A Pragmatic Approach to the Management of Dry Eye Disease: Evidence into Practice

Protective effect of Tisochrysis lutea on dry eye syndrome via NF-κB inhibition

Dry eye syndrome (DES) affects the cornea, causes pain and hypersensitivity to light. Although inflammation and endoplasmic reticulum stress are known to be involved, the detailed mechanisms remain unknown. DES is characterized by a decrease in corneal thickness, tear volume, and lacrimal gland size, and damage to corneal cells. Tisochrysis lutea is a microalga that has been shown to reduce immune factors. Therefore, we hypothesized that T. lutea could ameliorate DES. We investigated the role of T. lutea in scopolamine-induced DES in BALB/c mice. Oral administration of T. lutea increased corneal thickness, tear volume, and size of the corneal cells, and reduced damage to the corneal cells. Furthermore, treatment of ARPE-19 human retinal pigmented epithelial cells with T. lutea reduced expression of the inflammatory factor, NF-κB, MAPK, and AKT. T. lutea may be used therapeutically to reduce the symptoms of DES.

In Vivo Anti-Inflammation Potential of Aster koraiensis Extract for Dry Eye Syndrome by the Protection of Ocular Surface

Dry eye syndrome (DES) is a corneal disease often characterized by an irritating, itching feeling in the eyes and light sensitivity. Inflammation and endoplasmic reticulum (ER) stress may play a crucial role in the pathogenesis of DES, although the underlying mechanism remains elusive. Aster koraiensis has been used traditionally as an edible herb in Korea. It has been reported to have wound-healing and inhibitory effects against insulin resistance and inflammation. Here, we examined the inhibitory effects of inflammation and ER stress by A. koraiensis extract (AKE) in animal model and human retinal pigmented epithelial (ARPE-19) cells. Oral administration of AKE mitigated DE symptoms, including reduced corneal epithelial thickness, increased the gap between lacrimal gland tissues in experimental animals and decreased tear production. It also inhibited inflammatory responses in the corneal epithelium and lacrimal gland. Consequently, the activation of NF-κB was attenuated by the suppression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Moreover, AKE treatment ameliorated TNF-α-inducible ocular inflammation and thapsigargin (Tg)-inducible ER stress in animal model and human retinal pigmented epithelial (ARPE-19) cells. These results prove that AKE prevents detrimental functional and histological remodeling on the ocular surface and in the lacrimal gland through inhibition of inflammation and ER stress, suggesting its potential as functional food material for improvement of DES.

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.

Omega-3 and omega-6 polyunsaturated fatty acids for dry eye disease

BACKGROUND

Polyunsaturated fatty acid (PUFA) supplements, involving omega-3 and/or omega-6 components, have been proposed as a therapy for dry eye. Omega-3 PUFAs exist in both short- (alpha-linolenic acid [ALA]) and long-chain (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) forms, which largely derive from certain plant- and marine-based foods respectively. Omega-6 PUFAs are present in some vegetable oils, meats, and other animal products.

OBJECTIVES

To assess the effects of omega-3 and omega-6 polyunsaturated fatty acid (PUFA) supplements on dry eye signs and symptoms.

SEARCH METHODS

CENTRAL, Medline, Embase, two other databases and three trial registries were searched in February 2018, together with reference checking. A top-up search was conducted in October 2019, but the results have not yet been incorporated.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) involving dry eye participants, in which omega-3 and/or omega-6 supplements were compared with a placebo/control supplement, artificial tears, or no treatment. We included head-to-head trials comparing different forms or doses of PUFAs.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 34 RCTs, involving 4314 adult participants from 13 countries with dry eye of variable severity and etiology. Follow-up ranged from one to 12 months. Nine (26.5%) studies had published protocols and/or were registered. Over half of studies had high risk of bias in one or more domains. Long-chain omega-3 (EPA and DHA) versus placebo or no treatment (10 RCTs) We found low certainty evidence that there may be little to no reduction in dry eye symptoms with long-chain omega-3 versus placebo (four studies, 677 participants; mean difference [MD] -2.47, 95% confidence interval [CI] -5.14 to 0.19 units). We found moderate certainty evidence for a probable benefit of long-chain omega-3 supplements in increasing aqueous tear production relative to placebo (six studies, 1704 participants; MD 0.68, 95% CI 0.26 to 1.09 mm/5 min using the Schirmer test), although we did not judge this difference to be clinically meaningful. We found low certainty evidence for a possible reduction in tear osmolarity (one study, 54 participants; MD -17.71, 95% CI -28.07 to -7.35 mOsmol/L). Heterogeneity was too substantial to pool data on tear break-up time (TBUT) and adverse effects. Combined omega-3 and omega-6 versus placebo (four RCTs) For symptoms (low certainty) and ocular surface staining (moderate certainty), data from the four included trials could not be meta-analyzed, and thus effects on these outcomes were unclear. For the Schirmer test, we found moderate certainty evidence that there was no intergroup difference (four studies, 455 participants; MD: 0.66, 95% CI -0.45 to 1.77 mm/5 min). There was moderate certainty for a probable improvement in TBUT with the PUFA intervention relative to placebo (four studies, 455 participants; MD 0.55, 95% CI 0.04 to 1.07 seconds). Effects on tear osmolarity and adverse events were unclear, with data only available from a single small study for each outcome. Omega-3 plus conventional therapy versus conventional therapy alone (two RCTs) For omega-3 plus conventional therapy versus conventional therapy alone, we found low certainty evidence suggesting an intergroup difference in symptoms favoring the omega-3 group (two studies, 70 participants; MD -7.16, 95% CI -13.97 to -0.34 OSDI units). Data could not be combined for all other outcomes. Long-chain omega-3 (EPA and DHA) versus omega-6 (five RCTs) For long-chain omega-3 versus omega-6 supplementation, we found moderate certainty evidence for a probable improvement in dry eye symptoms (two studies, 130 participants; MD -11.88, 95% CI -18.85 to -4.92 OSDI units). Meta-analysis was not possible for outcomes relating to ocular surface staining, Schirmer test or TBUT. We found low certainty evidence for a potential improvement in tear osmolarity (one study, 105 participants; MD -11.10, 95% CI -12.15 to -10.05 mOsmol/L). There was low level certainty regarding any potential effect on gastrointestinal side effects (two studies, 91 participants; RR 2.34, 95% CI 0.35 to 15.54).

AUTHORS' CONCLUSIONS

Overall, the findings in this review suggest a possible role for long-chain omega-3 supplementation in managing dry eye disease, although the evidence is uncertain and inconsistent. A core outcome set would work toward improving the consistency of reporting and the capacity to synthesize evidence.

Real-life results of switching from preserved to preservative-free artificial tears containing hyaluronate in patients with dry eye disease

Background

Dry eye disease (DED) is a chronic, multifactorial disease of the ocular surface leading to discomfort, visual disturbance, and tear film instability, with potential damage to the ocular surface.

Aim

The aim of this study was to assess the clinical benefit of a switch from preserved to preservative-free artificial tears (ATs) containing hyaluronate in patients with DED.

Materials and methods

This is a nationwide, multicenter, noninterventional, and transversal observational survey.

Results

The mean age was 51.0±15.4 years, ranging from 6 to 96 years. The majority (61.4%) was female. The mean Ocular Surface Disease Index (OSDI) before the switch was surprisingly high at 56.0±23.5, and 73.0% of the patients had superficial punctate keratitis (SPK). The mean duration of use of preserved ATs before the switch was 15.8±12.1 months. OSDI scores and the presence of SPK correlated with the patients’ ages but were independent of the duration of treatment with the preserved AT. The patients using ATs containing “soft” or “vanishing” preservatives presented exactly the same clinical pattern (level of OSDI and frequency of SPK) as those using ATs containing classical preservatives such as benzalkonium chloride (BAK). After switching to preservative-free AT containing hyaluronate (Hyabak^®), the OSDI of 97.0% of the patients improved, decreasing from an average of 56.0 to an average of 28.2, with 23% of patients reporting a normal value of OSDI. The SPK frequency as well improved dramatically, with a frequency of positive fluorescein staining dropping from 73% to 46.1% of patients. A total of 94.0% of the patients considered that they preferred being treated with the preservative-free AT.

Conclusion

In patients suffering from DED and treated with a preserved AT, switching to a preservative-free AT provides clinical benefit by decreasing the severity of DED and reducing the prevalence of SPK, even after only 3 weeks of daily use of the preservative-free AT.

Comparison of 0.1%, 0.18%, and 0.3% Hyaluronic Acid Eye Drops in the Treatment of Experimental Dry Eye

PURPOSE

To compare the efficacy of 0.1%, 0.18%, and 0.3% hyaluronic acid (HA) artificial tear in the treatment of experimental dry eye (EDE).

METHODS

EDE was established in female C57BL/6 mice through an air draft and subcutaneous scopolamine injection. The mice were divided into 5 groups according to topical treatment regimens (n = 5 each): EDE control, balanced salt solution (BSS), preservative-free 0.1% HA, 0.18% HA, and 0.3% HA. The tear film break-up time (TBUT) and corneal fluorescein staining scores were measured 5, 10, 14, 21, and 28 days after treatment. The corneal smoothness scores were measured. In addition, periodic acid-Schiff (PAS) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were performed.

RESULTS

The values for TBUT and corneal fluorescein staining showed greater improvements in all the HA groups (P < 0.05) than in the EDE and BSS groups after 10 days of treatment. Mice treated with 0.3% HA showed a more significant improvement in all clinical parameters than did those in the EDE control, BSS, 0.1% HA, and 0.18% HA groups (all P < 0.05) after 28 days of treatment. The goblet cell counts were higher in the 0.3% and 0.18% HA groups than in the 0.1% HA group. The number of TUNEL-positive cells was the lowest in the 0.3% HA group.

CONCLUSIONS

In EDE, 0.3% HA artificial tears are more effective than the 0.1% and 0.18% HA in improving tear film instability and ocular surface staining and irregularity, in increasing the number of conjunctival goblet cells, and in decreasing corneal epithelial apoptosis.

Evaluation of a new artificial tear formulation for the management of tear film stability and visual function in patients with dry eye

Purpose

Artificial tears are the first line of therapy for dry eye disease (DED) and are also the most frequently used treatment approach for this common condition. Despite this, there are few published studies that directly compare the effectiveness of different drop preparations, especially those formulated specifically for dry eye. In this study, we tested a new artificial tear product, Rohto^® Dry-Aid™, for its ability to relieve the signs and symptoms of DED. The study used a second drop, Systane^® Ultra, as a positive comparator.

Materials and methods

This was a prospective, single-center, open-label, parallel-group study comparing the effects of the two products when used continuously over ~30 days (Clinical Trials registration number NCT03183089). Subjects were randomly assigned to one of the two test groups and were monitored 2 and 4 weeks after enrollment. Efficacy endpoints included ocular staining, visual function, and ocular discomfort.

Results

Treatment groups had similar ocular staining and ocular comfort scores, and both showed statistically significant ocular discomfort score improvement. Subjects in the Rohto group reported significant improvements in visual tasking activities such as watching television and driving at night. There was also a tendency for diary symptom scores to worsen from morning to evening in the Systane group, but not in the Rohto group; this trend was not significant, but warrants further study.

Conclusion

The two products, Rohto Dry-Aid and Systane Ultra, elicited comparable effects on the signs and symptoms of DED. While both products are designed to provide long-lasting relief, subjects in the Rohto group experienced a superior relief from discomfort associated with visual tasking activities and daily diaries, indicating that the Rohto drops may provide a longer duration of symptomatic relief over the course of the day.

Prevalence of dry eye disease in visual display terminal workers: a systematic review and meta-analysis

OBJECTIVE

To evaluate the prevalence and risk factors of dry eye disease (DED) in workers using visual display terminals (VDT).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched PubMed, Cochrane Library, Embase and Science Direct databases for studies reporting DED prevalence in VDT workers.

RESULTS

16 of the 9049 identified studies were included, with a total of 11,365 VDT workers. Despite a global DED prevalence of 49.5% (95% CI 47.5 to 50.6), ranging from 9.5% to 87.5%, important heterogeneity (I(2)=98.8%, p<0.0001) was observed. Variable diagnosis criteria used within studies were: questionnaires on symptoms, tear film anomalies and corneoconjunctival epithelial damage. Some studies combined criteria to define DED. Heterogeneous prevalence was associated with stratifications on symptoms (I(2)=98.7%, p<0.0001), tears (I(2)=98.5%, p<0.0001) and epithelial damage (I(2)=96.0%, p<0.0001). Stratification of studies with two criteria adjusted the prevalence to 54.0% (95% CI 52.1 to 55.9), whereas studies using three criteria resulted in a prevalence of 11.6% (95% CI 10.5 to 12.9). According to the literature, prevalence of DED was more frequent in females than in males and increased with age.

CONCLUSIONS

Owing to the disparity of the diagnosis criteria studied to define DED, the global prevalence of 49.5% lacked reliability because of the important heterogeneity. We highlight the necessity of implementing common DED diagnostic criteria to allow a more reliable estimation in order to develop the appropriate preventive occupational actions.

α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways

Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10(-4) μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH's protective effects, suggesting that both pathways are necessary for α-MSH's protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED.