea, and conjunctiva.

Inflammatory profile of keratoconic corneal epithelium

BackgroundRecent studies have presented inflammatory features on keratoconus (KC) and many inflammatory markers are described in the tears of patients with this disease. The KC pathogenesis is still unknown just like the correlation with inflammatory patterns. However, environmental and genetic issues may be part of the progress of KC. In addition, some systemic features, such as allergy and obesity, seem to be related to the progression of KC. Our purpose was to evaluate the neuropeptides vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), chemokines ligand 2 (CCL-2) and 5 (CCL-5), and interleukins 6 (IL-6) and 8 (IL-8) on corneal epithelial cells and blood of patients with KC and in healthy controls. In addition, the neutrophil-to-lymphocyte ratio (NLR) was evaluated to predict inflammation.MethodsThis including prospective observational study included 32 KC patients who underwent corneal crosslinking (CXL) and 32 control patients who underwent photorefractive keratectomy (PRK). Patients’ corneal epithelial cells were removed surgically, and blood (buffy coat) was analyzed. Samples in triplicate were evaluated on rt-PCR for neuropeptides (VIP e NPY), interleukins (IL-6 e IL-8), and chemokines (CCL-2 and CCL-5).ResultsOur study showed statistically higher CCL-5 and IL-8 on corneal epithelial cells in patients with KC. Blood cells were statistically higher in VIP and NPY in the KC group. Interleukin-8 on blood cells was statistically significant in KC’S group; for CCL-2 and CCL-5 they were statistically lower in patients with KC compared with controls. NLR showed no difference between the groups.ConclusionsOur data support the findings of other studies that suggested altering KC status, such as inflammatory corneal disease. The presence of IL-8 in the cornea and blood samples of KC’s group suggested systemic disease with a possible local or repercussion action. Further studies are warranted to elucidate KC pathogenesis and its correlation to systemic disease.

Antibiotic Resistance Pattern of Enterococci Isolates from Nosocomial Infections in Imam Khomeini Hospital, Ahvaz City

Introduction: Enterococci are opportunistic bacteria that can become pathogenic if colonized. Resistance to commonly used antibiotics by Enterococci causing nosocomial infections is of concern, which necessitates judicious, responsible and evidence-based use of antibiotics. The aim of this study was to evaluate the pattern of antibiotic resistance of Enterococci isolated from patients admitted to Imam Khomeini Hospital in Ahvaz City, Iran.&#x0D; Methods: The data of this cross-sectional description study were collected from October to March 2019 in the Microbiology Department of Imam Khomeini Hospital, Ahvaz City, Iran. Ninety samples of patients aged 1 to 99 years with infection caused by Enterococcus faecalis and Enterococcus faecium were included. The samples included urine culture, wound swab, vaginal swab, blood culture, catheter, sputum, broncho-aspirate, cerebrospinal fluid and other cases (abscess, drainage, ascites fluid, pleural fluid, culture fluid and purulent material). The antibiotic sensitivity of the isolates was measured using the agar disk diffusion method.&#x0D; Results: Enterococci were collected from 53 urine samples, 10 blood samples, 1 cerebrospinal fluid sample, 1 abscess sample, 2 cornea samples, 9 wound samples and 14 other secretion samples. The resistance of enterococcus strains against ciprofloxacin, ampicillin, imipenem and nalidixic acid was 66.7%, 42.6%, 55.6% and 93.3%, respectively. The highest sensitivity of Enterococcus isolates against ampicillin (42.6%) was observed. 43.3% of the samples obtained were from men and 56.7% from women.&#x0D; Conclusion: Based on the results of this study, a significant percentage of Enterococci strains are resistant to ciprofloxacin, imipenem, and nalidixic acid. Over-the-counter and unnecessary use of available antibiotics should be avoided to prevent increased resistance to common antibiotics.

Cold Storage Media versus Optisol-GS in the Preservation of Corneal Quality for Keratoplasty: A Systematic Review

Optisol-GS is the most widely used pharmaceutical composition to preserve corneas for transplantation. This systematic review investigated the effects of different cold corneal storage media (CCSM) compared with Optisol-GS on the quality of stored corneas. The literature was searched throughout May 2022 on six databases and grey literature. Studies including corneas (population) exposed to distinct cold storage media (exposure) and Optisol-GS (comparison) that reported qualitative and/or quantitative parameters of cornea quality (outcome) were included. Methodological quality was assessed using ToxRTool. From 4520 identified studies, fourteen were included according to the eligibility criteria, comprising 769 evaluated cornea samples comparing Optisol-GS with commercial and noncommercial media. All studies showed good methodological quality. Experimental times ranged from 1–28 days, mainly using 4 °C as the preservation temperature. Viable endothelial cell density (ECD) and endothelial cell morphology (EC) were the most assessed parameters. ECD results for Cornisol were higher than Optisol-GS in 10 days (p = 0.049) and favored Cornea ColdTM up to 4 weeks (p &lt; 0.05), which also showed better qualitative results. While the standardization of test protocols could improve comparisons, evidence indicates that most CCSM present similar performances on cornea preservation for transplantation at seven days, while some formulations may increase preservation at extended times.

Prolactin Inducible Protein, but Not Prolactin, Is Present in Human Tears, Is Involved in Tear Film Quality, and Influences Evaporative Dry Eye Disease.

PurposeDecreased production of the aqueous component of the tear film is an important cause of the development of dry eye disease (DED). Tear production is influenced by hormones and hormone-like factors. Prolactin (PLR), a multifunctional pituitary gland hormone, is regularly present in the lacrimal gland of rats and rabbits. In humans, serum PLR concentration correlates with tear quality. To gain deeper insights of possible effects of PRL, prolactin receptor (PRLR) and prolactin inducible protein (PIP), we analyzed the three proteins in the human lacrimal apparatus and in reflex tears of healthy volunteers as well as patients suffering from DED.MethodsGene expression of PRLR and PIP was analyzed by RT-PCR in cadaveric human lacrimal gland and ocular surface tissues, immortalized human corneal epithelial cells (HCE and hTEPI) and human Meibomian gland epithelial cells (HMGECs). At the protein level, the expression and localization of PRL, PRLR and PIP in formalin-fixed paraffin sections of the lacrimal apparatus were studied by immunohistochemistry. In addition, tear fluid from DED patients and healthy volunteers was analyzed by ELISA to determine the concentration of PRL and PIP.ResultsRT-PCR analyses revealed gene expression of PRLR and PIP in human tissue samples of cornea, lacrimal glands, and eyelids, whereas only PIP, but not PRLR, was detectable in immortalized corneal epithelial cells. Immunohistochemistry revealed for the first time the expression and localization of PRL, PRLR, and PIP in human tissues of the lacrimal apparatus and at the ocular surface. PRL and PRLR were detectable in corneal epithelium, lacrimal glands, and Meibomian glands. Reflex tears from DED patients revealed significantly increased PIP concentrations, whereas PRL was undetectable in tears of DED patients and healthy volunteers.ConclusionPRL, PRLR, and PIP are found in the lacrimal apparatus and on the ocular surface. PIP, but not PRL, is present in human tears and appears to be involved in the physiology of tear film quality. Our clinical data revealed that PIP may affect tear quality, but further functional analyses are needed to fully elucidate the effects of PRL and PIP-associated factors in tear secretion as well as in the connection of DED.

Calibration Alignment Sensitivity in Corneal Terahertz Imaging.

Improving the longitudinal modes coupling in layered spherical structure contributes significantly to corneal terahertz sensing, which plays a crucial role in the early diagnosis of cornea dystrophies. Using a steel sphere to calibrate reflection from the cornea sample assists in enhancing the resolution of longitudinal modes. The requirement and challenges toward applying the calibration sphere are introduced and addressed. Six corneas with different properties are spotted to study the effect of perturbations in the calibration sphere in a frequency range from 100 GHz to 600 GHz. A particle-swarm optimization algorithm is employed to quantify corneal characteristics considering cases of accurately calibrated and perturbed calibrated scenarios. For the first case, the study is carried out with signal-to-noise values of 40 dB, 50 dB and 60 dB at waveguide bands WR-, WR-, and WR-. As expected, better estimation is achieved in high-SNR cases. Furthermore, the lower waveguide band is revealed as the most proper band for the assessment of corneal features. For perturbed cases, the analysis is continued for the noise level of 60 dB in the three waveguide bands. Consequently, the error in the estimation of corneal properties rises significantly (around ).

Mueller Matrix-Based Approach for the Ex Vivo Detection of Riboflavin-Treated Transparent Biotissue

Corneal collagen cross-linking is an established procedure for the treatment of certain eye diseases which is applied to enhance the mechanical stability of such biotissue without deteriorating its functionality. However, being transparent, the optical analysis of the outcome of such treatments is cumbersome and relies on relatively expensive experimental equipment. We aim to apply the Mueller matrix polarimetry for the detection of photo-induced collagen cross-linking in transparent biotissue after treatment with riboflavin and UV irradiation. A simple Mueller matrix polarimetry setup could provide a fast and non-invasive analysis of transparent media to sensitively detect small photo-induced cross-linking effects in biotissue. We demonstrated the current capabilities of the approach on non-planar porcine cornea samples ex vivo. We reported the distinction between untreated and riboflavin-treated samples. The differences observed were correlated with the variation of certain Mueller matrix elements and parameters derived from the decomposition. The measurement data show variation in the cross-linked and non-cross-linked samples, although the effect of the UV treatment on the riboflavin-treated samples was not at the same level of significance yet and needs further investigation. The Mueller matrix measurement represents a promising approach for the detection of the effects of corneal collagen cross-linking. Further studies with a larger sample number are required to validate this approach. In the future, this could enable the reliable and non-invasive detection of photo-induced effects in biotissue and open the possibility for in vivo application, e.g., in eye disease treatment or the detection of scar collagen development.

Full-field strain mapping for characterization of structure-related variation in corneal biomechanical properties using digital image correlation (DIC) technology

Characterization of structure-related variation in corneal biomechanical properties is important for the design of corneal implants with a controllable degradation. In the current study, we conducted an in-vitro inflation experiment on contact and structural-damaged porcine corneas and mapped the strain distribution during using digital image correlation (DIC) algorithm. The inflation experiment was performed with a pressure loading device, a steady-state pressure transducer and DIC system. Corneal samples with uniformly-distributed paint particles were fixed on the loading device, and then were subjected increasing pressure load through injection with a constant velocity (0.134 ​ml/min). Three-dimensional (3D) DIC algorithm was performed to present a map of the full-field strain distribution on the corneal surface. The results showed a significant difference in the strain distribution between the intact and damaged corneas. The time-strain history also exhibited differently when the two types of cornea samples were subjected to inflation. It indicated that the DIC technology is validated to characterize structure-related variation in corneal biomechanical properties.

The Influence of Size Effect on Strength and Deformation Characteristics of Different Types of Rock Samples

This paper presents the results of the experimental study of the influence of sizes effect on the strength and deformation characteristics of samples of hornfels, limestone, sandstone, siltstone and ore-bearing rocks. Tests were performed on cylindrical samples of three sizes of diameters - 10, 30 and 60 mm under uniaxial compression and tension loading. The results of the study demonstrated that the values of ultimate strength decrease when the size of samples increases for the samples of cornea, limestone, sandstone and siltstone. The ultimate strength increases with increasing of sample size for ore-bearing rocks containing viscous inclusions. The samples of smaller size of ore-bearing rocks exhibit a brittle character of the fracture for all types of rocks, and the viscosity of fracture increases with increasing size of samples. the obtained regularities were analysed from the positions of otwo types of size effect (volume and surface).

Comparison of polarization sensitive second harmonic generation ‎microscopy techniques for the study of biological tissues

Recently, polarization sensitive Second Harmonic Generation (pSHG) microscopy has become a powerful tool for the study of the noncenterosymmetric biological structures. This is due to the fact that pSHG has some intrinsically benefits such as high resolution and contrast, and it can also penetrate deeply inside the sample in a noninvasive manner. One drawback for the pSHG technique is that the imaging procedure is not fast enough to study in vivo samples or to monitor the dynamics of different tissues. This issue imposes some limitations on using the pSHG technique to study in vivo samples. Fortunately, recently Single Scan polarization sensitive Second Harmonic Generation (SS-pSHG) technique has been introduced as a fast alternative for the conventional pSHG technique. In this article, the results obtained from ex vivo biological samples of starch, human cornea and animal tendon have been compared in a pixel-to-pixel manner using pSHG and SS-pSHG techniques in forward direction. Even though the samples used here are ex vivo, the results of this study promise that the polarization sensitive SHG microscopy techniques have a great potential to study biological tissues in a noninvasive procedure. This issue is more important especially in the cases that samples are in vivo.

Evaluation of a Cationic Antimicrobial Peptide as the New Antibiotic Candidate to Treat Staphylococcus aureus Keratitis

Staphylococcus aureus is a most important reason of bacterial keratitis. The emergence of S. aureus resistance to methicillin necessitates searching for new antimicrobial components for keratitis. CM11 is a cationic peptide with strong antibacterial activity against a range of bacteria. In this study, in vitro bactericidal activity of CM11 was investigated using the time-killing assay. For this purpose, corneal methicillin-resistant S. aureus (MRSA)-infected rabbit models were experimentally developed through intrastromal injection of bacteria. The infected rabbits were treated in three groups by artificial tear, gentamicin, and CM11, and their conjunctiva, iris, and cornea were clinically examined using a slit lamp and histopathological examination. The variance analyses of microbial (colony counts) and pathological examinations on the harvested cornea samples showed a significant improvement in the treated groups (CM11 and gentamicin) compared to the control eyes (P ≤ 0.05). According to findings, CM11 and gentamicin could significantly reduce the CFU in comparison with the group received artificial tear. The mean bacterial counts (log CFU/ml) from corneal culture were 2.1, 5.02, and 8.89 for gentamicin, CM11, and control group, respectively (P ≤ 0.05). The above-mentioned findings displayed the efficacy of CM11 cationic peptide for curing the MRSA-mediated keratitis.

Ocular Surface Expression of SARS-CoV-2 Receptors

ABSTRACT Purpose The spike proteins of SARS-CoV-2 interact with ACE2 or basigin/CD147 receptors, regulating human-to-human transmissions of COVID-19 together with serine protease TMPRSS2. The expression of these receptors on the ocular surface is unknown. Material and Methods Gene expression of SARS-CoV-2 receptors was investigated in conjunctival epithelial cell samples and in ex-vivo cornea samples using microarray or transcriptome sequencing. Results ACE2 is expressed in conjunctival samples at a low level, while BSG and TMPRSS2 are expressed at intermediate levels in both conjunctiva and cornea. Other receptors such as ANPEP, AGTR2 are expressed at low level in the conjunctiva. Two RNA editing enzymes involved in antiviral responses, APOBEC3A, and ADAR-1 were also highly expressed. Conclusions The ocular surface may represent an entry point for the SARS-CoV-2 in the human body. The conjunctiva and the cornea can adopt antiviral countermeasures which may explain the low prevalence of eye involvement.

Analysis of CCR3 expression in corneal neovascularization in a murine model and human corneas

The aim of this study was to examine the expression of the cytokines and chemokines receptor-3 (CCR3) molecule in endothelial cells and vascular structures in a murine model of corneal neovascularization and in samples of neovascularized human corneas. An immunofluorescence assay using the murine model showed a greater proportion and intensity of CCR3 in the epithelium and corneal subepithelial regions in corneas with neovascularization. In the absence of vascularization, no CCR3 was found. Of the 32 studied tissues, eight were vascularized and 24 were avascular. In the human corneas, vascularized corneas showed positive labeling for CD31 in all the analzedtissues, as well as positive labeling for CCR3. Therefore, all vascularized tissues showed positive coexpression of CCR3 and CD31, whereas none of the avascular corneas showed immunolabeling for either of these receptors. These results suggest that CCR3 could be a possible marker for corneal neovascularization with potential to be a therapeutic target.

The 2018 Activity Report of the Tissue Transplantation and Biotechnology Section of the German Ophthalmological Society

The Section on Tissue Transplantation and Biotechnology presented its 9th annual report. On the one hand, the number of cornea samples has risen to 10,840, of which 7168 have been transplanted. On the other hand, 1340 transplants have still been imported from abroad and more than 3300 patients were waiting for a transplant at the end of the year. The transplant bottleneck has not yet been eliminated.