Corneal Imaging Techniques for Dry Eye Disease

Dry eye disease (DED) is a common ocular disorder affecting millions worldwide. It is characterized by reduced tear production and/or increased tear evaporation, leading to ocular discomfort and impaired vision. Corneal imaging techniques are valuable tools for diagnosing and monitoring DED, as they can provide objective and quantitative information on the structure and function of the ocular surface and the tear film. This chapter will review the principles and applications of various corneal imaging techniques for DED, such as Slit-Lamp Biomicroscopy, Fluorescein CorneoGraphy, In Vivo Confocal Microscopy, Optical Coherence Tomography, Lipid Layer Interferometry, Topography, and Fluorophotometry. The advantages and limitations of each technique are discussed, as well as their potential role in future research and clinical practice, such as monitoring treatment efficacy and guiding personalized treatment approaches

Genipin in an ex vivo corneal model of bacterial and fungal keratitis

Purpose: To determine whether genipin (a natural crosslinker) could reduce the colonization and proliferation of bacteria and fungi in an ex vivo model of corneal infection. Methods: This study, using an ex vivo model of bacterial and fungal keratitis, investigated the antimicrobial efficacy of genipin crosslinking. Excised corneoscleral buttons were wounded by scalpel incision and subsequently infected with Staphylococcus aureus, Pseudomonas aeruginosa, or Candida albicans. After inoculation, corneas were treated with genipin for 24 hours at 37°C. Histologic examinations were carried out, and the number of viable colony-forming units (CFU)/cornea was determined. Results: Genipin exerts bactericidal action against S. aureus and P. aeruginosa, as well as fungicidal action against C. albicans and significantly reduced the CFU compared to contralateral eyes that received saline treatment (P < 0.05). Conclusions: These data identify genipin as a novel ocular antimicrobial agent that has the potential to be incorporated into the therapeutic armamentarium against microbial keratitis. Translational Relevance: This study provided evidence for the antimicrobial and antifungal properties of genipin as an alternative crosslinker that could be used in the management of infectious keratitis

El oficio del comunicador gráfico.

El oficio del comunicador gráfico es una compilación de textos alrededor de algunas de las actividades que la comunicación gráfica permite realizar dentro de su campo disciplinar. El libro es el fruto de una idea: recoger las reflexiones y propuestas que la comunidad académica del programa de Tecnología en Comunicación Gráfica de la Corporación Universitaria Minuto de Dios - UNIMINUTO, ha ido insertando en su naturaleza a través del tiempo. La necesidad de conocer la visión de distintos profesionales, se enlaza en este libro, con la certeza de que el campo de la comunicación gráfica y en especial el grupo humano compuesto por estudiantes, futuros comunicadores, requieren elementos que sustenten su acciones, sus pensamientos y sus prácticas. Esta obra es, entonces, una forma de socializar y hacer perdurar los avances logrados en los procesos de construcción y reflexión en torno del comunicador gráfico

El potencial terapéutico y anti inflamatorio del Genipin en un modelo de infección corneal

Propósito: Investigar la efectividad de la reticulación de colágeno corneal con Genipin (GEN) para el tratamiento de la queratitis bacteriana, en un modelo de infección corneal ex vivo con córneas porcinas. Métodos: Se descontaminaron parejas de botones corneales y posteriormente se infectaron con Staphylococcus aureus (ATCC 25923) o Pseudomonas aeruginosa (ATCC 27853) según el grupo. Treinta minutos después de la inoculación bacteriana; un ojo se trató con solución salina y el ojo contralateral se trató con GEN (n = 6 pares para cada microorganismo). También se realizó un control de esterilidad con corneas no expuestas a bacterias. Después de 24 h de incubación, la mitad de cada córnea se homogenizo y la se realizaron diluciones seriadas de la suspensión resultante, posteriormente se sembraron en placas de agar para recuento de unidades formadoras de colonias (UFC) / córnea. La otra mitad de cada cornea se sometió a examen histológico. Resultados: Macroscópicamente las corneas infectadas tratadas con Solución Salina (SSN) mostraron más turbidez y ulceración corneal versus las tratadas con GEN. Histológicamente, las tinciones de H-E y Gram confirmaron una infiltración bacteriana extensa en toda la córnea. El número de UFC disminuyó significativamente en las córneas tratadas con GEN vs las tratadas con SSN (p <0,05). Las córneas de control de esterilidad no evidenciaron ninguna infección. Conclusiones: El entrecruzamiento corneal con GEN podría servir como una opción terapéutica novedosa para el tratamiento de la queratitis bacteriana. Se necesitan más estudios para esclarecer la actividad antibacteriana y el mecanismo de acción de GEN. Palabras clave: crosslinking, queratitis infecciosa, queratitis bacteriana, infección corneal por Staphylococcus aureus, infección corneal por Pseudomonas aeruginosa, Genipin, modelo de infección corneal ex vivo.Purpose: To investigate the effectiveness of corneal collagen crosslinking with Genipin (GEN) for the treatment of bacterial keratitis, in an ex vivo corneal infection model with porcine corneas. Methods: Previously decontaminated pairs of corneal buttons were infected with Staphylococcus aureus (ATCC 25923) or Pseudomonas aeruginosa (ATCC 27853). Thirty minutes after bacterial inoculation; one eye was treated with saline solution and the contralateral eye was treated with GEN (n = 6 pairs for each microorganism). A sterility control was also carried out. After 24 h of incubation, half of each cornea was homogenized and serial dilutions of the resulting suspension were made, later they were seeded on agar plates for the count of colony forming units (CFU) / cornea. The other half of each cornea underwent histological examination. Results: Macroscopically, infected corneas treated with Saline Solution (SSN) showed more turbidity and corneal ulceration versus corneas with GEN treatment. Histologically, H&E and Gram stains confirmed extensive bacterial infiltration throughout the cornea. The number of CFUs decreased significantly in corneas treated with GEN vs those treated with SSN (p <0.05). The sterility control corneas did not show any infection. Conclusions: Corneal crosslinking with GEN could serve as a novel therapeutic option for the treatment of bacterial keratitis. More studies are needed to clarify the antibacterial activity and mechanism of action of GEN. Keywords: corneal crosslinking, infectious keratitis, bacterial keratitis, Staphylococcus aureus corneal infection, Pseudomonas aeruginosa corneal infection, Genipin, Keratitis ex vivo animal model.GRANT 793328 MARIE CURIEEl potencial terapéutico y anti inflamatorio del Genipin en un modelo de infección cornealLínea de Investigación: Ciencias Básicas en OftalmologíaEspecialidades Médica

Novel treatments for dry eye syndrome

Dry eye syndrome (DES) is a prevalent and multifactorial disease that leads to a self-perpetuating cycle of inflammation and damage to the ocular surface. This results in symptoms such as redness, burning, and blurred vision, which can negatively affect a patient's quality of life. While treatments are available to manage DES, they only temporarily relieve symptoms. Furthermore, long-term use of certain medications can cause harm to the ocular surface. Therefore, there is a need for safer and effective treatments for DES. This review highlights the latest advancements in DES therapy, providing valuable insights into ongoing efforts to improve patient outcomes

The Evolving Therapeutics of Endothelial Disease

Endothelial dysfunction is one of the leading indications for corneal transplantation. Globally, there is a shortage of donor corneas, which is partly because of the lack of eye banking resources in emerging countries. Given this global shortage, there is naturally heightened interest surrounding pharmacological agents, genetic therapy, and endothelial cell–based therapeutic modalities. Endothelial cells have limited mitotic capacity in vivo, and thus, studies have been conducted for their ex vivo expansion using mitogens. Similarly, pluripotent stem cells have been used to differentiate into human corneal endothelial cells with varying degrees of success. Different strategies have also been developed for injecting and delivering these cells into the human eye. This review aims to compile the information published on the latest advances in endothelial disease therapy

The Potential of Stem Cells as Treatment for Ocular Surface Diseases

Purpose of Review In this article, we review recent studies that examine stem cells as a potential treatment for ocular surface diseases. Recent Findings Mesenchymal stem cells (MSCs) derived from non-ocular surface tissues were effective in treating limbal stem cell deficiency and corneal endothelial dysfunction. In dry eye, limbal stem cells reduced ocular symptoms, while MSCs improved tear secretion and tear quality and reduced symptoms and inflammatory cytokine expression. There were no clinically significant adverse effects associated with stem cell treatment. While available evidence supports stem cells as a potential treatment for ocular surface diseases, the applicability of these therapies in humans has yet to be fully established, given that over 80% of studies evaluating stem cell treatments have been carried out in animal models and non-human subjects. Future studies examining the safety and efficacy of stem cell therapies for ocular surface diseases in humans are thus warranted

Descemet Membrane Endothelial Keratoplasty as Treatment for Late-Onset Interface Fluid Syndrome After Laser In Situ Keratomileusis

We herein present Descemet membrane endothelial keratoplasty (DMEK) as an effective surgical means of treatment for the management of interface fluid syndrome (IFS) in a series of cases with distant history of laser in situ keratomileusis (LASIK). Three cases from a single institution were included. All patients had documented IFS in the setting of history of LASIK. All 3 patients underwent DMEK for the treatment of IFS. Visual acuity, clinical findings, pachymetry, endothelial cell count, and anterior segment optical coherence tomography were recorded. We describe 3 cases of late-onset IFS that developed in eyes many years after LASIK (ranging from 15 to 31 years). All 3 patients had clinically significant corneal edema and evidence of poor endothelial function at the time of IFS diagnosis. DMEK was subsequently performed in each case. All 3 eyes showed resolution of corneal edema and improvement in best-corrected visual acuity after DMEK. DMEK can provide successful visual and anatomical recovery in patients who have had previous LASIK and experience late-onset IFS due to endothelial cell dysfunction

Effect of Anterior Chamber Air on Central Corneal Thickness in Human Donor Eyes

The purpose of this study was to describe the effects of intracameral air on corneal edema. A laboratory investigation was performed on human donor corneas. Baseline pachymetry measurements through anterior segment optical coherence tomography and endothelial cell density were obtained for all corneas. Each pair of corneas was separated and randomly assigned to undergo air injection or Optisol-GS into a BIONIKO artificial anterior chamber for 5 minutes at physiologic intraocular pressure confirmed by digital palpation. Photographs were obtained immediately on connection of the cornea to the artificial anterior chamber and on completion of the 5 minutes of treatment, with anterior chamber air being exchanged for Optisol-GS. Pretreatment and posttreatment photographs were obtained. Immediately after treatment, pachymetry was again obtained on all corneas. Pachymetry data underwent statistical analysis. Corneal pachymetry improved from 690.5 ± 126.6 to 576.1 ± 87.2 μm, yielding a 114.4 ± 50.4 μm improvement of pachymetry in the group with air injected into the anterior chamber. This was a significant improvement of pachymetry when compared with the group with Optisol-GS injected into the anterior chamber, which showed an improvement from 662.3 ± 126.5 to 613.5 ± 108.0 μm, yielding an improvement of 48.8 ± 34.3 μm. Injection of air into the anterior chamber leads to a significant decrease in corneal pachymetry. We thereby propose that injecting air intracamerally is an effective intraoperative intervention when visualization is negatively affected by corneal edema

A Pilot Study to Evaluate Genipin in <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i> Keratitis Models: Modulation of Pro-Inflammatory Cytokines and Matrix Metalloproteinases

Infectious keratitis is a vision-threatening microbial infection. The increasing antimicrobial resistance and the fact that severe cases often evolve into corneal perforation necessitate the development of alternative therapeutics for effective medical management. Genipin, a natural crosslinker, was recently shown to exert antimicrobial effects in an ex vivo model of microbial keratitis, highlighting its potential to serve as a novel treatment for infectious keratitis. This study aimed to evaluate the antimicrobial and anti-inflammatory effects of genipin in an in vivo model of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) keratitis. Clinical scores, confocal microscopy, plate count, and histology were carried out to evaluate the severity of keratitis. To assess the effect of genipin on inflammation, the gene expression of pro- and anti-inflammatory factors, including matrix metalloproteinases (MMPs), were evaluated. Genipin treatment alleviated the severity of bacterial keratitis by reducing bacterial load and repressing neutrophil infiltration. The expression of interleukin 1B (IL1B), interleukin 6 (IL6), interleukin 8 (IL8), interleukin 15 (IL15), tumor necrosis factor-α (TNF-α), and interferon γ (IFNγ), as well as MMP2 and MMP9, were significantly reduced in genipin-treated corneas. Genipin promoted corneal proteolysis and host resistance to S. aureus and P. aeruginosa infection by suppressing inflammatory cell infiltration, regulating inflammatory mediators, and downregulating the expression of MMP2 and MMP9