Protecting the Ocular Surface in Cataract Surgery: The Efficacy of the Perioperative Use of a Hydroxypropyl Guar and Hyaluronic Acid Ophthalmic Solution

Role of postoperative lubrication in preventing dry eye after cataract surgery in high- and low-risk patients stratified by ocular surface frailty index

PURPOSE

Symptoms and signs of dry eye can significantly increase after cataract surgery. The present study seeks to investigate the effect of intensive lubrication using Systane HYDRATION multi-dose preservative free (MDPF) eye drops (Alcon Research, Ltd., Fort Worth, Texas, USA) on signs and symptoms of dry eye in the postoperative phase.

METHODS

Patients scheduled for cataract surgery were enrolled in this randomised, investigator-masked study and assigned to one of three groups. The risk of developing dry eye was stratified using the ocular surface frailty index (OSFI). The high risk - standard of care (HR-SOC) and treatment (HR-Treatment) group were the high-risk groups (OSFI 0.3 or greater), and the LR-SOC group was the low-risk group (OSFI less than 0.3). HR-SOC and LR-SOC group received the standard postoperative treatment. In the HR-Treatment group, Systane HYDRATION MDPF was added four times a day for three months after surgery. After the baseline examination prior to cataract surgery, three follow up visits were scheduled one week, one month and three months after surgery. OSDI scores, ocular surface staining, and fluorescein break-up time were assessed at each visit.

RESULTS

Ninety-five patients were included and 83 entered statistical analyses. OSDI increased in all groups after cataract surgery, and it was lowest in the HR-Treatment group three months after the surgery. In addition, fluorescein break-up time tended to be longer and ocular surface staining less in the HR treatment group at three months. However, there was no statistically significant difference between the groups during the three-month visit.

CONCLUSION

In this randomized, examiner-masked trial no statistically significant difference could be found between the groups, but Systane HYDRATION MDPF may have a positive effect after cataract surgery in high-risk groups for dry eye syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06555224.

Safety and Efficacy of Hydroxypropyl Guar-Hyaluronic Acid Dual-Polymer Lubricating Eye Drops in Indian Subjects with Dry Eye: A Phase IV Study

INTRODUCTION

This work aimed to evaluate the safety and efficacy of hydroxypropyl guar-hyaluronic acid (HPG-HA) dual-polymer lubricating drops in Indian subjects with dry eye disease (DED).

METHODS

This prospective, open-label, single-arm, phase IV study was conducted in India.

INCLUSION CRITERIA

Adults (18-65 years) with an average total ocular surface staining (TOSS) score ≥ 4, best-corrected visual acuity of ≥ 20/40 in each eye, tear break-up time (TBUT) ≤ 10 s, and dry eye questionnaire (DEQ-5) score ≥ 6. Subjects received the first dose of HPG-HA eye drops on day 1 and self-administered 1-2 drops four times daily for 90 ± 5 days.

PRIMARY ENDPOINTS

Frequency and characteristics of treatment-emergent adverse events (TEAEs) throughout the study and TOSS score at day 90. Secondary/other endpoints: Dry eye symptoms score (through dry eye questionnaire [DEQ-5]) and TBUT.

RESULTS

Of 175 subjects, 36 (20.6%) had ≥ 1 TEAE, and 27 (15.4%) of this reported ≥ 1 mild drug-related TEAE (eye irritation [n = 9], eye pruritus [n = 8], blurred vision [n = 6], increased lacrimation [n = 4], ocular hyperemia [n = 3], and ocular discomfort [n = 1]). One subject discontinued due to TEAEs, and none led to drug interruptions. No serious adverse events were reported. The mean TOSS score reduced from day 1 (6.12 ± 1.69, OU [both eyes]) to day 90 (2.40 ± 1.97, OU). The mean DEQ-5 score reduced from day 1 (11.50 ± 2.27) to day 90 (5.50 ± 2.50). TBUT increased from day 1 (right eye [OD], 5.70 ± 1.94; left eye [OS], 5.70 ± 1.96) to day 90 (OD, 9.51 ± 3.08; OS, 9.63 ± 3.01).

CONCLUSIONS

HPG-HA dual-polymer eye drop was safe and effective in relieving signs and symptoms of DED over 90 days in Indian subjects.

TRIAL REGISTRATION

Clinical Trial Registry India, CTRI/2022/03/041175.

Evaluation of Two Artificial Tears Containing Hyaluronic Acid for Post Cataract Surgery Dry Eye Disease: A Randomized Controlled Trial

INTRODUCTION

This study compared the efficacy of hydroxypropyl guar (HPG)/hyaluronic acid (HA) and carboxymethylcellulose (CMC)/HA lubricant eye drops for post-cataract surgery dry eye disease (DED).

METHODS

This was a prospective, open-label, assessor-masked, parallel, randomized controlled study. Seventy patients with DED who underwent cataract surgery were randomized in a 1:1 ratio to receive 1-2 drops of HPG/HA or CMC/HA lubricant four times daily for 3 weeks. Efficacy assessments included changes from baseline in corneal fluorescein staining (CFS) score, Ocular Surface Disease Index score, Schirmer's test score (without anesthesia), tear break-up time, and central corneal sensitivity at weeks 1 and 3.

RESULTS

There were 35 patients in each group. The HPG/HA group demonstrated superior improvements in CFS scores (expressed as means and standard deviations) to the CMC/HA group at week 1 ( - 1.0 [1.7] vs. - 0.1 [1.7], p = 0.039) and demonstrated comparable results at week 3 ( - 1.6 [1.8] vs. - 1.3 [1.9], p = 0.552). No statistical differences were observed in other secondary outcomes between groups at weeks 1 and 3 (p > 0.05). Only one adverse event was reported in this study, which occurred in the HPG/HA group. The AE of ocular hypertension was mild, deemed unrelated to the study treatment, and resolved within a week.

CONCLUSIONS

The HPG/HA lubricant eye drops resulted in greater CFS scores at 1 week after treatment compared with CMC/HA drops. The HPG/HA and CMC/HA drops were safe and well tolerated.

CLINICALTRIALS

GOV IDENTIFIER

NCT06221345.

Hyaluronic Acid in Nanopharmaceuticals: An Overview

Hyaluronic acid (HA) is a naturally occurring, long, unbranched polysaccharide that plays a critical role in maintaining skin structure and hydration. Its unique properties make it a valuable component in the field of nanopharmaceuticals. The combination of HA into nanopharmaceuticals enhances its ability to interact with various therapeutic agents, improving the delivery and efficacy of drugs. HA-based nanoparticles, including solid lipid nanoparticles, and polymeric nanogels, offer controlled release, enhanced stability, and targeted delivery of therapeutic agents. These innovations significantly improve therapeutic outcomes and reduce side effects, making HA an essential tool in modern medicine. In general, HA-modified liposomes enhance drug encapsulation and targeting, while HA-modified solid lipid nanoparticles (SLNs) provide a solid lipid core for drug encapsulation, offering controlled release and stability. This article provides an overview of the potential applications and recent advancements of HA in nanopharmaceuticals, emphasizing its significant impact on the evolving field of targeted drug delivery and advanced therapeutic strategies. By delving into the unique properties of HA and its compatibility with various therapeutic agents, this review underscores the promising potential of HA in revolutionizing nanopharmaceuticals.

Outcomes of low-level light therapy before and after cataract surgery for the prophylaxis of postoperative dry eye: a prospective randomised double-masked controlled clinical trial

BACKGROUND

Despite increasing evidence shows that optimising ocular surface before cataract surgery is fundamental in patients with pre-existing dry eye disease (DED) to achieve the desired postoperative outcomes, the prophylactic treatment of healthy patients undergoing surgery aiming at preventing iatrogenic DED is worth investigating.

METHODS

This was a prospective, interventional, randomised, controlled, double-masked clinical trial. Patients were randomly assigned 1:1 to receive either low-level light therapy (LLLT) or sham treatment (LLLT with a power output <30%). Patients underwent two treatment sessions: 7±2 days before cataract surgery (T0) and 7±2 days after (T1). Outcome measures evaluated 30±4 days after surgery (T2) included Ocular Surface Disease Index (OSDI) questionnaire, non-invasive break-up time (NIBUT), tear meniscus height, meibomian gland loss (MGL) and redness score.

RESULTS

Out of 153 patients randomised to receive LLLT (n=73) or sham treatment (n=80), 131 (70 men, 61 women, mean age 73.53±7.29 years) completed regularly the study. Patients treated with LLLT had significantly lower OSDI scores compared with controls at T1 and T2 (respectively, 7.2±8.8 vs 14.8±13.0 and 9.0±9.0 vs 18.2±17.9; both p<0.001), higher NIBUT values at T2 (12.5±6.6 vs 9.0±7.8; p=0.007) and lower MGL Meiboscore values at T1 (1.59±0.70 vs 1.26±0.69; p=0.008). Unlike controls, patients treated with LLLT had significantly lower OSDI scores and higher NIBUT values at T2 compared with T0 (respectively, 9.0±9.0 vs 21.2±16.1; p<0.001 and 12.5±6.6 vs 9.7±7.2; p=0.007).

CONCLUSION

Two sessions of LLLT performed before and after cataract surgery were effective in ameliorating tear film stability and ocular discomfort symptoms.

TRIAL REGISTRATION NUMBER

NCT05754437.

Preventing and Managing Iatrogenic Dry Eye Disease during the Entire Surgical Pathway: A Study Focusing on Patients Undergoing Cataract Surgery

Patient expectations for cataract surgery are continuously increasing, and dry eye disease (DED) represents a major cause of patient dissatisfaction in eye surgery. The present opinion paper aims to provide useful insights to improve the entire pathway of a patient undergoing cataract surgery, from the preoperative setting to the postoperative one. The available evidence from main clinical trials published on this topic is presented in association with experience-based points of view by the authors. Ocular surface disease (OSD) is common in patients presenting for cataract surgery, and more than half of these patients have DED and meibomian gland dysfunction (MGD), even in the absence of symptoms. Therefore, there is a need to encourage preoperative assessments for the risk of DED development or worsening in all patients as a routine approach to cataract surgery. New all-in-one diagnostic machines allow for fast and noninvasive screening of the ocular surface status. Once a preoperative diagnosis of DED/OSD is reached, ocular surface optimization should be obtained before surgery. In the case of unresolved OSD, the decision to delay surgery should be considered. The surgical procedure can be optimized by avoiding large incisions, limiting microscope light intensity and exposure, and avoiding an aspirating speculum or preserved eye drops. Postoperatively, the continued avoidance of preserved agents is advisable, as well as a limited exposure to epitheliotoxic antibiotics and nonsteroidal anti-inflammatory drugs. Short-term, preservative-free, soft corticosteroids may be useful for patients with extensive or persistent inflammation.

Comparison of Two Topical Lubricants on the Corneal Surface Recovery and Patient Discomfort After Photorefractive Keratectomy

INTRODUCTION

This study aimed to compare the effect of two preservative-free (PF) artificial tears, one containing carboxymethylcellulose (CMC) (control group) vs another containing hyaluronic acid and hydroxypropyl guar (HA + HP-guar) (study group), on the healing of the corneal epithelium and the ocular discomfort after bilateral photorefractive keratectomy (PRK) surgery.

METHODS

A total of 68 patients that were scheduled to have PRK to correct myopia were randomized into two groups: 34 patients (68 eyes) in the study group and 34 patients (68 eyes) in the control group. Ocular examinations were performed on postoperative days 1, 4, 7, 30, and 90, evaluating the diameter of the de-epithelized cornea, the fluorescein staining using the Oxford scale, the tear film osmolarity and stability (tear breakup time), and the pain using visual analog scale (VAS).

RESULTS

On postoperative day 4, 97% of the study eyes vs 84.4% of the control eyes were completely re-epithelized (p = 0.01). Less ocular pain was observed on postoperative day 3 in the study group (5.0 (3.0-6.0) vs 6.0 (3.5-7.0), p = 0.03). No differences were observed beyond postoperative day 7 in the healing of the corneal epithelium, non-invasive Keratograph breakup time (NIKBUT), and the self-perceived ocular discomfort between the two groups.

CONCLUSION

The current study shows faster healing of the corneal epithelium and less ocular pain and discomfort in the first days after PRK with the use of topical lubricants containing HA + HP-guar compared to conventional CMC artificial tears, probably due to the different trophic effect of the aforementioned tears on the corneal epithelial cells.

TRIAL REGISTRATION

EudraCT No. 2020-003488-25.

Safe and Effective Management of Dry Eye Symptoms with Hydroxypropyl Guar and Hyaluronic Acid Dual-Polymer Lubricating Eye Drops: A Review of Preclinical and Clinical Studies

Dry eye disease (DED) is a chronic ocular surface disorder often characterized by decreased tear production and rapid tear evaporation that affect tear film stability and homeostasis. The common symptoms of DED include ocular discomfort, visual disturbances, dryness, and itching. Artificial tears are the mainstay of DED management and supplement one or more layers of the tear film. Artificial tear drops are available as a combination of viscosity-enhancing agents (demulcents/lubricants), humectants, and buffers either with or without preservatives. Artificial tears, as a combination of components (polymers/demulcents/viscosity-enhancing agents), can provide synergistic action compared with a single component for the management of multifactorial signs and symptoms of DED. This review describes the formulation components, physicochemical properties, mechanism of action, and summary of preclinical and clinical evidence on the hydroxypropyl guar-hyaluronic acid (HPG-HA) dual-polymer lubricant eye drops (SYSTANE™ HYDRATION). The dual-polymer eye drops consist of dual demulcents (propylene glycol and polyethylene glycol 400) and the polymers hydroxypropyl guar (HPG) and hyaluronic acid (HA). When instilled on the ocular surface, HPG forms a cross-linked gel matrix with borate ions that prolongs the retention of demulcents, thus providing long-lasting lubrication and ocular surface protection. Additionally, HA stabilizes the tear film, increases corneal wettability, and reduces friction during blinks due to its hygroscopic and viscoelastic properties. Preclinical evidence demonstrates that HPG HA dual-polymer lubricant eye drops provide protection against desiccation by cell hydration and surface retention, cell barrier protection, prolonged lubrication, and promotion of corneal re-epithelialization. Clinical scientific evidence demonstrates that HPG HA dual-polymer lubricant eye drops are safe and effective in the management of DED. Specifically, they reduce the signs and symptoms of DED, reduce dry eye symptoms post-cataract surgery, and improve tear film quality in healthy eyes.

Assessment of the eye surface and subjective symptoms after using 0.1% dexamethasone drops with and without preservatives in patients after cataract surgery

Cataract surgery can cause dry eye symptoms. One of the many factors compromising the ocular surface is the use of benzalkonium chloride (BAC)-preserved topical eye drops administered during the postoperative period. In this open-label, prospective, randomized, comparative clinical trial, 40 patients not previously affected by dry eye disease were assigned to receive either preservative-free (PFD) or preserved (PD) dexamethasone 0.1% eye drops for two weeks after a standard phacoemulsification procedure. Fluorescein break-up time, ocular surface staining score, Schirmer test, Ocular Surface Disease Index and anterior chamber (AC) cells were evaluated at baseline prior to the surgery and 2 weeks after surgery. No statistically significant differences in baseline assessments were observed between groups. At week 2, a significant increase in corneal staining scores (p = 0.003) and foreign body sensation (p = 0.04) was observed for the PD group only. The conjunctival staining score was significantly higher in both groups. The mean AC cell grading was higher in the PFD group than in the PD group (0.28 ± 0.30 and 0.07 ± 0.18, respectively; p = 0.013). Preservative-free dexamethasone eye drops after cataract surgery caused milder dry eye symptoms as compared with preserved dexamethasone. The AC inflammation control comparison may require a larger study group. Trial registration: ClinicalTrials.gov identifier NCT05753787, 03/03/2023.

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.

The role of high molecular weight hyaluronic acid in mucoadhesion on an ocular surface model

Hyaluronic acid (HA) is frequently formulated in eye drops to improve the stability of the tear film by hydration and lubrication. Mucoadhesion is related to the ocular residence time and therefore to the effectiveness of the eye drops. The ocular residence time of the HA formulation is correlated with the ability of HA to create specific strong interactions in the ocular surface with the mucus layer, mainly composed of a mixture of secreted mucins (MUC; gel forming MUC5AC and MUC2) and shed membrane-bound soluble mucins (MUC1, MUC4, and MUC16). Dry eye disease (DED) is a multifactorial pathology of the preocular tear film with possible damage to the ocular surface classified in two types: (1) aqueous-deficient dry eye and (2) evaporative dry eye, caused by a decrease in goblet cell density that reduces MUC expression and/or by meibomian gland dysfunction, that results in a drop in the lipidic fraction of the tear film. In this work, the binding affinity between HA and MUC2 has been evaluated with three complementary approaches because the secreted MUCs play a pivotal role in the viscoelastic properties of the tear film: 1. Rheological analysis, measuring the mucoadhesive index and the complex viscosity in relation to MM (Molecular Mass) and concentration; 2. Fluorescence analysis, using a fluorescent hydrophobic probe, to investigate the conformational change of MUC2 during the interaction with the HA polymer; 3. Surface plasmon resonance analysis, used to measure the affinity between MUC2 (immobilized on the surface of a sensor chip) and the HA polymers that flowed on it at the molecular level. For all these tests, the mucoadhesive performance of the natural HA linearly increases with the MM, whereas cross-linked HA and other emollient and gelling agents (formulated in artificial tears) do not show the same mucoadhesive properties (with the exception of xanthan gum). The mucoadhesive performance of high MM HA has also been confirmed in conditions that simulate the pathological condition of the tear film during DED by decreasing the MUC2 or oleic acid concentration. Physico-chemical analysis of a series of marketed artificial tears confirms the linear correlation between the MM of the HA used in the products and the mucoadhesive index measured on the ocular surface model.

Efficacy of vector thermal pulsation treatment in reducing postcataract surgery dry eye disease in patients affected by meibomian gland dysfunction

PURPOSE

To evaluate the effect of a single LipiFlow vector thermal pulsation treatment performed before cataract surgery in reducing signs and symptoms of postoperative dry eye disease (DED) in patients with mild-moderate meibomian gland dysfunction (MGD).

SETTING

Eye Clinic, Careggi Hospital, University of Florence, Florence, Italy.

DESIGN

Prospective unmasked randomized controlled clinical trial.

METHODS

This study included patients affected by age-related cataract and mild-moderate MGD, who were randomized into 2 groups: (1) a single LipiFlow treatment performed at 5 preoperative weeks and (2) warm compresses and eyelid massages twice a day for 1 preoperative month (control group). Noninvasive break-up time (NI-BUT), Schirmer test, Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire, and MG functionality parameters were evaluated at visit 0 (5 preoperative weeks), visit 1 (1 preoperative week), and visit 2 (1 postoperative month). Confocal microscopy of the MG of lower eyelids was performed at visit 0 and visit 2.

RESULTS

A total of 46 patients (46 eyes) were enrolled. In the LipiFlow group (n = 23), NI-BUT, SPEED questionnaire, and MG functionality parameters significantly improved at visit 1 ( P < .05) and visit 2 ( P < .05) compared with baseline and remained stable postoperatively. In the control group (n = 23), they did not significantly improve after treatment, while worsened postoperatively. Moreover, the changes in all parameters from baseline were significantly different between the 2 groups. Confocal microscopy imaging highlighted lower postoperative MG alterations in the LipiFlow group.

CONCLUSIONS

A single preoperative LipiFlow treatment was effective in preventing postcataract surgery DED in patients with mild-moderate MGD. Postoperatively, treated patients displayed a better ocular surface status compared with warm compresses.

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/Trehalose Ophthalmic Solution in Reducing Post-Cataract Surgery Dry Eye Signs and Symptoms: A Prospective, Interventional, Randomized, Open-Label Study

The purpose of this prospective study was to evaluate the efficacy of the perioperative use of a hyaluronic acid (HA) and trehalose ophthalmic solution (Thealoz^® Duo) in reducing post-cataract surgery dry eye signs and symptoms in patients with mild/moderate dry eye disease (DED). One hundred and twenty patients, scheduled for unilateral cataract surgery, were randomized into three groups: (1) group A: HA/trehalose three times/day in the preoperative week and for 5 postoperative weeks; (2) group B: HA/trehalose for only 5 postoperative weeks; (3) group C: no artificial tears. In groups A and B, OSDI (Ocular Surface Disease Index) questionnaire scores were significantly lower than group C at all the postoperative visits; in group A they were significantly lower than group B on the day of surgery, with similar results in the first and fifth weeks after surgery. In groups A and B, break-up time (BUT) was significantly higher than group C during the postoperative period (p ≤ 0.001). In comparison to the preoperative values, BUT in group A remained stable 7 days after surgery; however, in groups B and C, it significantly decreased. In conclusion, the HA/trehalose ophthalmic solution effectively reduced post-cataract surgery DED signs and symptoms in patients with mild/moderate DED, particularly if also administered in the preoperative period.

Applications of Hyaluronic Acid in Ophthalmology and Contact Lenses

Hyaluronic acid (HA) is a glycosaminoglycan that was first isolated and identified from the vitreous body of a bull’s eye. HA is ubiquitous in the soft connective tissues of animals and therefore has high tissue compatibility for use in medication. Because of HA’s biological safety and water retention properties, it has many ophthalmology-related applications, such as in intravitreal injection, dry eye treatment, and contact lenses. Due to its broad range of applications, the identification and quantification of HA is a critical topic. This review article discusses current methods for analyzing HA. Contact lenses have become a widely used medical device, with HA commonly used as an additive to their production material, surface coating, and multipurpose solution. HA molecules on contact lenses retain moisture and increase the wearer’s comfort. HA absorbed by contact lenses can also gradually release to the anterior segment of the eyes to treat dry eye. This review discusses applications of HA in ophthalmology.