Antioxidant Carbon Dots Nanozyme Loaded in Thermosensitive in situ Hydrogel System for Efficient Dry Eye Disease Treatment.

Purpose: Dry eye disease (DED) is a multifactorial ocular surface disease with a rising incidence. Therefore, it is urgent to construct a reliable and efficient drug delivery system for DED treatment. Methods: In this work, we loaded C-dots nanozyme into a thermosensitive in situ gel to create C-dots@Gel, presenting a promising composite ocular drug delivery system to manage DED. Results: This composite ocular drug delivery system (C-dots@Gel) demonstrated the ability to enhance adherence to the corneal surface and extend the ocular surface retention time, thereby enhancing bioavailability. Furthermore, no discernible ocular surface irritation or systemic toxicity was observed. In the DED mouse model induced by benzalkonium chloride (BAC), it was verified that C-dots@Gel effectively mitigated DED by stabilizing the tear film, prolonging tear secretion, repairing corneal surface damage, and augmenting the population of conjunctival goblet cells. Conclusion: Compared to conventional dosage forms (C-dots), the C-dots@Gel could prolong exhibited enhanced retention time on the ocular surface and increased bioavailability, resulting in a satisfactory therapeutic outcome for DED.

Tear Proteomics in Infants at Risk of Retinopathy of Prematurity: A Feasibility Study.

Purpose: This feasibility study investigated the practicability of collecting and analyzing tear proteins from preterm infants at risk of retinopathy of prematurity (ROP). We sought to identify any tear proteins which might be implicated in the pathophysiology of ROP as well as prognostic markers. Methods: Schirmer's test was used to obtain tear samples from premature babies, scheduled for ROP screening, after parental informed consent. Mass spectrometry was used for proteomic analysis. Results: Samples were collected from 12 infants, which were all adequate for protein analysis. Gestational age ranged from 25 + 6 to 31 + 1 weeks. Postnatal age at sampling ranged from 19 to 66 days. One infant developed self-limiting ROP. Seven hundred one proteins were identified; 261 proteins identified in the majority of tear samples, including several common tear proteins, were used for analyses. Increased risk of ROP as determined by the postnatal growth ROP (G-ROP) criteria was associated with an increase in lactate dehydrogenase B chain in tears. Older infants demonstrated increased concentration of immunoglobulin complexes within their tear samples and two sets of twins in the cohort showed exceptionally similar proteomes, supporting validity of the analysis. Conclusions: Tear sampling by Schirmer test strips and subsequent proteomic analysis by mass spectrometry in preterm infants is feasible. A larger study is required to investigate the potential use of tear proteomics in identification of ROP. Translational Relevance: Tear sampling and subsequent mass spectrometry in preterm infants is feasible. Investigation of the premature tear proteome may increase our understanding of retinal development and provide noninvasive biomarkers for identification of treatment-warranted ROP.

The Role of Aquaporin 4 in Lacrimal Gland Ductal Fluid Secretion in Mice.

Purpose: Earlier reports highlighted the predominant presence of aquaporin 4 (AQP4) in the duct cells of rabbit lacrimal glands (LGs). Whereas significant alterations in AQP4 mRNA levels have been observed in experimental dry eye and during pregnancy, the impact of AQP4 in LG ductal fluid production remains unclear. In our recent work, the role of AQP4 in LG ductal fluid secretion was investigated utilizing wild type (WT) and AQP4 knock out (KO) mice. Methods: Tear production was assessed in both WT and KO animals. Immunostaining was used to identify AQP4 protein. Duct segments were harvested from LGs of WT and KO mice. Fluid secretion and filtration permeability (Pf) were quantified using video-microscopy. Ductal tear production, elicited by a cell-permeable cAMP analogue (8-bromo cAMP), carbachol, vasoactive intestinal peptide (VIP), and phenylephrine (PHE), were assessed in both WT and KO ducts. Results: A higher expression of AQP4 protein was noted in the duct cells from WT mice when compared to acinar cells. Pf did not show notable alterations between WT and AQP4 KO ducts. Carbachol elicited comparable secretory responses in ducts from both WT and KO animals. However, 8-bromo cAMP, VIP, and PHE stimulation resulted in decreased secretion in ducts from AQP4 KO LGs. Conclusions: Our findings underscore the functional relevance of AQP4 in the fluid production of mouse LG ducts. AQP4 seems to play different roles in fluid secretions elicited by different secretagogues. Specifically, cAMP-mediated, and adrenergic agonist-related secretions were reduced in AQP4 KO ducts.

Meibography-Guided Electroepilation for Congenital Distichiasis: A Novel Surgical Technique.

PURPOSE: Congenital distichiasis is managed either by ablation, using laser, cryotherapy, or electroepilation, or by surgical excision with mucous membrane grafting. Ablative procedures are usually blind as the exact depth of distichiatic eyelashes is unknown. The described surgical technique utilizes meibography for imaging the root and depth of distichiatic eyelashes that aided in performing electroepilation. METHODS: Six patients (n = 24 eyelids; mean age 15.5 ± 12.2 years) underwent infrared meibography (Oculus Keratograph 5 M) and noninvasive tear breakup time prospectively. Eyelashes were electroepilated using a premarked needle inserted at a depth based on meibography findings in 4 patients. Surgical success was defined as no distichiatic eyelash regrowth and functional success was defined as the resolution of symptoms at a minimum of 3 months of follow-up. RESULTS: All 6 patients had all 4 eyelids involved to varying degrees, with a total of 230 distichiatic eyelashes. The median number of distichiatic eyelashes was 9 in the upper eyelids and 4.5 in the lower eyelids. Meibography revealed visible distichiatic eyelash roots in 70% of eyelashes in the upper eyelid and 87.8% in the lower eyelid, respectively. The median eyelash root depth was 2.7 mm (mean 2.9 mm, range 1.8-5.4 mm). The mean noninvasive tear breakup time was 12.2 seconds despite absent or rudimentary meibomian gland segments seen on meibography. The anatomical success was 75% (12/16 eyelids), and functional success was 87.5% (7/8 eyes) at a median follow-up of 5.5 months. CONCLUSION: Preoperative infrared meibography in eyelids with congenital distichiasis helps estimate the eyelash depth and can be used to guide eyelash ablation procedures.

The effect of sodium hyaluronate on dry eye and corneal epithelial thickness following cataract surgery.

PURPOSE: To evaluate the effects of sodium hyaluronate drops on dry eye parameters and corneal epithelial thickness following cataract surgery. METHODS: The study included 84 patients who underwent uncomplicated phacoemulsification. In Group A, 0.15% sodium hyaluronate drops were added to the postoperative antibiotic/anti-inflammatory treatment. In Group B, only antibiotic/anti-inflammatory treatment was applied. Preoperatively and at 1 week and 1 month postoperatively, all the patients were evaluated in respect of tear break-up time (TBUT), the Schirmer test under anesthesia, the corneal fluorescein staining (CFS) score, mean central corneal thickness (CCT) and mean central corneal epithelial thickness (CCET), and the two groups were compared. RESULTS: A statistically significant difference was determined between the two groups at postoperative 1 month in respect of TBUT, Schirmer test, CFS score, and CCET (p < 0.01). In Group A, a statistically significant increase was determined in the TBUT and Schirmer values at 1 month postoperatively (p < 0.01, p = 0.01, respectively) and in Group B, these values were decreased compared to preoperatively (p < 0.01). The CCET was determined to be significantly thinner in Group B 1 month postoperatively (p < 0.01). A significant increase in CCT was observed in both groups at postoperative 1 week (p < 0.01) and preoperative values were reached at 1 month postoperatively. CONCLUSION: In the patient group using sodium hyaluronate, significant differences were determined in all dry eye parameters and CCET. The use of hyaluronate sodium drops after cataract surgery was seen to improve dry eye parameters and contribute to a healthy ocular surface by ensuring continuity of the corneal epithelium.

[Clinical study of the cytokine panel in the diagnosis of ocular chronic graft-versus-host disease].

Objective: To investigate the association between cytokines and ocular chronic graft-versus-host disease (cGVHD) and identify specific biomarkers for ocular cGVHD to enhance clinical diagnosis, treatment, and evaluation. Methods: A mouse model of cGVHD was established to explore the correlation between cGVHD and serum cytokines. Based on the findings from the animal experiments and literature review, a panel of 16 cytokine combinations was identified. Enzyme-linked immunosorbent assay (ELISA) was used to compare the cytokine concentrations in the serum and tear samples from patients who underwent allogeneic hematopoietic stem cell transplantation from June 2017 to March 2022 at the Medical Center of Hematology, Xinqiao Hospital, Army Medical University. Results: ① Compared with the control group, mice with cGVHD exhibited elevated serum IL-1ß, IL-6, IL-8, IL-17, IFN-γ, CX3CL1, CXCL11, CXCL13, CCL11, and CCL19 concentrations (all P<0.05). ② Analysis of the cytokine profiles of the serum and tear samples revealed that compared with patients without ocular cGVHD, those with ocular cGVHD exhibited increased serum IL-8 [P=0.032, area under the curve (AUC) =0.678]; decreased serum IL-10 (P=0.030, AUC=0.701) ; elevated IL-8, IFN-γ, CXCL9, and CCL17 in tear samples; and lower IL-10 and CCL19 in tear samples (all P<0.05, all AUC>0.7). Moreover, cytokines in tear samples showed correlations with ocular surface parameters related to ocular cGVHD. Conclusions: Tear fluid demonstrates greater specificity and sensitivity as a biomarker for diagnosing ocular cGVHD than serum biomarkers. Among the identified cytokines in tear samples, IL-8, IL-10, IFN-γ, CXCL9, CCL17, and CCL19 serve as diagnostic biomarkers for ocular cGVHD post-transplantation, offering practical reference value for diagnosis.

Tear biomarkers.

An extensive exploration of lacrimal fluid molecular biomarkers in understanding and diagnosing a spectrum of ocular and systemic diseases is presented. The chapter provides an overview of lacrimal fluid composition, elucidating the roles of proteins, lipids, metabolites, and nucleic acids within the tear film. Pooled versus single-tear analysis is discussed to underline the benefits and challenges associated with both approaches, offering insights into optimal strategies for tear sample analysis. Subsequently, an in-depth analysis of tear collection methods is presented, with a focus on Schirmer's test strips and microcapillary tubes methods. Alternative tear collection techniques are also explored, shedding light on their applicability and advantages. Variability factors, including age, sex, and diurnal fluctuations, are examined in the context of their impact on tear biomarker analysis. The main body of the chapter is dedicated to discussing specific biomarkers associated with ocular discomfort and a wide array of ocular diseases. From dry eye disease and thyroid-associated ophthalmopathy to keratoconus, age-related macular degeneration, diabetic retinopathy, and glaucoma, the intricate relationship between molecular biomarkers and these conditions is thoroughly dissected. Expanding beyond ocular pathologies, the chapter explores the applicability of tear biomarkers in diagnosing systemic diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and cancer. This broader perspective underscores the potential of lacrimal fluid analysis in offering non-invasive diagnostic tools for conditions with far-reaching implications.

Topical naltrexone increases aquaporin 5 production in the lacrimal gland and restores tear production in diabetic rats.

Diabetes mellitus is a prevalent disease that is often accompanied by ocular surface abnormalities including delayed epithelial wound healing and decreased corneal sensitivity. The impact of diabetes on the lacrimal functional unit (LFU) and the structures responsible for maintaining tear homeostasis, is not completely known. It has been shown that the Opioid Growth Factor Receptor (OGFr), and its ligand, Opioid Growth Factor (OGF), is dysregulated in the ocular surface of diabetic rats leading to overproduction of the inhibitory growth peptide OGF. The opioid antagonist naltrexone hydrochloride (NTX) blocks the OGF-OGFr pathway, and complete blockade following systemic or topical treatment with NTX restores the rate of re-epithelialization of corneal epithelial wounds, normalizes corneal sensitivity, and reverses dry eye in diabetic animal models. These effects occur rapidly and within days of initiating treatment. The present study was designed to understand mechanisms related to the fast reversal (<5 days) of dry eye by NTX in type 1 diabetes (T1D) by investigating dysregulation of the LFU. The approach involved examination of the morphology of the LFU before and after NTX treatment. Male and female adult Sprague-Dawley rats were rendered hyperglycemic with streptozotocin, and after 6 weeks rats were considered to be a T1D model. Rats received topical NTX twice daily to one eye for 10 days. During the period of treatment, tear production and corneal sensitivity were recorded. On day 11, animals were euthanized and orbital tissues including conjunctiva, eyelids, and lacrimal glands, were removed and processed for histologic examination including immunohistochemistry. Male and female T1D rats had significantly decreased tear production and corneal insensitivity, significantly decreased number and size of lacrimal gland acini, decreased expression of aquaporin-5 (AQP5) protein and decreased goblet cell size. Thus, 10 days of NTX treatment restored tear production and corneal sensitivity to normal values, increased AQP5 expression, and restored the surface area of goblet cells to normal. NTX had no effect on the number of lacrimal gland acini or the number of conjunctival goblet cells. In summary, blockade of the OGF-OGFr pathway with NTX reversed corneal and lacrimal gland complications and restored some components of tear homeostasis confirming the efficacy of topical NTX as a treatment for ocular defects in diabetes.

Ocular surface immune transcriptome and tear cytokines in corneal infection patients.

Background: Microbial keratitis is one of the leading causes of blindness globally. An overactive immune response during an infection can exacerbate damage, causing corneal opacities and vision loss. This study aimed to identify the differentially expressed genes between corneal infection patients and healthy volunteers within the cornea and conjunctiva and elucidate the contributing pathways to these conditions' pathogenesis. Moreover, it compared the corneal and conjunctival transcriptomes in corneal-infected patients to cytokine levels in tears. Methods: Corneal and conjunctival swabs were collected from seven corneal infection patients and three healthy controls under topical anesthesia. RNA from seven corneal infection patients and three healthy volunteers were analyzed by RNA sequencing (RNA-Seq). Tear proteins were extracted from Schirmer strips via acetone precipitation from 38 cases of corneal infection and 14 healthy controls. The cytokines and chemokines IL-1ß, IL-6, CXCL8 (IL-8), CX3CL1, IL-10, IL-12 (p70), IL-17A, and IL-23 were measured using an antibody bead assay. Results: A total of 512 genes were found to be differentially expressed in infected corneas compared to healthy corneas, with 508 being upregulated and four downregulated (fold-change (FC) <-2 or > 2 and adjusted p <0.01). For the conjunctiva, 477 were upregulated, and 3 were downregulated (FC <-3 or ≥ 3 and adjusted p <0.01). There was a significant overlap in cornea and conjunctiva gene expression in patients with corneal infections. The genes were predominantly associated with immune response, regulation of angiogenesis, and apoptotic signaling pathways. The most highly upregulated gene was CXCL8 (which codes for IL-8 protein). In patients with corneal infections, the concentration of IL-8 protein in tears was relatively higher in patients compared to healthy controls but did not show statistical significance. Conclusions: During corneal infection, many genes were upregulated, with most of them being associated with immune response, regulation of angiogenesis, and apoptotic signaling. The findings may facilitate the development of treatments for corneal infections that can dampen specific aspects of the immune response to reduce scarring and preserve sight.

Codetermination of antimicrobial agents in rabbit tear fluid using LC-MS/MS assay: Insights into ocular pharmacokinetic study.

Managing ocular microbial infections typically requires pharmacotherapy using antibiotic eye drops, such as moxifloxacin hydrochloride (MFX), combined with an antifungal agent like amphotericin B (AB). We carried out and validated an LC-MS/MS assay to quantify these compounds in rabbit tear fluid in order to look into the pharmacokinetics of these two drugs. We employed a protein precipitation technique for the extraction of drugs under examination. A Waters Symmetry C18 column was used to separate the analytes and internal standard. The composition of the mobile phase was like (A) 0.1% v/v formic acid in water and (B) methanol. The detection of MFX and AB was accomplished through the utilization of positive ion electrospray ionization under multiple reaction monitoring mode. The linearity curves for both analytes exhibited an acceptable trendline across a concentration range of 2.34-300 ng/mL for MFX and 7.81-1000 ng/mL for AB in surrogate rabbit tear fluid. The lower limit of quantitation for MFX was 2.34 ng/mL, while for AB, it was 7.81 ng/mL. The approach was strictly validated, encompassing tests of selectivity, linearity (with r2 > 0.99), precision, accuracy, matrix effects, and stability. Consequently, we employed this method to evaluate the pharmacokinetics profiles of MFX and AB in rabbit tear fluid following single topical doses.

Loose suture-related ocular surface inflammation and activation of conjunctiva-associated lymphoid tissue in patients after keratoplasty.

The purpose of this study is to evaluate loose suture-related inflammation and activation of conjunctiva-associated lymphoid tissue (CALT) in patients after keratoplasty. The patients who were treated with keratoplasty at the First Affiliated Hospital of Harbin Medical University between 2015 and 2022 were recruited into the study. We evaluated the time and location of loose suture development in patients after keratoplasty. In addition, in vivo confocal microscopy was used to evaluate the activation of CALT and the accumulation of inflammatory cells around loose sutures. Meso Scale Discovery assay detection kits were used to evaluate the inflammatory cytokines in the tears of patients before and after the loose suture was removed. In this study, we collected the information from 212 cases (212 eyes) who had PK (126 eyes) and DALK-treated (86 eyes) for corneal transplantation, including 124 males and 88 females, aged 14-84 years old. The average age was 50.65 ± 16.81 years old. Corneal sutures were more prone to loose at 3 months and 6 months after keratoplasty, and the frequent sites were at 5 and 6 o'clock. An increased number of inflammatory cells could be observed around the loose sutures than normal sutures (P < 0.001). In CALT, the density of diffuse lymphocytes (P < 0.001), follicles (P < 0.001), and parafollicular lymphocytes (P < 0.001) were higher and the central reflection of the follicles (P < 0.001) was stronger when suture loosening happened. The levels of inflammatory cytokines such as IL-1ß (P = 0.003), IL-8 (P = 0.012), and TNF-α (P < 0.001) were higher in the tears of the patients with loose sutures. The activation of CALT was partly settled after removing the loose sutures. In conclusion, loose sutures after corneal transplantation can lead to increased infiltration of inflammatory cells, activation of CALT, and increased secretion of inflammatory cytokines in the tears of patients. Regular follow-up to identify and solve the problem in time can avoid suture-related complications.

Meibum Lipidomic Analysis in Evaporative Dry Eye Subjects.

Meibomian Glands (MG) are sebaceous glands responsible for the production of meibum, the main component of the Tear Film Lipid Layer (TFLL). The TFLL facilitates the spread of the tear film over the ocular surface, provides stability and reduces tear evaporation. Alterations in meibum composition lead to different ocular alterations like Meibomian Gland Dysfunction (MGD) and subsequent Evaporative Dry Eye (EDE). The aim of the present study was to investigate the composition and abundance of meibum lipids and their relationship with eyelid margin abnormalities, lipid layer patterns and MG status. The study utilizes a lipidomic approach to identify and quantify lipids in meibum samples using an Elute UHPLC system. This system considered all four dimensions (mass/charge, retention time, ion mobility and intensity) to provide the accurate identification of lipid species. Samples were categorized as healthy or low/no signs of alteration (group 1) or severe signs of alteration or EDE/MGD (group 2). The current investigation found differences in Variable Importance in Projection lipid abundance between both groups for the MGD signs studied. Changes in meibum composition occur and are related to higher scores in eyelid margin hyperaemia, eyelid margin irregularity, MG orifice plugging, MG loss and lipid layer pattern.

A New Immortalized Human Lacrimal Gland Cell Line.

The lacrimal gland is crucial for maintaining ocular health by producing the aqueous component of the tear film, which hydrates and nourishes the ocular surface. Decreased production of this component results in dry eye disease, a condition affecting over 250 million people worldwide. However, the scarcity of primary human material for studying its underlying mechanisms and the absence of a cell model for human lacrimal gland epithelial cells present significant challenges. Here, we describe the generation of immortalized human lacrimal gland cell lines through the introduction of an SV40 antigen. We successfully isolated and characterized three cell clones from a female lacrimal gland donor, confirming their epithelial identity through genomic and protein analyses, including PCR, RNAseq, immunofluorescence and cultivation in a 3D spheroid model. Our findings represent a significant advancement, providing improved accessibility to investigate the molecular pathogenesis mechanisms of dry eye disease and potential therapeutic interventions. We identified the expression of typical epithelial cell marker genes and demonstrated the cells' capability to form 2D cell sheets and 3D spheroids. This establishment of immortalized human lacrimal gland cells with epithelial characteristics holds promise for future comprehensive studies, contributing to a deeper understanding of dry eye disease and its cellular mechanisms.

The level of cytokines in tears as a novel indicator of demyelinating diseases.

INTRODUCTION: A novel research objective is to identify new molecules in more readily accessible biological fluids that could be used in the diagnosis of multiple sclerosis (MS) and other demyelinating disorders. AIM: To compare the level of selected cytokines in tears between patients with MS or other demyelinating disorder and healthy controls. MATERIAL AND METHODS: 84 patients with diagnosed MS during remission or with other demyelinating disease of the CNS and 70 healthy controls were enrolled in the study. Tears were collected without any stimulation and stored till the day of assessment. The concentration of selected cytokines was measured by the Bio-Plex Pro Human cytokine screening panel 27 cytokines assay according to the manufacturer's instructions. Statistical analysis was performed with Statistica 13. RESULTS: IL-1b level was significantly lower in the study group compared to the control group [3,6 vs 8.71, p < 0.001]. The same pattern was observed for IL-6 [3,1 vs 5.26, p = 0.027] and IL-10 [1,7 vs 10.92, p < 0.001] (Table 1). In the study group, IL-1RA (p = 0.015), IL-5 (p = 0.04), IL-9 (p = 0.014), and IL-15 (p = 0.037) showed significant correlations with age. In the total sample, IL-1Ra (p = 0.016) and IFN-g (p = 0.041) were significantly correlated with age, while in the control group, IL-8 (p = 0.09), MIP-1a (p = 0.009), and RANTES (p = 0.031) showed significant correlations. CONCLUSIONS: Our results show that MS and other demyelination diseases lead to decrease in the overall level of cytokines in tears. Further research is needed to determine the role of tear fluid in the assessment of demyelinating disorders like MS.

Raman spectroscopy assisted tear analysis: A label free, optical approach for noninvasive disease diagnostics.

In recent times, tear fluid analysis has garnered considerable attention in the field of biomarker-based diagnostics due to its noninvasive sample collection method. Tears encompass a reservoir of biomarkers that assist in diagnosing not only ocular disorders but also a diverse list of systemic diseases. This highlights the necessity for sensitive and dependable screening methods to employ tear fluid as a potential noninvasive diagnostic specimen in clinical environments. Considerable research has been conducted to investigate the potential of Raman spectroscopy-based investigations for tear analysis in various diagnostic applications. Raman Spectroscopy (RS) is a highly sensitive and label free spectroscopic technique which aids in investigating the molecular structure of samples by evaluating the vibrational frequencies of molecular bonds. Due to the distinct chemical compositions of different samples, it is possible to obtain a sample-specific spectral fingerprint. The distinctive spectral fingerprints obtained from Raman spectroscopy enable researchers to identify specific compounds or functional groups present in a sample, aiding in diverse biomedical applications. Its sensitivity to changes in molecular structure or environment provides invaluable insights into subtle alterations associated with various diseases. Thus, Raman Spectroscopy has the potential to assist in diagnosis and treatment as well as prognostic evaluation. Raman spectroscopy possesses several advantages, such as the non-destructive examination of samples, remarkable sensitivity to structural variations, minimal prerequisites for sample preparation, negligible interference from water, and the aptness for real-time investigation of tear samples. The purpose of this review is to highlight the potential of Raman spectroscopic technique in facilitating the clinical diagnosis of various ophthalmic and systemic disorders through non-invasive tear analysis. Additionally, the review delves into the advancements made in Raman spectroscopy with regards to paper-based sensing substrates and tear analysis methods integrated into contact lenses. Furthermore, the review also addresses the obstacles and future possibilities associated with implementing Raman spectroscopy as a routine diagnostic tool based on tear analysis in clinical settings.

A surface-engineered contact lens for tear fluid biomolecule sensing.

The eyes provide rich physiological information and offer diagnostic potential as a sensing site, and probing tear constituents via the wearable contact lens could be explored for healthcare monitoring. Herein, we propose a novel adhesive contrast contact lens platform that can split tear film by natural means of tear secretion and blinking. The adhesive contrast is realized by selective grafting of a lubricant onto a polydimethylsiloxane (PDMS)-based contact lens, leading to high pinning zones on a non-adhesive background. The difference in contact angle hysteresis facilitates the liquid splitting. Further, the method offers control over the droplet volume by controlling the zone dimension. The adhesive contrast contact lens is coupled with fluorescent spectroscopic as well as colorimetric techniques to realize its potential as a diagnostic platform. The adhesive contrast contact lens is exploited to detect the level of lactoferrin in tear by sensitizing split droplets with Tb3+ ions. The adhesive contrast contact lens integrated with a fluorescence spectrometer was able to detect the lactoferrin level up to a concentration of 0.25 mg mL-1. Additionally, a colorimetric detection based on the fluorescence of the lactoferrin-terbium complex is demonstrated for the measurement of lactoferrin, with a limit of detection in the physiological range up to 0.5 mg mL-1.

Effects of Topical 0.05% Cyclosporine A on Dry Eye Symptoms and Parameters Following Small Incision Lenticule Extraction.

PURPOSE: To evaluate the effects of topical 0.05% cyclosporine A on Ocular Surface Disease Index (OSDI) score and ocular surface parameters after small incision lenticule extraction (SMILE) for myopia. METHODS: In this study, 151 patients who underwent SMILE were randomized into the control group (71 eyes) and the 0.05% cyclosporine A group (80 eyes). Both groups received standard treatment during the 1 month after SMILE. Over the next 3 months, The control group continued standard therapy (0.3% sodium hyaluronate) and the 0.05% cyclosporine A group received additional 0.05% cyclosporine A. OSDI total and subscale scores, non-invasive tear break-up time (NIBUT), tear lipid layer thickness (LLT), and tear meniscus height (TMH) were assessed preoperatively and postoperatively. RESULTS: Compared to baseline, the OSDI scores significantly increased in both groups (P < .001). The 0.05% cyclosporine A group exhibited lower OSDI total scores after administering 0.05% cyclosporine A versus the control group (P = .026). At 1 month of follow-up, NIBUT, LLT, and TMH values significantly decreased in both groups compared to baseline (P < .05). The 0.05% cyclosporine A group exhibited higher NIBUT, LLT, and TMH versus the control group, returning to preoperative values after 2 months. Overall, the OSDI total score and NIBUT values during follow-up were not significantly different between the two groups; however, the LLT and TMH values were significantly different between the two groups (P < .001 and .041, respectively) by repeated measures analysis of variance. CONCLUSIONS: Topical 0.05% cyclosporine A was effective in relieving subjective dry eye symptoms and maintaining ocular surface stability in the early postoperative period of SMILE. [J Refract Surg. 2024;40(4):e229-e238.].

Single-Nuclei Characterization of Lacrimal Gland in Scopolamine-Induced Dry Eye Disease.

Purpose: The lacrimal gland (LG) is the main organ responsible for tear secretion and an important pathogenic site for dry eye disease (DED). This study aimed to comprehensively characterize LG cellular heterogeneity under normal and DED conditions using single-nucleus RNA sequencing (snRNA-seq). Methods: Single LG nuclei isolated from mice with or without DED induced by scopolamine (SCOP)/desiccating stress (DS) were subjected to snRNA-seq using the 10x Genomics platform. These cells were clustered and annotated using the t-distributed stochastic neighbor embedding (t-SNE) method and unbiased computational informatic analysis. Cluster identification and functional analysis were performed based on marker gene expression and bioinformatic data mining. Results: The snRNA-seq analysis of 30,351 nuclei identified eight major cell types, with acinar cells (∼72.6%) being the most abundant cell type in the LG. Subclustering analysis revealed that the LG mainly contained two acinar cell subtypes, two ductal cell subclusters, three myoepithelial cell (MECs) subtypes, and four immunocyte subclusters. In the SCOP-induced DED model, three major LG parenchymal cell types were significantly altered, characterized by a reduced proportion of acinar cells with a lowered secretion potential and an augmented proportion of ductal cells and MECs. LG immunocytes in DED scenarios showed an intensified inflammatory response and dysregulated intercellular communication with three major LG parenchymal cells. Conclusions: Overall, this study offers a systemic single-nucleus transcriptomic profile of LGs in both normal and DED conditions and an atlas of the complicated interactions of immunocytes with major LG parenchymal cells. The findings also facilitate understanding the pathogenesis of DED.

Tear film stability in patients with symptoms of dry eye after instillation of dual polymer hydroxypropyl guar/sodium hyaluronate vs single polymer sodium hyaluronate.

PURPOSE: This study evaluated the tear film stability in patients with symptoms of dry eye after installation of dual polymer hydroxypropyl guar/sodium hyaluronate (DPHG/SH) vs single polymer SH. METHODS: Patients with recently diagnosed mild to moderate dry eye disease (OSDI score 23-32 points) were included. For each patient, the right eye was randomized to receive DPHG/SH or 0.15% SH. Just after the administration of the drop to the right eye, the fellow eye received the other eye drop. The first non-invasive Keratograph first break-up time (NIKBUT), average NIKBUT and tear meniscus height (TMH) were measured before administration of the eye drops, at 1-min, 15 min, 30 min, 60 min, 90 min, and 120 min after instillation. RESULTS: A total of 29 patients aged 22.8 ± 2.2 years participated in the study (21 women). No differences between the eye receiving DPHG/SH and single polymer SH were observed for the first NIKBUT (p = 0.45) and average NIKBUT (p = 0.24) variables at any time point. Both DPHG/SH and single polymer SH increased the TMH (p of time effect < 0.001), but with no difference between groups (p = 0.95). CONCLUSION: Both DPHG/SH and single polymer SH solutions provide lubrication of the eye surface, however, with no difference in NIKBUT and TMH evaluations for up to two hours following administration.