Local administration of myeloid-derived suppressor cells prevents progression of immune-mediated dry eye disease

Myeloid derived suppressor cells (MDSCs) are a heterogenous population of immature hematopoietic precursors with known immunoregulatory functions. The immunosuppressive role of MDSCs has been highlighted in several inflammatory ophthalmic disorders; however, their therapeutic application in suppressing the immune-mediated changes in dry eye disease (DED) has not been studied. We observed significant reduction in antigen presenting cell (APC) frequencies and their maturation in the presence of MDSCs. Moreover, co-culturing MDSCs with T helper 17 cells (Th17) resulted in reduced Th17 frequencies and their IL-17 expression. On the contrary, MDSCs maintained regulatory T cell frequencies and enhanced their function in-vitro. Furthermore, we delineated the role of interleukin-10 (IL-10) secreted by MDSCs in their immunoregulatory functions. We confirmed these results by flow cytometry analysis and observed that treatment with MDSCs in DED mice effectively suppressed the maturation of APCs, pathogenic Th17 response, and maintained Treg function and significantly ameliorated the disease. The results in this study highlight the potential therapeutic application of MDSCs in treating refractory DED.

Artificial Intelligence (AI) for Early Diagnosis of Retinal Diseases

Artificial intelligence (AI) has emerged as a transformative tool in the field of ophthalmology, revolutionizing disease diagnosis and management. This paper provides a comprehensive overview of AI applications in various retinal diseases, highlighting its potential to enhance screening efficiency, facilitate early diagnosis, and improve patient outcomes. Herein, we elucidate the fundamental concepts of AI, including machine learning (ML) and deep learning (DL), and their application in ophthalmology, underscoring the significance of AI-driven solutions in addressing the complexity and variability of retinal diseases. Furthermore, we delve into the specific applications of AI in retinal diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), Macular Neovascularization, retinopathy of prematurity (ROP), retinal vein occlusion (RVO), hypertensive retinopathy (HR), Retinitis Pigmentosa, Stargardt disease, best vitelliform macular dystrophy, and sickle cell retinopathy. We focus on the current landscape of AI technologies, including various AI models, their performance metrics, and clinical implications. Furthermore, we aim to address challenges and pitfalls associated with the integration of AI in clinical practice, including the "black box phenomenon", biases in data representation, and limitations in comprehensive patient assessment. In conclusion, this review emphasizes the collaborative role of AI alongside healthcare professionals, advocating for a synergistic approach to healthcare delivery. It highlights the importance of leveraging AI to augment, rather than replace, human expertise, thereby maximizing its potential to revolutionize healthcare delivery, mitigate healthcare disparities, and improve patient outcomes in the evolving landscape of medicine.

Effects of Diabetes Mellitus on Corneal Immune Cell Activation and the Development of Keratopathy

Diabetes mellitus (DM) is one of the most prevalent diseases globally, and its prevalence is rapidly increasing. Most patients with a long-term history of DM present with some degree of keratopathy (DK). Despite its high incidence, the underlying inflammatory mechanism of DK has not been elucidated yet. For further insights into the underlying immunopathologic processes, we utilized streptozotocin-induced mice to model type 1 DM (T1D) and B6.Cg-Lepob/J mice to model type 2 DM (T2D). We evaluated the animals for the development of clinical manifestations of DK. Four weeks post-induction, the total frequencies of corneal CD45+CD11b+Ly-6G- myeloid cells, with enhanced gene and protein expression levels for the proinflammatory cytokines TNF-α and IL-1β, were higher in both T1D and T2D animals. Additionally, the frequencies of myeloid cells/mm2 in the sub-basal neural plexus (SBNP) were significantly higher in T1D and T2D compared to non-diabetic mice. DK clinical manifestations were observed four weeks post-induction, including significantly lower tear production, corneal sensitivity, and epitheliopathy. Nerve density in the SBNP and intraepithelial terminal endings per 40x field were lower in both models compared to the normal controls. The findings of this study indicate that DM alters the immune quiescent state of the cornea during disease onset, which may be associated with the progressive development of the clinical manifestations of DK.

Ocular Surface Disease as Extraesophageal Gastroesophageal Reflux Disease Manifestation: A Specific Therapeutic Strategy

PURPOSE

Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are common gastrointestinal disorders with extraesophageal manifestations (EGERD). Studies showed a correlation between GERD/LPR and ocular discomfort. Our aim was to report the prevalence of ocular involvement in patients with GERD/LPR, describe clinical and biomolecular manifestations, and provide a treatment strategy for this novel EGERD comorbidity.

METHODS

Fifty-three patients with LPR and 25 healthy controls were enrolled in this masked randomized controlled study. Fifteen naive patients with LPR were treated with magnesium alginate eye drops and oral therapy (magnesium alginate and simethicone tablets) with a 1-month follow-up. Clinical ocular surface evaluation, Ocular Surface Disease Index questionnaire, tear sampling, and conjunctival imprints were performed. Tear pepsin levels were quantified by ELISA. Imprints were processed for human leukocyte antigen-DR isotype (HLA-DR) immunodetection and for HLA-DR, IL8, mucin 5AC (MUC5AC), nicotine adenine dinucleotide phosphate (NADPH), vasoactive intestinal peptide (VIP), and neuropeptide Y (NPY) transcript expression (PCR).

RESULTS

Patients with LPR had significantly increased Ocular Surface Disease Index ( P < 0.05), reduced T-BUT ( P < 0.05), and higher meibomian gland dysfunction ( P < 0.001) compared with controls. After treatment, tear break-up time (T-BUT) and meibomian gland dysfunction scores improved to normal values. Pepsin concentration increased in patients with EGERD ( P = 0.01) and decreased with topical treatment ( P = 0.0025), significantly. HLA-DR, IL8, and NADPH transcripts were significantly increased in the untreated versus controls and comparable significant values were obtained after treatment ( P < 0.05). MUC5AC expression significantly increased with treatment ( P = 0.005). VIP transcripts were significantly higher in EGERD than in controls and decreased with the topical treatment ( P < 0.05). No significant changes were observed in NPY.

CONCLUSIONS

We report an increase in prevalence of ocular discomfort in patients with GERD/LPR. The observations of VIP and NPY transcripts demonstrate the potential neurogenic nature of the inflammatory state. Restoration of the ocular surface parameters suggests the potential usefulness of topical alginate therapy.

Unlocking the versatile potential: Adipose-derived mesenchymal stem cells in ocular surface reconstruction and oculoplastics

This review comprehensively explores the versatile potential of mesenchymal stem cells (MSCs) with a specific focus on adipose-derived MSCs. Ophthalmic and oculoplastic surgery, encompassing diverse procedures for ocular and periocular enhancement, demands advanced solutions for tissue restoration, functional and aesthetic refinement, and aging. Investigating immunomodulatory, regenerative, and healing capacities of MSCs, this review underscores the potential use of adipose-derived MSCs as a cost-effective alternative from bench to bedside, addressing common unmet needs in the field of reconstructive and regenerative surgery.

Therapeutic Effects of Stimulating the Melanocortin Pathway in Regulating Ocular Inflammation and Cell Death

Alpha-melanocyte-stimulating hormone (α-MSH) and its binding receptors (the melanocortin receptors) play important roles in maintaining ocular tissue integrity and immune homeostasis. Particularly extensive studies have demonstrated the biological functions of α-MSH in both immunoregulation and cyto-protection. This review summarizes the current knowledge of both the physiological and pathological roles of α-MSH and its receptors in the eye. We focus on recent developments in the biology of α-MSH and the relevant clinical implications in treating ocular diseases.

HYPERACUTE PSEUDOPHAKIC MACULAR EDEMA VANISHING WITHIN 72 HOURS: A CASE SERIES

PURPOSE

To report three cases of massive pseudophakic macular edema occurring the day after uneventful cataract surgery and resolving in 24 to 72 hours.

METHODS

Observational case series.

RESULTS

A 68-year-old woman affected by systemic lupus erythematosus and antiphospholipid syndrome displayed massive macular edema on optical coherence tomography scan one day after uneventful cataract surgery. Routine postoperative topical eye drops (chloramphenicol/betamethasone 4 times a day and bromfenac 2 times a day) were continued without additional medications. Three days later, optical coherence tomography showed a completely recovered, normal fovea. Two similar cases were documented. A 73-year-old man and a 53-year-old man underwent cataract surgery and started the mentioned topical postoperative therapy. Severe macular edema was diagnosed the day after surgery and resolved in 24 and 48 hours, respectively.

CONCLUSION

Massive macular edema may occur immediately after uncomplicated cataract and then disappear within 1 to 3 days, without invasive therapies. This is a very significant event that may follow cataract surgery, and that was previously unreported.

Corneal Superficial Plaque Formation After Recombinant Human Nerve Growth Factor Use in a Patient With Neurotrophic Keratopathy and Limbal Stem Cell Deficiency From Mucous Membrane Pemphigoid

PURPOSE

The aim of this study was to report a rare observation of corneal superficial plaque formation after topical recombinant human nerve growth factor (rhNGF) treatment for a nonhealing epithelial defect in a patient with advanced mucous membrane pemphigoid, limbal stem cell deficiency, and neurotrophic keratopathy.

METHODS

This study was a case report.

RESULTS

A 72-year-old man with a complex course of mucous membrane pemphigoid, leading to cicatrizing keratoconjunctivits, limbal stem cell deficiency, and neurotrophic keratopathy presented with a recurrent persistent epithelial defect in the right eye. After a long course of unsuccessful epithelial healing, despite various treatment modalities, he was administered topical rhNGF (cenegermin 0.002%; Oxervate, Dompé US Inc., Boston, MA) which successfully resolved the epithelial defect. However, on day 22 posttreatment, an unusual white, thick, adherent corneal superficial plaque formed. rhNGF was stopped and the plaque was carefully removed. Subsequently, there was no recurrence, and the patient's epithelial healing remained stable.

CONCLUSIONS

Although the successful resolution of the persistent epithelial defect with rhNGF administration was notable, the development of the unusual epithelial overgrowth emphasizes the importance of vigilant monitoring and evaluation when using rhNGF in complex ocular conditions. Making informed decisions on the timing of discontinuing rhNGF can lead to desirable effects of the drug while mitigating additional side effects when managing such challenging cases.

Insights into mustard gas keratopathy- characterizing corneal layer-specific changes in mice exposed to nitrogen mustard

Exposure to mustard agents, such as sulfur mustard (SM) and nitrogen mustard (NM), often results in ocular surface damage. This can lead to the emergence of various corneal disorders that are collectively referred to as mustard gas keratopathy (MGK). In this study, we aimed to develop a mouse model of MGK by using ocular NM exposure, and describe the subsequent structural changes analyzed across the different layers of the cornea. A 3 μL solution of 0.25 mg/mL or 5 mg/mL NM was applied to the center of the cornea via a 2-mm filter paper for 5 min. Mice were evaluated prior to and after exposure on days 1, 3, 7, 14, and 28 for 4 weeks using slit lamp examination with fluorescein staining. Anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM) tracked changes in the epithelium, stroma, and endothelium of the cornea. Histologic evaluation was used to examine corneal cross-sections collected at the completion of follow-up. Following exposure, mice experienced central corneal epithelial erosion and thinning, accompanied by a decreased number of nerve branches in the subbasal plexus and increased activated keratocytes in the stroma in both dosages. The epithelium was recovered by day 3 in the low dose group, followed by exacerbated punctuate erosions alongside persistent corneal edema that arose and continued onward to four weeks post-exposure. The high dose group showed persistent epitheliopathy throughout the study. The endothelial cell density was reduced, more prominent in the high dose group, early after NM exposure, which persisted until the end of follow-up, along with increased polymegethism and pleomorphism. Microstructural changes in the central cornea at 4 weeks post-exposure included dysmorphic basal epithelial cells and reduced epithelial thickness, and in the limbal cornea included decreased cellular layers. We present a mouse model of MGK using NM that successfully replicates ocular injury caused by SM in humans who have been exposed to mustard gas.

Meningococcal Conjunctivitis in a 54-Year-Old Man: Case Report and Review of the Literature

Neisseria meningitidis represents an uncommon pathogen of acute bacterial conjunctivitis. In this brief report, we describe a case of meningococcal conjunctivitis in an immunocompetent adult male, with a review of the literature. The patient went to the outpatient ophthalmology clinic complaining of severe ocular discomfort, burning, and redness for more than 2 weeks and, at slit lamp examination, he was diagnosed with a mild conjunctivitis. Microbiology cultures of ocular swabs revealed the growth of colonies, as pure culture, identified as N. meningitidis of serogroup B. A diagnosis of primary meningococcal conjunctivitis was made and treatment of patient with intramuscular injections of ceftriaxone in addition to topical moxifloxacin eye drops for 2 weeks led to clinical improvement and, finally, to a complete recovery, in accordance with microbiological findings. Ophthalmologists must be aware of the possibility of primary meningococcal conjunctivitis cases, even uncommon, and the need to treat with systemic antibiotics and their close contacts with adequate antibiotic chemoprophylaxis.

Inflammation and Dry Eye-like Symptoms as Concomitant Manifestations of Laryngo-Pharyngeal Reflux

PURPOSE

Laryngo-pharyngeal reflux (LPR) is a common worldwide disease. LPR symptoms may involve distant organs and tissues including the ocular surface with manifestations of a Dry Eye-like disease. We evaluated the concomitant involvement of the ocular surface in patients with LPR. We also defined the clinical signs and the roles of chemical and neuro-inflammatory mediators in the tears of LPR patients.

METHODS

Seventy-seven patients with LPR (mean age 65.8 ± 16.8 SD) and 25 healthy controls (mean age 56.5 ± 16.3 SD) were recruited from the otorhinolaryngology unit. Each subject was evaluated for the presence of concomitant ocular surface disease through clinical examination, including the measurement of tear break-up time (TBUT) and the Ocular Surface Disease Index (OSDI) questionnaire. Tears and conjunctival imprints were collected. The presence of pepsin in tears was detected by ELISA. HLA-DR in conjunctival imprints were imaged by immunofluorescence microscopy. RT-PCR quantified conjunctival mRNA transcripts of HLA-DR, IL-8, MUC5AC, NADPH, VIP, and NPY.

RESULTS

Patients with LPR had significantly increased OSDI and reduced TBUT scores compared to control subjects (p < 0.05 each). Pepsin was detected in 51% of patient tears while it was not measurable in the controls (p < 0.01). Immunoreactivity for HLA-DR in the conjunctival impressions was greater than for the controls with an increased mRNA expression (p < 0.05). mRNA transcripts for IL-8, NADPH, and VIP were significantly increased in LPR patients (p < 0.05 each), but neither MUC5AC nor NPY were different from controls.

CONCLUSIONS

LPR can adversely affect the ocular surface, leading to moderate signs and symptoms of dry eye. This study provides evidence that the presence of pepsin, HLA-DR immunoreactivity, and increased mRNA expression of neuro-inflammatory markers in the tears and conjunctival imprints of LPR patients suggests a potential link between LPR inflammation and ocular surface disease.

Role of Immune Cell Diversity and Heterogeneity in Corneal Graft Survival: A Systematic Review and Meta-Analysis

Corneal transplantation is one of the most successful forms of solid organ transplantation; however, immune rejection is still a major cause of corneal graft failure. Both innate and adaptive immunity play a significant role in allograft tolerance. Therefore, immune cells, cytokines, and signal-transduction pathways are critical therapeutic targets. In this analysis, we aimed to review the current literature on various immunotherapeutic approaches for corneal-allograft rejection using the PubMed, EMBASE, Web of Science, Cochrane, and China National Knowledge Infrastructure. Retrievable data for meta-analysis were screened and assessed. The review, which evaluated multiple immunotherapeutic approaches to prevent corneal allograft rejection, showed extensive involvement of innate and adaptive immunity components. Understanding the contribution of this immune diversity to the ocular surface is critical for ensuring corneal allograft survival.

Pharmacogenomics and Pharmacogenetics: In Silico Prediction of Drug Effects in Treatments for Novel Coronavirus SARS-CoV2 Disease

The latest developments in precision medicine allow the modulation of therapeutic approaches in different pathologies on the basis of the specific molecular characterization of the patient. This review of the literature coupled with in silico analysis was to provide a selected screening of interactions between single-nucleotide polymorphisms (SNPs) and drugs (repurposed, investigational, and biological agents) showing efficacy and toxicityin counteracting Covid-19 infection. In silico analysis of genetic variants related to each drug was performed on such databases as PharmGKB, Ensembl Genome Browser, www.drugs.com, and SNPedia, with an extensive literature review of papers (to May 10, 2020) on Covid-19 treatments using Medline, Embase, International Pharmaceutical Abstracts, PharmGKB, and Google Scholar. The clinical relevance of SNPs, known as both drug targets and markers, considering genetic variations with known drug responses, and the therapeutic consequences are discussed. In the context of clinical treatment of Covid-19, including infection prevention, control measures, and supportive care, this review highlights the importance of a personalized approach in the final selection of therapy, which is probably essential in the management of the Covid-19 pandemic.

KRAS and BRAF Concomitant Mutations in a Patient with Metastatic Colon Adenocarcinoma: An Interesting Case Report

A 68-year-old female patient with tenesmus and blood in the stool was admitted to the S.G. Moscati Hospital of Taranto. Investigations revealed infiltrative mucinous colon adenocarcinoma accompanied by lymph node metastases. Following surgery and adjuvant chemotherapy, computed tomography (CT) and carcinoembryonic antigen screening were negative. Two years later, CT demonstrated a liver lesion. Histologic and genetic analyses confirmed the diagnosis of metastatic colorectal cancer with the coexistence of KRAS and BRAF mutations in hepatic metastases and the presence of the BRAF V600E in the primary tumour. It is unclear whether the lack of response was due to BRAF mutations, but the data suggest that mutated BRAF confers resistance to anti-epidermal growth factor receptor therapy. In our patient, BRAF mutation turned out to be a negative prognostic factor, and it may have been the cause of clinical implications for disease progression and therapeutic responses.