INS365 suppresses loss of corneal epithelial integrity by secretion of mucin-like glycoprotein in a rabbit short-term dry eye model

Diquafosol Improves Corneal Wound Healing by Inducing NGF Expression in an Experimental Dry Eye Model

Dry eye disease (DED) is caused by inflammation and damage to the corneal surface due to tear film instability and hyperosmolarity. Various eye drops are used to treat this condition. Each eye drop has different properties and mechanisms of action, so the appropriate drug should be used according to clinical phenotypes. This study aims to compare the therapeutic mechanisms of cyclosporine A (CsA) and diquafosol tetrasodium (DQS). An experimental in vivo/in vitro model of DED using hyperosmolarity showed decreased cell viability, inhibited wound healing, and corneal damage compared to controls. Treatment with cyclosporine or diquafosol restored cell viability and wound healing and reduced corneal damage by hyperosmolarity. The expression of the inflammation-related genes il-1β, il-1α, and il-6 was reduced by cyclosporine and diquafosol, and the expression of Tnf-α, c1q, and il-17a was reduced by cyclosporine. Increased apoptosis in the DED model was confirmed by increased Bax and decreased Bcl-2 and Bcl-xl expression, but treatment with cyclosporine or diquafosol resulted in decreased apoptosis. Diquafosol increased NGF expression and translocation into the extracellular space. DED has different damage patterns depending on the progression of the lesion. Thus, depending on the type of lesion, eye drops should be selected according to the therapeutic target, focusing on repairing cellular damage when cellular repair is needed or reducing inflammation when inflammation is high and cellular damage is severe.

Efficacy and safety of artificial tears containing Artemia salina extract with dinucleotides for dry eye

CLINICAL RELEVANCE

This clinical trial was conducted as part of the marketing procedures for a medical device comprising artificial tears containing Artemia salina extract with dinucleotides. These molecules previously demonstrated secretagogue properties by enhancing the production of aqueous, mucinous, and lipidic components of the tears.

BACKGROUND

After confirming the efficacy of artificial tears containing Artemia salina extract in an animal model, this study proceeded to evaluate their efficacy and safety on dry eye participants.

METHODS

A randomised controlled clinical trial was performed on 36 dry eye participants (41.6 ± 20.6 years). Half of the participants were treated with saline solution as a placebo for four weeks, while the other half were treated with artificial tears containing Artemia salina, randomly assigned. After a wash-out period of two weeks, the treatments were crossed for another four weeks. Participants were assessed at baseline and after one week, two weeks, and four weeks. Efficacy variables were: eye dryness frequency (primary), eye comfort, visual satisfaction, tear secretion, tear break-up time, corneal staining, conjunctival staining, and conjunctival hyperaemia. Safety variables were: high- and low-contrast visual acuity, intraocular pressure, and eye fundus images analysis.

RESULTS

Compared with the baseline, the saline solution showed no significant changes in any of the studied variables after four weeks of treatment (p ≥ 0.05). However, the topical instillation of the artificial tears with Artemia salina for four weeks significantly improved eye dryness frequency (p = 0.014) and corneal staining (p = 0.010). No systemic or ocular adverse events were reported during the clinical trial.

CONCLUSION

The topical instillation of artificial tears containing Artemia salina in mild to moderate dry eye participants for four weeks slightly improved their symptoms related to eye dryness frequency and reduced corneal damage, with no undesirable side effects observed.

Effectiveness of Single-Dose Oral Pilocarpine Administration in Patients with Sjögren's Syndrome

In this study, we evaluated the effectiveness of a single-dose oral pilocarpine administration on tear film (TF), as well as dry eye and dry mouth symptoms, in 53 eyes of 27 Sjögren syndrome (SS) patients who were experiencing dry mouth. To evaluate the changes in tear volume, a digital video-meniscometer was used to measure the radius of the lower central tear meniscus curvature (R, mm) of each eye at prior to the administration of 5 mg oral pilocarpine, and at 15 (R:(15)), 30 (R:(30)), and 60 (R:(60)) minutes after administration. The fluorescein breakup time (FBUT, seconds) and ocular and oral dryness symptoms were evaluated before and at 60 min after administration using a visual analogue scale (VAS, mm). A significant increase in R was observed at 15 and 30 min after administration compared to that at prior to administration. FBUT showed significant improvement at 60 min after administration, and the VAS score for ocular and oral dryness symptoms was found to have decreased significantly at 60 min after administration. A single-dose administration of 5 mg oral pilocarpine had a beneficial effect on TF, as well as on ocular and oral dryness symptoms, in patients with SS.

The Combined Impact of Intense Pulsed Light Combined and 3% Diquafosol Ophthalmic Solution on Evaporative Dry Eye: A Randomized Control Study

INTRODUCTION

The primary objective of this study is to assess whether the combination of intense pulsed light (IPL) with 3% diquafosol (DQS) ophthalmic solution is more effective than intense pulsed light in alleviating signs and symptoms of dry eye disease (DED).

METHODS

This randomized study included 66 participants with evaporative dry eye (EDE) who received IPL + DQS therapy (n = 44 eyes), IPL therapy (n = 44 eyes), or sham therapy (n = 44 eyes). All participants were examined at baseline (D0), day 14 (D14), and day 28 (D28) for non-invasive break-up time (NITBUT), tear-film lipid layer (TFLL), corneal conjunctival staining (CS), meibomian gland quality (MGQ), meibomian gland expression (MGEx), and ocular surface disease index (OSDI).

RESULTS

At day 28, comparison among the IPL + DQS therapy, IPL therapy, and sham therapy found significant differences in the mean NITBUT (12.03 ± 1.27 versus 10.47 ± 3.48 versus 4.57 ± 0.46; p < 0.001), TFLL (2.09 ± 0.29 versus 2.27 ± 0.45 versus 2.89 ± 0.65; p < 0.001), CS (1.43 ± 0.82 versus 1.93 ± 1.32 versus 3.52 ± 1.00; p < 0.001), MGQ (1.55 ± 0.66 versus 1.91 ± 0.77 versus 2.66 ± 0.53; p < 0.001), MGEx (1.27 ± 0.45 versus 1.75 ± 0.44 versus 2.41 ± 0.50; p < 0.001), and OSDI score (19.36 ± 7.01 versus 24.77 ± 4.68 versus 42.61 ± 7.49; p < 0.001); significant improvements in NITBUT, TFLL, CS, MGQ, MGEx, and OSDI were found in the IPL + DQS therapy and IPL therapy, while the sham therapy had no significant improvements.

CONCLUSION

Combining 3% diquafosol ophthalmic solution with intense pulsed light was superior to IPL therapy alone in relieving the signs and symptoms of patients with severe evaporative DED.

TRIAL REGISTRATION

Clinical Trials Identifier: NCT05694026.

A Comprehensive Assessment of Tear-Film-Oriented Diagnosis (TFOD) in a Dacryoadenectomy Dry Eye Model

Tear film instability is a major cause of dry eye disease. In order to treat patients with short tear film breakup time (TBUT)-type dry eye, the development of tear film stabilizing agents is essential. However, the lack of an appropriate animal model of tear film instability has made drug development difficult. Although rabbit dry eye models have been reported in the past, there are only a few reports that focus on tear film instability. Herein, we assessed the tear film stability of a rabbit dry eye model induced by dacryoadenectomy. A clinical evaluation of the ocular surface, interferometry, and histological assessments of the cornea and conjunctiva were performed. Following the removal of the lacrimal glands, TBUT was shortened significantly, with dimple and random breakup patterns prominently observed. Furthermore, the blink rate in this model increased after dacryoadenectomy, suggesting that this model partially captured the phenotypes of human short TBUT-type dry eye and may be useful as an animal model for investigating potential drug candidates.

A randomized controlled trial involving college student: Comparing 0.15% hyaluronic acid with 0.05% cyclosporine A and 3% diquafosol sodium in the Treatment of Dry Eye

BACKGROUND

To compare the efficacy of 0.15% hyaluronic acid (HA), 0.05% cyclosporine A (CsA) and 3% diquafosol sodium (DQS) ophthalmic solution for the treatment of moderate-to-severe dry eye disease (DED) in college students and the effect on inflammatory factors in tears.

METHODS

This was a prospective, randomized, multicenter trial. A total of 282 college students diagnosed with moderate-to-severe DED between October 2, 2022 and March 1, 2023 were included. A total of 282 patients were randomized to treatment in the group of 0.15% HA or 0.05% CsA or 3% DQS in a 1:1:1 assignment. There was a main end point which is the variations in the corneal staining score to determine non-inferiority of 0.15% HA. Secondary target end points were ocular surface disease index score, Schirmer test, tear meniscus height and tear film breakup time. In addition, the inflammatory factor levels of Interleukin-1β, Interleukin-6, transforming growth factor-β1 in tears were measured. Effectiveness was assessed at baseline, 4- and 12-weeks.

RESULTS

In our analysis, the average change from baseline in corneal staining score confirmed non-inferiority of 0.15% HA to 0.05% CsA and 3% DQS and manifested obvious improvement of all groups as well (P < .05). Values for ocular surface disease index score, Schirmer test, tear meniscus height and tear film breakup time showed obvious improvements in all groups (P < .05), however, the difference intergroup was not statistically significant. Value for inflammatory factor was significant improvement across all groups, although inflammatory factor scores in the 0.05% CsA group showed a clear trend of better improvement at 12 weeks compared with 0.15% HA groups (P < .01). No serious adverse reactions were observed.

CONCLUSIONS

College students taking 0.15% HA had clinically and statistically significant improvement in corneal staining score and other indicators, but it was inferior to 0.05% CsA in anti-inflammatory therapy for moderate to severe DED. However, 0.15% HA is still an effective, safe and well-tolerated treatment option that may offer additional benefits in terms of convenience and compliance.

Protocol for a parallel assignment prospective, randomised, comparative trial to evaluate the safety and efficacy of intense pulsed light (IPL) combined with 3% diquafosol (DQS) ophthalmic solution in dry eye syndrome

INTRODUCTION

Evaporative dry eye (EDE) is common and can lead to ocular pain, decreased visual quality and reduced quality of life. Intense pulsed light (IPL) and 3% diquafosol ophthalmic solution have been found to be beneficial in reducing signs and symptoms of dry eye.

METHODS AND ANALYSIS

A randomised clinical trial will be performed at He Eye Specialist Hospital in Shenyang. 360 dry eye disease patients will be equally divided randomly into the IPL group, DQS group (3% diquafosol ophthalmic solution eye-drops) and IPL+group (IPL combined with 3% diquafosol eye-drops). All groups will be followed up for 4 weeks. The primary outcome measures will be the non-invasive tear break-up time and the Ocular Surface Disease Index change from the baseline. The secondary outcome measures willincludeconjunctival and cornea staining with fluorescein and lissamine, meibomian gland function and secretion quality, tear film lipid layer score, tear meniscus height, conjunctival hyperemia (redness score) changes . Adverse events also will be monitored and documented.

DISCUSSION

This study aimed to assess whether the combination of IPL with 3% diquafosol ophthalmic solution (study group), IPL+ (study group), is more effective than IPL (active control group) or DQS (active control group) in participants with EDE.

ETHICS AND DISSEMINATION

Management of dry eye with IPL combined with 3% diquafosol ophthalmic solution, registered on 23 January 2023. Ethics approval number: IRB (2022) K029.01. The study's findings will be shared regardless of the effect's direction.

TRIAL REGISTRATION NUMBER

NCT05694026.

Short-term application of diquafosol ophthalmic solution benefits children with dry eye wearing orthokeratology lens

Purpose

This aim of this study was to evaluate the effect of 3% Diquafosol Ophthalmic Solution (DQS) on children with dry eye from wearing overnight orthokeratology (OrthoK) lenses.

Methods

Myopic children aged 8-18 years with dry eye syndrome were enrolled in this prospective observational study, and they were grouped according to their OrthoK treatment history for at least 1 year. All participants received DQS 4 times per day for 1 month. The following indicators were measured at baseline 1 month after treatment: the Dry Eye Questionnaire-5 (DEQ-5), non-invasive tear meniscus height (TMH), non-invasive tear film break-up time (first and average, NIBUT-F and NIBUT-A), meibomian gland score (MG score), conjunctival hyperemia redness score (R-scan), and blink pattern analysis.

Results

A total of 104 participants (189 eyes) including 40 OrthoK wearers (72 eyes) and 64 Orthok candidates (117 eyes) completed the study. Of all, after DQS treatment for 1 month, DEQ-5 scores reduced from 5.54 ± 3.25 to 3.85 ± 2.98 (t = -3.36, p = 0.00). TMH increased from 0.20 ± 0.05 mm to 0.21 ± 0.05 mm (t = 2.59, p = 0.01), NIBUT-F and NIBUT-A were prolonged from 6.67 ± 4.71 s to 10.32 ± 6.19 s and from 8.86 ± 5.25 s to 13.30 ± 6.03 s (all p = 0.00), respectively. R-scan decreased from 0.69 ± 0.28 to 0.50 ± 0.25 (t = -9.01, p = 0.00). Upper MG scores decreased from 1.04 ± 0.32 to 0.97 ± 0.36 (t = -2.14, p = 0.03). Lower MG scores, partial blink rate, partial blinks, and total blinks did not change significantly. Both break-up time (BUT) and R-scan improved significantly after DQS treatment for 1 month (all p = 0.00) in OrthoK candidates and OrthoK wearers. Among the OrthoK wearers, TMH and dry eye symptoms increased significantly (all p = 0.00) but did not increase in OrthoK candidates (p > 0.05). There were no adverse events related to DQS.

Conclusion

Diquafosol Ophthalmic Solution was effective for children wearing overnight orthokeratology in relieving dry eye symptoms and improving ocular surface parameters, which may help improve children's OrthoK wearing tolerance and compliance.

Tear secretion by Diquafosol suppresses the excitability of trigeminal brainstem nuclear complex neurons by reducing excessive P2Y2 expression in the trigeminal ganglion in dry eye rats

The P2Y₂ receptor agonist, diquafosol sodium, is commonly used to treat the signs and symptoms of dry eye disease (DE) patients. Although diquafosol improves tear film stability, the neural mechanisms underlying the reduction in ocular pain are not well defined. This study determined if repeated application of diquafosol reduces the sensitization of nociceptive neurons in the lower trigeminal brainstem nuclear complex (TBNC) via peripheral P2Y₂ mechanisms in a rat model for DE. Diquafosol was applied to the ocular surface daily for 28 days, starting at day 0 or day 14, after exorbital gland removal. The number of eyeblinks, P2Y₂-immunoreactive neurons in the trigeminal ganglion (TG), and correlates of TBNC neural excitability (i.e., cFos protein and phosphorylated extracellular signal-regulated kinase (pERK) expression) were assessed in male rats. Diquafosol increased spontaneous tear volume and reduced the number of ocular surface-evoked eyeblinks in DE rats. Fluorogold-labeled TG neurons that supply the cornea expressed P2Y₂. The number of P2Y₂-immunoreactive neurons was increased in DE rats and suppressed by diquafosol. Diquafosol also reduced the number of cFos- and pERK-immunoreactive neurons in the TBNC in DE rats. These findings suggest that diquafosol, regardless of late-phase treatment, relieves ocular nociception in DE by reducing peripheral P2Y₂ expression.

Prevention of Surgery-Induced Dry Eye by Diquafosol Eyedrops after Femtosecond Laser-Assisted Cataract Surgery

Purpose: To analyze the protective effects of diquafosol eyedrops on the ocular surface following femtosecond laser-assisted cataract surgery (FLACS). Design: A prospective, randomized contralateral study. Methods: Bilateral FLACS with a trifocal IOL (PanOptix) implantation was performed in 40 eyes in 20 patients (10 males, 10 females, average age 68.8 ± 6.3 years old). Patients received 3% diquafosol eyedrops six times daily in one randomly chosen eye (diquafosol group), and physiological saline six times a day in the other eye (control group). Other medication included 1.5% levofloxacin, 0.1% dexamethasone and 0.1% diclofenac three times daily in both eyes. The pre and post-operative tear break-up time (BUT), superficial punctate keratopathy (SPK) scores and visual function were compared between both eyes, and all patients answered the dry-eye-related quality of life score (DEQS) questionnaire. Results: The BUT between groups was similar pre-operatively and on the first day post-op; however, the BUT was statistically longer in the diquafosol group compared to saline at 1 week (5.5/3.7 s) and 2 weeks (4.8/3.0 s) (p < 0.05). There was no difference in the SPK score, best corrected distance visual acuity, tear meniscus height, contrast sensitivity, DEQS and Schirmer test at all time points. Spherical aberration was statistically lower in the diquafosol group at 1 week. The protective effects of diquafosol on the BUT was more pronounced in patients with a pre-operative BUT of less than 5 s compared with those with a BUT longer than 6 s. Conclusions: Diquafosol eyedrops prevented the shortening of the BUT following FLACS, even in patients with short pre-operative BUT values.

Comparison of Treatment Modalities for Dry Eye in Primary Sjögren’s Syndrome

Purpose: To evaluate the effectiveness of different treatment modalities for dry eye in primary Sjögren’s syndrome with their potential overlapping influences. Methods: This study included 199 patients with newly diagnosed primary Sjögren’s syndrome from 2005 to 2020. Various treatment modalities for primary Sjögren’s syndrome were compared. Improvement of corneal staining based on Sjögren’s International Collaborative Clinical Alliance (SICCA) scores was the primary outcome. Results: The average follow-up period was 5.4 ± 3.1 (range, 2.0–14.1) years. Analysis of the individual treatments showed that punctal plug insertions in the lower and upper eyelids were strongly associated with improvement of SICCA scores (β = 2.70 and 1.80, p < 0.001 and <0.001, respectively). With ocular surface inflammation, corneal staining scores improved significantly with steroid eye drops. Prednisolone (1%) had the strongest association with improvement of corneal staining scores (β = 1.48, p < 0.001); this was based on the frequency of administration. Without ocular surface inflammation, diquafosol (3%), carbomer gel, and lanolin ointment were effective (β = 1.37, 1.06, and 1.17; p = 0.003, 0.003, and <0.001, respectively). Conclusions: Punctal plug insertion, primarily targeting aqueous deficiency, is the mainstay of the treatment for dry eye in primary Sjögren’s syndrome even in the presence of ocular surface inflammation. Furthermore, the effectiveness of treatment modalities for dry eye in primary Sjögren’s syndrome was dependent on the presence of ocular surface inflammation.

Efficacy of Artificial Tears Based on an Extract of Artemia salina Containing Dinucleotides in a Rabbit Dry Eye Model

(1) Background: Artemia salina is a brine shrimp containing high concentrations of dinucleotides, molecules with properties for dry eye treatment. For this reason, the purpose of the study was to evaluate the effect of the artificial tears based on an extract of Artemia salina in a rabbit dry eye model. (2) Methods: A prospective and randomized study was carried out. Twenty rabbits were divided into 4 groups (n = 5, each group): healthy rabbits, dry eye rabbits, dry eye rabbits treated with hypromellose (HPMC), and dry eye rabbits treated with Artemia salina. Dry eye was induced by the topical instillation of 0.2% benzalkonium chloride. The measurements were performed before and after the treatment for 5 consecutive days. (3) Results: The topical instillation of artificial tears containing Artemia salina showed beneficial effects on tear secretion, tear break-up time, corneal staining, the density of Goblet cells, heigh of mucin cloud secreted by these cells, and mRNA levels of IL-1β and MMP9 in conjunctival cells. Compared with the HPMC, there was a statistically significant improvement (p < 0.05) with the Artemia salina in all the variables under study, except for the conjunctival hyperemia, density of Goblet cells, and mRNA levels of IL-6. (4) Conclusions: The potential of artificial tears based on Artemia salina as a secretagogue agent for dry eye treatment was confirmed, opening the door for future clinical trials and studies to extrapolate the findings for dry eye patients.

Isorhamnetin Ameliorates Dry Eye Disease via CFTR Activation in Mice

Dry eye disease is one of the most common diseases, with increasing prevalence in many countries, but treatment options are limited. Cystic fibrosis transmembrane conductance regulator (CFTR) is a major ion channel that facilitates fluid secretion in ocular surface epithelium and is a potential target of therapeutic agent for the treatment of dry eye disease. In this study, we performed a cell-based, high-throughput screening for the identification of novel natural products that activate CFTR and restore the aqueous deficiency in dry eye. Screening of 1000 natural products revealed isorhamnetin, a flavonol aglycone, as a novel CFTR activator. Electrophysiological studies showed that isorhamnetin significantly increased CFTR chloride current, both wild type and ∆F508-CFTR. Isorhamnetin did not alter intracellular cAMP levels and the activity of other ion channels, including ANO1, ENaC, and hERG. Notably, application of isorhamnetin on mouse ocular surface induced CFTR activation and increased tear volume. In addition, isorhamnetin significantly reduced ocular surface damage and expression of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in an experimental mouse model of dry eye. These data suggest that isorhamnetin may be used to treat dry eye disease.

Rabbit models of dry eye disease: Current understanding and unmet needs for translational research

Dry eye disease (DED) is emerging as an eye health pandemic, affecting millions worldwide. The development of novel drugs, drug delivery systems, and targeted therapies for addressing the inflammation in DED necessitates progress in experimental models of DED. Animal models of DED have been created for simulating the two clinically described forms of DED: lacrimal insufficiency and the evaporative DED models. Although most DED models have relied upon rodents, the larger eye size and longer life span of rabbits and the closer resemblance to human lacrimal glands, render rabbits a promising near-ideal model for studying DED. Since the first rabbit DED model was described, numerous modifications including the use of topical epitheliotoxic drugs, neural abolition, activated lymphocytes injection, and surgical dacryoadenectomy have been introduced. The stability of these models, whether short-term or long-term, accordingly guides their experimental or therapeutic utility. A rabbit autoimmune dacryoadenitis model has successfully simulated DED signs and features of lacrimal gland inflammation, as observed in Sjogren's syndrome, that improved with mesenchymal stem cell therapy. This review summarizes the comparative microscopic anatomy of rabbit and human lacrimal glands, various existing rabbit DED models and their respective suitability for understanding pathogenetic mechanism of DED or for experimental drug testing. Also, the insights gained from animal models in dry eye management is described along with the future perspectives. There is still a pressing need of developing rabbit models for studying the pathogenesis of complex ocular surface changes in evaporative and aqueous deficiency DED other than autoimmune dacryoadenitis.

Cataract surgery and dry eye disease: A review

AIM

To review published literature concerning cataract surgery and dry eye disease (DED).

METHODS

A search was undertaken using the following: PubMed (all years), Web of Science (all years), Ovid MEDLINE(R) (1946 to 12 December 2019), Ovid MEDLINE(R) Daily Update 10 December 2019, MEDLINE and MEDLINE non-indexed items, Embase (1974-2019, week 49), Ovid MEDLINE (R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily (1946 to 12 December 2019), CENTRAL (including Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 12 of 12 December 2019), metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). Search terms included 'cataract surgery', 'phacoemulsification' and 'cataract extraction', combined with 'dry eyes' and 'ocular surface'. Relevant in-article references not returned in our searches were also considered.

RESULTS

Publications identified included systematic reviews, meta-analysis, randomized controlled trials, cohort studies, case series and laboratory-based studies. Published data highlighting the burden of DED both prior and following cataract surgery were reviewed as well as studies highlighting the effects of cataract surgery on the ocular surface, intra-operative measures to reduce deleterious effects on the ocular surface and current evidence on the management options of post-operative DED.

CONCLUSIONS

DED is common and can be exacerbated by cataract surgery. Ophthalmologists need to assess for pre-existing DED and instigate treatment before surgery; be aware of reduced accuracy of measurements for surgical planning in the presence of DED; limit intra-operative surgical factors damaging to the ocular surface; and consider management to reduce DED post-operatively.

Preclinical Development of Artificial Tears Based on an Extract of Artemia Salina Containing Dinucleotides in Rabbits

PURPOSE

To evaluate the preclinical efficacy of eye drops based on an extract of Artemia salina on the ocular surface of rabbits. Tear secretion, tear break-up time and corneal staining were measured.

MATERIAL AND METHODS

A preclinical and short-term prospective study was performed. Twenty New Zealand white rabbits were divided into five groups, with four rabbits per group, each receiving a different concentration of Artemia salina. In each rabbit, an extract of Artemia salina (2%, 4%, 6%, 8% or 10%) was randomly instilled in one eye and saline solution (negative control) in the other eye. Tear secretion, tear break-up time and corneal staining were measured before and after the instillation of five drops per eye (one drop per hour) on the same day.

RESULTS

In tear secretion, there was an increase of 43.88 ± 6.73% with 4% Artemia salina in comparison with its baseline measurement (P = .049). The rest of the groups did not show differences (P ≥ 0.05). For tear break-up time, none of the groups showed differences (P ≥ 0.05), while for corneal staining score, there was an improvement of 0.88 ± 0.83 with 4% Artemia salina (P = .038) and a deterioration of 0.50 ± 0.83 with control solution (P = .008).

CONCLUSIONS

Short-term instillation of eye drops with 4% Artemia salina produced both stimulation of tear secretion and a slight improvement of physiological corneal staining. Besides, all the doses of up to 10% Artemia salina did not produce undesirable side effects on the ocular surface. Therefore, these eye drops are presented as a possible new treatment for dry eye due to their secretagogue properties and ocular surface regeneration.

Effect of Diquafosol Ophthalmic Solution on Airflow-Induced Ocular Surface Disorder in Diabetic Rats

Purpose

To examine the effect of 3% diquafosol ophthalmic solution (DQS) on ocular surface disorders in diabetic model rats maintained in a continuous airflow condition.

Methods

Goto–Kakizaki (GK) rats, a spontaneous model of type 2 diabetes, were exposed to constant airflow for 8 weeks. After the establishment of the animal model in this environment, DQS or saline was instilled six times a day into GK rat eyes for 6 weeks. Schirmer’s test was performed before and after 6-week instillations. Corneal fluorescein staining was scored at 2-, 4-, and 6-week instillations. Touch thresholds for the cornea were also determined using a Cochet–Bonnet esthesiometer before and after 6-week instillations.

Results

The mean Schirmer’s test score after instillation of DQS was twice higher than that recorded for saline alone. DQS significantly decreased corneal staining scores at 4- and 6-week instillations. No changes in touch thresholds were observed before and after 6-week instillations.

Conclusion

These results suggest that DQS improves corneal epithelial damage by stimulating tear secretion without influencing corneal sensation in diabetic keratopathy. Thus, DQS may have potential for treatment of diabetic patients with dry eye.

Involvement of P2 receptors in hematopoiesis and hematopoietic disorders, and as pharmacological targets

Several reports have shown the presence of P2 receptors in hematopoietic stem cells (HSCs). These receptors are activated by extracellular nucleotides released from different sources. In the hematopoietic niche, the release of purines and pyrimidines in the milieu by lytic and nonlytic mechanisms has been described. The expression of P2 receptors from HSCs until maturity is still intriguing scientists. Several reports have shown the participation of P2 receptors in events associated with modulation of the immune system, but their participation in other physiological processes is under investigation. The presence of P2 receptors in HSCs and their ability to modulate this population have awakened interest in exploring the involvement of P2 receptors in hematopoiesis and their participation in hematopoietic disorders. Among the P2 receptors, the receptor P2X7 is of particular interest, because of its different roles in hematopoietic cells (e.g., infection, inflammation, cell death and survival, leukemias and lymphomas), making the P2X7 receptor a promising pharmacological target. Additionally, the role of P2Y12 receptor in platelet activation has been well-documented and is the main example of the importance of the pharmacological modulation of P2 receptor activity. In this review, we focus on the role of P2 receptors in the hematopoietic system, addressing these receptors as potential pharmacological targets.

Advances in the diagnosis and treatment of dry eye

The core mechanism of dry eye is the tear film instability. Tear film-oriented diagnosis (TFOD) is a concept to clarify the cause of tear film instability by tear film, and tear film-oriented treatment (TFOT) is a concept to treat dry eye disease by replacing the lacking components of the tear film layer based on the TFOD. In TFOD, the fluorescein breakup pattern of the tear film is important, and the subtype of dry eye can be judged to some extent from the breakup patterns. Current noninvasive devices related to the dynamic analysis of the tear film and visual acuity enabled the diagnosis of dry eye, subtype analysis, and the extent of severity. In Asian countries, secretagogues represent the main treatment in TFOT. Since meibomian gland dysfunction is a factor that greatly affects the tear breakup time, its treatment is also essential in the dry eye treatment strategy. A newly discovered dry eye subtype is the short breakup time-type (BUT) of dry eye. The only abnormal finding in this disease is the short BUT, suggesting a relationship with ocular neuropathic pain and eye strain. Recently, data from many studies have accumulated which show that dry eye is a life-style disease. In addition to the treatment of dry eyes, it is becoming possible to prevent the onset by intervening with the daily habits, diet, exercise and sleep, etc. It has been pointed out that oxidative stress is also involved in the pathology of dry eye, and intervention is being carried out by improving diet and taking supplements. Future research will be needed to link clinical findings to the molecular biological findings in the tear film.

Efficacy of Topical Cyclosporine Nanoemulsion 0.05% Compared with Topical Cyclosporine Emulsion 0.05% and Diquafosol 3% in Dry Eye

PURPOSE

To evaluate the efficacy and safety of cyclosporine nanoemulsion 0.05% compared to cyclosporine emulsion 0.05% and diquafosol sodium 3%.

METHODS

This was a multicenter, randomized, evaluator-masked, active control, parallel, phase IV study. A total of 227 patients were randomly allocated to instill cyclosporine nanoemulsion 0.05% (CN) twice daily, cyclosporine emulsion 0.05% (CE) twice daily, or diquafosol sodium 3% (DQ) six times daily. Non-inferiority of CN was analyzed by primary endpoint (cornea and conjunctival staining scores at week 12). The secondary endpoints were scores of corneal staining, conjunctival staining, tear break-up time, Schirmer test, and Ocular Surface Disease Index at weeks 4 and 12.

RESULTS

Primary endpoints showed statistically significant improvements in all groups. Primary endpoints were -6.60 for the CN group, -5.28 for the CE group, and -6.63 for the DQ group (National Eye Institute scale from 0 to 33), verifying the non-inferiority of CN compared to CE (95% confidence interval, -0.15 to 2.80, Δ>-2.88). In intergroup comparison between CN and CE groups, the CN group had significantly more decreased conjunctival staining score at week 12. Intergroup comparison between CN and DQ groups showed consistent statistically significant improvements in TBUT and Schirmer test in the CN group. In the DQ group, TBUT showed late statistically significant improvement at week 12 and Schirmer test showed relatively short-term statistically significant improvement at week 4.

CONCLUSIONS

Cyclosporine nanoemulsion 0.05% was equivalently efficient compared to cyclosporine emulsion 0.05% and diquafosol sodium 3%. In addition, CN showed significant improvements in several parameters for treatment of dry eyes.

Changes of tear film lipid layer thickness by 3% diquafosol ophthalmic solutions in patients with dry eye syndrome

AIM

To evaluate the quantitatively changes in lipid layer thickness (LLT) when 3% diquafosol eye drop is used for dry eye patients using the tear film interferometer.

METHODS

A total 124 participants (32 males, 92 females; mean age, 28.9y) diagnosed with dry eye disease (DED) received topical instillation of 4 ophthalmic solutions in one eye: diquafosol, normal saline, 0.1% sodium hyaluronate and 0.3% gatifloxacin, in a masked manner. LLT was measured using an interferometer at baseline and 20min after the instillation of each ophthalmic solutions.

RESULTS

Changes of LLT after instillation (nm, mean± standard error) were as follows: 12.6±2.0 for diquafosol (P<0.001), 1.2±2.2 for normal saline (P=0.301), 1.5±2.0 for hyaluronate (P=0.495), and 0.5±3.2 for gatifloxacin (P=0.884).

CONCLUSION

Topical instillation of diquafosol increases tear film LLT in DED patients. Diquafosol 3% eye drop might be effective treatment option of evaporative DED with meibomian gland dysfunction.

A New Ophthalmic Pharmaceutical Formulation, Topical Sulglycotide, Enhances the Ocular Mucin Secretion in Desiccation Stress-Mediated Dry Eye Disease

Purpose

The aim of this study was the investigation of the effect of sulglycotide (SOS), a polysulfated glycopeptide derived from porcine duodenal mucin, for the treatment of dry eye disease.

Methods

NOD.B10.H2b mice were exposed to an air draft for 10 days, and, simultaneously, scopolamine hydrobromide was injected subcutaneously. The mice were randomly divided into nine groups as follows: four kinds of SOS formulations and three kinds of commercial medicine. After 10 days of treatment, we estimated the effect of treatment on tear production, epithelium stabilization, mucin secretion, and inflammation.

Results

The desiccation stress significantly decreased tear production and corneal epithelium stabilization, as well as markedly decreased the numbers of goblet cells and mucin-stained cells in conjunctiva. However, the topical 4% SOS eye drops markedly increased tear production and corneal stabilization, which recovered to baseline levels. In addition, topical 4% SOS significantly induced an increase in the numbers of goblet cells and the expression of membrane-associated mucins including MUC1, MUC4, and MUC16, as well as the gel-forming mucin, MUC5AC. Furthermore, SOS formulations provided anti-inflammatory improvement in a dose-dependent manner.

Conclusions

In summary, we suggest that a new ophthalmic pharmaceutical formulation, topical sulglycotide, enhances the ocular mucin secretion in dry eye disease and can be used as a new ophthalmic pharmaceutical material to treat dry eye disease.

Medical Treatment for Dry Eye in Japan

The etiology of dry eye has not been clarified. In the United States, the inflammation theory is supported as the main cause of dry eye, whereas the Asia Dry Eye Society has identified tear instability as the main cause. Based on this tear instability concept, the P2Y2 antagonist Diquas and the mucin secretagogue Mucosta were developed and launched in Japan over the last 5 years, and they have been widely prescribed to patients with dry eye. Moreover, Diquas has also been launched in other Asian countries, such as Korea, Thailand, and Vietnam. This report summarizes the efficacy and characteristics of these two eye drops to improve our understanding of dry eye.

Efficacy of topical ophthalmic drugs in the treatment of dry eye disease: A systematic literature review

Dry eye disease (DED) is a multifactorial and complex disease of the ocular surface, with a high prevalence in adults. We systematically reviewed efficacy and safety data from published articles reporting results from prospective, controlled trials of topical ophthalmic drugs for DED. PubMed was searched for articles from January 1997 to October 2017. Twenty-six unique trials investigating 13 ophthalmic drugs were identified, including trials of the approved drugs cyclosporine A, cyclosporine A cationic emulsion, diquafosol, rebamipide and lifitegrast. All identified studies provided level 1 evidence. None of the large (N > 100) studies demonstrated statistical significance of primary endpoints for both a sign and a symptom endpoint versus a control treatment in the same published trial. Publications on lifitegrast reported statistical superiority in a symptom or sign endpoint versus the control group in a large (N > 200), multicenter trial, with results repeated in trials of similar design. The most common adverse events associated with the approved drugs related to ocular discomfort upon instillation, especially burning/stinging and ocular irritation. The trial design and endpoints used across the studies varied considerably, highlighting the importance of standardization in clinical trials for DED. Recent advances in drug delivery and improved understanding of DED should contribute to new ophthalmic drug approvals.

Emerging targets of inflammation and tear secretion in dry eye disease

The underlying mechanisms of dry eye are thought to be part of a vicious circle involving a hyperosmolarity-triggered inflammatory cascade, resulting in loss of goblet cells and glycocalyx mucin and observed corneal and conjunctival epithelial cell damage. This damage leads to increased tear film instability, further hyperosmolarity and hence perpetuating of a vicious circle. The aim of dry eye management is to restore the homeostasis of the tear film and break the perpetuation of this vicious circle. Despite the plethora of treatment options available, many of these are largely palliative, short-lived and require repeated instillations. Two emerging areas in dry eye therapy aim to promote tear secretion and to safely manage dry eye-associated inflammation and are the focus of this review.

Long-Term Topical Diquafosol Tetrasodium Treatment of Dry Eye Disease Caused by Chronic Graft-Versus-Host Disease: A Retrospective Study

OBJECTIVES

The aim of this study was to assess the safety and efficacy of long-term use of 3% diquafosol ophthalmic solution (DQS), an eye drop for mucin production and water secretion, for treating dry eye disease (DED) caused by chronic graft-versus-host disease (cGVHD).

METHODS

We retrospectively evaluated the safety and efficacy of DQS in 10 patients with mild to moderate cGVHD-induced DED. The efficacy was assessed by (1) degree of symptoms, (2) Schirmer I test value, (3) tear film breakup time (TFBUT), and (4) fluorescein and rose bengal scores.

RESULTS

The median duration of DQS treatment was 12.0 months (range 6-17 months). DQS was effective for relieving severe pain caused by cGVHD-related DED. Although the Schirmer I test value was enhanced only marginally, the long-term application of DQS significantly improved the corneal/conjunctival epitheliopathy and tear film stability: the fluorescein score improved from 5.9±0.6 to 1.3±1.1 points (P=1.771×10); rose bengal staining from 4.7±1.6 to 2.0±1.5 points (P=0.008); and TFBUT from 2.6±0.9 to 4.6±1.6 mm (P=0.009). Furthermore, the long-term DQS treatment caused no major adverse events.

CONCLUSIONS

This study suggested that long-term DQS treatment is a safe and robust approach for alleviating cGVHD-related DED.

A Prospective, Randomized Trial of Two Mucin Secretogogues for the Treatment of Dry Eye Syndrome in Office Workers

The purpose of the study was to compare the two mucin secretogogues, diquafosol (DQS) and rebamipide (RBM), for the treatment of dry eye syndrome (DES) in office workers. Dry eye patients using computers for >4 h/day were randomly assigned treatment with either DQS or RBM. Main outcomes measures included changes in tear film break-up time (TBUT) and subjective symptoms assessed by the Dry Eye-Related Quality of Life Score (DEQS). The subjects had scheduled examinations at 0 and 4 weeks, and the examinations at 2 and 8 weeks were optional. Changes in keratoconjunctival fluorescein score and a patient satisfaction questionnaire were also recorded. Both groups showed significant improvements in the DEQS scores at 2, 4, and 8 weeks following the initiation of the study. Both groups showed significant increases in the TBUT at 2 and 4 weeks. No significant difference was found between the DQS and RBM groups at any time periods. Patients reported more comfort with the use of DQS compared with the use of RBM. No local or systemic side effects were noted. The results of the present study indicated that both DQS and RBM were effective for the treatment of DES in office workers.

Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time

PURPOSE

The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT).

METHODS

The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph^® 5 M before and 1 and 3 months after treatment.

RESULTS

OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P < 0.05). At each follow-up visit, the total OSDI, OSDI symptom, and all VAS scores were significantly lower in group 3 compared with groups 1 and 2 (all P < 0.05). In addition, TBUT and NIBUT were significantly higher in group 3 compared with groups 1 and 2 (all P < 0.05). No significant adverse effects were noted in the groups during treatment.

CONCLUSIONS

Mucin or lipid-targeting agents combined with aqueous supplements in patients with refractory EDE with short TBUT might improve subjective symptoms and TBUT. Of this, targeting whole tear film layers was most effective in improving ocular symptoms and tear film quality.

Effect of diquafosol tetrasodium 3% on the conjunctival surface and clinical findings after cataract surgery in patients with dry eye

PURPOSE

To investigate the effects of diquafosol tetrasodium (DT) 3% on conjunctival impression cytologic findings in addition to clinical symptoms and signs after cataract surgery in patients with preexisting dry eye disease (DED).

METHODS

Ninety-four eyes of 94 patients with DED who underwent uneventful cataract surgery were included. In total, 50 patients were treated with DT 3% (group A), while 44 patients were treated with sodium hyaluronate 0.1% (group B) postoperatively, along with topical antibiotics and steroids. Conjunctival impression cytology was performed at baseline and at 4 and 12 weeks after surgery. Visual acuity, ocular surface disease index (OSDI), tear film breakup time (TBUT), keratoepitheliopathy score, Schirmer's test, and tear clearance rate were measured at baseline and at 1, 4, and 12 weeks, and corneal aberration was analyzed at baseline and at 4 and 12 weeks.

RESULTS

The grade of conjunctival squamous metaplasia was lower at 12 weeks, and goblet cell density was higher at 4 and 12 weeks in group A than in group B (P < 0.05). Compared with group B, group A showed significantly lower OSDI scores at 4 and 12 weeks, longer TBUT at 1, 4, and 12 weeks, lower keratoepitheliopathy scores at 1 and 12 weeks, and lower total root-mean-square score and spherical aberrations at 4 weeks after surgery (P < 0.05).

CONCLUSIONS

DT 3% eye drops application after cataract surgery was effective in improving conjunctival epithelial morphology and goblet cell density as well as clinical findings in patients with DED.

Anti-inflammatory effect of hydroxyproline-GQDGLAGPK in desiccation stress-induced experimental dry eye mouse

The purpose of this study has been the investigation of the effect of novel peptide hydroxyproline-GQDGLAGPK (Hyp-GQDGLAGPK) in desiccation stress-induced dry eye mouse model and compared medicines for dry eye disease including cyclosporine, diquafosol and sodium hyaluronate. Seventy eight NOD.B10.H2^b mice were injected with scopolamine and exposed to an air draft for 10 days, and then the mice were treated with normal saline (n = 13), 1% Hyp-GQDGLAGPK (n = 13), 0.05% cyclosporine (n = 13), 3% diquafosol (n = 13), and 0.1% hyaluronate (n = 13) for 10 days. Thirteen mice were used for histopathologic analysis at DS 10d. The desiccation stress significantly decreased tear production, but the topical treatment of Hyp-GQDGLAGPK recovered to the baseline levels, which was similar to cyclosporine and diquafosol. In addition, Hyp-GQDGLAGPK improved facilitating epithelium stabilization including the corneal irregularity score, fluorescein score and detachment of the corneal epithelium. These improvements in stabilization of the corneal epithelium was superior to that in the cyclosporine and sodium hyaluronate groups. Furthermore, desiccation stress markedly induced expression of autoimmune inflammation-related factors in the lacrimal glands, but it was significantly suppressed by Hyp-GQDGLAGPK treatment. Overall, we found that novel peptide Hyp-GQDGLAGPK has multi-functional effects such as stabilizing the tear film and inhibiting inflammation.

Do Cyclosporine A, an IL-1 Receptor Antagonist, Uridine Triphosphate, Rebamipide, and/or Bimatoprost Regulate Human Meibomian Gland Epithelial Cells?

PURPOSE

Researchers have hypothesized that treatment with cyclosporine A (CyA), interleukin-1 receptor antagonists (IL-1RA; e.g., anakinra), P2Y2 receptor agonists (e.g., uridine triphosphate; UTP), and rebamipide may alleviate human meibomian gland dysfunction (MGD) and/or dry eye disease. Investigators have also proposed that prostaglandin analogues (e.g., bimatoprost) may induce MGD. Our goal was to determine whether these compounds directly influence human meibomian gland epithelial cell (HMGEC) function.

METHODS

Multiple concentrations of each compound were tested for effects on immortalized (I) HMGEC morphology and survival. Nontoxic dosages were used for our studies. Immortalized HMGEC were cultured in the presence of vehicle, CyA, IL-1RA, UTP, rebamipide, or bimatoprost for up to 6 days in various media. Experiments included positive controls for proliferation (epidermal growth factor and bovine pituitary extract), differentiation (azithromycin), and signaling pathway activation (insulin-like growth factor 1). Cells were analyzed for neutral lipid staining, lysosome accumulation, lipid composition, and phosphatidylinositol-3-kinase/Akt (AKT), phosphorylation.

RESULTS

Our findings demonstrate that CyA, IL-1RA, UTP, rebamipide, and bimatoprost had no effect on the proliferation; neutral lipid content; lysosome number; or levels of free cholesterol, triglycerides, or phospholipids in IHMGECs. Cylosporine A, IL-1RA, rebamipide, and bimatoprost significantly reduced the phosphorylation of AKT, as compared to control. Of interest, tested doses of CyA above 8 nM killed the IHMGECs.

CONCLUSIONS

Our results show that CyA, IL-1RA, UTP, rebamipide, and bimatoprost do not influence the proliferation or differentiation of IHMGEC. However, with the exception of UTP, these compounds do decrease the activity of the AKT signaling pathway, which is known to promote cell survival.

Influence on ocular surface after cataract surgery and effect of topical diquafosol on postoperative dry eye: a multicenter prospective randomized study

Purpose

To investigate influences of 3% diquafosol sodium ophthalmic solution (DQS) on ocular surface after cataract surgery and effects on postoperative dry eye.

Design

This study had two consecutive prospective study phases. The former was an observational study from before cataract surgery to 4 weeks after surgery and the latter was a randomized open-label study from 4 to 8 weeks after surgery.

Methods

Subjects were 433 eyes of 433 patients undergoing cataract surgery with intraocular lens implantation. Dry eye examination of tear breakup time (BUT), corneal and conjunctival fluorescein staining scores, total subjective symptom score (12 symptoms), and Schirmer I test were conducted before surgery and 4 weeks after surgery. Patient demographics and these examination results were used to analyze risk factors to predict postoperative dry eye. In a randomized study, 154 eyes diagnosed with dry eye postoperatively were applied either DQS or artificial tears (AT) six times daily for 4 weeks. The data of the examinations were compared.

Results

At 4 weeks after surgery, BUT was shortened significantly (P=0.036), fluorescein staining score increased significantly (P=0.012), but total subjective symptom score was significantly improved (P<0.001). The majority of postoperative dry eye was shortened BUT type (53.1%). The dry eye prevalence after surgery decreased (55.7%) compared with before surgery (69.7%). Females and the patient with dry eye symptoms before surgery had significant risk factors for postoperative dry eye. In a randomized study, BUT was significantly prolonged in the DQS group (P=0.015), but not in the AT group. Fluorescein staining score was significantly improved in both groups (P<0.001). Total subjective symptom score was significantly decreased in the AT group (P<0.001), but not in the DQS group.

Conclusion

Our study suggests that cataract surgery has harmful effects on tear film stability and ocular surface, and DQS has a capability to improve them.

Effects of 3% diquafosol sodium ophthalmic solution on higher-order aberrations in patients diagnosed with dry eye after cataract surgery

Purpose

To evaluate the effects of diquafosol sodium ophthalmic solution 3% (DQS) and artificial tears (AT) on higher-order aberrations (HOAs) in patients with dry eye after cataract surgery.

Design

This was a post hoc analysis of a previously conducted randomized clinical study.

Methods

Fifty-nine eyes from 42 patients (17 males and 25 females, aged 72.6±8.0 years) with verified or suspected dry eye at 4 weeks after cataract surgery were evaluated. The dry eye patients were randomly assigned to receive DQS or AT for 4 weeks. Tear breakup time (BUT), corneal and conjunctival fluorescein staining scores, and HOAs were analyzed before and after instillation. HOAs were measured consecutively for 10 seconds with a wavefront analyzer. Average HOAs, HOA fluctuations (fluctuation index [FI]) and changes in HOAs (stability index [SI]) were compared within and between the two groups.

Results

After 4 weeks of instillation, BUT significantly increased (P=0.001) compared with preinstillation values in the DQS group, but not in the AT group. This increase in BUT in the DQS group was significantly greater than in the AT group (P=0.014). Corneal and conjunctival fluorescein staining scores after instillation significantly improved compared with preinstillation values in the DQS group (P=0.018). In HOAs, the cornea aberration changed from an upward curve (a sawtooth pattern) to an almost constant value (a stable pattern) in the DQS group, but not in the AT group. In FI and SI, there were no significant changes in either group; however, FI and SI were significantly lower in the DQS group than in the AT group (both, P=0.004).

Conclusion

The dry eye patients after cataract surgery had a visual dysfunction in HOAs. DQS is effective to treat dry eye disease after cataract surgery with improvement of visual function.

Evaluation of Tear Meniscus Dynamics Using Anterior Segment Swept-Source Optical Coherence Tomography After Topical Solution Instillation for Dry Eye

PURPOSE

To investigate tear meniscus dynamics using anterior segment swept-source optical coherence tomography (SS-OCT) after the instillation of topical solutions for dry eye.

DESIGN

Prospective, observational, cross-sectional study.

METHODS

Thirty-six healthy subjects (28 men and 8 women; mean age, 34.4 ± 6.7 years) were enrolled in this study. The lower tear meniscus height, tear meniscus area, and tear meniscus volume were assessed using anterior SS-OCT. After baseline measurements, 40 μL of 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol ophthalmic solution, or 2% rebamipide ophthalmic solution was instilled in one eye of 10 subjects each, whereas 40 μL saline was instilled in the other eye. Tear meniscus measurements were obtained using SS-OCT at 30 seconds and 1, 3, 5, 10, 15, 20, and 30 minutes after instillation.

RESULTS

The tear meniscus measurements showed a significant increase until 1, 3, 10, 10, and 3 minutes after the instillation of saline, 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol, and 2% rebamipide, respectively, compared with the baseline levels (P < 0.05). Compared with those after saline instillation, the tear meniscus measurements were significantly higher until 30 seconds and 3, 30, and 15 minutes after the instillation of 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol, and 2% rebamipide, respectively (P < 0.05).

CONCLUSIONS

The instillation of ophthalmic solutions for the treatment of dry eye greatly increased tear meniscus measurements in healthy subjects. Thus, SS-OCT can be a practical tool for the quantitative evaluation of early-phase tear fluid dynamics.

New Perspectives on Dry Eye Definition and Diagnosis: A Consensus Report by the Asia Dry Eye Society

For the last 20 years, a great amount of evidence has accumulated through epidemiological studies that most of the dry eye disease encountered in daily life, especially in video display terminal (VDT) workers, involves short tear film breakup time (TFBUT) type dry eye, a category characterized by severe symptoms but minimal clinical signs other than short TFBUT. An unstable tear film also affects the visual function, possibly due to the increase of higher order aberrations. Based on the change in the understanding of the types, symptoms, and signs of dry eye disease, the Asia Dry Eye Society agreed to the following definition of dry eye: "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The definition stresses instability of the tear film as well as the importance of visual impairment, highlighting an essential role for TFBUT assessment. This paper discusses the concept of Tear Film Oriented Therapy (TFOT), which evolved from the definition of dry eye, emphasizing the importance of a stable tear film.

The role of dinucleoside polyphosphates on the ocular surface and other eye structures

Dinucleoside polyphosphates comprises a group of dinucleotides formed by two nucleosides linked by a variable number of phosphates, abbreviated NpnN (where n represents the number of phosphates). These compounds are naturally occurring substances present in tears, aqueous humour and in the retina. As the consequence of their presence, these dinucleotides contribute to many ocular physiological processes. On the ocular surface, dinucleoside polyphosphates can stimulate tear secretion, mucin release from goblet cells and they help epithelial wound healing by accelerating cell migration rate. These dinucleotides can also stimulate the presence of proteins known to protect the ocular surface against microorganisms, such as lysozyme and lactoferrin. One of the latest discoveries is the ability of some dinucleotides to facilitate the paracellular way on the cornea, therefore allowing the delivery of compounds, such as antiglaucomatous ones, more easily within the eye. The compound Ap₄A has been described being abnormally elevated in patient's tears suffering of dry eye, Sjogren syndrome, congenital aniridia, or after refractive surgery, suggesting this molecule as biomarker for dry eye condition. At the intraocular level, some diadenosine polyphosphates are abnormally elevated in glaucoma patients, and this can be related to the stimulation of a P2Y₂ receptor that increases the chloride efflux and water movement in the ciliary epithelium. In the retina, the dinucleotide dCp₄U, has been proven to be useful to help in the recovery of retinal detachments. Altogether, dinucleoside polyphosphates are a group of compounds which present relevant physiological actions but which also can perform promising therapeutic benefits.

The Efficacy of Diquafosol Ophthalmic Solution in Non-Sjögren and Sjögren Syndrome Dry Eye Patients Unresponsive to Artificial Tear

PURPOSE

This study evaluates the efficacy of 3% diquafosol tetrasodium ophthalmic solution in Sjögren's syndrome (SS) and non-SS dry eye patients unresponsive to conventional artificial tear.

METHODS

This retrospective study included 38 dry eye patients (11 with SS and 27 with non-SS) who were treated with 3% diquafosol due to lack of response to artificial tear treatment for more than 3 months. Signs such as tear film break-up time (TBUT), Schirmer-I test, and total ocular staining score (OSS), which consisted of corneal OSS and conjunctival OSS, were evaluated at baseline and the first visit after treatment. Symptoms were quantified using visual analog scale (VAS) and ocular surface disease index (OSDI) scores. Changes of parameters after treatment in all the patients and differences of changes in SS and non-SS were evaluated.

RESULTS

In total population, total OSS and corneal OSS improved average 6 weeks after diquafosol treatment (all P < 0.05, paired t-test), although conjunctival OSS had no improvement. TBUT increased after treatment (P = 0.036), while Schirmer-I test, OSDI, and VAS showed no improvement. With respect to comparisons, total and corneal OSS improved in non-SS patients and TBUT improved in SS patients (all P < 0.05).

CONCLUSIONS

Three percent diquafosol tetrasodium treatment could be considered as an additive or substitute treatment when artificial tear treatment is insufficient, as it improved OSS and TBUT. This study also demonstrated that diquafosol treatment is beneficial for TBUT improvement in SS, while it is beneficial for OSS improvement in non-SS dry eye patients.

Age-related Defects in Ocular and Nasal Mucosal Immune System and the Immunopathology of Dry Eye Disease

Dry eye disease (DED) is a prevalent public health concern that affects up to 30% of adults and is particularly chronic and severe in the elderly. Two interconnected mechanisms cause DED: (1) an age-related dysfunction of lacrimal and meibomian glands, which leads to decreased tear production and/or an increase in tear evaporation; and (2) an age-related uncontrolled inflammation of the surface of the eye triggered by yet-to-be-determined internal immunopathological mechanisms, independent of tear deficiency and evaporation. In this review we summarize current knowledge on animal models that mimic both the severity and chronicity of inflammatory DED and that have been reliably used to provide insights into the immunopathological mechanisms of DED, and we provide an overview of the opportunities and limitations of the rabbit model in investigating the role of both ocular and nasal mucosal immune systems in the immunopathology of inflammatory DED and in testing novel immunotherapies aimed at delaying or reversing the uncontrolled age-related inflammatory DED.

Improvements in Signs and Symptoms of Dry Eye after Instillation of 2% Rebamipide

PURPOSE

Because dry eye greatly reduces quality of life, this study aimed to examine rebamipide instillation in patients with dry eye and assess the improvement of signs and symptoms as evaluated with the Ocular Surface Disease Index, which is the most popular index and is highly reliable.

METHODS

From June 2013 through January 2014, we examined 50 eyes of 25 patients with dry eye (6 men and 19 woman) at our institution. Dry eye was diagnosed on the basis of the presence of symptoms, tear dynamics, and ocular surface abnormalities according to the Japanese criteria for dry eye. Before being enrolled, all patients underwent ocular surface health assessment, including history interviews, and completed the Ocular Surface Disease Index questionnaire. Patients received 2% rebamipide ophthalmic solution 4 times daily for 4 weeks. Signs and symptoms were analyzed before and 4 weeks after rebamipide administration. Tear dynamics, tear break-up time, and ocular surface abnormalities were measured and compared between before and 4 weeks after rebamipide administration.

RESULTS

Of the 25 patients, 9 had definite dry eye and 16 had probable dry eye. Tear break-up time and the fluorescein staining score significantly improved after 4 weeks. However, no significant change was observed for the Schirmer test I and the lissamine green staining score.

CONCLUSIONS

The administration of 2% rebamipide 4 times daily for 4 weeks improves the signs and symptoms of dry eye and improves patients' quality of life.

The increase of aqueous tear volume by diquafosol sodium in dry-eye patients with Sjögren's syndrome: a pilot study

PurposeTo investigate the effect of 3% diquafosol sodium ophthalmic solution (DQS) on aqueous tear volume increase in dry-eye patients with Sjögren's syndrome (SS).MethodsIn this pilot study, 17 dry-eye patients with SS (1 male and 16 females; mean age: 66.4 years) were enrolled and underwent topical instillation of two ophthalmic solutions, artificial tears (AT) in one eye and DQS in the fellow eye, in a masked manner. The central lower tear meniscus radius (TMR) curvature was measured before and at 15 min after instillation by video-meniscometry. Simultaneously, all patients self-evaluated their symptoms of wetness and stinging using a visual analog scale (VAS, in millimeters).ResultsTopical instillation of DQS significantly increased the TMR at 15 min (mean: 0.21±0.08 (SD) mm) compared with at baseline (mean: 0.16±0.07 mm) (P<0.001, paired t-test), whereas AT had no effect at baseline (mean: 0.18±0.09 mm) or at 15 min (mean: 0.18±0.09 mm). The visual VAS score of wetness at 15-min post-instillation increased in both groups compared with at baseline. In the DQS-treated eyes, the post-instillation change in TMR from baseline was not correlated with the baseline value of the Schirmer test, corneal staining score, or conjunctival staining score.ConclusionsTopical instillation of DQS increased aqueous tear volume on the ocular surface of dry-eye patients with SS, with its action being independent of lacrimal gland function.

Is the main lacrimal gland indispensable? Contributions of the corneal and conjunctival epithelia

The ocular surface system is responsible for ensuring that the precorneal tear film is sufficient in both quality and quantity to preserve optimal vision. Tear secretion is a complex, multifactorial process, and dysfunction of any component of the ocular surface system can result in tear film instability and hyperosmolarity with resultant dry eye disease. The tear film is primarily composed of lipids, aqueous, and mucins, with aqueous accounting for most of its thickness. The aqueous is produced by the main lacrimal gland, accessory lacrimal glands, and corneal and conjunctival epithelia. Although the main lacrimal gland has long been considered an indispensable source of the aqueous component of tears, there is evidence that adequate tear secretion can exist in the absence of the main lacrimal gland. We review and discuss the basics of tear secretion, the tear secretory capacity of the ocular surface, and emerging treatments for dry eye disease.

Clinical Effects and Safety of 3% Diquafosol Ophthalmic Solution for Patients With Dry Eye After Cataract Surgery: A Randomized Controlled Trial

PURPOSE

To compare the efficacies and safety profiles of 3% diquafosol and 0.1% sodium hyaluronate in patients with dry eye after cataract surgery.

DESIGN

Randomized controlled trial.

METHODS

setting: Soonchunhyang University Hospital, Seoul, South Korea.

STUDY POPULATION

In all, 130 eyes of 86 dry eye patients who had undergone cataract surgery between January 2014 and January 2015 were enrolled and randomly divided into a diquafosol group and a sodium hyaluronate group.

INTERVENTION

The diquafosol group used diquafosol 6 times a day and the hyaluronate group used sodium hyaluronate 6 times a day after cataract surgery.

MAIN OUTCOME MEASURES

Evaluations of efficacy were conducted based on an Ocular Surface Disease Index questionnaire, tear breakup time (TBUT), Schirmer I test, corneal fluorescein and conjunctival lissamine green staining scores, serial measurement of ocular higher-order aberrations (HOAs), corneal HOAs, and uncorrected distance visual acuity test. Safety evaluations were based on anterior chamber inflammation and discontinuation of the eye drops.

RESULTS

Objective signs and subjective symptoms were aggravated at 1 week postoperatively and began to recover significantly 4 weeks after surgery. The diquafosol group showed significantly superior TBUT (P < .001), corneal fluorescein (P = .045), and conjunctival staining (P = .001) compared to the sodium hyaluronate group throughout the study period. TBUT (P < .001) and the change in HOAs (P = .018) recovered significantly more quickly in the diquafosol group. The safety evaluations showed no intergroup differences.

CONCLUSIONS

Eye drops of 3% diquafosol may be an effective and safe treatment for the management of cataract surgery-induced dry eye aggravation in patients with preexisting dry eye.

Diquafosol ophthalmic solution 3 %: a review of its use in dry eye

Diquafosol ophthalmic solution 3 % (Diquas(®)) is a P2Y2 receptor agonist that promotes tear fluid and mucin secretion and is currently approved in Japan and South Korea for the treatment of dry eye. In randomized, double-blind, multicentre trials in patients with dry eye, significantly greater improvements in fluorescein and rose bengal staining scores were seen with diquafosol ophthalmic solution 3 % than with placebo, and diquafosol ophthalmic solution 3 % was noninferior to sodium hyaluronate ophthalmic solution 0.1 % in terms of the improvement in the fluorescein staining score and more effective than sodium hyaluronate ophthalmic solution 0.1 % in terms of the improvement in the rose bengal staining score. The efficacy of diquafosol ophthalmic solution 3 % in the treatment of dry eye was maintained in the longer term, with improvements also seen in subjective dry eye symptoms, and was also shown in a real-world setting. Diquafosol ophthalmic solution 3 % also demonstrated efficacy in various specific dry eye disorders, including aqueous-deficient dry eye, short tear film break-up time dry eye, obstructive meibomian gland dysfunction, dry eye following laser in situ keratomileusis surgery and dry eye following cataract surgery, as well as in contact lens wearers and visual display terminal users. Diquafosol ophthalmic solution 3 % was generally well tolerated in patients with dry eye, with eye irritation the most commonly reported adverse event. In conclusion, diquafosol ophthalmic solution 3 % is a useful option for the treatment of dry eye.

Clinical evaluation of the effect of diquafosol ophthalmic solution in glaucoma patients with dry eye syndrome

PURPOSE

To investigate the effects of diquafosol on intraocular pressure (IOP) and dry eye symptoms in glaucoma patients with dry eye syndrome (DES).

METHODS

This study evaluated a total of 138 glaucoma patients with DES who were treated with diquafosol ophthalmic solution (DIQUAS(®)). Before treatment and 1, 4, 12, 36, and 52 weeks after treatment, IOP, ocular surface disease index (OSDI), tear film break-up time (BUT), Schirmer I test scores, fluorescein staining, conjunctival impression cytology, and adverse drug reactions were evaluated.

RESULTS

Throughout the treatment period, the mean IOP for all the patients remained stable after treatment with diquafosol (15.4 ± 2.8 mmHg at baseline and 16.0 ± 2.8 mmHg at 52 weeks). The mean OSDI score improved significantly at 4, 12, and 52 weeks after diquafosol treatment. The BUT and Schirmer I test scores were significantly increased after diquafosol treatment. The Oxford scheme score was significantly decreased at 1, 4, 12, 36, and 52 weeks after diquafosol treatment. A significant improvement in goblet cell density was observed after 4 weeks of treatment with diquafosol. Adverse drug reactions were reported in 22 (15.9 %) patients. There were no serious adverse drug reactions.

CONCLUSIONS

Diquafosol was effective in improving objective and subjective symptoms and maintained a stable IOP in glaucoma patients with DES. Therefore, the addition of diquafosol treatment in glaucoma patients with DES or ocular surface side effects using anti-glaucoma medication may be beneficial.

Comparison of Topical Cyclosporine and Diquafosol Treatment in Dry Eye

PURPOSE

To compare the treatment effects of topical cyclosporine A (CsA) and diquafosol sodium (DQS) for the treatment of moderate to severe dry eye disease (DED).

METHODS

This prospective, nonrandomized, comparative study involved 60 eyes of 60 patients with moderate to severe DED who were treated with topical CsA 0.05% (group 1, 31 patients) or DQS 3% (group 2, 29 patients) in addition to artificial tears for 3 months. Before treatment, and at 1 and 3 months after treatment, the Ocular Surface Disease Index, tear breakup time, Schirmer score, tear clearance rate, and corneal and conjunctival staining scores were compared.

RESULTS

Significant improvements in Ocular Surface Disease Index score, tear clearance rate, and corneal staining score were observed 1 month after treatment in group 2 (p = 0.014, p = 0.002, and p < 0.001, respectively), when compared with group 1. However, no significant differences were observed between the two groups 3 months after treatment (p > 0.05). Tear breakup times were significantly higher in group 2 compared with group 1 for the duration of the study (p < 0.001). Three months after treatment, Schirmer score was significantly higher and conjunctival staining score was significantly lower in group 1 compared with group 2 (p < 0.001).

CONCLUSIONS

Both topical CsA 0.05% and DQS 3% are effective in patients with moderate to severe DED. However, the timing and degree of therapeutic effects on tear film and ocular surface parameters, as well as symptoms, can be different between the two treatments.