Pharmacotherapy of dry eye

New advances in medical management of dry eye: optimizing treatment strategies for enhanced relief

PURPOSE

Dry eye disease (DED) is a prevalent ocular surface disease that is conventionally characterized by tear film hyperosmolarity and instability. This review presents a summarized classification of DED, followed by a comprehensive discussion of the most recent topical and systemic medications and clinical recommendations for selecting the most appropriate option for each patient.

METHODS

An extensive literature search was conducted on electronic databases, such as PubMed, Scopus, and Web of Science, using keywords including "dry eye syndrome," "ocular surface disease," "medical management," "artificial tears," "topical immunomodulators," and "meibomian gland dysfunction."

RESULTS

The underlying reasons for DED can range from insufficient aqueous tear production to increased tear evaporation. Recent literature has provided a more in-depth understanding of the pathophysiology of DED by examining the tear film's lipid, aqueous, and mucin layers. However, despite these advancements, medical management of patients with symptomatic DED has not fully reflected this modernized knowledge of its pathophysiology.

CONCLUSION

To develop a rationalized strategy for treating DED, it is crucial to have updated knowledge of therapeutic options, their mechanisms of actions, and indications based on the DED type and underlying causes.

Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

BACKGROUND/AIMS

This study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.

METHODS

At our single institution, PRP and AS eye-drops were prepared using peripheral blood obtained from six healthy volunteers and stored at 4°C. Platelet and leucocyte counts and transforming growth factor (TGF)-β1, epidermal growth factor (EGF), and fibronectin levels were assessed during storage for up to 4 weeks. Sterility was assessed by culturing 4-week poststorage samples. PRP, AS, and phosphate-buffered saline (PBS) eye-drop efficacies were compared using corneal epithelial wound healing assays in vitro and in vivo and monitoring wound areas under a microscope every 3 hours.

RESULTS

Higher platelet and lower leucocyte counts were seen in PRP than in whole blood on the day of preparation. After storage, TGF-β1, EGF, and fibronectin levels were significantly higher in PRP than in AS eye-drops. In vitro and in vivo, PRP eye-drops used on the day of preparation significantly promoted corneal epithelial wound healing compared with PBS. Moreover, PRP eye-drops stored for 4 weeks significantly promoted corneal wound healing compared with PBS and AS eye-drops.

CONCLUSION

PRP eye-drops stored at 4°C for 4 weeks promoted corneal epithelial wound healing with higher levels of growth factors than those observed in AS eye-drops, while maintaining sterility, suggesting that this preparation satisfies the unmet medical needs in the treatment of refractory keratoconjunctival epithelial disorders.

The Ins and Outs of Clusterin: Its Role in Cancer, Eye Diseases and Wound Healing

Clusterin (CLU) is a glycoprotein originally discovered in 1983 in ram testis fluid. Rapidly observed in other tissues, it was initially given various names based on its function in different tissues. In 1992, it was finally named CLU by consensus. Nearly omnipresent in human tissues, CLU is strongly expressed at fluid-tissue interfaces, including in the eye and in particular the cornea. Recent research has identified different forms of CLU, with the most prominent being a 75-80 kDa heterodimeric protein that is secreted. Another truncated version of CLU (55 kDa) is localized to the nucleus and exerts pro-apoptotic activities. CLU has been reported to be involved in various physiological processes such as sperm maturation, lipid transportation, complement inhibition and chaperone activity. CLU was also reported to exert important functions in tissue remodeling, cell-cell adhesion, cell-substratum interaction, cytoprotection, apoptotic cell death, cell proliferation and migration. Hence, this protein is sparking interest in tissue wound healing. Moreover, CLU gene expression is finely regulated by cytokines, growth factors and stress-inducing agents, leading to abnormally elevated levels of CLU in many states of cellular disturbance, including cancer and neurodegenerative conditions. In the eye, CLU expression has been reported as being severely increased in several pathologies, such as age-related macular degeneration and Fuch's corneal dystrophy, while it is depleted in others, such as pathologic keratinization. Nevertheless, the precise role of CLU in the development of ocular pathologies has yet to be deciphered. The question of whether CLU expression is influenced by these disorders or contributes to them remains open. In this article, we review the actual knowledge about CLU at both the protein and gene expression level in wound healing, and explore the possibility that CLU is a key factor in cancer and eye diseases. Understanding the expression and regulation of CLU could lead to the development of novel therapeutics for promoting wound healing.

The Lubricating Effect of Eye Drops Containing Hyaluronic Acid and Mallow Extract in Patients with Dry Eye Disease-A Pilot Study

Background and Objectives: Mucilaginous substances from plants are known to be able to support the lubricating effect of hyaluronic acid (HA) in dry eye disease (DED). In this pilot study, the combined lubricating effect of HA and mallow extract (Malva sylvestris L.) in patients with DED was assessed. Materials and Methods: Twenty patients at five ophthalmological practices in Italy were treated with eye drops containing HA and mallow extract on the one hand, and with eye drops containing HA only, on the other hand, in a two-period crossover design. As primary endpoints, the tear film breakup time (TBUT), the reduction of lissamine green staining of the ocular surface (Oxford Scheme, OS), and the safety and efficacy assessment by the ophthalmologists were evaluated. As secondary variables, the patient symptom score, the ocular surface index (OSDI) and the satisfaction, preference and efficacy assessment by the patients were evaluated. All data were analysed descriptively in addition to an exploratory analysis being made of the target variables. Results: Both products were well-tolerated. There were no statistically significant differences with regard to the TBUT, OS and OSDI between the two treatments. Anyway, the efficacy and safety assessments by the ophthalmologists and the patients showed results in favour of the combined product. Conclusion: The addition of mallow extract to HA-containing eye drops enhances the treatment of DED, at least with respect to subjective measurements. Further assessments will have to be done to prove and explain this observation in terms of measurable parameters, e.g., markers for inflammatory cytokines.

Anthocyanin oligomer (grape skin extract) administration improves dry eye disease: A randomised, double-blind, placebo-controlled study

BACKGROUND

Dry eye disease is a chronic, progressive ocular disease characterised by ocular discomfort and is one of the most common ophthalmological disorders that affects people's lives.

METHODS

This study investigated the clinical efficacy of anthocyanin oligomers (grape skin extract) for the treatment of dry eye. One hundred and eight patients with dry eye were randomly divided into placebo and treatment groups, each with 54 cases. The placebo group received maltodextrin (800 mg/day) and the treatment group received anthocyanin oligomers (800 mg/day). Clinical efficacy, clinical indices, and occurrence of adverse reactions were compared between the two groups.

RESULTS

Anthocyanin oligomers were safe and effective in mild-to-moderate dry eye disease, improving the tear break-up time, intraocular pressure, ocular surface disease, and patient symptomatology.

CONCLUSIONS

The use of oral anthocyanin oligomers in the treatment of dry eye patients can enhance the therapeutic effect and improve the quality of life of patients while ensuring the safety of treatment, making this therapeutic option suitable for wider application.

Dry Eye Disease: What Is the Role of Vitamin D?

Dry eye disease (DED) is a multifactorial condition resulting from reduced tear secretion from the lacrimal glands, increased tear water evaporation or the production of poor-quality tears. Such tear instability can lead to inflammation and damage of the ocular surface, as well as to abnormal nociception. Historically, tear substitutes and corticosteroids have been the bastion of DED therapy, but a substantial number of patients still suffer from residual symptoms even after being treated with traditional treatments. Aiming to find safe and effective alternative therapies, recent efforts have been focused on the role of vitamin D in the cellular physiology of the eye. Possibly because of its positive effect in modulating the immune and inflammatory responses, the systemic supplementation of vitamin D seems, indeed, to be an effective therapeutic strategy, especially, but not only, for patients affected by DED that does not respond to conventional treatments. In this context, this review focuses on the literature reporting on the pathogenesis and treatment of DED, with a special emphasis on the recent investigations reporting on the potential role of the systemic administration of vitamin D as a therapeutic approach in the management of such condition.

Modern approach to the treatment of dry eye, a complex multifactorial disease: a P.I.C.A.S.S.O. board review

Dry eye disease (DED) is a growing public health concern affecting quality of life and visual function, with a significant socio-economic impact. It is characterised by the loss of homoeostasis, resulting in tear film instability, hyperosmolarity and inflammation of the ocular surface. If the innate immune response is unable to cope with internal bodily or environmental adverse conditions, the persistent, self-maintaining vicious circle of inflammation leads to the chronic form of the disease. Treatment of DED should be aimed at the restoration of the homoeostasis of the ocular surface system. A proper diagnostic approach is fundamental to define the relevance and importance of each of the DED main pathogenic factors, namely tear film instability, epithelial damage and inflammation. Consideration also needs to be given concerning two other pathogenic elements: lid margin changes and nerve damage. All the factors that maintain the vicious circle of DED in the patient's clinical presentation have to be considered and possibly treated simultaneously. The treatment should be long-lasting and personalised since it has to be adapted to the different clinical conditions observed along the course of the disease. Since DED treatment is frequently unable to provide fast and complete relief from symptoms, empathy with patients and willingness to explain to them the natural history of the disease are mandatory to improve patients' compliance. Furthermore, patients should be instructed about the possible need to increase the frequency and/or change the type of treatment according to the fluctuation of symptoms, following a preplanned rescue regimen.

A Meta-Analysis of the Efficacy of Hyaluronic Acid Eye Drops for the Treatment of Dry Eye Syndrome

Hyaluronic acid (HA) is commonly used for treating dry eye syndrome (DES). This meta-analysis was performed to compare the efficacies of HA- and non-HA-based eye drops, including saline and conventional artificial tears (ATs), for the treatment of dry eye disease. Eight databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, DBpia, KoreaMed, KMBASE, RISS, KISS) were searched for studies comparing the efficacies of HA- and non-HA-based ATs in patients with DES published up to September 2020. Two independent reviewers assessed the quality and extracted the relevant data. The mean differences of Schirmer's (SH) test scores, tear breakup times (TBUT), corneal fluorescein staining scores (Oxford scale, 0-4), and ocular surface disease indexes were calculated. The standard mean difference and 95% confidence interval were calculated using a random effect model. Nineteen studies, including 2078 cases, were included. HA eye drops significantly improved tear production compared with non-HA-based eye drops (standard mean difference (SMD) 0.18; 95% confidence interval (CI) 0.03, 0.33). In a subgroup analysis, the SH test scores and TBUT values after using HA significantly increased compared to those measured after using saline (SMD 0.27; 95% CI 0.05, 0.49 and SMD 0.28; 95% CI 0.03, 0.52, respectively). Based on these results, HA eye drops may be superior to non-HA eye drops including normal saline and ATs. Further research is needed to assess the efficacies stratified by age, treatment duration, the severity of dry eye, and optimal dosages.

Therapeutic Potential of the Molecular Chaperone and Matrix Metalloproteinase Inhibitor Clusterin for Dry Eye

Evidence is presented herein supporting the potential of the natural homeostatic glycoprotein CLU (clusterin) as a novel therapeutic for the treatment of dry eye. This idea began with the demonstration that matrix metalloproteinase MMP9 is required for damage to the ocular surface in mouse dry eye. Damage was characterized by degradation of OCLN (occludin), a known substrate of MMP9 and a key component of the paracellular barrier. Following up on this finding, a yeast two-hybrid screen was conducted using MMP9 as the bait to identify other proteins involved. CLU emerged as a strong interacting protein that inhibits the enzymatic activity of MMP9. Previously characterized as a molecular chaperone, CLU is expressed prominently by epithelia at fluid-tissue interfaces and secreted into bodily fluids, where it protects cells and tissues against damaging stress. It was demonstrated that CLU also protects the ocular surface in mouse dry eye when applied topically to replace the natural protein depleted from the dysfunctional tears. CLU is similarly depleted from tears in human dry eye. The most novel and interesting finding was that CLU binds selectively to the damaged ocular surface. In this position, CLU protects against epithelial cell death and barrier proteolysis, and dampens the autoimmune response, while the apical epithelial cell layer is renewed. When present at high enough concentration, CLU also blocks staining by vital dyes used clinically to diagnose dry eye. None of the current therapeutics have this combination of properties to "protect, seal, and heal". Future work will be directed towards human clinical trials to investigate the therapeutic promise of CLU.

Preparation and characterization of a pterostilbene-peptide prodrug nanomedicine for the management of dry eye

In the present study, a pterostilbene-peptide amphiphile (PS-GA-RGD) that can spontaneously self-assemble into prodrug nanomedicine, was rationally designed and developed as a novel ophthalmic formulation for the potential management of dry eye. The formed PS-GA-RGD nanomedicine was characterized by dynamic latter scattering (DLS) and transmission electron microscopy (TEM). After esterase treatment, active pterostilbene (PS) sustainably released from the PS-GA-RGD nanomedicine within 48 h, as indicated by an in vitro release study. In comparison with native PS, the formed PS-GA-RGD nanomedicine caused minimal cytotoxicity towards RAW 264.7 and HCEC cells in the 0-20 μM range and did not delay wound healing of HCEC monolayer within 6 h. Furthermore, PS-GA-RGD nanomedicine effectively reduced the intracellular reactive oxygen species (ROS) level in H₂O₂ challenged RAW264.7 macrophages and remarkably suppressed the secretion of inflammatory cytokines (e.g., NO, TNF-α, and IL-6) in lipopolysaccharide (LPS) activated RAW264.7 macrophages. Ocular tolerance to the proposed PS-GA-RGD nanomedicine was good after a single instillation in in vivo ocular irritation tests. Overall, the proposed PS-GA-RGD nanomedicine had potent anti-oxidant capacity and anti-inflammatory efficacy, which may be a promising ophthalmic formulation for the management of dry eye.

False Myths versus Medical Facts: Ten Common Misconceptions Related to Dry Eye Disease

Since the first definition of dry eye, rapid progress has been made in this field over the past decades that has guided profound changes in the definition, classification, diagnosis and management of the disease. Although dry eye is one of the most frequently encountered ocular conditions, various “old” misconceptions persist, in particular among comprehensive ophthalmologists not specialized in ocular surface diseases. These misconceptions hamper the correct diagnosis and the proper management of dry eye in the routine clinical practice. In the present review, we described the 10 most common misconceptions related to dry eye and provided an evidence-based guide for reconsidering them using the format “false myth versus medical fact”. These misconceptions concern the dry eye definition and classification (#1, #2, #3), disease physiopathology (#4), diagnosis (#5), symptoms (#6, #7) and treatment (#8, #9, #10). Nowadays, dry eye is still an under-recognized and evolving disease that poses significant clinical challenges to ophthalmologists. The two major reasons behind these challenges include the heterogeneity of the conditions that fall under the umbrella term of dry eye and the common discrepancy between signs and symptoms.

Impact of Attrition, Intercellular Shear in Dry Eye Disease: When Cells are Challenged and Neurons are Triggered

The mechanical component in the pathophysiology of dry eye disease (DED) deserves attention as an important factor. The lubrication deficit induced impaired mechano-transduction of lid pressure to the ocular surfaces may lead to the dysregulation of homeostasis in the epithelium, with sensations of pain and secondary inflammation. Ocular pain is possibly the first sign of attrition and may occur in the absence of visible epithelial damage. Attrition is a process which involves the constant or repeated challenge of ocular surface tissues by mechanical shear forces; it is enhanced by the thinning of corneal epithelium in severe DED. As a highly dynamic process leading to pain and neurogenic inflammation, the identification of the impact of attrition and its potential pathogenic role could add a new perspective to the current more tear film-oriented models of ocular surface disease. Treatment of DED addressing lubrication deficiencies and inflammation should also consider the decrease of attrition in order to stimulate epithelial recovery and neural regeneration. The importance of hyaluronic acid, its molecular characteristics, the extracellular matrix and autoregulative mechanisms in this process is outlined. The identification of the attrition and recognition of its impact in dry eye pathophysiology could contribute to a better understanding of the disease and optimized treatment regimens.

The Role of Multisystem Disease in Composition of Autologous Serum tears and ocular surface symptom improvement

PURPOSE

Autologous serum tears (AST) contain growth factors and vitamins similar to those in healthy tears and are an effective treatment option for ocular surface disease. This study determined the differences in composition of AST in patients with systemic diseases versus patients with localized ocular surface diseases and the effects on ocular surface symptom improvement.

METHOD

An observational study was performed on 53 patients with either systemic diseases (Group I) or localized ocular surface diseases (Group II) who were prescribed AST. Concentrations of epidermal growth factor (EGF), interleukin 8 (IL-8), fibronectin, vitamin A, and tumor necrosis factor-α (TNF-α) were determined through ELISA assays from patients in both groups. The Ocular Surface Disease Index (OSDI) scores were calculated prior to and 6 weeks after initiation of treatment with AST for new patients.

RESULTS

The average concentration of EGF in Group I (29.39 pg/ml ± 52.85 pg/ml) was significantly lower than in Group II (88.04 pg/ml ±113.75 pg/ml) (p < 0.05). Levels of fibronectin, IL-8, and vitamin A were similar in both groups. There was a 24% reduction in OSDI score 6 weeks after initiation in Group I compared to a 36% reduction reported in Group II (p = 0.065). The OSDI score was reduced significantly after the treatment in all subjects (p = 0.002).

CONCLUSION

Serum tears are a promising therapy for management of ocular surface disease and associated symptoms. The differences between levels of EGF in patients with localized ocular surface disease and systemic inflammatory disease may account for differences in therapeutic outcome.

Fluorometholone modulates gene expression of ocular surface mucins

PURPOSE

Mucins are vital to keep the ocular surface hydrated. Genes encoding for mucins contain a glucocorticoid response element. The purpose of this study was to evaluate the effect of fluorometholone, a glucocorticoid receptor agonist used in the management of dry eye, on the gene expression of conjunctival and corneal epithelial cell mucins.

METHODS

Stratified cultures of human conjunctival and corneal epithelial cells were exposed to 25, 50 and 100 nM of fluorometholone alone or in presence of mifepristone, a glucocorticoid receptor antagonist. The mRNA was isolated from the cells and reverse transcribed to cDNA. The cDNA was used for quantification of gene expression of mucin (MUC) 1, 4, 16 and 19 using real-time PCR.

RESULTS

Fluorometholone caused a dose- and time-dependent increase in the gene expression of MUC1, MUC4, MUC16 and MUC19 in the conjunctival as well as corneal epithelial cells. Mifepristone, a glucocorticoid receptor antagonist, inhibited fluorometholone-mediated increase in the gene expression of conjunctival and corneal mucins. At the tested concentration, neither fluorometholone nor mifepristone caused any notable changes in the cellular phenotype or viability of conjunctival and corneal epithelial cells.

CONCLUSION

Fluorometholone increases the gene expression of MUC1, MUC4, MUC16 and MUC19 in the conjunctival and corneal epithelial cells through activation of glucocorticoid receptors. The increased expression of mucins can be an additional possible mechanism contributing to the beneficial effects of fluorometholone in dry eye in addition to its well-known anti-inflammatory effects.

Physicochemical Properties of Hyaluronic Acid-Based Lubricant Eye Drops

Purpose

To assess the physicochemical properties of hyaluronic acid (HA)-based artificial tears.

Methods

The average molecular weight (MW) and polydispersion index (PDI) of HA in 18 commercially available artificial tears were determined by light scattering/high-performance liquid chromatography. Osmolality, pH, viscosity, and sodium concentration were determined using an osmometer, pH meter, rheometer, and inductively coupled plasma mass spectrometer, respectively.

Results

The MW of HA varied considerably between formulations. The PDI was >2.0 in two formulations (2.28 and 4.94), suggesting the presence of a copolymer and/or HA size variability. Three formulations exhibited viscosity exceeding the blur threshold at different shear rates. Viscosity at low shear rates was generally highest in formulations containing high-MW HA. Correlations were found between observed viscosity and a predictive/calculated value, except for four copolymer-containing formulations, and osmolality (range, 154–335 mOsm/kg) and sodium concentration (range, 22–183 mM), with two exceptions. Compared with organic osmolytes, adding sodium decreased viscosity, particularly at lower shear rates.

Conclusions

In the context of the literature, our findings suggest that for most patients with dry eye disease, the ideal HA-based artificial tear should include high-MW HA with a low PDI and exhibit enhanced viscosity at low shear rate (without exceeding the blur threshold). The inclusion of synergistic copolymers and a low sodium concentration may increase viscosity, but whether any of these physicochemical properties or correlations can predict clinical efficacy will require further investigation.

Translational Relevance

Understanding the properties of HA-based artificial tears will support the development of unique formulations that target specific ocular surface conditions.

Hyaluronic Acid as an Alternative to Autologous Human Serum Eye Drops: Initial Clinical Results with High-Molecular-Weight Hyaluronic Acid Eye Drops

Introduction

Autologous serum eye drops (ASED) are used in the treatment of most severe stages of dry eye. Once introduced, it is currently considered impossible to return to other lubricating eye drops or other commercially available therapeutic regimen.

Materials and Methods

In a randomized study, non-preserved high-molecular-weight hyaluronic acid eye drops were offered as an alternative to 11 patients using autologous serum treatment for at least 3 months. The control group (n = 5) continued their treatment with ASED. The verum group (n = 6) used very-high-molecular-weight hyaluronic eye drops (Comfort Shield®) instead of the ASED.

Results

From four of initially six patients in the verum group that finished the study, 2 (50%) preferred to stay with the very-high-molecular-weight hyaluronic acid eye drops beyond the trial period, the other two returned to the earlier therapy with ASED. The control group continued their treatment as before and finished the study after 8 weeks.

Conclusion

For the first time, artificial eye drops, i.e., high-molecular-weight hyaluronic acid eye drops, offered an acceptable alternative to ASED. Some patients perceived these drops as even better than the patient's own serum. This is the first evidence that optimization of the molecular structure of hyaluronic acid can be used to create eye drops that are perceived to be better than other tested tear substitutes and even patients' own serum. This offers a new treatment perspective for patients with very severe dry eye disease.

Current Management and Treatment of Dry Eye Disease

A better understanding of the pathophysiology and etiology of dry eye disease leads to more efficient management and treatment of the disease process. However, there is substantial variation among both clinicians and countries in terms of dry eye treatment modalities. The latest 2017 International Dry Eye Workshop II report aimed to reduce these differences and emphasized the use of a stepped care algorithm. The algorithm includes treatment forms ranging from artificial tear drops, the primary conventional treatment method, to the latest surgical applications. The aims of the algorithm are to restore homeostasis in the ocular surface, break the vicious cycle of inflammation, and ensure long-term ocular surface comfort.

Plasma rich in growth factors for the treatment of dry eye from patients with graft versus host diseases

Purpose:

To evaluate the efficacy and safety of plasma rich in growth factors eye drops for the treatment of corneal and ocular surface disorders in patients with graft versus host disease.

Methods:

This retrospective and longitudinal study included graft versus host disease patients with ocular disorders. The resolution of corneal ulcers (area and density staining) was evaluated as primary outcome. Best corrected visual acuity, intraocular pressure, tear film breakup time, Schirmer test, ocular surface disease index, and visual analog score were evaluated as secondary outcomes. All variables were analyzed before and after plasma rich in growth factors treatment. The safety of plasma rich in growth factors treatment was also assessed.

Results:

Twelve patients (23 eyes) with ocular graft versus host disease were evaluated. Statistically significant improvement in the area (75.7%) and density (73.3%) of the corneal staining, in best corrected visual acuity (74.7%), in ocular surface disease index scale (75.4%), visual analog score frequency (81.4%) and visual analog score severity (81.9%), and an increase of 3.8 s in tear film breakup time and 6 mm in Schirmer test was observed after plasma rich in growth factors treatment (p < 0.001). Some potential modifiers of the therapeutic effect were identified. All patients achieved corneal stability without perforation risk. No adverse events associated with the plasma rich in growth factors were observed.

Conclusion:

Immunosafe plasma rich in growth factors eye drops for the treatment of patients with ocular graft versus host disease could be safe and effective, showing a high rate of corneal ulcer resolution and dry eye disease control. Plasma rich in growth factors eye drops may help to maintain corneal stability and prevent it against higher ocular complications.

Effects of Lycium barbarum (goji berry) on dry eye disease in rats

Lycium barbarum (goji berry) has long been used as a food and traditional herbal medicine. This study aimed to investigate the beneficial effect of the goji berry on dry eye disease in rats. Male Sprague-Dawley rats with induced dry eye disease were randomly assigned to four groups: Vehicle (control), low-dose goji berry extract [GBE; 250 mg/kg/body weight (bw)], median-dose GBE (350 mg/kg/bw), and high-dose GBE (500 mg/kg/bw). Three methods, Schirmer's test, tear break-up time (BUT) measurement and keratoconjunctival fluorescein staining, were used to evaluate the effect of GBE on symptoms of dry eye disease experienced by the rats. The results of the present study revealed that both the Schirmer's test score and tear BUT significantly increased following 1 week of GBE administration. Furthermore, the severity of the keratoconjunctival staining decreased significantly. In addition, the results suggested that administration of GBE may ameliorate dry eye disease symptoms in a dose-dependent manner. There were no mortalities and no apparent abnormal histopathology changes in the liver or kidney tissues of rats administered GBE for 21 consecutive days. Polysaccharides and betaine present in GBE may have important effects in alleviating dry eye disease induced by oxidative stress and inflammation. In conclusion, the goji berry is a safe, functional food with beneficial effects in alleviating dry eye disease.

Clinical utility of cyclosporine (CsA) ophthalmic emulsion 0.05% for symptomatic relief in people with chronic dry eye: a review of the literature

To review the literature on the efficacy of cyclosporine (CsA) ophthalmic emulsion 0.05% on symptomatic relief in chronic dry eye disease. There is consistent evidence of objective improvements in chronic dry eye disease (Schirmer score, corneal and interpalpebral dye staining, and tear breakup time) with CsA, but variable results with symptomatic improvement, possibly due to patient tolerance of CsA, similar comforting effect with artificial tears and CsA vehicle, and the inherent subjective nature of symptom monitoring and analysis. This review explores the literature on CsA with special attention to symptomatic relief.

[New approaches to the treatment of keratoconjunctivitis sicca]

A new method has been developed for the treatment of severe forms of keratoconjunctivitis sicca (KCS) that involves the use of an original cyclosporine A (CyA) saturated soft contact lens (SCL) together with preservative-free artificial tears therapy.

AIM

to evaluate the effectiveness of the newly developed treatment for KCS based on the use of medical SCL saturated with 0.05% CyA.

MATERIAL AND METHODS

The patients (43 men, 60 eyes) with severe KCS were divided into 2 groups. Group 1 included 21 patients (30 eyes), who received artificial tears and wore 0.05% CyA-saturated silicone-hydrogel SCLs. Group 2 included 22 patients (30 eyes), who wore unsaturated original SCLs and received CyA instillations 2 times daily and, also, artificial tears. Apart from a standard ophthalmic examination, the assessment included Schirmer's test, Norn's test, vital eye stain tests, tear osmometry, laser confocal tomography of the cornea, optical coherence tomography of the anterior segment with meniscometry, impression cytology of the conjunctiva, tear pH measurement, plating of the content of the conjunctival cavity, measurement of the width of the palpebral fissure, and calculation of the ocular surface disease index. Treatment results were followed up at 1, 3, 6, and 12 months.

RESULTS

The use of 0.05% CyA-saturated SCLs allows to halve treatment time for patients with severe KSC (down to 1 week - 1 month) as compared to unsaturated original SCLs in combination with 0.05% CyA instillations and to reduce it 5 times as compared to 0.05% CyA instillations only.

CONCLUSION

The new method of KSC treatment that involves the use of medical SCL of original design (ensures even distribution of 0.05% CyA across the ocular surface) and preservative-free artificial tears has demonstrated high therapeutic effectiveness as compared to existing methods.

Autologous serum eye drops for dry eye

BACKGROUND

Theoretically, autologous serum eye drops (AS) offer a potential advantage over traditional therapies on the assumption that AS not only serve as a lacrimal substitute to provide lubrication but contain other biochemical components that allow them to mimic natural tears more closely. Application of AS has gained popularity as second-line therapy for patients with dry eye. Published studies on this subject indicate that autologous serum could be an effective treatment for dry eye.

OBJECTIVES

We conducted this review to evaluate the efficacy and safety of AS given alone or in combination with artificial tears as compared with artificial tears alone, saline, placebo, or no treatment for adults with dry eye.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2016), Embase (January 1980 to July 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (December 2016) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 July 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared AS versus artificial tears for treatment of adults with dry eye.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts and assessed full-text reports of potentially eligible trials. Two review authors extracted data and assessed risk of bias and characteristics of included trials. We contacted investigators to ask for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95% confidence intervals (CIs) for continuous outcomes. We did not perform meta-analysis owing to differences in outcome assessments across trials.

MAIN RESULTS

We identified five eligible RCTs (92 participants) that compared AS versus artificial tears or saline in individuals with dry eye of various origins (Sjögren's syndrome-related dry eye, non-Sjögren's syndrome dry eye, and postoperative dry eye induced by laser-assisted in situ keratomileusis (LASIK)). We assessed the certainty of evidence as low or very low because of lack of reporting of quantitative data for most outcomes and unclear or high risk of bias among trials. We judged most risk of bias domains to have unclear risk in two trials owing to insufficient reporting of trial characteristics, and we considered one trial to have high risk of bias for most domains. We judged the remaining two trials to have low risk of bias; however, these trials used a cross-over design and did not report data in a way that could be used to compare outcomes between treatment groups appropriately. Incomplete outcome reporting and heterogeneity among outcomes and follow-up periods prevented inclusion of these trials in a summary meta-analysis.Three trials compared AS with artificial tears; however, only one trial reported quantitative data for analysis. Low-certainty evidence from one trial suggested that AS might provide some improvement in participant-reported symptoms compared with artificial tears after two weeks of treatment; the mean difference in mean change in symptom score measured on a visual analogue scale (range 0 to 100, with higher scores representing worse symptoms) was -12.0 (95% confidence interval (CI) -20.16 to -3.84; 20 participants). This same trial found mixed results with respect to ocular surface outcomes; the mean difference in mean change in scores between AS and artificial tears was -0.9 (95% CI -1.47 to -0.33; 20 participants; low-certainty evidence) for fluorescein staining and -2.2 (95% CI -2.73 to -1.67; 20 participants; low-certainty evidence) for Rose Bengal staining. Both staining scales range from 0 to 9, with higher scores indicating worse results. The mean change in tear film break-up time was 2.00 seconds longer (95% CI 0.99 to 3.01; 20 participants; low-certainty evidence) in the AS group than in the artificial tears group. Investigators reported no clinically meaningful differences in Schirmer's test scores between groups (mean difference -0.40 mm, 95% CI -2.91 to 2.11; 20 participants; low-certainty evidence). None of these three trials reported tear hyperosmolarity and adverse events.Two trials compared AS versus saline; however, only one trial reported quantitative data for analysis of only one outcome (Rose Bengal staining). Trial investigators of the two studies reported no differences in symptom scores, fluorescein staining scores, tear film break-up times, or Schirmer's test scores between groups at two to four weeks' follow-up. Very low-certainty evidence from one trial suggested that AS might provide some improvement in Rose Bengal staining scores compared with saline after four weeks of treatment; the mean difference in Rose Bengal staining score (range from 0 to 9, with higher scores showing worse results) was -0.60 (95% CI -1.11 to -0.09; 35 participants). Neither trial reported tear hyperosmolarity outcomes. One trial reported adverse events; two of 12 participants had signs of conjunctivitis with negative culture that did resolve.

AUTHORS' CONCLUSIONS

Overall, investigators reported inconsistency in possible benefits of AS for improving participant-reported symptoms and other objective clinical measures. There might be some benefit in symptoms with AS compared with artificial tears in the short-term, but we found no evidence of an effect after two weeks of treatment. Well-planned, large, high-quality RCTs are warranted to examine participants with dry eye of different severities by using standardized questionnaires to measure participant-reported outcomes, as well as objective clinical tests and objective biomarkers to assess the benefit of AS therapy for dry eye.

Corneal sensitivity, ocular surface health and tear film stability after punctal plug therapy of aqueous deficient dry eye

AIM

To evaluate the effect of punctal occlusion using thermosensitive (smart plug) versus silicone plug for management of aqueous deficient dry eye on corneal sensitivity, ocular surface health and tear film stability.

METHODS

A comparative prospective interventional case study included 45 patients with bilateral severe form of aqueous deficient dry eye. In each patient, the smart plug was inserted in the lower punctum of the right eye which was considered as study group 1 and silicone plug was inserted in the lower punctum of the left eye of the same patient which was considered as study group 2. All patients were subjected to careful history taking and questionnaire for subjective assessment of severity of symptoms. Corneal sensitivity, corneal fluorescein, rose bengal staining, Schirmer's I test, tear film break up time and conjunctival impression cytology were performed pre and 1, 3 and 6mo post plug insertion.

RESULTS

A statistically significant improvement in subjective and objective manifestations occurred following treatment with both types of plugs (P<0.01). The thermosensitive plug caused significant overall improvement, decrease in frequency of application of tear substitutes and improvement of conjunctival impression cytology parameters in the inserted side (P<0.01). Canaliculitis was reported in two eyes (4.4%) following punctal occlusion using thermosensitive plug (study group 1). Spontaneous plug loss occurred in 21 eyes (46.6%) in the silicone plug group (study group 2).

CONCLUSION

Improvement of subjective and objective manifestations of aqueous deficient dry eye occurs following punctal plug occlusion. Thermosensitive plug has good patient's compliance with fewer complications and lower rates of loss compared to the silicone plug.

[Effectiveness of soft contact lenses in severe keratoconjunctivitis sicca treated with local immunosuppressive therapy]

AIM

To study the effectiveness of soft contact lenses in severe keratoconjunctivitis sicca (KCS) treated with local immunosuppressive therapy.

MATERIAL AND METHODS

We have examined 41 patients (60 eyes) with severe KCS, including 3 men (4 eyes) and 38 women (56 eyes) aged from 27 to 76 years. Group 1 consisted of 22 persons (30 eyes) who were prescribed cyclosporine А 0.05% instillations 2 times daily, artificial tears, and soft contact lenses. Group 2 consisted of 19 patients (30 eyes) who received instillations of cyclosporine А 0.05% 2 times daily for no less than 6 months and artificial tears. Apart from the standard ophthalmic examination, the assessment included Schirmer's test, tear break-up time test, fluorescein eye stain test, tear osmometry, Heidelberg tomography of the cornea, optical coherence tomography of the anterior segment with meniscometry, impression cytology of the conjunctiva, tear pH measurement, plating of the content of the conjunctival cavity for its microflora, measurement of the width of the palpebral fissure, and calculation of the ocular surface disease index (OSDI). Treatment outcomes were evaluated at 1, 3, 6, and 12 months.

RESULTS

In group 1, complete re-epithelialization of the cornea (confirmed by all the methods used) was achieved rather shortly, in 1-3 months, while in group 2 - in 6 months.

CONCLUSION

The use of soft contact lenses in addition to cyclosporine A instillation therapy promotes restoration of corneal and conjunctival epithelium, reduces treatment time, and improves quality of life for patients, thus, proving itself a safe and effective treatment of autoimmune KCS.

A Case-Control Study on the Oxidative Balance of 50% Autologous Serum Eye Drops

Importance. Autologous serum (AS) eye drops are recommended for severe dry eye in patients with ocular surface disease. No description of the antioxidant balance of AS eye drops has been reported in the literature. Objective. This study sought to evaluate the total reactive antioxidant potential (TRAP) and concentration of reactive oxygen species (ROS) in samples of 50% AS eye drops and their correlations with the demographic characteristics and lifestyle habits of patients with ocular surface disease and healthy controls. Design. This was a case-control study with a 3-month follow-up period. Participants. 16 patients with severe dry eye disease of different etiologies and 17 healthy controls matched by age, gender, and race were included. Results. TRAP and ROS were detected at all evaluated times. There were no differences in the mean ROS (p = 0.429) or TRAP (p = 0.475) levels between cases and controls. No statistically significant differences in the concentrations of ROS or TRAPs were found at 0, 15, or 30 days (p for ROS = 0.087 and p for TRAP = 0.93). Neither the demographic characteristics nor the lifestyle habits were correlated with the oxidative balance of the 50% AS eye drops. Conclusions and Relevance. Both fresh and frozen 50% AS eye drops present antioxidant capacities and ROS in an apparently stable balance. Moreover, patients with ocular surface disease and normal controls produce equivalent AS eye drops in terms of oxidative properties.

Immunomodulation on the ocular surface: a review

The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated.

The IMPACT study: a prospective evaluation of the effects of cyclosporine ophthalmic emulsion 0.05% on ocular surface staining and visual performance in patients with dry eye

Objective

The aim of this study was to evaluate the effects of cyclosporine ophthalmic emulsion 0.05% on ocular surface staining and visual performance in patients with dry eye.

Methods

This was a single-center, 6-month, open-label, Phase IV study. Patients with bilateral dry eye disease and a symptom score of ≥2 on the Ocular Discomfort and 4-Symptom Questionnaire, an Ocular Surface Disease Index score of >12, at least one eye with Schirmer’s score <10 mm/5 minutes, and central corneal staining graded as ≥2 on the Ora Calibra™ Corneal and Conjunctival Staining Scale were enrolled. Cyclosporine ophthalmic emulsion 0.05% (Restasis^®) was instilled twice daily in each eye. The primary efficacy endpoints were ocular surface staining and visual function at 6 months. Secondary outcome measures included Schirmer’s test, tear film breakup time, symptoms, and adverse events.

Results

A total of 40 patients with the mean age of 59.4 years (range, 40–78 years) were enrolled; 35 (87.5%) were female and 37 (92.5%) completed the study. At 6 months, inferior corneal, central corneal, total corneal, and total ocular surface fluorescein staining were significantly improved from baseline in both eyes (P<0.001). Patient responses on the Ocular Surface Disease Index showed significant improvement in blurred vision and visual function related to reading, driving at night, working with a computer or bank machine, and watching television (P≤0.041). At 6 months, 35.1% of patients achieved ≥5 mm improvement and 18.9% achieved ≥10 mm improvement in the average eye Schirmer score. Mean tear film breakup time improved by >50% in both eyes (P>0.001). Patients reported significant improvement in ocular discomfort and dry eye symptoms (P<0.001). No patients discontinued treatment because of stinging or any other ocular adverse event.

Conclusion

Dry eye patients with difficulties with day-to-day visual function demonstrated improvement in both signs and symptoms of dry eye and reported improved visual function after 6 months of treatment with cyclosporine ophthalmic emulsion 0.05%.

Over the counter (OTC) artificial tear drops for dry eye syndrome

BACKGROUND

Over the counter (OTC) artificial tears historically have been the first line of treatment for dry eye syndrome and dry eye-related conditions like contact lens discomfort, yet currently we know little regarding the overall efficacy of individual, commercially available artificial tears. This review provides a much needed meta-analytical look at all randomized and quasi-randomized clinical trials that have analyzed head-to-head comparisons of OTC artificial tears.

OBJECTIVES

To evaluate the effectiveness and toxicity of OTC artificial tear applications in the treatment of dry eye syndrome compared with another class of OTC artificial tears, no treatment, or placebo.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to December 2015), EMBASE (January 1980 to December 2015), Latin American and Caribbean Health Sciences (LILACS) (January 1982 to December 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) and the US Food and Drugs Administration (FDA) website (www.fda.gov). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 4 December 2015. We searched reference lists of included trials for any additional trials not identified by the electronic searches.

SELECTION CRITERIA

This review includes randomized controlled trials with adult participants who were diagnosed with dry eye, regardless of race and gender. We included trials in which the age of participants was not reported, and clinical trials comparing OTC artificial tears with another class of OTC artificial tears, placebo, or no treatment. This review did not consider head-to-head comparisons of artificial tears with another type of dry-eye therapy.

DATA COLLECTION AND ANALYSIS

We followed the standard methodological procedures expected by Cochrane. Two authors independently screened the search results, reviewed full-text copies for eligibility, examined risk of bias, and extracted data. We performed meta-analysis for trials that compared similar interventions and reported comparable outcomes with sufficient data. We summarized all other included trial results in the text.

MAIN RESULTS

We included 43 randomized controlled trials (3497 participants with dry eye). Due to the heterogeneity of study characteristics among the included trials with respect to types of diagnostic criteria, interventions, comparisons, and measurements taken, our ability to perform meta-analyses was limited. The review found that, in general, there was uncertainty whether different OTC artificial tears provide similar relief of signs and symptoms when compared with each other or placebo. Nevertheless, we found that 0.2% polyacrylic acid-based artificial tears were consistently more effective at treating dry eye symptoms than 1.4% polyvinyl alcohol-based artificial tears in two trials assessing this comparison (175 participants). All other included artificial tears produced contradictory between-group results or found no between-group differences. Our review also found that OTC artificial tears may be generally safe, but not without adverse events. Overall, we assessed the quality of evidence as low due to high risks of bias among included trials and poor reporting of outcome measures which were insufficient for quantitative analysis. Furthermore, we identified an additional 18 potentially eligible trials that were reported only in clinical trial registers with no associated results or publications. These trials reportedly enrolled 2079 total participants for whom no data are available. Such lack of reporting of trial results represents a high risk of publication bias.

AUTHORS' CONCLUSIONS

OTC artificial tears may be safe and effective means for treating dry eye syndrome; the literature indicates that the majority of OTC artificial tears may have similar efficacies. This conclusion could be greatly skewed by the inconsistencies in study designs and inconsistencies in reporting trial results. Additional research is therefore needed before we can draw robust conclusions about the effectiveness of individual OTC artificial tear formulations.

Wakayama symposium: role of canonical Notch signaling in conjucntival goblet cell differentiation and dry eye syndrome

This review summarizes a recent finding regarding the intrinsic canonical Notch signaling pathway in regulating normal ocular surface morphogenesis and its role in the pathogenesis of goblet cell deficiency-associated keratoconjunctivitis sicca (KCS, or dry eye). Specifically, we used novel transgenic mice to investigate the mechanism of how the Notch1 activation may serve as the upstream control of expression of transcription factors Krüppel-like factors 4 or 5 (Klf4 or Klf5) which in turn controls goblet cell differentiation and activates mucin 5/ac synthesis during ocular surface morphogenesis.

Autologous serum and plasma rich in growth factors in ophthalmology: preclinical and clinical studies

The use of blood derivatives represents an alternative therapeutic approach that is gaining interest in regenerative medicine due to its potential to stimulate and accelerate tissue healing. Autologous serum eye drops and platelet-enriched plasma eye drops are being used in the treatment of different ophthalmological disorders. In this review, we summarize the different blood-derived formulations used in the treatment and care of ocular surface disorders. The biological basis and use of autologous serum and plasma rich in growth factors are deeply evaluated as well as the challenges to be addressed in the future in this new generation of blood-derived therapies.

Human Serum Eye Drops in Eye Alterations: An Insight and a Critical Analysis

Human serum contains a physiological plethora of bioactive elements naturally released by activated platelets which might have a significant effect on the regeneration of corneal layers by stimulating the cell growth. This mechanism supported the use of human serum eye drops in some ocular diseases associated with dystrophic changes and alterations of the tear film, such as persistent corneal epithelial defects and dry eye syndrome. We focused our effort on potential benefits and limitations of the use of human serum eye drops when conventional therapies failed. We reviewed the recent literature by reporting published studies from 2010 to 2014. Despite the limited evaluated study populations, most of the clinical studies have confirmed that serum eye drop therapy is effective in corneal healing by reducing ocular symptom, particularly during the short-term follow-up. In addition, three recent published studies have shown the efficacy of the serum eye drop therapy in comparison to traditional ones in intractable patients. Besides, reported ongoing clinical studies confirmed the open debate regarding the use of biologic tools for cornea regeneration. Results from these studies might open novel challenges and perspectives in the therapy of such refractory patients.

Punctal plug: a medical device to treat dry eye syndrome and for sustained drug delivery to the eye

Punctal plugs (PPs) are miniature medical implants that were initially developed for the treatment of dry eyes. Since their introduction in 1975, many PPs made from different materials and designs have been developed. PPs, albeit generally successful, suffer from drawbacks such as epiphora and suppurative canaliculitis. To overcome these issues intelligent designs of PPs were proposed (e.g. SmartPLUG™ and Form Fit™). PPs are also gaining interest among pharmaceutical scientists for sustaining drug delivery to the eye. This review aims to provide an overview of PPs for dry eye treatment and drug delivery to treat a range of ocular diseases. It also discusses current challenges in using PPs for ocular diseases.

[Treating severe keratoconjunctivitis sicca]

Keratoconjunctivitis sicca is a widespread disease with a complex multifactorial pathogenesis. Current understanding of its pathogenesis and existing treatments are summarized in this literature review.

Hyperosmolar tears enhance cooling sensitivity of the corneal nerves in rats: possible neural basis for cold-induced dry eye pain

PURPOSE

Tear hyperosmolarity is a ubiquitous feature of dry-eye disease. Although dry-eye patients' sensitivity to cooling is well known, the effects of tear hyperosmolarity on a small amount of cooling in the corneal nerves have not been quantitatively examined. Recently reported corneal afferents, high-threshold cold sensitive plus dry-sensitive (HT-CS + DS) neurons, in rats is normally excited by strong (>4°C) cooling of the cornea, which, when applied to healthy humans, evokes the sensation of discomfort. However, corneal cooling measured between blinks does not exceed 2°C normally. Thus, we sought to determine if these nociceptors could be sensitized by hyperosmolar tears such that they are now activated by small cooling of the ocular surface.

METHODS

Trigeminal ganglion neurons innervating the cornea were extracellularly recorded in isoflurane-anesthetized rats. The responses of single corneal neurons to cooling stimuli presented in the presence of hyperosmolar (350-800 mOsm NaCl) tears were examined.

RESULTS

The HT-CS + DS neurons with thresholds averaging 4°C cooling responded to cooling stimuli presented after 15 minutes of hyperosmolar tears with thresholds of less than 1°C. The response magnitudes also were enhanced so that the responses to small (2°C) cooling emerged, where none was observed before.

CONCLUSIONS

These results demonstrate that after exposure to hyperosmolar tears, these nociceptive corneal neurons now begin to respond to the slight cooling normally encountered between blinks, enabling the painful information to be carried to the brain, which could explain the cooling-evoked discomfort in dry eye patients.

The role and treatment of inflammation in dry eye disease

Dry eye syndrome is a common ocular surface problem, affects 10-30 % of the population, especially in those who are older than 40 years. As a consequence of the demographic pressure created by the aging population, its prevalence is expected to increase as well as its burden on ophthalmologic practices. Thus, understanding the complex underlying mechanisms and development of thoughtful, effective strategies that involve these mechanisms are critical. Many factors causing ocular surface damage and inflammation have been shown to contribute to the etiopathogenesis. Increased osmolarity induces ocular surface inflammation leading to disruption of both the quality and quantity of tears. Pathologic tear function and the ocular surface inflammation affects the neural arcade and increases apoptosis in the ocular surface cells thus creating a viscous cycle for dry eye by causing unstable and hyperosmolar tears. Thus, the treatment objective is to prevent severe dry eye complications via preventing inflammation and apoptosis of the ocular surface cells. The ultimate target is a normalized ocular surface, increased tear stability, and decreased osmolarity of the tear film. In the light of current literature, this review aims to elucidate the role of inflammation as the main etiological factor in dry eye disease and discuss current therapeutic approaches to overcome it.

The eye: a window of opportunity in rheumatoid arthritis?

Rheumatoid arthritis (RA), the most common autoimmune disorder associated with dry eye syndrome, is also associated with sight-threatening ocular diseases such as peripheral ulcerative keratitis, scleritis and corneal melts. Tissue damage on the ocular surface of patients with RA is autoimmune-mediated. Findings from patients with dry eye have implicated defects in innate immunity (Toll-like receptors, S100A and resident antigen-presenting cells), cytokines, chemokines and T helper (TH)-cell subsets (including TH1 and TH17) in disease pathogenesis. Some of these features are probably important in dry eye related to RA, which can occur at a different time from articular disease and is more clinically severe than idiopathic dry eye. Ocular surface immune factors can be influenced by the systemic immune landscape. Depending on the severity of ocular inflammation in RA, treatment can include ciclosporin, topical corticosteroids, tacrolimus, autologous serum and systemic immunosuppression. Tissue damage is treated by inhibiting matrix metalloproteinases. Potential therapeutic strategies benefit from an improved understanding of ocular surface immunology, and include targeting of T-cell subsets, B-cell signalling or cytokines.

Symptom burden of patients with dry eye disease: a four domain analysis

PURPOSE

To determine which sensory (symptom persistence and intensity) and reactive (activity and affective interference) domains of symptom analysis are essential for assessing symptom burden in dry eye disease (DED) patients.

METHODS

A symptom domain tool was developed to investigate all four symptom domains in DED. In a cross-sectional pilot study, we administered the symptom burden tool and the Ocular Surface Disease Index (OSDI) questionnaire to 48 DED patients. Total and domain scores from the symptom burden tool and the OSDI were normalized to achieve comparability. Spearman correlation coefficients were calculated to measure the relationship between domains and subscales. Agreement between the symptom burden tool and OSDI was assessed by Bland-Altman plot. Assigned treatments were compared by symptom burden to determine whether treatment aggressiveness is linked to symptom intensity.

RESULTS

There was high agreement between the symptom burden tool and the OSDI. Symptom persistence had a stronger correlation with affective interference (r  =  0.62 for the symptom burden tool and r = 0.73 for the OSDI) than activity interference (r = 0.58 for the symptom burden tool and r = 0.60 for the OSDI). Symptom intensity correlated weakly with affective interference (r = 0.38) and activity interference (r = 0.37) in the symptom burden tool (OSDI does not have a subscale for intensity). In patients with equal persistence of symptoms, those having high symptom intensity were receiving more aggressive treatment (66.7%) than those with lower symptom intensity (33.3%).

CONCLUSIONS

Persistence of symptoms correlates better with affective interference than activity interference. Intensity of symptoms may be important for treatment decisions.

Autologous serum eye drops for dry eye

BACKGROUND

=Theoretically, autologous serum eye drops (AS) have a potential advantage over traditional therapies based on the assumption that ASserve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AS in dry eye treatment has gained popularity as a second-line therapy in the treatment of dry eye.Published studies on the subject indicate that autologous serum could be an effective treatment for dry eye.

OBJECTIVES

To evaluate the efficacy and safety of AS compared to artificial tears for treating dry eye.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3),Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE,(January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences(LILACS) (January 1982 to April 2013), themetaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov(www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (September 2013) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which AS was compared to artificial tears in the treatment of dry eye in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts and assessed full-text articles of potentially eligible trials. Two review authors extracted data and assessed the methodological quality and characteristics of the included trials.We contacted investigators for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95% confidence intervals(CIs) for continuous outcomes.

MAIN RESULTS

We identified four eligible RCTs in which AS was compared with artificial tear treatment or saline in individuals (n = 72 participants)with dry eye of various etiologies (Sjögren’s syndrome-related dry eye, non-Sjögren’s syndrome dry eye and postoperative dry eye induced by laser-assisted in situ keratomileusis (LASIK)). The quality of the evidence provided by these trials was variable. A majority of the risk of bias domains were judged to have an unclear risk of bias in two trials owing to insufficient reporting of trial characteristics.One trial was considered to have a low risk of bias for most domains while another was considered to have a high risk of bias for most domains. Incomplete outcome reporting and heterogeneity in the participant populations and follow-up periods prevented the inclusion of these trials in a summary meta-analysis. For the primary outcome, improvement in participant-reported symptoms at one month, one trial (12 participants) showed no difference in participant-reported symptoms between 20% AS and artificial tears. Based on the results of two trials in 32 participants, 20% AS may provide some improvement in participant-reported symptoms compared to traditional artificial tears after two weeks of treatment. One trial also showed positive results with a mean difference in tear breakup time (TBUT) of 2.00 seconds (95% CI 0.99 to 3.01 seconds) between 20% AS and artificial tears after two weeks, which were not similar to findings from the other trials. Based on all other objective clinical assessments included in this review, AS was not associated with improvements in aqueous tear production measured by Schirmer's test (two trials, 33 participants), ocular surface condition with fluorescein (four trials, 72 participants) or Rose Bengal staining (three trials, 60 participants), and epithelial metaplasia by impression cytology compared to artificial tears (one trial, 12 participants). Data on adverse effects were not reported by three of the included studies. In one study, there were no serious adverse events reported with the collection of and treatment with AS.

AUTHORS' CONCLUSIONS

Overall there was inconsistency in the possible benefits of AS in improving participant-reported symptoms and TBUT and lack of effect based on other objective clinical measures. Well-planned, large, high-quality RCTs are warranted, in different severities of dry eye and using standardized questionnaires to measure participant-reported outcomes and objective clinical tests as well as objective biomarkers to assess the benefit of AS therapy for dry eye.

Topical biological agents targeting cytokines for the treatment of dry eye disease

Because inflammation plays a key role in the pathogenesis of dry eye disease and Sjögren’s syndrome, topical anti-inflammatory agents such as corticosteroids and cyclosporine A have been used to treat inflammation of the ocular surface and lacrimal gland. Systemic biological agents that target specific immune molecules or cells such as tumor necrosis factor (TNF)-α, interferone-α, interleukin (IL)-1, IL-6, or B cells have been used in an attempt to treat Sjögren’s syndrome. However, the efficacy of systemic biological agents, other than B-cell targeting agents, has not yet been confirmed in Sjögren’s syndrome. Several studies have recently evaluated the efficacy of topical administration of biological agents targeting cytokines in the treatment of dry eye disease. Topical blockade of IL-1 by using IL-1 receptor antagonist could ameliorate clinical signs and inflammation of experimental dry eye. Using a mouse model of desiccating stress-induced dry eye, we have demonstrated that topical application of a TNF-α blocking agent, infliximab, could improve tear production and ocular surface irregularity, decrease inflammatory cytokines and Th-1 CD4+ cells on the ocular surface, and increase goblet cell density in the conjunctiva. Although controversy still remains, the use of topical biological agents targeting inflammatory cytokines may be a promising therapy for human dry eye disease.

Ocular inflammation and corneal permeability alteration by benzalkonium chloride in rats: a protective effect of a myosin light chain kinase inhibitor

PURPOSE

The aim of this study was to evaluate the interest of an ophthalmic eyedrop preparation containing a myosin light chain kinase (MLCK) inhibitor, ML-7, in the treatment of ocular surface. The local protective effect on the inflammation and the increase of corneal permeability induced by benzalkonium (BAK) was evaluated.

METHODS

An ocular instillation of 10 lL BAK at a concentration of 0.1% in PBS was performed on rats. The eyes were rinsed with sterilized water, 10 minutes after BAK preceded by instillation at T -24, -12, and -0.5 hours of 10 lL ofML-7: 100 μg (10 μL) into a gel form vehicle. All animals were sacrificed 6 hours after BAK instillation. The eyes were isolated for study in a masked manner. The ocular surface inflammation was assessed by measuring the inflammatory cell infiltration by a histologic quantitative analysis and for total ocular myeloperoxidase (MPO) activity. The tight junction permeability was tested.

RESULTS

Instillation of 0.1% BAK increased the inflammation of the eye. The quantitative analysis showed an increase in the number of eosinophil and neutrophil polynuclears, and MPO activity. Pretreatment with ML-7 reduced inflammation (P < 0.05). The vehicle alone produced no notable effects. BAK instillation also thickened the fluorescent corneal front on frozen sections, indicating an increase of tight junction permeability. Pretreatment with ML-7 suppressed BAK-induced alterations of paracellular permeability while the vehicle had no visible effects.

CONCLUSIONS

Our study indicates that the inhibition of corneal cytoskeleton contraction by an MLCK inhibitor prevents BAK-induced ocular inflammatory response, and that ML-7 may be a new and original preparation in the treatment of ocular surface pathologies.

The effect of topical pranoprofen 0.1% on the clinical evaluation and conjunctival HLA-DR expression in dry eyes

PURPOSE

To investigate the effect of topical pranoprofen 0.1% on the clinical evaluation and conjunctival human leukocyte antigen II (HLA-DR) expression in dry eyes.

METHODS

Sixty patients with dry eyes were randomized to 2 groups. Patients in group 1 received topical pranoprofen 0.1% plus topical sodium hyaluronate 0.1%; and patients in group 2 received sodium hyaluronate without pranoprofen. Ocular surface disease index (OSDI), tear &filig;lm break-up time (TBUT), Schirmer I test, ocular surface staining (OSS), and conjunctival HLA-DR expression were evaluated before treatment and at 15 and 30 days after treatment.

RESULTS

On day 15, patients in group 1 had significantly lower OSDI, OSS, and HLA-DR-positive cells compared with patients in group 2 (P < 0.01), and the TBUT was significantly longer in patients in group 1 than that of patients in group 2 (P < 0.01). On day 30, the difference between the 2 groups in OSS lost significance; however, there continued to be significant differences in the OSDI, TBUT, and HLA-DR expression between the 2 groups (P < 0.01). On days 15 and 30, the values in group 1 patients had significant improvement compared with their baseline values in terms of the above-mentioned parameters. The comparisons within group 2 did not reveal any significant differences. There was no significant effect in the Schirmer I test value in eyes of patients in group 1 or group 2 at days 15 or 30 (P > 0.05).

CONCLUSIONS

Topical pranoprofen 0.1% has a beneficial effect in reducing the ocular signs and symptoms of dry eyes and decreasing the inflammatory markers of conjunctival epithelial cells.