Keratitis in Dry Eye Disease and Topical Ciclosporin A

Bacterial contamination of multi-use tear drops, gels, and ointments

PURPOSE

This study aimed to investigate the bacterial contamination of multi-use tear drops, gels, and ointments that patients use at home.

METHOD

A total of 271 multi-use containers used by 168 patients were examined. Conjunctival culture samples were obtained from patients who used tear drops, gels, and ointments that were found to be contaminated.

RESULTS

Bacterial contamination was detected in 33 (12.2 %) out of the 271 containers. The contamination rate was 7.9 % in tear drops, 11.7 % in gels, and 32 % in ointments. A statistically significant difference was found between the drops, gels, and ointment groups (P = 0.04). Bacterial contamination was detected in 25 (18.9 %) out of 132 collapsible tubes and 8 (5.8 %) out of 139 plastic bottles (P = 0.01). Important bacteria, including Pseudomonas stutzeri, Pseudomonas aeruginosa, Bacillus licheniformis, Paenibacillus pabuli, Proteus mirabilis, Pantoea agglomerans, Morganella morganii, Serratia marcescens, and Serratia liquefaciens, were detected. Mucorales spp. fungus was seen in a gel. Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, and M. morganii were found in the conjunctival microbiota of three patients.

CONCLUSION

The overall contamination rate of ocular lubricants was low (12.2%); however, a significant difference was found between the drops, gels, and ointments. The contamination rate was higher in gels and ointments than that in drops. The contamination rate was found to be increased in the collapsible tube. The use of ocular lubricants is safe; however, patients must be cautious when using multi-use tear drops, gels, and ointments to avoid contamination. Whenever possible, bottles should be preferred instead of collapsible tubes.

Expression of GPR-68 in Human Corneal and Conjunctival Epithelium. Possible indicator and mediator of attrition associated inflammation at the ocular surface

INTRODUCTION

Attrition and osmotic stress have been identified as major forces in the pathophysiology of dry eye. Impaired tolerance to mechano-transduction in the presence of insufficient lubrication has been associated with disturbances of ocular surface homeostasis and encouragement of inflammatory reactions, challenging the usual regulatory coping mechanisms. In spite of the probable link between enhanced attrition and secondary inflammation, the key mediators driving the vicious cycle of severe dry eye disease have not yet been identified. The goal of this study was therefore to investigate human corneal and conjunctival epithelium for the presence of the G protein-coupled receptor GPR-68. This protein had most recently been shown to be not only chemically activated but also mechanically, possibly through attrition.

METHODS

De-identified sections of human cornea and conjunctiva were stained for the presence of G protein-coupled receptor 68 with specific antibodies using immunohistochemical methods. Results Specific staining for G-protein-coupled receptor 68 (GPR68) was observed in all samples of the cornea throughout the epithelial layers of the corneal epithelium, most prominently in the area of the wing cells and the basement membrane. Even in the conjunctiva, specific staining for GPR-68 was found.

DISCUSSION

The detection of G protein-coupled receptor GPR-68 in human corneal and conjunctival epithelium raises the question of its function and purpose. The mechanical activation of GPR68 in situations with enhanced friction and attrition could modify various cellular functions and possibly jeopardize normal inflammatory homeostasis at the ocular surface. Accordingly, decreased lubrication in dry eye disease could result in activation of GPR-68. This could lead to secondary inflammation, initially in the epithelium and surrounding stroma. Continuous mechanical stress could result in chronic inflammation, also reaching deeper structures of the cornea, possibly making GPR-68 an important actor in the vicious cycle of dry eye disease.

CONCLUSION

G protein-coupled receptor GPR-68, sensitive to flow and mechanic stimulation, is present in the human corneal epithelium and conjunctiva. Decreased lubrication and increased attrition, accompanied by sensations typical for dry eye, might lead to local inflammation. It is possible that subtle signs of conjunctival, and later corneal, surface damage in the context of these sensations could be a better indicator of the need for and success of therapy than the clinical signs of dry eye disease alone, at least in the early stages of the disease. Inhibition of G protein-coupled receptor GPR-68 could represent a new strategy in the treatment of dry eye disease.

The Nasopharyngeal Carcinoma and Its Effect on the Infectious Eye Disease: A Nationwide Cohort Study

The purpose of this study is to investigate the potential correlation between nasopharyngeal carcinoma (NPC) and both infectious keratitis and orbital cellulitis. The retrospective cohort study used the National Health Insurance Research Database (NHIRD) as a data source. A total number of 4184 patients with NPC diagnosis were selected and matched to 16,736 non-NPC patients via the propensity-score matching (PSM). The main outcomes are the development of infectious keratitis and orbital cellulitis according to diagnostic codes and related medications. The Cox proportional hazard regression was adopted to estimate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) of outcomes between the two groups. A total of 35 and 19 episodes of orbital cellulitis occurred in the NPC and non-NPC groups and the aHR was significantly higher in the NPC group (aHR: 1.34, 95% CI: 1.23−1.46, p = 0.0024). There were 2185 and 659 events of infectious keratitis in the NPC and non-NPC groups, and the NPC group revealed a significantly higher aHR than non-NPC group (aHR: 1.34, 95% CI: 1.23−1.46, p < 0.0001). Besides, the cumulative probability of infectious keratitis was significantly higher in the NPC group than the non-NPC group (p < 0.0001). The other risk factors of infectious keratitis include age from 20 to 30 years old, allergic respiratory diseases, allergic dermatological diseases, and external eye diseases (all p < 0.0001). In subgroup analyses, both the incidences of infectious keratitis (aHR: 1.33, 95% CI: 1.21−1.47) and orbital cellulitis (aHR: 2.36, 95% CI: 1.27−4.39) were significantly higher than the non-NPC group. The incidence of infectious keratitis was significantly higher in NPC patients without radiotherapy (aHR: 1.40, 95% CI: 1.26−1.55) compared to non-NPC population, while the rate of orbital cellulitis was similar between the NPC patients without radiotherapy (aHR: 0.76, 95% CI: 0.27−2.14) and non-NPC population. In conclusion, the existence of NPC associates with higher incidence of infectious keratitis which increases with NPC period, and the radiotherapy may be account for the higher rate of orbital cellulitis in NPC population.

Current trends in pharmaceutical treatment of Dry Eye Disease: A review

Dry eye disease (DED), keratoconjunctivitis sicca or dysfunctional tear syndrome, is the most prevalent ophthalmic disease which affects a substantial segment of people worldwide with increasing frequency. It is considered a multifactorial disease of the ocular surface and tear film, characterized by a variation of signs and symptoms. The symptoms range from mild to severe itching, burning, irritation, eye fatigue, and ocular inflammation that may lead to potential damage to the cornea, conjunctiva and even vision loss. Correspondingly, depending on the different manifestations and pathophysiology, the treatment must be tailored specifically to each patient by targeting the specific mechanisms implicated in their disease. Currently, there are several medical products and techniques available or under investigation for the treatment of DED. The present article focused on the pathophysiology of DED, the new diagnostic approach and the recently developed drug delivery systems or devices reducing the progress of the disease and treating the causes.

Real-World Effectiveness, Tolerability and Safety of Cyclosporine A 0.1% Cationic Emulsion in Severe Keratitis and Dry Eye Treatment

Introduction

The PERSPECTIVE study evaluated, in routine clinical practice, the effectiveness, tolerability and safety of cyclosporine A (CsA) 0.1% cationic emulsion (CE) in controlling severe keratitis in adults with dry eye who remained insufficiently controlled despite artificial tear (AT) use.

Methods

A prospective, multicenter, observational study was conducted at 44 ophthalmology clinics across Finland, Germany, Norway, Sweden and the UK. Adults treated with ATs for severe keratitis and dry eye received CsA 0.1% CE therapy (1 drop in both eyes at bedtime) and were followed up at weeks 4, 12 and 24 and at month 12. Primary endpoint was mean [standard deviation (SD)] change from baseline in corneal fluorescein staining (CFS; Oxford Grade Scale) at month 12 following CsA 0.1% CE initiation. Secondary endpoints examined ocular sign and symptom severity and adverse events (AEs).

Results

The full analysis set included 472 adults (75.9% female). Mean (SD) age was 61.9 (15.41) years. Mean (SD) CFS score was significantly reduced from baseline [2.56 (1.10)] at month 12 [1.10 (SD 1.13); P < 0.0001]. CFS score reductions were statistically significant from week 4, with further incremental decreases reported at study visits through month 12 (P < 0.0001). Severity of eyelid and conjunctival erythema was significantly reduced from baseline at week 4 and maintained through month 12 (P < 0.001). Tear film breakup time increased significantly from baseline at all study visits through month 12 (P < 0.001). Ocular symptom severity was significantly reduced from baseline at all study visits through month 12 (P < 0.001). Overall, 101 treatment-related AEs were reported. Most were mild/moderate (83.6%) and resolved by month 12 (73.3%).

Conclusions

In routine clinical practice, CsA 0.1% CE provided statistically significant reductions in dry eye signs and symptoms. Improvements were seen at week 4 and maintained over 12 months. Treatment tolerability was good and consistent with previous CsA 0.1% CE clinical studies.

Trial registration

EU PAS register number: EUPAS 22376.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00487-x.

Copolymer micelle-administered melatonin ameliorates hyperosmolarity-induced ocular surface damage through regulating PINK1 mediated mitophagy

PURPOSE

To investigate the role and mechanism of melatonin-loaded polymer polyvinyl caprolactam-polyvinyl acetate-polyethyleneglycol graft copolymer (PVCL-PVA-PEG) micelles (Mel-Mic) in dry eye disease (DED).

METHODS

In vitro, the apoptosis and reactive oxygen species (ROS) generation in HCECs were analyzed by immunostaining and flow cytometry (FCM). The effect of Mel-Mic on autophagy and mitophagy was evaluated by immunostaining and western blots. PINK1 knockdown was analyzed by small interfering RNA (siRNA). In vivo, sodium fluorescein staining, tear secretion test, and periodic acid-schiff (PAS) staining were used to determine whether Mel-Mic can alleviate the severity of DED. Small molecule antagonists were pretreated to investigate whether melatonin type 1 and/or 2 receptors (MT1/MT2) mediate the effects of Mel-Mic.

RESULTS

Mel-Mic improved the solubility and biological activities of Mel in aqueous solutions. Treatment with Mel-Mic decreased the apoptosis of HCECs exposed to hyperosmotic medium, accompanied by downregulation of cleaved Caspase-3 and upregulation of Bcl-2. In addition, Mel-Mic application suppressed ROS overproduction, rescued mitochondrial function, and decreased the level of oxidative stress associated biomarkers (COX-2 and 4-HNE) in HCECs. Interestingly, HCECs treated with Mel-Mic exhibited increased levels of mitophagy markers (PINK1, PARKIN, Beclin 1 and LC3B) and restored impaired mitophagic flux under hyperosmolarity. While PINK1 knock down largely abolished its protective effects. In vivo, compared to vehicle group, topical Mel-Mic solution treated mice showed significantly improved clinical parameters, increased tear production and decreased goblet cells loss in a dose-dependent manner. Also, TEM assay revealed increased autophagosome number in the corneal epithelium of Mel-Mic group. Moreover, luzindole, a non-selective MT1/MT2 antagonist, but not 4-P-PDOT, a selective MT2 antagonist, blocked the protective effect of Mel-Mic.

CONCLUSIONS

Our findings demonstrated that Mel-Mic ameliorates hyperosmolarity induced ocular surface damage via PINK1 mediated mitophagy and may represent an effective treatment for DED possibly through acting MT1 receptor.

Repository Corticotropin Injection (Acthar® Gel) for Refractory Severe Noninfectious Keratitis: Efficacy and Safety from a Phase 4, Multicenter, Open-Label Study

Introduction

Noninfectious keratitis is a painful corneal inflammation treated with topical cyclosporine and other immunosuppressants. Additional treatment options are needed for keratitis that does not improve with standard therapies. Repository corticotropin injection (RCI; Acthar^® Gel) is approved to treat severe acute and chronic allergic and inflammatory processes involving the eye and its adnexa, including keratitis. This phase 4, multicenter, open-label study assessed the efficacy and safety of RCI for refractory severe noninfectious keratitis.

Methods

Patients were ≥ 18 years old with persistent severe keratitis despite treatment with topical immunosuppressants. Patients received 80 U of RCI subcutaneously twice weekly for 12 weeks followed by a 4-week taper. Assessments included all domains of the Impact of Dry Eye on Everyday Life (IDEEL) Questionnaire, Ocular Discomfort and 4-Symptom Questionnaire, and Visual Analog Scale (VAS). Corneal fluorescein and conjunctival lissamine green staining, Conjunctival Redness Scale, tear production (Schirmer’s test), visual acuity, slit lamp examination, and intraocular pressure were also assessed. Safety was evaluated via treatment-emergent adverse events. Analyses were performed using the modified intent-to-treat (mITT) population (patients who received ≥ 1 dose of RCI and contributed any post-baseline efficacy data).

Results

In the mITT population (N = 35), 50.0% (95% confidence interval, 33.2% to 66.8%) of patients experienced clinically important improvements in the symptom bother domain of the IDEEL Questionnaire at week 12 of RCI therapy. All domains of the IDEEL and the Ocular Discomfort and 4-Symptom Questionnaire showed improvements at week 12 of RCI treatment. The most pronounced improvements in the VAS at week 12 were for eye dryness and eye discomfort. Corneal staining, conjunctival staining, conjunctival redness, and tear production showed early improvements that were sustained through week 12. No new safety signals for RCI were identified.

Conclusions

RCI is safe and effective for refractory severe noninfectious keratitis that has not improved with other approved therapies.

Trial registration number

ClinicalTrials.gov NCT04169061.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00400-y.

A Narrative Review of Current Understanding and Classification of Dry Eye Disease with New Insights on the Impact of Dry Eye during the COVID-19 Pandemic

Dry eye disease (DED) is a complex, progressive and multifactorial condition that is commonly seen in clinical practice and can be challenging to accurately diagnose. Untreated or suboptimally managed dry eye can progress to severe, chronic disease which may become resistant to treatment. Symptoms include ocular irritation and visual impairment. Patients frequently report negative consequences regarding quality of life (QoL), productivity and psychological wellbeing. Certain lifestyle factors (e.g. use of screen-based devices, air conditioning) can induce or exacerbate symptoms of DED, leading to progressive and debilitating complications. Exposures to such triggers are likely to have increased significantly during the ongoing COVID-19 pandemic with people across the globe living with heightened levels of stress/anxiety while being forced to adapt most aspects of their daily lives (from work and education through to social activities) to accommodate social distancing, primarily through the use digital technologies. This review aims to provide a concise and practical overview of current understanding regarding DED, highlighting proposals for refined diagnostic categories and therapeutic terminologies that are designed to improve identification and management of dry eye as well as reduce or slow disease progression. Finally, the findings of a European survey are shared to illustrate the impact of the COVID-19 pandemic on the lives of people with DED. The survey was conducted during the first lockdown period (March–September 2020) and explored issues relating to psychological wellbeing, QoL and engagement with healthcare services. The results demonstrate the ways in which the pandemic amplified the impact of dry eye on daily life and may be valuable in enhancing understanding among clinicians of the challenges faced by people with DED, which extend beyond the signs and symptoms of disease.

The Risks of Corneal Surface Damage in Aqueous-Deficient Dry Eye Disease: A 17-Year Population-Based Study in Taiwan

PURPOSE

To investigate the epidemiologic characteristics and risk of corneal surface damage in patients with aqueous-deficient dry eye disease (DED) in Taiwan.

DESIGN

Retrospective, population-based cohort study.

METHODS

We used claims data in the Taiwan National Health Insurance Research Database from 1997 to 2013 of patients with DED, defined according to diagnoses, drug codes, and clinical follow-up. A comparison cohort without DED was selected through propensity score matching. The main outcome measures were corneal surface damage, including corneal erosion, corneal ulcers, or corneal scars.

RESULTS

Patients with DED had a significantly higher rate of corneal surface damage (hazard ratio [HR]: 2.70; 95% confidence interval [CI] 2.38-3.06, P < .001), especially higher in patients aged <18 years (HR 6.66; 95% CI 3.58-12.41) than in older patients and in women (HR 2.98; 95% CI 2.57-3.46) than in men (HR 2.22; 95% CI 1.78-2.77), compared to those in the non-DED cohort. DED with diabetes mellitus (P = .002), rheumatoid arthritis (P = .029), or systemic lupus erythematosus (P = .005) was positively associated with corneal surface damage. The overall prevalence of DED was 7.85%, higher among women (10.49%) than men (4.92%), and increased with age (0.53%, 3.94%, 10.08%, and 20.72% for ages <18, 18-39, 40-64, and >65 years, respectively). The prevalence increased gradually during the study period.

CONCLUSIONS

The younger age group (<18 years) had the highest risk of corneal surface damage in aqueous-deficient DED. Other predisposing factors included female sex, diabetes, and autoimmune diseases. To improve clinical care, special attention is required for patients with DED with these risk factors.

Cyclosporine Anionic and Cationic Ophthalmic Emulsions in Dry Eye Disease: A Literature Review

PURPOSE

There are no clinical studies directly comparing anionic and cationic emulsions of cyclosporine for the treatment of dry eye disease (DED). We therefore conducted a literature review to evaluate the efficacy and safety of these different formulations.

METHODS

A literature search was performed in Embase and Medline from January 1999 to May 2019 to identify publications that evaluated clinical outcomes with either cyclosporine anionic or cationic emulsion in patients with moderate-to-severe or severe DED.

RESULTS

Thirteen publications met criteria. In patients with moderate-to-severe disease, evidence demonstrated improvement in the signs of DED with both formulations. However, improvement in symptoms was not consistently demonstrated. Studies specifically in severe DED were only identified with the cationic emulsion and showed improvement in the objective signs of DED. There were no obvious differences in tolerability between products.

CONCLUSIONS

Both formulations are effective for the treatment of moderate-to-severe DED and are well tolerated.

Role of tear film biomarkers in the diagnosis and management of dry eye disease

In recent years, there has been increasing scientific interest in the use of tear film biomarkers in the diagnosis and management of dry eye disease (DED), owing to their potential important roles in the pathogenesis of ocular surface damage, as well as the technical feasibility of tear sample collection techniques. An Entrez PubMed search was conducted on March 2, 2019, to include papers investigating the use of tear film biomarkers in DED, and the results were classified according to whether the DED is associated with systemic inflammatory disease or not and further classified within each section according to the molecular nature of the biomarker for further discussion. A total of 58 relevant articles were reviewed. Certain cytokines, including interleukin-6 (IL-6), tumor necrosis factor-alpha, IL-17, and IL-8, were found by a number of studies to consistently reflect disease severity well and had strong correlations with tear film metrics and tests for ocular surface damage in dry eye without systemic inflammatory disease. For dry eye with systemic inflammatory disease, IL-17, IL-8, and IL-1 receptor antagonists were shown to be consistently higher in affected eyes and correlated well with ocular surface disease severity in more than one type of inflammatory disease. With the advancement in technology and lowered costs in the future, tear film biomarker counts would allow better diagnosis and monitoring of DED, as well as facilitate personalized treatment strategies.

Effects of Vitamin A on Expressions of Apoptosis Genes Bax and Bcl-2 in Epithelial Cells of Corneal Tissues Induced by Benzalkonium Chloride in Mice with Dry Eye

Background

The apoptosis of corneal epithelial cells participates in the pathological processes of dry eye, which is expected to be a treatment target for dry eye. The aim of this study was to investigate the effects of vitamin A (VA) on apoptosis of corneal epithelial cells in a mouse model with dry eye induced by benzalkonium chloride (BAC).

Material/Methods

We randomly divided 60 male BALB/c mice aged 8–10 weeks into 3 groups: the blank control group, the dry eye+vehicle group, and the dry eye+drug group. On the 7^th day after the dry eye model successfully induced, the mouse eyeballs removed, and the mouse corneal tissues were isolated. The expression levels of Bax and Bcl-2 in corneal tissues were detected via reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The apoptotic corneal epithelial cells were quantified using terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) staining technique.

Results

VA suppressed the upregulation of the Bax gene at the mRNA and protein levels, and upregulated the expression of the Bcl-2 gene (P<0.05). TUNEL results revealed that the number of apoptotic epithelial cells in the dry eye group was 40 times larger as that in the blank control group. After the intervention of VA at an appropriate concentration, the number of apoptotic corneal epithelial cells was remarkably reduced to about 10 times that in the blank control group (P<0.05).

Conclusions

VA can inhibit upregulation of the expressions of Bax and Bcl-2 in the epithelial cells of mice with dry eye induced by BAC, so as to suppress the apoptosis of epithelial cells in mice with dry eye.

Synergistically dual-functional nano eye-drops for simultaneous anti-inflammatory and anti-oxidative treatment of dry eye disease

We have developed a rapid and straightforward topical treatment method for dry eye disease (DED) using poly(catechin) capped-gold nanoparticles (Au@Poly-CH NPs) carrying amfenac [AF; a nonsteroidal anti-inflammatory drug (NSAID)] through effective attenuation of ocular surface tissue damage in dry eyes. A dual-targeted strategy based on ocular therapeutics was adopted to simultaneously block the cyclooxygenase enzymes-induced inflammation and reactive oxygen species (ROS)-induced oxidative stress, the primary two causes of DED. The self-assembled core-shell Au@Poly-CH NPs synthesized via a simple reaction between tetrachloroaurate(iii) and catechin possess a poly(catechin) shell (∼20 nm) on the surface of each Au NP (∼60 nm). The anti-oxidant and anti-inflammatory properties of AF/Au@Poly-CH NPs were evaluated by DCFH-DA and prostaglandin E2/VEGF assays, respectively. Our results demonstrate that Au@Poly-CH NPs not only act as an anti-oxidant to suppress ROS-mediated processes, but also serve as a drug carrier of AF for a synergistic effect on anti-inflammation. In vivo biocompatibility studies show good tolerability of AF/Au@Poly-CH NPs for potential use in the treatment of ocular surface pathologies. The dual-targeted therapeutic effects of AF/Au@Poly-CH NPs lead to rapid recovery from DED in a rabbit model. Au@Poly-CH NPs loaded with NSAIDs is a promising multifunctional nanocomposite for treating various inflammation- and oxidative stress-related diseases.