Dry eye and inflammation of the ocular surface after cataract surgery: effectiveness of a tear film substitute based on trehalose/hyaluronic acid vs hyaluronic acid to resolve signs and symptoms

Research progress of corneal characteristics and changes in primary angle‑closure glaucoma (Review)

The cornea plays a crucial role in the refractive system of the eyeball, and its changes can significantly impact the visual quality of patients with glaucoma. In patients with primary angle-closure glaucoma, several corneal alterations occur, including changes in corneal thickness and curvature, modification in corneal epithelial cells and nerves, activation of inflammatory cells, and variations in the number and morphology of stromal and endothelial cells. These morphological and structural changes in the cornea are mainly influenced by acute or chronic elevation of intraocular pressure and treatment. In the present review the corneal morphological changes and regularities associated with primary angle-closure glaucoma are examined.

Is Thermal Pulsation Therapy Effective for Dry Eyes Before and After Cataract Surgery? A Systematic Review and Meta-Analysis

Background

Meibomian gland dysfunction (MGD) is a primary cause of evaporative dry eye disease (DED), which is often exacerbated by cataract surgery due to surgical trauma and inflammation. Thermal pulsation therapy (TPT) aims to enhance meibomian gland function and relieve dry eye symptoms. We conducted a systematic review and meta-analysis to evaluate the effectiveness of TPT in managing dry eye symptoms associated with cataract surgery.

Methods

A systematic search was performed in December 2024 across PubMed, ScienceDirect, CINAHL, and the Cochrane Central Register of Controlled Trials to identify original research on the efficacy of TPT in addressing cataract surgery-related dry eye symptoms. The quality of the included studies was evaluated using the Risk of Bias in Non-Randomized Studies of Interventions tool, with results visualized through the Robvis 2.0 tool developed by the Cochrane Collaboration.

Results

The search yielded 365 records, of which seven studies met the inclusion criteria for this meta-analysis. Key outcomes analyzed included the meibomian gland yielding liquid secretion (MGYLS) score, tear break-up time (TBUT), ocular surface disease index (OSDI) score, and lipid layer thickness (LLT). The meta-analysis revealed a moderate effect of TPT, with a small but clinically significant improvement observed in MGYLS scores (Cohen's d = 0.29, p = 0.033) and TBUT (Cohen's d = 0.15, p = 0.029). However, the effects on OSDI scores and LLT were not statistically significant. Study heterogeneity varied, with some outcomes exhibiting considerable variability.

Conclusion

TPT provides moderate and clinically meaningful improvements in MGYLS scores and TBUT for patients experiencing dry eye symptoms after cataract surgery, although improvements in OSDI scores and LLT did not achieve statistical significance. The variability in study quality and heterogeneity highlights the need for well-designed, high-quality research to confirm these findings and evaluate the durability of TPT's therapeutic effects both before and after cataract surgery.

A Preservative-Free Combination of Sodium Hyaluronate and Trehalose Improves Dry Eye Signs and Symptoms and Increases Patient Satisfaction in Real-Life Settings: The TEARS Study

INTRODUCTION

Dry eye disease (DED) is a frequently observed condition characterized by ocular discomfort and visual disturbance. It is highly prevalent and impairs patients' quality of life (QoL). This study assessed the benefit of a preservative-free bioprotectant eye drop formulation containing sodium hyaluronate and trehalose (SH-trehalose) with regards to DED, as well as patient satisfaction, through a large-scale real-life survey.

METHODS

In a multi-center, international, prospective observational study, subjects with DED received SH-trehalose for 84 days. Ocular Surface Disease Index (OSDI), Dry Eye Questionnaire-5 items (DEQ-5), and patient satisfaction were assessed at baseline, day 28, and day 84, and clinical evaluations included ocular surface staining, Schirmer test, tear film break-up time (TBUT), and conjunctival hyperemia at baseline and day 84.

RESULTS

A total of 312 patients were evaluated, of whom 82.4% were women. The mean age was 57.9 ± 15.2 years. The mean OSDI score at baseline was 41.7 ± 20.6. After 84 days, the mean OSDI score was 27.3 ± 19.8 (p < 0.001). The percentage of patients with a severe OSDI score decreased from 60.3 to 34.5%. The DEQ-5 score significantly (p < 0.001) improved after 28 and 84 days, as did patient satisfaction. Ocular surface staining, Schirmer test, TBUT, and conjunctival hyperemia scores improved significantly (all p < 0.001) for both eyes with SH-trehalose between baseline and day 84. Tolerance of SH-trehalose was good.

CONCLUSIONS

SH-trehalose significantly improved the clinical signs and symptoms of DED after 84 days. Moreover, it significantly increased patient satisfaction and was well tolerated.

TRIAL REGISTRATION

NCT04803240.

Assessing the therapeutic role of trehalose and hyaluronic acid: implications for patient care

OBJECTIVE

This Systematic review aims to assess the efficacy of trehalose and hyaluronic acid in enhancing ocular recovery post-cataract surgery, focusing on their impact on tear film stability, ocular surface integrity, and patient-reported outcomes.

METHODS

A comprehensive search was conducted across MEDLINE, PubMed, and Cochrane Library databases to identify randomized controlled trials investigating the efficacy of trehalose, hyaluronic acid, or their combination in post-cataract surgery care. The inclusion criteria focused on peer-reviewed studies in English, detailing outcomes relevant to ocular recovery such as tear film stability, ocular surface integrity, patient-reported discomfort, or visual acuity (VA). The quality of the included studies was assessed using the Cochrane Risk of Bias Tool and synthesized the data qualitatively.

RESULTS

Four qualitative investigations met the inclusion criteria. The studies collectively assessed the efficacy of a 3% trehalose and 0.15% hyaluronic acid eye drop solution in reducing postoperative eye symptoms compared to various control solutions. Parameters measured included tear break-up time (TBUT), Fluorescein staining, tear production (Schirmer test), and Ocular Surface Disease Index (OSDI) scores. The results indicated significant improvements in tear film stability and ocular surface health for the treatment groups compared to controls, with a notable decrease in patient-reported discomfort. The study showed an improvement of - 18 (± 14.6) in the treatment group compared to - 7 (± 8.0) in the control group for OSDI. For TBUT, the treatment group improved by 3 (± 1.2) s, whereas the control group improved by 0.3 (± 0.71) s. VA, measured on a scale of 0-100, increased to 17 (± 0.7) in the treatment group compared to 15 (± 1.1) in the control group.

CONCLUSIONS

Trehalose and hyaluronic acid may be beneficial in the postoperative period by enhancing tear film stability and ocular surface health. While the results are promising, further research is needed to confirm these findings, understand the mechanisms of action, and explore broader applications.

The Mid-Term Effect of Preservative-Free Artificial Tears Containing Hyaluronic Acid on Dry Eye Incidence after Cataract Surgery: A Retrospective Cohort Study

The aim of this study is to survey the effectiveness of preservative-free artificial tears containing hyaluronic acid (HA) on post-cataract surgery dry eye disease (DED) prevention. A retrospective cohort study was performed, and patients that received cataract surgeries were divided into either an HA group or non-HA group depending on the artificial tear they used. A total of 37 and 74 eyes were enrolled into the HA and non-HA groups, respectively, after the selection. The primary outcomes are postoperative superficial keratitis and multiple (>3) DED symptoms. The generalized linear model was utilized to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of primary outcomes between the two groups. There were 10 and 2 episodes of superficial keratitis in the non-HA group and HA group, respectively, and the HA group demonstrated a significantly lower incidence of superficial keratitis (p < 0.001). Moreover, 13 and 5 patients developed multiple DED symptoms in the non-HA and HA groups, and the HA group illustrated fewer multiple DED symptoms (p = 0.024). The lower preoperative tear break-up time (TBUT) was correlated with superficial keratitis in the HA group (p = 0.043), while old age, low preoperative TBUT and ocular surface staining were associated with superficial keratitis in the non-HA group (all p < 0.05). Lower preoperative TBUT was correlated with multiple DED symptoms in the HA group (p = 0.020), while female sex, low preoperative TBUT and any DED symptoms were associated with multiple DED symptoms in the non-HA group (all p < 0.05). In conclusion, the usage of preservative-free artificial tears containing HA is associated with lower postoperative DED events.

Study of IL-17 and Intercellular Adhesion Molecule-1 in Conjunctivochalasis Using Correlation Analysis

PURPOSE

The aim of this study was to observe the expression of interleukin (IL)-17 and intercellular adhesion molecule (ICAM)-1 in conjunctivochalasis (CCH) and to analyze the correlations between cytokines and the severity of CCH.

METHODS

Serum samples were collected from 22 patients with CCH and 18 normal controls (NCs). The Ocular Surface Disease Index, tear film break-up time, Schirmer I test, and corneal fluorescein staining were used to evaluate the ocular surface signs and symptoms. The concentrations of IL-17, IL-23, and ICAM-1 in serum and cellular supernatants were measured by enzyme-linked immunosorbent assays, and the gene expression levels of cytokines were measured by a quantitative real-time polymerase chain reaction. The relationships between serum concentrations of IL-17, IL-23, and ICAM-1 with clinical ocular surface parameters in CCH were analyzed using the Spearman correlation analysis.

RESULTS

The concentrations of IL-17 and ICAM-1 in serum and cellular supernatants of CCH were significantly higher than those of NCs (all P < 0.001). The concentrations of IL-23 in serum and cellular supernatants of CCH showed no significant difference from those of NCs ( P > 0.05). The mRNA expression levels of IL-17 and ICAM-1 in conjunctival fibroblasts of CCH were significantly higher than those of NCs (all P < 0.001). The mRNA expression of IL-23 in conjunctival fibroblasts of CCH was higher than that of NCs, without a significant difference ( P > 0.05). Furthermore, the serum concentrations of IL-17 and ICAM-1 were positively correlated with Ocular Surface Disease Index and fluorescein staining (all P < 0.05), and negatively correlated with break-up time and Schirmer I test of CCH (all P < 0.05).

CONCLUSIONS

The expression levels of IL-17 and ICAM-1 were significantly increased in CCH serum and associated with the disease severity. We postulate that IL-17 and ICAM-1 may play a role in the pathogenesis of CCH. IL-17 and ICAM-1 antagonists may be a potential treatment option for CCH in the future.

Intracellular Protective Functions and Therapeutical Potential of Trehalose

Trehalose is a naturally occurring, non-reducing saccharide widely distributed in nature. Over the years, research on trehalose has revealed that this initially thought simple storage molecule is a multifunctional and multitasking compound protecting cells against various stress factors. This review presents data on the role of trehalose in maintaining cellular homeostasis under stress conditions and in the virulence of bacteria and fungi. Numerous studies have demonstrated that trehalose acts in the cell as an osmoprotectant, chemical chaperone, free radical scavenger, carbon source, virulence factor, and metabolic regulator. The increasingly researched medical and therapeutic applications of trehalose are also discussed.

A Preservative-Free Approach - Effects on Dry Eye Signs and Symptoms After Cataract Surgery

Purpose

To compare the effect of treatment with preservative-free dexamethasone, NSAIDs and trehalose/hyaluronic acid eye drops with the preservative benzalkonium chloride containing dexamethasone and NSAIDs after cataract surgery in dry versus non-dry eyes.

Patients and Methods

In this prospective randomized intervention study, dry eye tests were performed before and 6 weeks after cataract surgery. Patients were considered as having dry eye, SDE (sign of dry eye), if at least one of the following dry eye tests were abnormal; corneal fluorescein staining (CFS), non-invasive keratograph breakup time (NIKBUT) or tear osmolarity. Patients with SDE were randomly assigned to one of two groups. Group 1 patients were treated with dexamethasone and bromfenac eye drops with the preservative benzalkonium chloride (BAC). Group 2 patients were treated with preservative-free dexamethasone and preservative-free diclofenac, as well as a preservative-free lubricant with trehalose and hyaluronic acid both before and after surgery. Patients with normal tear film status acted as the control group (group 3) and received same treatment as group 1.

Results

A total of 215 patients were enrolled six weeks after surgery, the number of patients with SDE decreased significantly in groups 1 and 2 (p <0.001). Subjective symptoms and objective measures including osmolarity, NIKBUT, CFS, and tear film thickness (TFT) improved after surgery, tear production remained unchanged, while corneal sensitivity and meibomian gland dysfunction (MGD) parameters worsened. In the control group with normal tear-film status, SDE increased significantly after the surgery (p <0.001). There were no statistically significant differences in tear film parameters between the three groups after surgery.

Conclusion

After cataract surgery, patients with mild to moderate dry eyes may experience improved tear film status and reduced symptoms. However, we found no additional beneficial effect on dry eye parameters with treatment with preservative-free dexamethasone, NSAIDs, and lubricants compared to preservative-containing eye drops.

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.

Trehalose and Dry Eye Disease: A Comprehensive Systematic Review of Randomized Controlled Trials

The purpose of the research project was to extensively review the efficacy and safety of a trehalose tear-substitute treatment in cases of dry eye disease (DED). A systematic review that included only full-length randomized controlled studies (RCTs) reporting the effects of trehalose tear-substitute treatment in three databases, PubMed, Scopus and Web of Science, was performed according to the PRISMA statement. The search period included papers published before 8 August 2023. The Cochrane risk-of-bias tool was used to analyze the quality of the studies selected. A total of 10 RCTs were included in this systematic review. Trehalose tear-substitute treatments achieved a higher improvement than did control group interventions in all reported variables. The mean differences between both groups were in favor of trehalose, and were as follows: ocular surface disease index (OSDI) questionnaire score of -8.5 ± 7 points, tear film breakup time (TBUT) of 1.9 ± 1 s, tear film thickness (TFT) of 0.25 ± 0.1 μm, tear meniscus height (TMH) of 0.02 ± 0.02 mm, Schirmer test (ST) of 0.8 ± 1.4 mm, corneal fluorescein staining (CFS) of -0.7 ± 0.1 points and visual acuity (VA) of 0.3 ± 2.1 letters. No adverse events after trehalose tear-substitute treatments were reported. Trehalose tear substitutes are a safe and effective treatment for DED. Therefore, trehalose tear substitutes should be recommended for patients with dry eye disease. In addition, there is specific evidence to support its use in the preoperative cataract surgery period.

Tear Film Stabilization and Symptom Improvement in Dry Eye Disease: The Role of Hyaluronic Acid and Trehalose Eyedrops versus Carmellose Sodium

This study evaluated the effectiveness of hyaluronic acid and trehalose (HA/trehalose) eyedrops in managing dry eye disease (DED) symptoms by measuring tear stability and administering a DED questionnaire. Sixty patients were treated with either HA/trehalose eyedrops (Tear A) or carmellose sodium eyedrops (Tear B) as controls. The tear breakup time (TBUT) and non-invasive breakup time (NIBUT) were monitored, and patients completed the standard patient evaluation of eye dryness (SPEED) questionnaire. After two months of twice-daily applications, patients treated with the HA/trehalose eyedrops demonstrated significant improvements in the NIBUT (12.98 ± 3.22 s) and TBUT (12.95 ± 2.98 s), indicating increased tear stability. Moreover, they reported lower dry eye sensation (6.70 ± 4.94 SPEED score points), suggesting a reduction in DED symptoms. These findings underscore the efficacy of HA/trehalose eyedrops in improving both the objective and subjective signs of DED, with twice-daily application enhancing ocular surface conditions and reducing patient-reported symptoms.

Occurrence of Corneal Staining after Cataract Surgery with and without Chitosan-N-Acetylcysteine Eye Drops

INTRODUCTION

The objective of this study was to evaluate the prevalence of ocular surface damage assessed by corneal staining scores right after cataract surgery and whether it can be prevented using chitosan-N-acetylcysteine (C-NAC) eye drops.

METHODS

We included patients scheduled for routine cataract surgery. Each patient was randomly assigned to one of three groups. Patients in group 1 underwent routine cataract surgery with no additional eye drops. In group 2, patients received C-NAC eye drops after cataract surgery, and in group 3, C-NAC was applied both before and after surgery. Both groups continued the treatment once daily for 4 days. Ocular surface alteration was assessed using the National Eye Institute (NEI) score, and the visual analog scale (VAS) was used to evaluate subjective complaints.

RESULTS

Thirty-six patients were included in the final analyses. One hour after cataract surgery, a statistically significant increase in corneal fluorescein staining was observed in all groups, which decreased again after 1 week. There was no significant difference between the groups 1 h after cataract surgery, though a tendency toward lower NEI scores was observed during this time point in group 3.

DISCUSSION

Cataract surgery induced ocular surface staining and subjective complaints after 1 h. However, the increase in VAS score was small and probably not clinically relevant. The application of perioperative C-NAC eye drops did reduce the rate of corneal staining after cataract surgery in a clinically relevant manner.

Management of inflammation in dry eye disease: Recommendations from a European panel of experts

Introduction

Early initiation of anti-inflammatory therapies is recommended for dry eye disease (DED) to break the vicious cycle of pathophysiology. However, there is limited guidance on how to implement topical ciclosporin (CsA) and corticosteroid treatment into clinical practice. This expert-led consensus provides practical guidance on the management of DED, including when and how to use topical CsA.

Methods

A steering committee (SC) of seven European DED experts developed a questionnaire to gain information on the unmet needs and management of DED in clinical practice. Consensus statements on four key areas (disease severity and progression; patient management; efficacy, safety and tolerability of CsA; and patient education) were generated based on the responses. The SC and an expanded expert panel of 22 members used a nine-point scale (1  =  strongly disagree; 9  =  strongly agree) to rate statements; a consensus was reached if ≥75% of experts scored a statement ≥7.

Results

A stepwise approach to DED management is required in patients presenting with moderate corneal staining. Early topical CsA initiation, alone or with corticosteroids, should be considered in patients with clinical risk factors for severe DED. Patient education is required before and during treatment to manage expectations regarding efficacy and tolerability in order to optimise adherence. Follow-up visits are required, ideally at Month 1 and every 3 months thereafter. Topical CsA may be continued indefinitely, especially when surgery is required.

Conclusion

This consensus fills some of the knowledge gaps in previous recommendations regarding the use of topical corticosteroids and CsA in patients with DED.

Evaluation of Ocular Surface after Cataract Surgery—A Prospective Study

This study evaluated tear film and ocular surface parameters in patients after cataract surgery. Methods: a prospective clinical study included 48 eyes of 48 patients who underwent uncomplicated phacoemulsification performed by one surgeon. Tear break-up time (TBUT), Schirmer’s I test, Cochet–Bonnet esthesiometry and in vivo laser scanning confocal microscopy was carried out and the OSDI questionnaire was filled out. All tests were assessed before and 1 month after the surgery. Results: there were 32 (66.7%) women; 16 (33.3%) men, mean age was 74.08 ± 5.37. Mean TBUT at baseline was 8.6 ± 1.9 s, after the surgery, it was 7.7 ± 2.7 s, p = 0.004. Schirmer’s I test was 8.7 ± 3.9 mm versus 8.1 ± 3.7 mm, p = 0.002. Mean corneal nerve density at baseline was 15.70 ± 2.34 and at the first postoperative month 14.94 ± 1.48 mm/mm², p = 0.02. The OSDI questionnaire score increased from 12.15 ± 10.34 before the surgery to 13.79 ± 10.88 in the first postoperative month, p = 0.001. Conclusions: the ocular surface was affected 1 month after the cataract surgery: TBUT was shorter, Schirmer’s I test and corneal nerve density were decreased while the OSDI score increased.

Hyaluronic Acid and Galacto-Xyloglucan Eyedrop Efficacy in Young-Adult Oral Contraceptive Users of Childbearing Age

To assess the efficacy of 0.4% hyaluronic acid and 0.2% galacto-xyloglucan for the subjective symptoms of dry eye disease and tear film invasive and noninvasive signs in 34 young-adult oral contraceptive users of childbearing age, a prospective, longitudinal, single-blind, clinical study was performed in a population of childbearing-age oral-contraceptive consumers. Subjective dry eye disease questionnaires, and invasive and noninvasive tear film assessments were reported before and after six weeks of hyaluronic acid with galacto-xyloglucan (HA-GX) treatment versus hyaluronic acid alone (HA). HA-GX treatment resulted in a greater decrease in the ocular surface disease index (17.01 ± 11.36 score points, p < 0.01) than the HA variation (11.61 ± 11.18 score points, p < 0.01). The standard patient evaluation of eye dryness also decreased more in the HA-GX group (4.06 ± 5.50 score points, p < 0.01) than in the HA alone group (0.70 ± 3.16, p = 0.21). Regarding noninvasive break-up time (NIBUT), the HA-GX group’s first NIBUT achieved an increase of 1.75 ± 1.16 s, p < 0.01, while the HA-alone group increased by only 0.54 ± 1.01 s, p < 0.01. The HA-GX group’s mean NIBUT reported an increase of 3.72 ± 5.69 s, p < 0.01; however, the HA-alone group achieved 2.19 ± 5.26 s, p = 0.05. Hyaluronic acid in combination with galacto-xyloglucan significantly decreased subjective dry eye disease symptoms and increased first and mean NIBUT compared to hyaluronic acid alone. Galacto-xyloglucan added efficacy in young-adult childbearing-age oral contraceptive users.

Alpha-Glycerylphosphorylcholine and D-Panthenol Eye Drops in Patients Undergoing Cataract Surgery

Cataract surgery is widespread. The surgical procedure is associated with damage to the epithelial barrier and interruption of the corneal innervation. In addition, pathological events sustain signs and symptoms that may persist for a long time. Recently, a fixed combination of alpha-glycerylphosphorylcholine and D-Panthenol (Oftassiale) has been available as eye drops. The present study investigated the effects of an Oftassiale therapy in 20 patients undergoing cataract surgery. A comparison group included 20 patients treated with topical hyaluronic acid. Standard prophylactic and anti-inflammatory treatment was prescribed to all patients. Clinical signs and symptoms were assessed over time. In vivo confocal microscopy (IVCM) was performed accordingly. Oftassiale treatment significantly reduced clinical features and improved IVCM outcomes. In addition, therapy was well-tolerated, and no clinically significant adverse events occurred. In conclusion, this study confirmed that IVCM helps assess the tunnel after cataract surgery due to its ability to provide microscopic details in vivo. Topical therapy with alpha-glycerylphosphorylcholine and D-Panthenol eye drops promoted and stabilized the reepithelialization process. This fixed combination also accelerated and modulated the repair of the corneal innervation. Moreover, this treatment was well-tolerated and safe.