Conjunctival Goblet Cell Density Following Cataract Surgery With Diclofenac Versus Diclofenac and Rebamipide: A Randomized Trial

Efficacy of Topical Cyclosporine Combined with Punctal Plugs in Treating Dry Eye Disease and Inflammation

PURPOSE

To evaluate the effect of punctal plugs combined with cyclosporine eye drops on dry eye disease (DED) and ocular surface inflammation.

METHODS

In a clinical trial, 73 patients were randomly allocated into three groups: punctal plug group, combination therapy group, and cyclosporine group. At the baseline and four weeks after treatment, the Schirmer I test score, fluorescein tear film break-up time (FBUT), ocular surface staining score and dry eye symptoms were assessed. Tear samples were collected to detect the level of inflammatory factors (interleukins, matrix metalloproteinase 9 (MMP-9) and tumor necrosis factor alpha (TNF-α)). In an animal experiment, a New Zealand rabbit dry eye model was induced. The rabbits were randomly divided into control group, punctal plug group, and combination therapy group (n = 6). Conjunctival goblet cell density, protein level of MMP-9 in conjunctiva and mRNA levels of inflammatory factors in conjunctiva and cornea were measured before and after treatment.

RESULTS

In combination therapy group of the clinical trial, the following results were observed: significant improvement in Schirmer I test scores and FBUT compared to the cyclosporine group and punctal plug group, respectively; a decrease in the tear levels of IL-6, IL-1, and MMP-9 compared to the punctal plug group; and a decrease in the tear levels of IL-1α, IL-6, and IL-17 compared to the baseline (all p < 0.05). In the animal experiment, rabbits in combination therapy group had a higher goblet cell density (p < 0.01) and lower mRNA levels of IL-16 (p < 0.05), IL-17 (p < 0.05), and MMP-9 (p < 0.01) in conjunctiva and that of MMP-9 (p < 0.01) in cornea compared to punctal plug group.

CONCLUSION

Cyclosporine eye drops combined with degradable punctal plugs is a more optimized clinical treatment strategy for DED compared with degradable punctal plugs or cyclosporine eye drops alone, considering the influence of comprehensive clinical efficacy and ocular surface inflammation.

The Effect of Topical Rebamipide 2% in Managing Dry Eye Following Cataract Surgery

Purpose: To evaluate the potential advantages of using topical rebamipide 2% to manage dry eye following cataract surgery.Methods: Patients who underwent cataract surgery (phacoemulsification and intraocular lens insertion) were evaluated for dry eye 1 week postoperatively. Randomly selected patients were divided into the rebamipide group, who received 2% rebamipide eye drops, and the control group, who did not receive rebamipide. Various dry eye-related tests, including Schirmer’s test, the tear break-up time (TBUT), ocular surface staining, tear film osmolarity, tear lipid layer thickness, and the ocular surface disease index (OSDI) were performed in both groups 1 week, and 1 and 2 months postoperatively.Results: In the rebamipide group, we observed significant improvement in TBUT, the ocular surface staining score, and OSDI at 2 months postoperatively, as compared to 1 week (<i>p</i> = 0.002, 0.014, and 0.013, respectively). Schirmer’s test, tear film osmolarity, and tear lipid layer thickness remained unchanged in the rebamipide group. Throughout the entire follow-up period, the rebamipide group had a significantly prolonged TBUT (1 month: <i>p</i> = 0.007, 2 months: <i>p</i> = 0.000), and lower ocular surface staining score (1 month: <i>p</i> = 0.000, 2 months: <i>p</i> = 0.000), as compared to the control.Conclusions: Following cataract surgery, the use of rebamipide eye drops produced improvements in TBUT, ocular surface staining scores, and OSDI. This suggests that rebamipide offers benefits in managing dry eye that can occur after cataract surgery.

Effects of topical ketorolac tromethamine on tear parameters, meibography, goblet cell density, and conjunctival oxidative stress in healthy dogs

OBJECTIVES

The objective of the study was to evaluate whether a twice-daily instillation of 0.45% preservative-free ketorolac tromethamine (FKT) or 0.4% benzalkonium chloride-preserved ketorolac tromethamine (BACKT), every 12 h for 30 days may affect tear film parameters and the meibography in healthy dogs. Additionally, we assessed whether the same treatments irritated the ocular surface, affected goblet cell density (GCD), and the levels of oxidative stress biomarkers (OSB) in the conjunctiva of the same dogs.

PROCEDURES

Experimental and masked comparison study. In 11 healthy dogs baseline values of the lipid layer thickness, tear meniscus height, non-invasive tear breakup time (NI-TFBT), and the meibomian gland (MG) loss were assessed by OSAvet®. For each dog, one eye received 40 μL of BACKT, while the other received 40 μL FKT, every 12 h for 30 consecutive days. Tear parameters and meibography were repeated 15, 30, and 60 days post-treatments. Conjunctival hyperemia and blepharospasm were monitored at the same time points. At baseline and Day 30, a conjunctival biopsy was collected for GCD and OSB determination.

RESULTS

Conjunctival hyperemia and blepharospasm were not observed. At Day 15, the MG loss increased only in FKT-treated eyes (p < .001). On Day 30, both treatment groups showed increased MG loss, shortened NI-TFBT, and reduced GCD and catalase (p < .05). At Day 30, BACKT-treated eyes showed lower levels of superoxide dismutase (SOD) (p = .006) and higher levels of malondialdehyde (MDA) (p = .02). Differences between treatments were not observed for any parameter at any time point (p > .05). 60 days after treatment, OSAvet® parameters tended to return to values assessed at baseline; however, significant differences remained for MG loss (p < .05).

CONCLUSIONS

Twice-daily instillation of KT, containing or not BAC, for 30 consecutive days shortened NI-TFBT, decreased GCD, and increased the MG loss in healthy dogs. KT should be used with caution when prescribed for long periods, particularly in patients with tear film abnormalities. However, future controlled studies using KT, BAC, and other topical NSAIDs are indicated to further support this finding.

Update on Dry Eye Disease Treatment: Evidence From Randomized Controlled Trials

ABSTRACT

Although the ultimate goal of dry eye disease (DED) management is to restore the ocular surface and tear film homeostasis and address any accompanying symptoms, addressing this is not an easy task. Despite the wide range of current treatment modalities targeting multiple aspects of DED, the available DED management literature is quite heterogeneous, rendering evaluation or comparison of treatment outcomes hard or almost impossible. There is still a shortage of well-designed, large-scale, nonsponsored, randomized, controlled trials (RCTs) evaluating long-term safety and efficacy of many targeted therapies individually or used in combination, in the treatment of identified subgroups of patients with DED. This review focuses on the treatment modalities in DED management and aims to reveal the current evidence available as deduced from the outcomes of RCTs.

The Efficacy and Safety of Rebamipide Ophthalmic Suspension (OPC-12759) in Patients with Dry Eye Disease: A Systematic Review of Randomized Controlled Trials

The aim of this paper is to evaluate the efficacy and safety of Rebamipide (REB) ophthalmic suspension in dry eye disease (DED). A systematic review that only included full-length randomized controlled studies (RCTs) reporting the effects of REB ophthalmic suspension in three databases, PubMed, Scopus and Web of Science, was performed according to the PRISMA statement. The Cochrane risk of bias tool was used to analyze the quality of the studies selected. A total of seven studies were included in this systematic review. Although the overall risk of bias was low, most studies were sponsored by the manufacturer. REB ophthalmic suspension treatment achieved higher improvement than the control group in all reported variables. The mean differences between both groups were in favor of the REB group and were as follows: dry eye-related quality of life score (DEQS) -3.5 ± 2.9 points, tear film break-up time (TBUT) of 0.7 ± 0.6 s, Schirmer test (ST) without anesthesia of 0.3 ± 0.6 mm and total corneal fluorescein staining (tCFS) of -1.2 ± 0.7 points. Adverse events (AEs) were 5.2 ± 7.6% superior in the REB group, with an overall compliance > 95%. Therefore, REB ophthalmic suspension is a safe and effective treatment that could be recommended in patients with DED.

The effect of 3% diquafosol on the improvement of ocular surface post cataract surgery: A meta-analysis for time of intervention

Purpose

The effect of interventional time for 3% Diquafosol reatment in post-cataract surgery has not been well established. A meta-analysis was performed to evaluate the improvement of ocular surface condition in post-cataract surgery patients who received 3% DQS for various treatment durations.

Methods

Studies were performed based on 5 databases: PubMed, Cochrane Library, Web of Science, Embase, and China National Knowledge Infrastructure. Data on changes in Schirmer's test, tear breakup time (TBUT), corneal staining score, and OSDI score were collected for meta-analysis.

Results

A total of 621 affected eyes from 9 independent clinical studies were included. 6 studies conducted Schirmer's test after the application of 3% DQS. Meta-analysis showed that the difference between 3% DQS and control groups was not statistically significant for short-term application (less than or equal to 1 month) (WMD ​= ​0.14, P ​= ​0.27, 95% CI:-0.11 to 0.39), but was statistically different for long-term application (longer than or equal to 3 months) (WMD ​= ​0.76, P ​= ​0.03, 95% CI:0.08 to 1.45). For the corneal fluorescence staining score, the data from 6 studies indicated that the improvement was statistically significant for short-term application (WMD ​= ​-0.40, P <0.00001, 95% CI:-0.72 to -0.08) and but not long-term application (WMD ​= ​-0.21, P ​= ​0.26, 95% CI:-0.57 to 0.15). For TBUT, the data from 9 studies indicated that both short-term and long-term application showed significant improvement (WMD ​= ​1.70, P <0.00001, 95% CI:1.38 to 2.03; WMD ​= ​1.52, P <0.00001, 95% CI:1.09 to 1.95). Similar results were observed in data from 5 studies with OSDI scores, where both short-term and long-term application showed statistically significant improvements (WMD ​= ​-5.41, P <0.00001, 95% CI: -7.02 to -3.81; WMD ​= ​-6.10, P <0.00001, 95% CI:-8.52 to -3.67).

Conclusions

The application of 3% DQS in post-operative cataract patients has a positive effect on improving the ocular surface conditions. Short-term application resulted in lower corneal staining scores, prolonged TBUT, and improved OSDI scores. Long-term application improved Schirmer's test results, TBUT, and subjective symptoms.

Key messages

The updated article suggests that 3% Diquafosol is less effective in the short term after cataract surgery, and that application over three months can improve the patient's ocular surface condition.

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.

Impact of Perioperative Dry Eye Treatment with Rebamipide Versus Artificial Tears on Visual Outcomes After Cataract Surgery in Japanese Population

Introduction

The present study aimed to compare the effects of rebamipide and artificial tears during the perioperative period of cataract surgery on the postoperative visual outcomes.

Methods

Seventy-two eyes from 36 patients with a cataract were enrolled. Rebamipide (group R) was administered in one eye and Mytear® artificial tear ophthalmic solution (group A) in the other eye from 4 weeks preoperatively to 3 months postoperatively. Tear breakup time (TBUT), high-order aberrations (HOAs), superficial punctate keratopathy in the central part of the cornea (C-SPK), and corrected distance visual acuity (CDVA) were assessed at baseline, 1 week, 1 month, and 3 months after cataract surgery with trifocal intraocular lens (IOL) implantation. Contrast sensitivity and disability glare with visual angle values compatible with spatial frequencies of 1.1, 1.8, 2.9, 4.5, 7.1, and 10.2 cycles/degree (CPD) were evaluated postoperatively. Between-group differences of all variables were analyzed.

Results

At baseline, no significant differences in the variables were noted between the two groups. Mean TBUT was significantly higher, while mean C-SPK and HOAs were significantly lower in group R than in group A at each assessment. Mean CDVA was significantly higher at 1 week and 1 month postoperatively in group R compared with group A; this value was not significant at 3 months. Between-group differences in contrast sensitivity and disability glare were statistically significant at all spatial frequencies, 1 week and 1 month postoperatively. At 3 months postoperatively, there were significant differences in contrast sensitivity and disability glare at most spatial frequencies.

Conclusion

Dry eye management with rebamipide in the perioperative period of cataract surgery with trifocal IOL implantation was significantly more effective than artificial tears in improving ocular surface condition, contrast sensitivity, and disability glare postoperatively.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00523-w.

Prevalence and Characteristics of Dry Eye Disease After Cataract Surgery: A Systematic Review and Meta-Analysis

Dry eye disease (DED) after cataract surgery is associated with various risk factors, while causing a wide range of heterogeneous symptoms including decreased quality of vision. This systematic review and meta-analysis aimed to determine the prevalence and characteristics of DED after cataract surgery. We searched PubMed and EMBASE and included studies on patients with DED after cataract surgery, between January 2011 and June 2020. Study-specific estimates (DED prevalence rates after cataract surgery in patients without preexisting DED) were combined using one-group meta-analysis in a random-effects model. We included 36 studies published between 2013 and 2020. We included nine of these in the meta-analysis of DED prevalence after cataract surgery. Overall 37.4% (95% CI 22.6-52.3; 206/775) of patients without preexisting DED developed DED after cataract surgery. The risk factors for DED after cataract surgery included age, female sex, systemic diseases, systemic medications, psychiatric conditions, preexisting DED, meibomian gland dysfunction, preservatives in eye drops, surgery techniques, and lifestyle. DED severity peak occurred 1 day postoperatively and persisted for at least 1-12 months following cataract surgery; therefore, consistent follow-up for DED is warranted for at least 1 month after cataract surgery. Topical administration of preservative-free diquafosol tetrasodium solution and preoperative meibomian gland treatment were effective in preventing and treating DED following cataract surgery. As more than one-third of patients develop DED after cataract surgery, careful DED management and treatment is needed after cataract surgery to improve satisfaction and vision quality.

Clinical Efficacy of an Eyedrop Containing Hyaluronic Acid and Ginkgo Biloba in the Management of Dry Eye Disease Induced by Cataract Surgery

Objective: To evaluate the prevalence of dry eye disease (DED) after cataract surgery, and the impact of hyaluronic acid and ginkgo biloba eyedrops (HA-GB). Methods: Forty patients with no DED received Ocular Surface Disease Index (OSDI) questionnaire, assessment of conjunctival hyperemia and epithelial damage, fluorescein tear break-up time (TBUT) at baseline, day 1, week 1, and 4; adherence and tolerability were checked at weeks 1 and 4. At day 0 patients underwent cataract surgery and were randomized to standard postoperative care (control group) or standard postoperative care + HA-GB 3 times a day for 4 weeks (HA-GB group). Results: At baseline, TBUT was 9.6 ± 2.6 sec in controls and 9.0 ± 1.6 in HA-GB; thereafter it was higher in HA-GB group: 5.8 ± 2.3 versus 7.8 ± 3.2 (week 1, P = 0.03) and 6.4 ± 2.3 versus 8.5 ± 2.5 (week 4, P = 0.009). OSDI and conjunctival hyperemia were better in HA-GB group at week 4; respectively, 9.0 ± 5.7 versus 14.8 ± 7.3 (P = 0.004) and 5% versus 35% (P = 0.04). In the last 2 visits 50% of controls were symptomatic (OSDI of 13 or higher) compared with 16% on HA-GB group (P < 0.001). In addition, tolerability was higher in HA-GB group (week 1: 0.81 ± 0.20 versus 0.70 ± 0.24, P = 0.007; week 4: 0.93 ± 0.17 versus 0.80 ± 0.28, P = 0.001). Conclusion: Treatment with HA-GB is effective in reducing DED signs and symptoms in patients receiving cataract surgery, with high tolerability and safety profiles. clinicaltrials.gov (ID number NCT05002036).

Clinical efficacy of diquafosol sodium 3% versus hyaluronic acid 0.1% in patients with dry eye disease after cataract surgery: a protocol for a single-centre, randomised controlled trial

INTRODUCTION

The number of cataract surgeries, the most common ophthalmic surgery, is expected to increase due to ageing populations. Dry eye disease (DED) is a frequent side effect of cataract surgery, contributing to lower postoperative patient satisfaction and suboptimal quality of vision. It is unclear which eye-drops commonly used in these patients should be recommended for postoperative DED treatment. This study aims to compare the efficacy of topical administration of diquafosol sodium 3% vs hyaluronic acid 0.1% eye-drops in patients with DED after cataract surgery.

METHODS AND ANALYSIS

The study is designed as a single-blind randomised controlled trial. The participants will be randomly (1:1) allocated to either the diquafosol sodium 3% topical administration group (n=21) or the hyaluronic acid 0.1% topical administration group (n=21). Each group will receive its assigned eye-drop intervention over a 12-week period. The primary outcome will be measured using the total score of the Japanese version of the Ocular Surface Disease Index during the visit 5 weeks postoperatively. Both groups will be followed up after their respective eye-drop application for 12 weeks according to the intervention regimens. Secondary outcome measures including meibomian gland function assessment, tear film break-up time, keratoconjunctival staining score, maximum blink interval and tear secretion volume using Schirmer's test I will be assessed at 1, 5, 9, 13 and 25 weeks postoperatively.

ETHICS AND DISSEMINATION

This study has been approved by the Juntendo Hospital Certified Review Board, Tokyo, Japan (Approved protocol V.7.0 dated 7 May 2021. Approval number: J20-018) and has been registered with the Japan Registry of Clinical Trials. Written informed consent will be collected from every patient prior to study participation. The results of this trial will be presented at local and international meetings and submitted to peer-reviewed journals for publication.

TRIAL REGISTRATION NUMBER

jRCT1031210018.

Current Advances in Mechanisms and Treatment of Dry Eye Disease: Toward Anti-inflammatory and Immunomodulatory Therapy and Traditional Chinese Medicine

Dry eye is currently one of the most common ocular surface disease. It can lead to ocular discomfort and even cause visual impairment, which greatly affects the work and quality of life of patients. With the increasing incidence of dry eye disease (DED) in recent years, the disease is receiving more and more attention, and has become one of the hot research fields in ophthalmology research. Recently, with the in-depth research on the etiology, pathogenesis and treatment of DED, it has been shown that defects in immune regulation is one of the main pathological mechanisms of DED. Since the non-specific and specific immune response of the ocular surface are jointly regulated, a variety of immune cells and inflammatory factors are involved in the development of DED. The conventional treatment of DED is the application of artificial tears for lubricating the ocular surface. However, for moderate-to-severe DED, treatment with anti-inflammatory drugs is necessary. In this review, the immunomodulatory mechanisms of DED and the latest research progress of its related treatments including Chinese medicine will be discussed.

Preoperative Management of MGD with Vectored Thermal Pulsation before Cataract Surgery: A Prospective, Controlled Clinical Trial

Purpose: To investigate the efficacy of preoperative monocular treatment in elderly cataract patients with Meibomian Gland Dysfunction (MGD) utilizing vectored thermal pulsation treatment.Materials and Methods: This study was a prospective, examiner-masked contralateral eye clinical trial. Patients previously diagnosed with MGD undergoing uncomplicated cataract surgery in two eyes were enrolled. The eye perceived by the patient to be more symptomatic of MGD received a 12 min vectored thermal pulsation treatment using the LipiFlow Thermal Pulsation System, and was referred to as the LipiFlow-surgery eye. The contralateral eye then served as the nonLipiFlow-surgery eye. Patients with MGD not undergoing cataract surgery were enrolled as the control group. Within the control group, the eye that received LipiFlow treatment was considered the LipiFlow-nonsurgery eye, while the contralateral eye served as the nonLipiFlow-nonsurgery eye. All patients were examined before treatment and at one-week, one-month, and three-month intervals after treatment. Clinical parameters included dry eye symptoms, average lipid layer thickness (LLT-ave), tear breakup time (TBUT), corneal staining, Schirmer I tests, Meibomian glands yielding liquid secretion (MGYLS), and meibomian gland dropout.Results: A total of 32 patients (64 eyes) were examined during the three-month follow-up. There was a significant reduction in dry eye symptoms in non-surgery patients with monocular treatment of MGD, while no change in surgery patients was observed. Significant improvement of MGYLS in LipiFlow-surgery and LipiFlow-nonsurgery eyes during the follow-up time (p < .001) was reported, while no difference was observed in nonLipiFlow-surgery and nonLipiFlow-nonsurgery eyes. A statistically significant difference was seen in TBUT between LipiFlow-surgery and nonLipiFlow-surgery eyes at one-week and one-month intervals (p = .019 and 0.019, respectively). Differences in other clinical parameters were not statistically significant.Conclusions: Our findings suggest that although subjective symptoms were not alleviated, a single application of LipiFlow treatment before cataract surgery is effective in alleviating blockage of meibomian glands and preventing the decline of TBUT after cataract surgery.

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.

Altered mucins and aquaporins indicate dry eye outcome in patients undergoing Vitreo-retinal surgery

Vitreo-retinal (VR) surgeries induce conjunctival changes. However, there are no study reports regarding prevalence and severity of dry eye after these surgeries. This study evaluated dry eye outcome after VR surgery. Patients undergoing VR surgery classified as scleral buckle and microincision vitrectomy surgery (n = 44, mean age: 56.09±10.2 years) were recruited. Dry eye evaluation was done before and 8 weeks after surgery (2 weeks after omitting topical eye drops). Conjunctival imprint cytology for goblet cell count and tear Mucin 5AC (MUC5AC) protein estimation was done. Gene expressions of MUC5AC, MUC4, MUC16, Aquaporin 4 (AQP4) and AQP5 were analyzed in the conjunctival imprint cells by qPCR. None of the patients exhibited clinical signs of dry eye after VR surgery. But the conjunctival goblet cell density (GCD) was significantly lowered post-VR surgery (63% cases, **p = 0.012) with no alterations in the tear MUC5AC protein. Post-VR surgery, the conjunctival cell gene expression of MUC4, MUC16 and AQP4 were significantly increased (*p = 0.025, *p = 0.05 and *p = 0.02 respectively) and AQP5 was significantly lowered (*p = 0.037), with no change in MUC5AC expression. Tear cytokines were significantly increased post-VR surgery (anti-inflammatory: IL1RA, IL4, IL5, IL9, FGF; PDGFbb and pro-inflammatory: IL2, IL6, IL15, GMCSF and IFNg). Though clinical signs of dry eye were not observed after VR surgery, ocular surface changes in the form of reduced GCD, altered MUC5AC, MUC4, MUC16, AQP4, AQP5 and cytokines are suggestive of dry eye outcome at the molecular level especially inpatients aged above 51 years, especially female gender and those who are diabetic.

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.

Conjunctival goblet cells: Ocular surface functions, disorders that affect them, and the potential for their regeneration

Conjunctival goblet cells (CGCs) are specialized cells that produce and secrete soluble mucins to the tear film that bathes the ocular surface. CGC numbers and functions are affected in various ocular surface diseases including dry eye disease with diverse etiologies. In this review we will (i) summarize the important functions of CGCs in ocular surface health, (ii) describe the ocular surface diseases that affect CGC numbers and function, (iii) provide an update on recent research outcomes that elucidate CGC differentiation, gene expression and functions, and (iv) present evidence in support of the prediction that restoring CGC numbers and/or functions is a viable strategy for alleviating ocular surface disorders that impact the CGCs.

Evaluation of the Protective Effect of an Ophthalmic Viscosurgical Device on the Ocular Surface in Dry Eye Patients during Cataract Surgery

Purpose

To evaluate the protective effect of applying an ophthalmic viscosurgical device (OVD) to the ocular surface during cataract surgery and its ability to prevent dry eye syndrome.

Methods

Twenty-four patients aged 50 to 75 years who underwent cataract surgery at Seoul National University Bundang Hospital and agreed to participate in the study were included and divided into two groups: a study group who underwent cataract surgery after application of an OVD to the ocular surface, and a control group who underwent cataract surgery without application of an OVD. DisCoVisc was used as the OVD in the study group, while other factors including surgical techniques and administration of anesthetic agents were performed in both groups in the same manner. Indicators of dry eye syndrome including ocular staining score, tear break-up time, and tear osmolality were analyzed. Ocular surface disease index and a visual analog scale were analyzed for dry eye symptoms, and the amount of balanced salt solution used during surface irrigation and operation time were also analyzed.

Results

Significant improvement in the tear break-up time, corneal ocular staining score, and ocular surface disease index score in the study group compared with the control group one week after operation (by the Mann-Whitney test). Use of OVD was associated with longer operating time.

Conclusions

OVD applied to the ocular surface during cataract surgery had a protective effect on the ocular surface one week after surgery.

Management of Postoperative Inflammation and Dry Eye After Cataract Surgery

Surgical intervention is the most effective treatment for decreased vision resulting from cataracts. Although the current procedures for cataract surgery are safe and effective, it is well known that several complications can develop after surgery. Postoperative cystoid macular edema (CME) is a well-known complication, and prophylactic medications such as steroids and/or nonsteroidal antiinflammatory drugs are routinely used for its prevention. Ocular surface abnormalities, such as dry eye, have also been reported to develop after cataract surgery. However, the causative mechanisms for postoperative dry eye have not been definitively determined. At present, there are no prophylactic medications that are commonly used to prevent the development of postoperative dry eye. Although nonsteroidal antiinflammatory drugs are very effective in reducing the incidence and degree of postoperative CME, it is known that they can cause adverse side effects, including ocular surface abnormalities. Thus, perioperative medications must be carefully selected to improve surgical outcomes and patient satisfaction. Here, we summarize the results of recent studies on postoperative dry eye and CME that can develop after cataract surgery. We suggest appropriate combinations of medications that can be used to minimize these postsurgical complications.

The Ocular Surface Glycocalyx and its Alteration in Dry Eye Disease: A Review

Many studies have revealed that transmembrane mucins, large glycoproteins with heavily glycosylated glycans, are essential for maintaining ocular surface epithelium lubrication and wettability. Recent reports indicate that transmembrane mucins and galectin-3, a chimera type of galectin that binds β-galactoside in the glycan, play a crucial role in maintaining the epithelial glycocalyx barrier. This review summarizes current evidence regarding the role of galectin-3, the role of the three major transmembrane mucins (i.e., MUC1, MUC4, and MUC16), in the maintenance of ocular surface wettability and transcellular barrier. Pathological mechanisms of glycocalyx barrier disruption and epithelial surface wettability decreases in dry eye disease are also summarized. Lastly, new ophthalmic drugs that target transmembrane mucin are described.

Secreted Mucins on the Ocular Surface

Mucins, which play important roles on the ocular surface in wettability, lubrication, and barrier function, are classified into two categories: secreted mucins and membrane-associated mucins. The most important secreted mucin on the ocular surface is MUC5AC, which is secreted by the conjunctival goblet cells. In the human conjunctiva, goblet cells are present in higher concentrations in the fornix, inferior nasal bulbar, and the lid wiper on the lid margin. The number of conjunctival goblet cells and MUC5AC expression/secretion are decreased in a patient with dry eye. In Japan, drugs that stimulate mucin secretion or increase the number of conjunctival goblet cells are commercially available. A P2Y2 receptor, diquafosol, stimulates tear fluid secretion from conjunctival epithelial cells and promotes mucin secretion from conjunctival goblet cells. Rebamipide was marketed originally as an oral therapeutic drug to treat gastritis in Japan. Topical rebamipide increases numbers of goblet cells in the bulbar conjunctiva and the lid wiper area of palpebral conjunctiva. Many researchers have reported decreases in the ocular surface mucin expression including MUC5AC secreted by goblet cells in patients with dry eye. However, it is unknown whether changes in mucin expression on the ocular surface cause or result from dry eye. Further study is needed to determine the true mechanism of 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.

Rebamipide ophthalmic solution modulates the ratio of T helper cell 17/regulatory T cells in dry eye disease mice

The aim of the present study was to confirm the effect of 2% rebamipide ophthalmic solution on a scopolamine‑induced dry eye (DE) mouse model, and to investigate its effect on the ratio of T helper cell 17 (Th17)/regulatory T cell (Treg) numbers. C57BL/6 mice received subcutaneous injections of scopolamine and were exposed to a low‑humidity environment in order to establish a DE model. Rebamipide eye drops (2%) administered four times daily for 2 weeks, significantly reduced the corneal staining scores and increased the tear film breakup time and tear production in the DE mice. Pathologically, the rebamipide restored the histological changes induced by DE in the cornea, conjunctiva and lacrimal gland. At a molecular level, it downregulated pro‑inflammatory and upregulated anti‑inflammatory cytokines in the conjunctiva and lacrimal gland. Furthermore, the increased Th17 and Treg levels were restored following treatment with rebamipide. In conclusion, the anti‑inflammatory and Th17/Treg balance‑preserving effects of rebamipide may contribute to the treatment of DE in mice.

Discrepancies in Persistent Dry Eye Signs and Symptoms in Bilateral Pseudophakic Patients

Despite the increased awareness of early prophylaxis and treatment for dry eye disease (DED) during the first few weeks after cataract surgery, the chronic effect of cataract surgery on the risk of ocular surface abnormalities has not been fully explored. This study was to assess the prevalence of DE subjective symptoms and clinical tests according to the cataract surgery. A total of 172 patients who underwent bilateral cataract surgeries at least 5 months before the recruitment date and 1225 controls with no cataracts were evaluated for their subjective DE symptoms (dry sensation, foreign-body sensation, ocular pain, ocular fatigue, sensitivity to bright light, and blurred vision) and ophthalmic parameters (tear break-up time, keratoconjunctival staining scores, and maximum blinking interval). The presence of subjective DE symptoms was generally inversely associated with cataract surgeries, whereas abnormal clinical tests were more pronounced among postsurgical cataract patients than among controls. Pseudophakic patients showed a 57% increased prevalence of severe keratoconjunctivitis, compared to controls (P = 0.02). In contrast, among subjective DE symptoms, significantly lower odds of sensitivity to bright light were detected among cases than controls; the multivariable-adjusted odds ratio (95% confidence interval) comparing pseudophakic patients with noncataract patients was 0.56 (0.34–0.92) (P = 0.02). In conclusion, persistent tear instability and corneal epitheliopathy were found even at several months or more after cataract surgery. This study demonstrates the importance of evaluating ocular surface conditions in pseudophakic patients, even if they lack DE symptoms.

Incidence and pattern of dry eye after cataract surgery

PURPOSE

The objectives of the study were to identify the incidence and pattern of dry eye after phacoemulsification and manual small incision cataract surgeries.

METHODS

The study consisted of two groups of patients - Group 1 underwent manual small incision cataract surgery (SICS) and Group 2 underwent phacoemulsification. The dry eye-related data was collected preoperatively and at 1 week, 1 month and 3 months postoperatively. Ocular Surface Disease Index questionnaire, tear break-up time (TBUT) and Schirmer test - 1 were used to record the type of dry eye.

RESULTS

One hundred eyes of 96 patients, including 35 (36.5%) men and 61 (63.5%) women with the mean age of 63.1 (±8.3) years were studied. Dry eyes were found in 42% eyes (p < 0.001) of patients at 1 week follow-up. Fifteen percent and 9% of the eyes were dry at 1 month and 3 months after surgery, respectively. There were 34 (53.1%) and 8 (22.2%) dry eyes in SICS and phacoemulsification groups, respectively at one week postoperative follow-up which was a statistically significant difference.Majority of eyes (27/42, 64.3%) had mild dryness. There were significant differences in TBUT at 1 week, 1 month and 3 months postoperatively. At 1 week review, the SICS group had mean TUBT of 10.0 (±0.55) sec as compared to 13.9 (±0.70) sec in phacoemulsification group (p < 0.001).

CONCLUSION

Incidence of dry eye is higher in SICS than phacoemulsification due to tear film instability. The clinicians should be conscious about dry eye symptoms and signs in an otherwise healthy eye after cataract surgery.

Reconsidering the central role of mucins in dry eye and ocular surface diseases

Mucins are key actors in tear film quality and tear film stability. Alteration of membrane-bound mucin expression on corneal and conjunctival epithelial cells and/or gel-forming mucin secretion by goblet cells (GCs) promotes in ocular surface diseases and dry eye disease (DED). Changes in the mucin layer may lead to enhanced tear evaporation eventually contributing to tear hyperosmolarity which has been associated with ocular surface inflammation. Inflammatory mediators in turn may have a negative impact on GCs differentiation, proliferation, and mucin secretion. This sheds new light on the position of GCs in the vicious circle of DED. As contributor to ocular surface immune homeostasis, GC loss may contribute to impaired ocular surface immune tolerance observed in DED. In spite of this, there are no tools in routine clinical practice for exploring ocular surface mucin deficiency/dysregulation. Therefore, when selecting the most appropriate treatment options, there is a clear unmet need for a better understanding of the importance of mucins and options for their replacement. Here, we comprehensively revisited the current knowledge on ocular surface mucin biology, including functions, synthesis, and secretion as well as the available diagnostic tools and treatment options to improve mucin-associated homeostasis. In particular, we detailed the potential link between mucin dysfunction and inflammation as part of the uncontrolled chronic inflammation which perpetuates the vicious circle in DED.

Conjunctival MUC5AC+ goblet cell index: relationship with corneal nerves and dry eye

PURPOSE

To evaluate the relative proportion of conjunctival MUC5AC+ and MUC5AC- goblet cells in a post-LASIK population and their association with dry eye indicators and corneal nerve morphology using a MUC5AC+ Goblet Cell Index.

METHODS

Twenty subjects who had undergone LASIK > 12 months previously and 20 age-matched controls were recruited. Dry eye symptoms, tear breakup time, osmolarity, meniscus area and corneal nerve morphology were examined. Conjunctival impression cytology samples were collected from inferior-temporal bulbar conjunctiva using Millicell® inserts. Total goblet cell density was determined from positive cytokeratin-7 (CK7) immunolabelling; MUC5AC+ goblet cell density was determined from both CK7+- and MUC5AC+-immunolabelled cells. The ratio of MUC5AC+ to total density was defined as the "MUC5AC+ Goblet Cell Index". Differences in variables between groups and the associations between goblet cell variables and clinical assessments were examined.

RESULTS

No significant differences in the total and MUC5AC+ goblet cell density and tear film parameters were found between groups, although greater ocular discomfort was reported in the post-LASIK group (P = 0.02). A higher MUC5AC+ Index was associated with worse/greater dry eye symptoms (ρ = 0.55, P = 0.01) and higher nerve tortuosity (ρ = 0.57, P = 0.01) in the post-LASIK group; lower nerve density and thickness was found in controls (ρ > -0.45, P < 0.05), but not associated with tear film parameters.

CONCLUSIONS

The MUC5AC+ Goblet Cell Index provides an indicator of mucin secretion for assessing the goblet cell function in dry eye. In the post-LASIK participants, we found an increased MUC5AC+ Index associated with worse dry eye symptoms and adverse changes in corneal nerve morphology.

Changes in ocular surface status after phacoemulsification in patients with senile cataract

AIM

To evaluate the signs and symptoms of dry eye after phacoemulsification; effects on the status of ocular surface using impression cytology; and associated risk factors.

METHODS

Prospective study included 50 eyes (50 patients) with no dry eye signs or symptoms, who underwent clear corneal phacoemulsification for senile cataract. Dry eye indices used included Ocular Surface Disease Index scoring, Schirmer I test, tear break up time, tear meniscus height, corneal fluorescein staining, lissamine green staining and goblet cell density (GCD) with the help of impression cytology. Primary outcome measures included post-operative changes in the dry eye indices. Secondary outcome measures included correlation of the dry eye signs and symptoms with various risk factors.

RESULTS

Aggravation of both the signs and symptoms of dry eye were noted in immediate post-operative period. The sharp deterioration was followed by a recovering trend towards the end of sixth week. A decrease in GCD was also noted. Risk factors for deterioration include age, duration of exposure to microscope light and effective phacoemulsification time. Diabetic status, socio-economic status and site of incision did not have any effect on dry eye status.

CONCLUSION

There is a transient deterioration of "dry eye" status post-phacoemulsification. The patients should be carefully counselled about the evanescent nature of the disease. Incision can be given at the site of high corneal curvature to neutralize astigmatism without any fear of inducing dry eye. Minimum light exposure and ultrasound energy should be used during the surgery.