Effect of Hypotonic 0.4% Hyaluronic Acid Drops in Dry Eye Patients: A Cross-Over Study

Tear film stability in patients with symptoms of dry eye after instillation of dual polymer hydroxypropyl guar/sodium hyaluronate vs single polymer sodium hyaluronate

PURPOSE

This study evaluated the tear film stability in patients with symptoms of dry eye after installation of dual polymer hydroxypropyl guar/sodium hyaluronate (DPHG/SH) vs single polymer SH.

METHODS

Patients with recently diagnosed mild to moderate dry eye disease (OSDI score 23-32 points) were included. For each patient, the right eye was randomized to receive DPHG/SH or 0.15% SH. Just after the administration of the drop to the right eye, the fellow eye received the other eye drop. The first non-invasive Keratograph first break-up time (NIKBUT), average NIKBUT and tear meniscus height (TMH) were measured before administration of the eye drops, at 1-min, 15 min, 30 min, 60 min, 90 min, and 120 min after instillation.

RESULTS

A total of 29 patients aged 22.8 ± 2.2 years participated in the study (21 women). No differences between the eye receiving DPHG/SH and single polymer SH were observed for the first NIKBUT (p = 0.45) and average NIKBUT (p = 0.24) variables at any time point. Both DPHG/SH and single polymer SH increased the TMH (p of time effect < 0.001), but with no difference between groups (p = 0.95).

CONCLUSION

Both DPHG/SH and single polymer SH solutions provide lubrication of the eye surface, however, with no difference in NIKBUT and TMH evaluations for up to two hours following administration.

A comparison between hyaluronic acid and other single ingredient eye drops for dry eye, a review

Dry eye disease (DED) is a highly prevalent and debilitating condition. Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan that has a long history as a safe and effective DED treatment. HA is frequently used as a comparator when assessing other topical DED treatments. This study aims to summarise and critically evaluate the literature describing all isolated active ingredients that have been directly compared with HA in the treatment of DED. A literature search was conducted in Embase using Ovid on the 24th of August 2021 and in PubMed including MEDLINE on the 20th of September 2021. Twenty-three studies met the inclusion criteria, 21 of which were randomised controlled trials. Seventeen different ingredients representing six treatment categories were compared with HA treatment. Most measures showed no significant difference between treatments, suggesting either equivalency of treatments or that studies were underpowered. Only two ingredients were represented in more than two studies; carboxymethyl cellulose treatment appears equivalent to HA treatment, while Diquafosol treatment appears superior to HA treatment. Drop-frequency varied from one to eight drops daily. No single study explained the choice of drop frequency. Nine studies used a HA concentration of 0.1% which may be below therapeutic levels. Nine studies reported using preserved formulations, six of them with differences in preservatives between the compared groups. Thirteen studies were financially linked to industry. No major complications were reported. Studies were not designed to find differences in treatment effects for different types or severities of DED. HA is a good comparator treatment when assessing other DED treatments, although consensus after decades of use is still lacking for best choice of concentration, molecular weight and drop tonicity. Well-designed studies are needed to determine an evidence-based standard for HA treatment to be used as comparator.

The Molecular Mechanisms Responsible for Tear Hyperosmolarity-Induced Pathological Changes in the Eyes of Dry Eye Disease Patients

Dry eye disease (DED) is a multifactorial disorder of the lacrimal system and ocular surface, characterized by a deficiency in the quality and/or quantity of the tear fluid. The multifactorial nature of DED encompasses a number of interconnected underlying pathologies, including loss of homeostasis, instability and hyperosmolarity of the tears, and the induction and propagation of detrimental inflammatory responses in the eyes, which finally results in the development of neurosensory dysfunction and visual disruption. Dryness, grittiness, scratchiness, discomfort, inflammation, burning, watering, ocular fatigue, pain, and decreased functional visual acuity are common symptoms of DED. Eye dysfunction drastically attenuates patients' quality of life. Accordingly, a better understanding of the pathogenic processes that regulate the development and progression of DED is crucially important for the establishment of new and more effective DED-related treatment approaches, which would significantly improve the quality of life of DED patients. Since the process of osmoregulation, which guards the ocular surface epithelia and maintains normal vision, is affected when the osmolarity of the tears is greater than that of the epithelial cells, tear hyperosmolarity (THO) is considered an initial, important step in the development, progression, and aggravation of DED. In order to delineate the role of THO in the pathogenesis of DED, in this review article, we summarize current knowledge related to the molecular mechanisms responsible for the development of THO-induced pathological changes in the eyes of DED patients, and we briefly discuss the therapeutic potential of hypo-osmotic eye drops in DED treatment.

NOV03 for Signs and Symptoms of Dry Eye Disease Associated With Meibomian Gland Dysfunction: The Randomized Phase 3 MOJAVE Study

PURPOSE

To evaluate the efficacy and safety of NOV03 (perfluorohexyloctane) ophthalmic drop for the treatment of signs and symptoms of dry eye disease (DED) associated with meibomian gland dysfunction (MGD).

DESIGN

Randomized, double-masked, controlled trial.

METHODS

Patients ≥18 years of age with a history of DED and signs of MGD were randomly assigned 1:1 to treatment with NOV03 or hypotonic saline (0.6%) 4 times daily for 8 weeks. The primary sign and symptom endpoints were change from baseline to week 8 in total corneal fluorescein staining (tCFS; National Eye Institute scale) and eye dryness score (0-100 visual analog scale), respectively.

RESULTS

A total of 620 patients (NOV03, n = 311; saline, n = 309) were randomized and treated. Least-squares (LS) mean change from baseline to week 8 was statistically significantly greater for NOV03 compared with saline for both tCFS (-2.3 vs -1.1; LS mean treatment difference, -1.2 [95% confidence interval -1.7 to -0.8]; P < .001) and visual analog scale dryness score (-29.4 vs -19.2; LS mean treatment difference, -10.2 [95% CI -14.4 to -6.1]; P < .001), with statistically significant between-group differences observed as early as week 2. The incidence of ocular adverse events was similar for NOV03 (12.9%) and saline (12.3%). There were no serious adverse events and no adverse events leading to treatment discontinuation.

CONCLUSIONS

In this randomized controlled trial of patients with DED associated with MGD, NOV03 significantly reduced both signs and symptoms of DED compared with hypotonic saline control. NOV03 was well tolerated, with an adverse event profile similar to that of saline.

Short-term changes in tear osmolarity after instillation of different osmolarity eye drops in patients with dry eye

This study investigated short-term changes in tear osmolarity of dry eye patients after using artificial tears containing sodium hyaluronate (SH) at different osmolarities. It comprised 80 patients with dry eye whose tear osmolarity measurement using the TearLab osmolarity system was 300 mOsm/L or greater. Patients who had external ocular disease, glaucoma, or other concomitant ocular pathology were excluded. After being randomly divided into four groups, the participants received different kinds of SH eye drops as follows: Groups 1-3 were given one of three concentrations (0.1%, 0.15%, and 0.3%) of isotonic drops, while Group 4 received 0.18% hypotonic SH eye drops. The tear osmolarity concentrations were evaluated at baseline and again at 1-, 5-, and 10-min after instillation of each eye drop. Tear osmolarity showed a significant decrease after instillation of four types of SH eye drops after up to 10 min compared to baseline. Patients who received hypotonic SH eye drops showed an enhanced decrease in tear osmolarity compared with the isotonic SH eye drops after 1 min (p < 0.001) and 5 min (p = 0.006), but the difference was not significant at 10 min (p = 0.836). The enhanced immediate effect of hypotonic SH eye drops at lowering tear osmolarity in patients with dry eye seems to be limited unless these drops were used frequently.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Perfluorohexyloctane Eye Drops for Dry Eye Disease Associated With Meibomian Gland Dysfunction in Chinese Patients: A Randomized Clinical Trial

Importance

Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye disease (DED). Medical and surgical management for DED is limited; therefore, new treatment options are sought.

Objective

To evaluate the efficacy and safety of SHR8058 (perfluorohexyloctane) eye drops in Chinese patients with DED associated with MGD through 57 days.

Design, Setting, and Participants

This was a randomized, multicenter, double-masked, saline-controlled, phase 3 clinical trial conducted from February 4, 2021, to September 7, 2022. Patients were recruited from the departments of ophthalmology in 15 hospitals in China. Patients with DED associated with MGD were enrolled between February 4 and July 1, 2021. The diagnosis was based on patient complaint of DED symptoms, an ocular surface disease index of 25 or higher, tear film break-up time of 5 seconds or less, Schirmer I test without anesthesia results of 5 mm or more at 5 minutes, total corneal fluorescein staining (tCFS) score of 4 to 11, and an MGD score of 3 or higher.

Interventions

Eligible participants were randomly assigned 1:1 to receive perfluorohexyloctane eye drops or 0.6% sodium chloride [NaCl]) 4 times per day.

Main Outcomes and Measures

The primary end points were the changes from baseline in tCFS and eye dryness scores at day 57.

Results

A total of 312 participants were included in the analysis: 156 (mean [SD] age, 45.4 [15.2] years; 118 female [75.6%]) in the perfluorohexyloctane group and 156 (mean [SD] age, 43.7 [15.1] years; 127 female [81.4%]) in the NaCl group. Both primary end points were achieved, ie, changes from baseline at day 57 of tCFS score (mean [SD], -3.8 [2.7] vs -2.7 [2.8]) and eye dryness score (mean [SD], -38.6 [21.9] vs -28.3 [20.8]) in the perfluorohexyloctane group were superior to the control group, with estimated mean differences of -1.14 (95% CI, -1.70 to -0.57; P < .001) and -12.74 (95% CI, -17.20 to -8.28, P < .001), respectively. Improvements on both end points appeared to be noted on day 29 and day 15, respectively, and maintained through day 57. Compared with the control, perfluorohexyloctane eye drops also alleviated symptoms including pain (mean [SD] tCFS score, 26.7 [23.7] vs -18.7 [22.5]; P = .003), awareness of DED symptoms (mean [SD] tCFS score, -38.1 [25.1] vs -23.7 [27.6]; P < .001), and frequency of dryness (mean [SD] tCFS score, -43.3 [23.8] vs -29.1 [24.8]; P < .001). Treatment-emergent adverse events occurred in 34 participants (21.8%) and 40 participants (25.6%) in the perfluorohexyloctane and control groups, respectively.

Conclusions and Relevance

Results of this randomized clinical trial demonstrate that perfluorohexyloctane eye drops significantly ameliorated the signs and symptoms of DED associated with MGD with a rapid efficacy as well as satisfactory tolerability and safety through 57 days. Findings support the use of these eye drops if results can be confirmed independently and over longer time periods.

Trial Registration

ClinicalTrials.gov Identifier: NCT05515471.

Artificial Tears: A Systematic Review

Artificial tears are the mainstay of dry eye disease management, but also have a role in corneal abrasion and wound healing, pain and inflammation management, conjunctivitis, keratitis, contact lens rewetting and removal, and foreign body removal. A systematic review of randomized controlled trials (PROSPERO registration CRD42022369619) comparing the efficacy of artificial tears in patients with dry eye to inform prescribing choices using Web of Science, PubMed and Medline databases identified 64 relevant articles. There is good evidence that artificial tears improve symptoms of dry eye disease within a month of regular use, applied about four times a day, but signs generally take several months to improve. Not all patients with dry eye disease benefit from artificial tears, so if there is no benefit over a month, alternative management should be considered. Combination formulations are more effective than single active ingredient artificial tears. Artificial tears containing polyethylene glycol are more effective than those containing carboxymethylcellulose/carmellose sodium and hydroxypropyl methylcellulose. Those classified as having evaporative dry eye disease, benefit from artificial tears with liposomes, especially of higher concentration. The data available is limited by the definition of dry eye disease applied in published studies being variable, as well as the disease severity examined and compliance with artificial tears being rarely quantified.

Hyaluronic acid in the treatment of dry eye disease

Dry eye disease (DED) is a highly prevalent and debilitating condition affecting several hundred million people worldwide. Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan commonly used in the treatment of DED. This review aims to critically evaluate the literature on the safety and efficacy of artificial tears containing HA used in DED treatment. Literature searches were conducted in PubMed, including MEDLINE, and in Embase via Ovid with the search term: "(hyaluronic acid OR hyaluronan OR hyaluronate) AND (dry eye OR sicca)". A total of 53 clinical trials are included in this review, including eight placebo-controlled trials. Hyaluronic acid concentrations ranged from 0.1% to 0.4%. Studies lasted up to 3 months. A broad spectrum of DED types and severities was represented in the reviewed literature. No major complications or adverse events were reported. Artificial tears containing 0.1% to 0.4% HA were effective at improving both signs and symptoms of DED. Two major gaps in the literature have been identified: 1. no study investigated the ideal drop frequency for HA-containing eyedrops, and 2. insufficient evidence was presented to recommend any specific HA formulation over another. Future investigations assessing the optimal drop frequency for different concentrations and molecular weights of HA, different drop formulations, including tonicity, and accounting for DED severity and aetiology are essential for an evidence-based, individualized approach to DED treatment.

Cysteamine Eye Drops in Hyaluronic Acid Packaged in Innovative Single-Dose Systems: Stability and Ocular Biopermanence

Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in different tissues and organs causing, among other symptoms, severe ocular manifestations. Cysteamine eye drops are prepared in hospital pharmacy departments to facilitate access to treatment, for which vehicles that provide adequate biopermanence, as well as adaptable containers that maintain its stability, are required. Difficulties related to cysteamine preparation, as well as its tendency to oxidize to cystamine, show the importance of conducting rigorous galenic characterization studies. This work aims to develop and characterize an ophthalmic compounded formulation of cysteamine prepared with hyaluronic acid and packaged in innovative single-dose systems. For this task, the effect of different storage temperatures and the presence/absence of nitrogen on the physicochemical stability of the formulation and its packaging was studied in a scaled manner, until reaching the optimal storage conditions. The results showed that 0.55% cysteamine, prepared with hyaluronic acid and packaged in single-dose containers, is stable for 30 days when stored at −20 °C. In addition, opening vials every 4 h at room temperature after 30 days of freezing maintains the stability of the cysteamine formulation for up to 16 h. Moreover, ocular biopermanence studies were conducted using molecular imaging, concluding that the biopermanence offered by the vehicle is not affected by the freezing process, where a half-life of 31.11 min for a hyaluronic acid formulation stored for 30 days at −20 °C was obtained, compared with 14.63 min for 0.9% sodium chloride eye drops.

Fabrication and Characterization of Tedizolid Phosphate Nanocrystals for Topical Ocular Application: Improved Solubilization and In Vitro Drug Release

Positively charged NCs of TZP (0.1%, w/v) for ocular use were prepared by the antisolvent precipitation method. TZP is a novel 5-Hydroxymethyl-Oxazolidinone class of antibiotic and is effective against many drug-resistant bacterial infections. Even the phosphate salt of this drug is poorly soluble, therefore the NCs were prepared for its better solubility and ocular availability. P188 was found better stabilizer than PVA for TZP-NCs. Characterization of the NCs including the particle-size, PDI, and ZP by Zeta-sizer, while morphology by SEM indicated that the preparation technique was successful to get the optimal sized (151.6 nm) TZP-NCs with good crystalline morphology. Mannitol (1%, w/v) prevented the crystal growth and provided good stabilization to NC₁ during freeze-drying. FTIR spectroscopy confirmed the nano-crystallization did not alter the basic molecular structure of TZP. DSC and XRD studies indicated the reduced crystallinity of TZP-NC₁, which potentiated its solubility. An increased solubility of TZP-NC₁ (25.9 µgmL⁻¹) as compared to pure TZP (18.4 µgmL⁻¹) in STF with SLS. Addition of stearylamine (0.2%, w/v) and BKC (0.01%, w/v) have provided cationic (+29.4 mV) TZP-NCs. Redispersion of freeze-dried NCs in dextrose (5%, w/v) resulted in a clear transparent aqueous suspension of NC₁ with osmolarity (298 mOsm·L⁻¹) and viscosity (21.1 cps at 35 °C). Mannitol (cryoprotectant) during freeze-drying could also provide isotonicity to the nano-suspension at redispersion in dextrose solution. In vitro release in STF with SLS has shown relatively higher (78.8%) release of TZP from NC₁ as compared to the conventional TZP-AqS (43.4%) at 12 h. TZP-NC₁ was physically and chemically stable at three temperatures for 180 days. The above findings suggested that TZP-NC₁ would be a promising alternative for ocular delivery of TZP with relatively improved performance.

Artificial Tears: Biological Role of Their Ingredients in the Management of Dry Eye Disease

Dry eye disease (DED) is the most common ocular surface disease, characterized by insufficient production and/or instability of the tear film. Tear substitutes are usually the first line of treatment for patients with DED. Despite the large variety of tear substitutes available on the market, few studies have been performed to compare their performance. There is a need to better understand the specific mechanical and pharmacological roles of each ingredient composing the different formulations. In this review, we describe the main categories of ingredients composing tear substitutes (e.g., viscosity-enhancing agents, electrolytes, osmo-protectants, antioxidants, lipids, surfactants and preservatives) as well as their effects on the ocular surface, and we provide insight into how certain components of tear substitutes may promote corneal wound healing, and/or counteract inflammation. Based on these considerations, we propose an approach to select the most appropriate tear substitute formulations according to the predominant etiological causes of DED.

A Rapid Corneal Healing Microneedle for Efficient Ocular Drug Delivery

Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the treatment is to develop a minimally invasive, safe, and effective method for ocular drug delivery. Here, a minimally invasive delivery system is reported for treating FK by using a dissolving microneedle (MN)-array patch based on Poly(D,L-lactide) (PLA) and hyaluronic acid (HA). By altering the concentration of PLA, MN patches with excellent properties are modified and optimized. The 30% PLA-HA MN patches penetrate the corneal epithelial layer reversibly with no apparent ocular irritation as well as a short recovery time of less than 12 h, and increase the residence time by 2.5 h in the conjunctival sac, thereby offering higher drug bioavailability. Remarkably, the rabbit model of FK shows that the topical MN(+) patch medication exerts superior therapeutic effects compared with the conventional eye drop formulation, and also presents comparable therapeutic efficacy with that of the clinical mainstay strategy (i.e., intrastromal injection). Therefore, the MN patch, acting as an ocular drug delivery system with high efficacy and ability of rapid corneal healing, promises a cost-effective household solution for the treatment of FK, which may also lead to a new approach for treating FK in clinics.

Synergistic Properties of Arabinogalactan (AG) and Hyaluronic Acid (HA) Sodium Salt Mixtures

The properties of mixtures of two polysaccharides, arabinogalactan (AG) and hyaluronic acid (HA), were investigated in solution by the measurement of diffusion coefficients D of water protons by DOSY (Diffusion Ordered SpectroscopY), by the determination of viscosity and by the investigation of the affinity of a small molecule molecular probe versus AG/HA mixtures in the presence of bovine submaxillary mucin (BSM) by 1HNMR spectroscopy. Enhanced mucoadhesive properties, decreased mobility of water and decreased viscosity were observed at the increase of AG/HA ratio and of total concentration of AG. This unusual combination of properties can lead to more effective and long-lasting hydration of certain tissues (inflamed skin, dry eye corneal surface, etc.) and can be useful in the preparation of new formulations of cosmetics and of drug release systems, with the advantage of reducing the viscosity of the solutions.

Therapie des Trockenen Auges

Die Therapie des Trockenen Auges stellt eine schwierige Aufgabe für den behandelnden Augenarzt dar. Fortschritte in unserem Verständnis der Risikofaktoren, der Ätiologie und Pathophysiologie des Trockenen Auges haben zu einer Weiterentwicklung der Behandlungsstrategien geführt. Vor Beginn der Therapie ist die korrekte Zuordnung in eine wässrig-muzinöse Tränenfilmdysfunktion (Mindersekretion), in eine lipidbedingte Tränenfilmdysfunktion (hyperevaporative Form durch eine abnormen Meibom-Drüsen-Physiologie) oder in eine variable Kombination wichtig. Unter Berücksichtigung aktueller Empfehlungen der DOG, des BVA und des TFOS DEWS II Unterausschusses wurde ein Behandlungsalgorithmus abgeleitet, der ein schrittweises Vorgehen je nach Schweregrad der Erkrankung darstellt.

A Meta-Analysis of the Efficacy of Hyaluronic Acid Eye Drops for the Treatment of Dry Eye Syndrome

Hyaluronic acid (HA) is commonly used for treating dry eye syndrome (DES). This meta-analysis was performed to compare the efficacies of HA- and non-HA-based eye drops, including saline and conventional artificial tears (ATs), for the treatment of dry eye disease. Eight databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, DBpia, KoreaMed, KMBASE, RISS, KISS) were searched for studies comparing the efficacies of HA- and non-HA-based ATs in patients with DES published up to September 2020. Two independent reviewers assessed the quality and extracted the relevant data. The mean differences of Schirmer's (SH) test scores, tear breakup times (TBUT), corneal fluorescein staining scores (Oxford scale, 0-4), and ocular surface disease indexes were calculated. The standard mean difference and 95% confidence interval were calculated using a random effect model. Nineteen studies, including 2078 cases, were included. HA eye drops significantly improved tear production compared with non-HA-based eye drops (standard mean difference (SMD) 0.18; 95% confidence interval (CI) 0.03, 0.33). In a subgroup analysis, the SH test scores and TBUT values after using HA significantly increased compared to those measured after using saline (SMD 0.27; 95% CI 0.05, 0.49 and SMD 0.28; 95% CI 0.03, 0.52, respectively). Based on these results, HA eye drops may be superior to non-HA eye drops including normal saline and ATs. Further research is needed to assess the efficacies stratified by age, treatment duration, the severity of dry eye, and optimal dosages.

Formulation Considerations for the Management of Dry Eye Disease

Dry eye disease (DED) is one of the most common ocular surface disorders characterised by a deficiency in quality and/or quantity of the tear fluid. Due to its multifactorial nature involving several inter-related underlying pathologies, it can rapidly accelerate to become a chronic refractory condition. Therefore, several therapeutic interventions are often simultaneously recommended to manage DED efficiently. Typically, artificial tear supplements are the first line of treatment, followed by topical application of medicated eyedrops. However, the bioavailability of topical eyedrops is generally low as the well-developed protective mechanisms of the eye ensure their rapid clearance from the precorneal space, thus limiting ocular penetration of the incorporated drug. Moreover, excipients commonly used in eyedrops can potentially exhibit ocular toxicity and further exacerbate the signs and symptoms of DED. Therefore, formulation development of topical eyedrops is rather challenging. This review highlights the challenges typically faced in eyedrop development, in particular, those intended for the management of DED. Firstly, various artificial tear supplements currently on the market, their mechanisms of action, as well as their application, are discussed. Furthermore, formulation strategies generally used to enhance ocular drug delivery, their advantages and limitations, as well as their application in commercially available DED eyedrops are described.

Novel Poly(vinylpyrrolidone)-Coated Silicone Contact Lenses to Improve Tear Volume During Lens Wear: In Vitro and In Vivo Studies

Poly(vinylpyrrolidone) (PVP-K90) is widely used to manage dry eye syndrome (DES). The marketed eye drop solutions (high dose) need frequent instillation, affecting the routine lifestyle of patients. PVP-K90-laden contact lenses can be used to overcome the limitations of eye drop solutions (low bioavailability and frequent instillation). However, the conventional methods of PVP-K90 loading show poor loading capacity and short duration of effect. In the present study, we have developed PVP-K90-coated contact lenses via a short curing approach to increase the PVP-K90 loading capacity with a sustained release profile to manage dry eye syndrome. PVP-K90 was loaded by a soaking method (SM-PVP), direct loading (during fabrication, DL-PVP), a combination of soaking and direct loading (DL-SM-PVP), and a novel coating process (SM-PVP-C and DL-SM-PVP-C). The swelling studies suggested improvement in the water uptake (hydration) property of the contact lenses due to the presence of PVP-K90. The optical transparency was within an acceptable range. The in vitro release of PVP-K90 was in the following order: PVP-coated contact lens (168 h) > DL-SM-PVP (168 h) > DL-PVP (96 h) > SM-PVP (72-96 h). PVP-coated contact lenses showed a high burst effect (lubricating effect) and sustained release (3161-448 ng/h between 24 and 168 h) due to high PVP loading/coating in comparison to the uncoated respective contact lenses (964-113 ng/h between 24 and 96 h). In animal studies, the PVP-K90-coated contact lens showed higher tear volume in comparison to the respective uncoated contact lenses and an eye drop solution. This study demonstrates a novel approach of coating a high amount of PVP-K90 on contact lenses for sustained release to manage several ocular diseases like dry eye syndrome, conjunctivitis, and other ocular injuries.

Arabinogalactan and hyaluronic acid in ophthalmic solution: Experimental effect on xanthine oxidoreductase complex as key player in ocular inflammation (in vitro study)

Dry eye syndrome is a common disease associated to eyes inflammation, irritation and tear film instability. The enzymatic complex of xanthine oxidoreductase (XOR) is involved in the generation of reactive oxygen species (ROS) and uric acid that, in the end, can cause reperfusion injuries, irritation and pathological conditions. Furthermore, in the eye, it has been proposed that oxygen free radicals might play a significant role in retinal ischemic damage. A new artificial drop formulation based on arabinogalactan and hyaluronic acid has been proposed in this article. The uric acid and the ROS formation have been monitored. The effect of the arabinogalactan, the hyaluronic acid and their mixture has been studied. The arabinogalactan entails a uric acid and ROS reduction of 27% and 38% respectively; no significant reduction of uric acid or ROS has been observed after the addition of hyaluronic acid alone. Notably the combination of arabinogalactan and hyaluronic acid involves the reduction of uric acid and ROS equal to 38% and 62%, namely. This study demonstrates that this artificial drop formulation can markedly reduce the uric acid and ROS formation in vitro; thus, the use of this formulation may contribute in the resolution of the dry eye syndrome.

Facial paralysis: Clinical practice guideline of the Spanish Society of Otolaryngology

Bell's palsy is the most common diagnosis associated with facial nerve weakness or paralysis. However, not all patients with facial paresis/paralysis have Bell's palsy. Other common causes include treatment of vestibular schwannoma, head and neck tumours, iatrogenic injuries, Herpes zoster, or trauma. The approach to each of these conditions varies widely. The purpose of this guideline is to provide clinicians with guidance on the treatment and monitoring of patients with different causes of facial paralysis. We intend to draft a practical guideline, focusing on operationalised recommendations deemed to be useful in the daily management of patients. This guideline was promoted by the Spanish Society of Otolaryngology and developed by a group of physicians with an interest in facial nerve disorders, including at least one physician from each Autonomous Community. In a question and answer format, it includes 56 relevant topics related to the facial nerve.

Physicochemical Properties of Hyaluronic Acid-Based Lubricant Eye Drops

Purpose

To assess the physicochemical properties of hyaluronic acid (HA)-based artificial tears.

Methods

The average molecular weight (MW) and polydispersion index (PDI) of HA in 18 commercially available artificial tears were determined by light scattering/high-performance liquid chromatography. Osmolality, pH, viscosity, and sodium concentration were determined using an osmometer, pH meter, rheometer, and inductively coupled plasma mass spectrometer, respectively.

Results

The MW of HA varied considerably between formulations. The PDI was >2.0 in two formulations (2.28 and 4.94), suggesting the presence of a copolymer and/or HA size variability. Three formulations exhibited viscosity exceeding the blur threshold at different shear rates. Viscosity at low shear rates was generally highest in formulations containing high-MW HA. Correlations were found between observed viscosity and a predictive/calculated value, except for four copolymer-containing formulations, and osmolality (range, 154–335 mOsm/kg) and sodium concentration (range, 22–183 mM), with two exceptions. Compared with organic osmolytes, adding sodium decreased viscosity, particularly at lower shear rates.

Conclusions

In the context of the literature, our findings suggest that for most patients with dry eye disease, the ideal HA-based artificial tear should include high-MW HA with a low PDI and exhibit enhanced viscosity at low shear rate (without exceeding the blur threshold). The inclusion of synergistic copolymers and a low sodium concentration may increase viscosity, but whether any of these physicochemical properties or correlations can predict clinical efficacy will require further investigation.

Translational Relevance

Understanding the properties of HA-based artificial tears will support the development of unique formulations that target specific ocular surface conditions.

Assessment of Phosphate and Osmolarity Levels in Chronically Administered Eye Drops

Objectives

To assess phosphate and osmolarity levels of chronically administered eye drops commercially available in Turkey.

Materials and Methods

A total of 53 topical eye drops including 18 antiglaucoma drugs, 4 nonsteroidal anti-inflammatory drugs (NSAIDs), 10 corticosteroids, 7 antihistaminics, and 14 artificial tears identified using the Vademecum Modern Medications Guideline (2018) were included in the study. Phosphate levels were assessed using Roche Cobas C501 analyzer (Roche Diagnostics GmbH, Mannheim, Germany) and the respective kits. Osmolarity was assessed using Vescor Vapro 5600 vapor pressure osmometer (Sanova Medical Systems, Vienna, Austria). Mean phosphate and osmolarity levels were obtained after averaging three measurements. Eye drops were categorized as isoosmolar, hypoosmolar and hyperosmolar based on physiologic tear osmolarity range (296.5±9.8 mOsm/L).

Results

The highest phosphate concentration was found in the antiglaucoma group (20.3±35.4 mmol/L), followed by antihistaminics (17.3±17.9 mmol/L), corticosteroids (15.2±19.1 mmol/L), artificial tears (0.8±1.0), and NSAIDs (0.04±0.08). Percentage of medications in the hyperosmolar category was highest in the NSAI group (75%), followed by antihistaminics (43%), corticosteroids (20%), and antiglaucoma drugs (19%). Nearly all of the artificial tear formulations were in the hypoosmolar (71%) or isoosmolar (21%) categories.

Conclusion

Approximately 40% of glaucoma medications and approximately 60% of corticosteroid and antihistaminic medications had a phosphate concentration higher than the physiologic tear phosphate level (1.45 mmol/L).

Comparative study of 0.1% hyaluronic acid versus 0.5% carboxymethylcellulose in patients with dry eye associated with moderate keratitis or keratoconjunctivitis

Background

Eye drops containing 0.1% hyaluronic acid (HA) and 0.5% carboxymethylcellulose (CMC) applied one drop three times a day per affected eye were compared in patients with moderate keratitis or keratoconjunctivitis related to dry eye disease (DED).

Patients and methods

This was a prospective, randomized, multicenter, Phase IIIB noninferiority study, with a single-masked phase in parallel mode with two groups over 84 days. The primary efficacy outcome was change in ocular surface (OS) staining between day 0 (D0) and day 35 (D35). The conjunctiva and cornea were stained with lissamine green and fluorescein. Secondary efficacy measures at day 84 (D84) were OS-staining score (SS), ocular comfort index, tear-film breakup time and how patients and investigators rated treatment efficacy and safety.

Results

At D35, 0.1% HA achieved a 46.6% reduction in OS-SS (−2.03±1.35 points, n=39 patients) and 0.5% CMC treatment, followed by a 34.9% reduction (−1.61±1.69 points, n=38 patients) compared to D0. At D84, the SS difference to D0 improved by −2.58±1.45 points (−59.2%) for 0.1% HA and −2.59±2.27 points (−54.4%) for 0.5% CMC. Ocular comfort-index scores improved, with significantly lower (better) values for stinging and itching on D84 for 0.1% HA. Patients assessed treatment with 0.1% HA as significantly better than 0.5% CMC (Likert scale, 4.82 vs 3.97; P=0.018). Four adverse events (AEs) occurred in four of 41 patients (9.8%) treated with 0.1% HA, and three AEs in two of 39 patients (5.1%) treated with 0.5% CMC. No serious AEs were noted.

Conclusion

DED signs and symptoms of DED significantly improved with both eye drops. OS staining improved >54% at D84. Treatment was well tolerated, with only minor AEs <10%. 0.1% HA and 0.5% CMC were equally safe and effective. Significant and nonsignificant results were constantly in favor of 0.1% HA.

Impact of Hyaluronic Acid-Containing Artificial Tear Products on Reepithelialization in an In Vivo Corneal Wound Model

PURPOSE

To evaluate the effect of 6 commercially available hyaluronic acid (HA)-containing topical artificial tear products on corneal reepithelialization following injury, in an in vivo mouse model.

METHODS

Ninety-six C57Bl/6 mice (16 per treatment group; male to female ratio, 1:1 per group) were anesthetized. Epithelial debridement was performed on 1 cornea per animal, and the debrided eye was imaged. A 30 μL masked test solution containing 1 of 6 artificial tear products was instilled, immediately on debridement, and subsequently, every 2 h, for a total of 4 administrations. At 24 h post debridement, corneas were stained with fluorescein and imaged to calculate corneal healing rate (number of fluorescein-negative corneas).

RESULTS

All 6 artificial tear products used in this study permitted the initial process of corneal wound healing. However, the corneal reepithelialization rate after 24 h was higher with Hydroxypropyl guar (HPG)/HA (53.33%) compared with other HA-containing artificial tear products [HA1 (12.5%), HA2 (26.67%), HA3 (31.25%), HA4 (6.25%), and HA5 (43.75%)]. The average area and percentage area of reepithelialization after 24 h were also higher with HPG/HA compared with other treatment groups.

CONCLUSIONS

Percentage of eyes with complete corneal reepithelialization 24 h post debridement was highest with HPG/HA compared with other HA-containing artificial tear products tested. The results of this study provide additional evidence on the potential benefits of HPG/HA in the management of dry eye and its role in the rapid restoration of a healthy ocular epithelium. However, further studies are required to confirm the effects on human corneal wounds.

Prospective, Randomized, Single Masked, Parallel Study Exploring the Effects of a Preservative-Free Ophthalmic Solution Containing Hyaluronic Acid 0.4% and Taurine 0.5% on the Ocular Surface of Glaucoma Patients Under Multiple Long-Term Topical Hypotensive Therapy

INTRODUCTION

To compare the effects of a preservative-free (PF) ophthalmic solution containing hyaluronic acid (HA) 0.4% and taurine (TAU) 0.5% with those of a PF ophthalmic solution containing HA 0.2% on ocular surface signs, symptoms, and morphological parameters in glaucoma patients under multiple long-term topical hypotensive therapy.

METHODS

Eligible patients underwent evaluation of ocular surface parameters by ocular surface disease index (OSDI) and glaucoma symptom scale (GSS) questionnaires, breakup time test (BUT), Schirmer I test, corneal and conjunctival staining (Oxford scale), and conjunctival in vivo confocal microscopy (Heidelberg Retina Tomograph 3, Heidelberg Engineering GmbH, Heidelberg, Germany). After the baseline visit, patients were randomized to use a PF ophthalmic solution containing HA 0.4% and TAU 0.5%, QID, in both eyes (group 1) or to use a PF ophthalmic solution containing HA 0.2%, QID (group 2) in addition to the ongoing preserved hypotensive treatment. Follow-up visits were scheduled at 30 and 90 days.

RESULTS

Thirty-nine eyes of 39 glaucoma patients were included in the study. At baseline, results of study tests of both groups were similar. After 90 days in group 1 the BUT (p = 0.01), the Oxford score (p = 0.03), the conjunctival goblet cells (CGC) density (p = 0.0005) ,and the two questionnaires score significantly improved (OSDI, p = 0.003; GSS, p = 0.003) compared to baseline values, while in group 2 all these parameters did not differ from baseline (BUT, p = 0.39; Oxford score, p = 0.54; CGC density, p = 0.33, OSDI p = 0.65, GSS, p = 0.25). The BUT and the CGC density were statistically different between groups both at 30 and 90 days (p = 0.04 and p = 0.04, respectively). The Schirmer I test did not statistically change after 90 days in both groups.

CONCLUSIONS

The PF ophthalmic solution with HA 0.4% and TAU 0.5% seems to improve CGC density and reduce signs and symptoms of dry eye in glaucoma patients under long-term multiple preserved hypotensive therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03480295.

Investigating the potential benefits of a new artificial tear formulation combining two polymers

PURPOSE

Artificial tear formulations typically contain a water-soluble polymer to enhance residence time, moisture retention, and binding to the mucin coat of the ocular surface, which facilitate corneal healing. This study investigated the potential advantages of combining carboxymethylcellulose (CMC) and hyaluronic acid (HA) polymers in a single formulation.

MATERIALS AND METHODS

Individual CMC and HA solutions were prepared and tested for bulk viscosity in comparison to a solution that combined CMC and HA. Rheometry determined the differences between solutions at increasing shear rates, simulating eye movement and blinking.

RESULTS

The bulk viscosity of the individual 0.5% CMC and 0.1% HA solutions was 2.5 and 5.7 cP, respectively. The viscosity of the combined solution (13.1 cP) was 60% higher than predicted by additive effects. Rheometry revealed shear rates between 10/second (open eye) and 10,000/second (blinking eye). At these rates, viscosity ranged from 2.7 to 3.5 cP for 0.5% CMC, 2.8 to 6.8 cP for 0.1% HA, and 5.2 to 15.3 cP for the 0.5% CMC-0.1% HA combination. Low-shear viscosity of the CMC-HA combination increased 48% over the sum of the individual solutions, but high-shear viscosity remained virtually unchanged. Data from CMC and HA solutions at higher concentrations were consistent with these results.

CONCLUSION

Combining CMC and HA polymers produced a synergistic increase in low-shear viscosity (which cannot be fully explained by simple molecular entanglement), while the high-shear viscoelasticity of the combined solution remained unaffected. These data suggest that CMC-HA combinations have properties that may be used to formulate artificial tears that optimize ocular retention (through higher low-shear viscosity), while minimizing blur and stickiness during blinking (through lower high-shear viscosity).

Comparison of 0.3% Hypotonic and Isotonic Sodium Hyaluronate Eye Drops in the Treatment of Experimental Dry Eye

PURPOSE

To compare the efficacy of 0.3% hypotonic and isotonic sodium hyaluronate (SH) eye drops in the treatment of experimental dry eye.

METHODS

Experimental dry eye was established in female C57BL/6 mice by subcutaneous scopolamine injection and an air draft. The mice were divided into three groups (n = 15): control, preservative-free 0.3% isotonic SH, and preservative-free 0.3% hypotonic SH. The tear volume, tear film break-up time, and corneal fluorescein staining scores were measured 5 and 10 days after treatment. After conjunctival tissues were excised at 10 days, the levels of interleukin (IL)-6, IL-17, interferon (IFN)-γ, and IFN-γ inducible protein-10 were determined using the multiplex immunobead assay. In addition, PAS staining and flow cytometry were performed to evaluate the counts of conjunctival goblet cells and CD4+ IFN-γ+ T cells.

RESULTS

Mice treated with 0.3% hypotonic SH showed a significant decrease in corneal staining scores (P = 0.04) and the levels of IL-6 (16.7 ± 1.4 pg/mL, P = 0.02) and IFN-γ (46.5 ± 11.5 pg/mL, P = 0.02) compared to mice treated with 0.3% isotonic SH (IL-6; 32.5 ± 8.8 pg/mL, IFN-γ; 92.0 ± 16.0 pg/mL) at day 10. Although no significant difference in CD4+ IFN-γ+ T cell numbers was observed, goblet cell counts were higher in the hyopotonic SH group than in the isotonic SH group (P = 0.02).

CONCLUSIONS

When compared to 0.3% isotonic SH eye drops, 0.3% hypotonic SH eye drops can be more effective by improving corneal staining scores, decreasing inflammatory molecules, and increasing goblet cell counts for experimental dry eye. These data suggest that hypotonic artificial tears may be useful as an adjunctive treatment for inflammatory dry eye.

Comparison of 0.2% and 0.18% hyaluronate eye drops in patients with moderate to severe dry eye with keratitis or keratoconjunctivitis

PURPOSE

Comparison of efficacy and safety of 0.2% and 0.18% hyaluronic acid (HA) eye drops three times a day (tid) in patients with moderate to severe dry eye disease, related to keratitis or keratoconjunctivitis.

PATIENTS AND METHODS

Prospective, multicenter, randomized, single-masked, phase IIIb, noninferiority study (0.2% HA vs 0.18% HA) in two parallel groups over a period of 84 days. N=70 patients were evaluated. Primary efficacy outcome was ocular surface (OS) staining change on day 35 (D35), compared to baseline. Fluorescein and lissamine green were used for staining of cornea and conjunctiva. Secondary efficacy outcome included tear film breakup time, OS staining score on day 84 (D84), ocular comfort index, as well as patients' and doctors' evaluation.

RESULTS

Compared to day 0 (D0), 0.2% HA achieved a 47.7% reduction in staining score (-3.00±2.81 [standard deviation] points, n=38 patients) at D35; 0.18% HA showed a 41.2% reduction (-2.59±2.20 [standard deviation] points, n=32 patients). Statistical analysis showed noninferiority in efficacy of 0.2% HA compared to 0.18% HA on D35. At D84, the reduction in staining score had further increased to 64.5% for 0.2% HA and to 56.4% for 0.18% HA. Both eye drops improved tear film breakup time and ocular comfort index values. Investigators and patients assessed both treatments with 5 of 7 points (Likert Scale, medians). The rate of adverse events (AE) was 2.3% for 0.2% HA and 7.1% for 0.18% HA with no serious AE.

CONCLUSION

0.2% and 0.18% HA eye drops significantly improved signs and symptoms of dry eye disease and were well tolerated with few AEs. Noninferiority of 0.2% HA compared to 0.18% HA was demonstrated for reduction of OS lesions. In some parameters, there was a nonsignificant trend in favor of 0.2% HA concentration.

Hyaluronan as a promising excipient for ocular drug delivery

Hyaluronan (HA) is a naturally occurring polysaccharide and well known for its exceptional properties such as high biocompatibility and biodegradability, along with a low immunogenicity. Besides its use for various biomedical applications it recently came into focus as a favorable excipient for the formulation of various ocular therapeutics. This review article summarizes the ocular distribution of HA and its most heavily investigated binding protein "cluster of differentiation 44" (CD44) which is the rationale for the clinical use of HA, primarily as an additive in ocular applications ranging from eye drops to contact lenses. Moreover, examples will be given for using HA in various pre-clinical approaches to generate entirely new therapeutics, most notably in the field of nanotechnology.

Comparison of the Anti-Inflammatory Effects of Artificial Tears in a Rat Model of Corneal Scraping

PURPOSE

Artificial tears (ATs) are used routinely to alleviate the symptoms of mild to moderate dry eye. Preservative-free cationic emulsions (eg, Cationorm(®)) are an innovative approach for the management of signs and symptoms of dry eye. The aim of the present exploratory experiment was to evaluate the efficacy of this cetalkonium chloride (CKC)-containing cationic emulsion on debrided cornea and to characterize its effects on scraping-induced inflammation.

METHODS

Four ATs were assessed in a rat model of corneal scraping. The upper part of the corneal epithelium was scraped before a 5-day treatment, followed by clinical evaluations and fluorescein staining to evaluate cornea recovery. The anti-inflammatory efficacy of the ATs was assessed in vivo and in vitro.

RESULTS

In vivo confocal microscopy (IVCM) revealed a trend toward better corneal clinical signs (lower IVCM scores) for the animals treated with the unpreserved ATs. Benzalkonium chloride treatment decreased goblet cell count by 37.5%. While the soft-preserved Systane Balance(®) and Optive(®) and the preservative-free Vismed(®) had no effect on the goblet cell count, Cationorm increased this count by almost 40%. Interestingly, inflammatory cell infiltration in the stroma was at its lowest following treatment with the preservative-free Cationorm. Cationorm is also the only AT decreasing IL6- and IL8-stimulated secretion by 59% and 74%, respectively.

CONCLUSION

By restoring an adequately hydrated ocular surface environment, the different ATs promote corneal epithelium healing. These data position Cationorm as a promising AT for the management of signs and symptoms of dry eye in patients with mild to moderate dry eye disease presenting chronic subclinical levels of ocular inflammation.

Osmolarity of prevalent eye drops, side effects, and therapeutic approaches

PURPOSE

Little is known about how the osmolarity of ophthalmic formulations affects the ocular surface. Because hyperosmolar eye drops could be therapeutic for treating corneal edema, this article presents an ex vivo model of corneal edema for testing ophthalmic drugs based on their osmolarity. The respective osmolarity of common eye drops found in the German market is also analyzed here.

METHODS

For modeling corneal edema, an Ex Vivo Eye Irritation Test was used to simulate an ocular anterior chamber with a physiological corneal barrier. To induce corneal edema, the anterior chamber was supplied with a hypoosmolar medium (148 mOsm/L) for 24 hours. Preserved and preservative-free 5% sodium chloride (hyperosmolar Omnisorb and Ocusalin 5% UD) were used for 1 hour, on 5 corneas each, to test their efficiency to reduce corneal edema in this model. Corneal thickness was determined by optical coherence tomography. Osmolarity of 87 common eye drops was measured by freezing point osmometry.

RESULTS

Ex vivo, the tested hypoosmolar condition induced corneal edema from 450 μm (±50 μm) at baseline to 851 μm (±94 μm, P < 0.0001). Omnisorb and Ocusalin 5% UD significantly reduced the corneal thickness by 279 μm (±28 μm, P < 0.001) for Omnisorb and 258 μm (±29 μm, P < 0.001) for Ocusalin 5% UD. Forty-three (49%) of the tested products had an osmolarity below and 44 (51%) above the physiological tear osmolarity of 289 mOsm/L. Osmolarity values of less than 200 mOsm/L were found in lubricant drops. The highest osmolarity was detected in Omnisorb (1955 mOsm/L).

CONCLUSIONS

The Ex Vivo Eye Irritation Test has proven to be a reliable novel model of corneal edema for evaluating osmotic eye drops. Osmolarity measurements revealed a wide range from hypotonic to hypertonic formulations for commonly marketed ophthalmic drugs.

Isotonic Glycerol and Sodium Hyaluronate Containing Artificial Tear Decreases Conjunctivochalasis after One and Three Months: A Self-Controlled, Unmasked Study

Dry eye complaints are ranked as the most frequent symptoms of patients visiting ophthalmologists. Conjunctivochalasis is a common dry eye disorder, which can cause an unstable tear film and ocular discomfort. The severe conjunctivochalasis characterized by high LId-Parallel COnjunctival Folds (LIPCOF) degree usually requires surgical intervention, where a conservative therapy would be highly desirable. Here we examined the efficacy of a preservative-free, inorganic salt-free unit-dose artificial tear, called Conheal containing isotonic glycerol and 0.015% sodium hyaluronate in a prospective, unmasked, self-controlled study involving 20 patients. The regular use of the glycerol/hyaluronate artificial tear in three months caused a significant improvement in the recorded parameters. Conjunctivochalasis decreased from a mean LIPCOF degree of 2.9±0.4 on both eyes to 1.4±0.6 on the right (median decrease of -2 points, 95% CI from -2.0 to -1.0), and to 1.4±0.7 on the left eye (median decrease of -1 points, 95% CI from -2.0 to -1.0) (p<0.001 for both sides). The tear film breakup time (TFBUT) lengthened from 4.8±1.9 seconds on both eyes to 5.9±2.3 seconds (mean increase of 1.1 seconds, 95% CI from 0.2 to 2.0) and 5.7±1.8 seconds (mean increase of 0.9 seconds, 95% CI from 0.3 to 1.5) on the right and left eyes, respectively (p_{right eyes} = 0.020, p_{left eyes} = 0.004). The corneal lissamine staining (Oxford Scheme grade) was reduced from 1.3±0.6 on the right and 1.4±0.6 on the left eye significantly (p<0.001) to 0.3±0.4 and 0.2±0.4 on the right and the left eyes. The Ocular Surface Disease Index (OSDI) questionnaire score indicating the subjective complaints of the patients also decreased from a mean value of 36.2±25.3 to 15.6±16.7 (p<0.001). In this study, the artificial tear, Conheal decreased the grade of the conjunctivochalasis significantly after one month of regular use already, from the LIPCOF degree 3, considered as indication of conjunctival surgery, to a LIPCOF degree 2 or lower requiring a conservative therapy. Our results raise the possibility that vision-related quality of life can be significantly improved by conservative therapies even in severe conjunctivochalasis.

Effects of a Hyaluronic Acid/Hydroxypropyl Guar Artificial Tear Solution on Protection, Recovery, and Lubricity in Models of Corneal Epithelium

PURPOSE

Hydroxypropyl guar (HPG) and hyaluronic acid (HA) have been individually shown to improve dry eye symptoms. The purpose of this in vitro study was to assess the potential benefits of a new lubricant eye drop formulation containing the demulcents propylene glycol and polyethylene glycol and an HA/HPG dual polymer in models of the human corneal epithelium.

METHODS

Cultured human corneal epithelial or corneal-limbal epithelial cells were treated with the HA/HPG dual-polymer formulation or single-polymer formulations containing either HPG or HA. Desiccation protection by cell hydration and surface retention was assessed using cell viability assays. Sodium fluorescein permeability, transepithelial resistance, and cell viability assays were conducted using pretreated cells exposed to a surfactant/detergent insult to evaluate cell and cell barrier protection. Surface lubricity was assessed in tribological experiments of pericardium-pericardium friction.

RESULTS

Hydration protection against desiccation and protection by surface retention were significantly greater with the HA/HPG formulation versus HPG or HA (P<0.001) alone and with HPG versus HA (P ≤ 0.016). Fluorescein permeability and transepithelial resistance assays demonstrated significantly better cell and barrier protection from surfactant insult with HA/HPG versus the single-polymer formulations (P ≤ 0.01). After insult, there were markedly more viable cells evident with HA/HPG compared with HPG or HA alone. HA/HPG and HPG reduced surface friction to a greater extent than HA (P ≤ 0.02) and maintained lubricity after the formulations were rinsed away.

CONCLUSIONS

HA/HPG provided effective hydration and lubrication and demonstrated prolonged retention of effect. HA/HPG may potentially promote desiccation protection and retention on the ocular surface.

Efficacy of hypotonic 0.18% sodium hyaluronate eye drops in patients with dry eye disease

PURPOSE

The aim of this study was to evaluate the efficacy of hypotonic 0.18% sodium hyaluronate (SH) eye drops under the clinical settings of the dry eye workshop treatment guideline for mild dry eye disease (DED).

METHODS

This analysis included 60 patients with DED. Patients with level 1 DED were treated with either isotonic 0.1% SH (group 1) or with hypotonic 0.18% SH eye drops (group 2). Patients with level 2 DED were treated with 0.1% fluorometholone, 0.05% cyclosporine A, and either isotonic 0.1% SH (group 3) or hypotonic 0.18% SH (group 4) eye drops. Tear film breakup time (TBUT), Schirmer test, corneal staining with fluorescein, and ocular surface disease index score were recorded at baseline, 1 month, and 3 months after treatment.

RESULTS

In group 2, TBUT at 3 months (P = 0.03) and corneal staining scores at 1 and 3 months (P ≤ 0.03) were significantly improved after the treatment compared with baseline scores, whereas these parameters were not changed during the follow-up period in group 1. In groups 3 and 4, TBUT and corneal staining scores at 1 and 3 months, and ocular surface disease index score and Schirmer test results at 3 months after the treatment showed significant improvements compared with the baseline score (P < 0.05). Group 4 patients showed an extended TBUT and an improved corneal staining score (P ≤ 0.01) at 3 months after treatment, compared with the values of group 3.

CONCLUSIONS

Hypotonic 0.18% SH eye drops seemed to be effective in improving tear film stability and ocular surface integrity compared with isotonic 0.1% SH eye drops in patients with mild DED.

Use of preservative-free hyaluronic acid (Hylabak(®)) for a range of patients with dry eye syndrome: experience in Russia

Artificial tear preparations are important in the management of dry eye syndrome. We present the findings from four recently published studies conducted in Russia assessing Hylabak(®) (marketed as Hyabak(®) in Europe), a preservative-free hyaluronic acid preparation, for the treatment of dry eye syndrome. All studies had an open, noncomparative design, but one compared the findings with those from 25 patients treated with Tear Naturale(®) in previous studies. A total of 134 children and adults were enrolled, and the etiologies of dry eye syndrome included contact lens use, intensive office work, adenovirus eye infection, postmenopausal status, persistent meibomian blepharitis, Sjögren's syndrome, phacoemulsification with intraocular lens implantation, and refractive surgery. The patients were treated with Hylabak for 2 weeks to 2 months. All studies showed that Hylabak resulted in marked improvement as assessed by subjective sensations/complaints, Schirmer's test, Norn's test, impression cytology and biomicroscopy, staining, and tear osmolarity. Greater benefits were also reported compared with Tear Naturale, including a faster onset of action. Hylabak was well tolerated. In conclusion, Hylabak provided rapid and safe relief from the signs and symptoms of dry eye syndrome, as well as improvement in objective measures, in a wide range of patients.

Purification and biocompatibility of fermented hyaluronic acid for its applications to biomaterials

Background

Hyaluronic acid (HA) is of importance due to its diverse applications in pharmaceuticals and medical devices such as dermal filler, adhesion barriers, carrier for cells and bioactive molecules as well as scaffold biomaterials for tissue engineering. Evaluations of purification and biocompatibility of HA are required for its applications to biomaterials.

Results

After synthesizing HA by fermentation of streptococcus zooepidemicus for 25 hr, extensively purification of the fermented broth was performed to remove impurities using a filtration process for insoluble components and cells, and diverse adsorbents for soluble impurities. Its in vitro biocompatibility has been evaluated by measurement of cell counting and assay of cell live and dead. 60% yield of white HA powder was obtained, having 15–17 dL/g intrinsic viscosity with a molecular weight of approximately 1,000 kDa. While low molecular weight impurities and insoluble impurities were successfully removed using a ultrafiltration membrane with 50 KDa molecular weight cut, endotoxins, high molecular weight proteins and nucleic acids were removed from the broth by employing adsorbents such as alumina and activated carbons. Alumina showed the best results for the removal of endotoxins, all of the activated carbons were very effective in the removal of high molecular weight proteins and nucleic acids. The purified HA solution showed excellent cell compatibility with no cell damages as observed by both measurement of cell proliferation and observation of cell viability.

Conclusions

We obtained high molecular weight HA with excellent biocompatibility as judged by both measurement of cell proliferation and viability, indicating high possibility of its applications to biomaterials.

Effect of hypotonic 0.18% sodium hyaluronate eyedrops on inflammation of the ocular surface in experimental dry eye

PURPOSE

To investigate the efficacy of hypotonic 0.18% sodium hyaluronate (SH) eyedrops in a mouse model of experimental dry eye (EDE).

METHODS

EDE was induced in C57BL/6 mice by a subcutaneous scopolamine injection and an air draft. The mice were divided into 4 groups according to topical treatment regimens: EDE control, isotonic 0.5% carboxymethycellulose (CMC), isotonic 0.1% SH, and hypotonic 0.18% SH. Tear volume, corneal smoothness, and corneal staining scores were measured at 5 and 10 days of EDE. Multiplex immunobead assay, immunohistochemistry, and flow cytometry for proinflammatory cytokines, chemokines, and inflammatory molecules were performed at 10 days of EDE.

RESULTS

The 0.18% SH group had a significantly lower corneal smoothness and staining scores than the 0.5% CMC and 0.1% SH groups at 10 days of EDE (P<0.05). The 0.18% SH group showed significantly low levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, monokine induced by interferon-γ, and interferon-γ-inducible protein 10 compared with the other groups (P<0.05). The mean percentages of CD4(+)CXCR3(+), CD40(+), and CD44(+) cells in the conjunctiva were significantly lower in the 0.18% SH group than in the other groups (P<0.05). In addition, the 0.1% SH group showed lower levels of TNF-α and IL-1β and percentages of CD40(+) and CD44(+) cells than the EDE and 0.5% CMC groups.

CONCLUSIONS

Hypotonic 0.18% SH eyedrops are more effective in improving ocular surface irregularity and staining and decreasing inflammatory cytokines, chemokines, and cells on the ocular surface compared with isotonic 0.5% CMC or 0.1% SH eyedrops in the treatment of EDE.

Autologous serum eye drops diluted with sodium hyaluronate: clinical and experimental comparative study

PURPOSE

To assess the efficacy of sodium hyaluronate as vehicle for diluting autologous serum.

METHODS

The concentration and temporal stability of EGF, TGF-β, PDGF-AB and albumin in fresh and frozen samples of autologous serum diluted with sodium hyaluronate and saline solution, as well as the pH, osmolarity and density was studied. In parallel, the clinic effects of autologous serum diluted to 20% with sodium hyaluronate were compared with another solution of autologous serum diluted to 20% with saline in a prospective, comparative, randomized and double-blind study in 26 patients (52 eyes) with Sjögren syndrome. Patients underwent a complete ophthalmic assessment including tear film evaluation and corneal and conjunctival impression cytology at the beginning of the study and 2 months later.

RESULTS

The growth factor (GF) concentration remained stable during 1 month at 4°C both in fresh and defrosted samples without any differences being found between both preparations. No differences were found related to osmolarity, pH and density between these preparations before and after frosting. Autologous serum diluted with sodium hyaluronate caused a significant improvement of the tear film stability, fluorescein and rose Bengal stain, break-up time, corneal and conjunctival squamous metaplasia as well as in the patient subjective perception.

CONCLUSIONS

Sodium hyaluronate is an excellent vehicle for diluting autologous serum due to the gradual release of GF and increasing their duration and effect on the ocular surface. Preparations diluted with sodium hyaluronate are better tolerated by patients and require a lower number of drops administrations.

Assessment of tear osmolarity and other dry eye parameters in post-LASIK eyes

PURPOSES

To assess the tear osmolarity using the TearLab device after laser in situ keratomileusis (LASIK) and to compare the values with those obtained by traditional tear film tests before and after the procedure.

METHODS

Thirty eyes of 15 refractive surgery candidates (5 men and 10 women of mean age: 30.55 ± 11.79 years) were examined. Using a special questionnaire (Ocular Surface Disease Index), subjective dry eye complaints were evaluated, and then, the tear osmolarity was measured with the TearLab system (TearLab Corporation) and conventional dry eye tests were carried out. Examinations were performed preoperatively and at 1, 30, and 60 days after the surgery.

RESULTS

The mean value of tear osmolarity was 303.62 ± 12.29 mOsm/L before the surgery and 303.58 ± 20.14 mOsm/L at 60 days after the treatment (P = 0.69). Mean lid parallel conjunctival folds value was 0.68 ± 0.68 before the procedure and 0.58 ± 0.65 subsequent to surgery (P = 0.25). Meibomian gland dysfunction was not detected. No significant deviation was observed in the values of Schirmer test, corneal staining, tear break-up time, and lid parallel conjunctival folds when compared with postoperatively obtained values during the follow-up period (P > 0.05).

CONCLUSIONS

During LASIK flap creation, intact corneal innervation is damaged, and the ocular surface lacrimal functional unit can be impaired. In our study, no abnormal dry eye test results were observed before or after the procedure. Based on our results, LASIK treatment is safe for dry eye involving the administration of adequate artificial tears for a minimum of 3 months.

Effectiveness of sodium hyaluronate eye gel in patients with dry eye disease: a multi-centre, open label, uncontrolled study

Objective: To assess the effectiveness of sodium hyaluronate Eye Gel in Dry Eye Disease (DED) patients

Methods: A Multi-center, Open-label, Uncontrolled clinical trial was conducted in different centers of Pakistan. Ten ophthalmologists conducted this study in which 250 diagnosed patients with dry eye disease were enrolled after obtaining a written informed consent. Ten patients were dropped out during the study period. All patients were assessed as per following criteria for enrolling a patient into the study: Tear Film Break – up time (TBUT) ≤ 10 seconds, Schirmer Test – 1 ≤ 6 mm / 5 minutes and Positive Corneal Staining. Tolerability/safety was assessed by the monitoring and recording of all adverse events. The physical examination was done at baseline, 4^th week and 8^th week.

Results: The mean age of the patients was 43.4 ±17.8 years and out of 240 patients 117 (48.7%) were males and 123 (51.3%) females. The Mean duration of symptoms was 19.3±23.9. At the initial visit the foreign body sensation was 50.6%, itching 35.9%, burning 50.6%, watering 42.9%, photophobia 25.3% and feeling of dryness in 14.7% of patients. After 4 weeks (2^nd visit), the symptoms were decreased to 47.1% foreign body sensation, 32.4% itching, 48.2% burning, 41.8% watering, 25.3% photophobia and 13.5% feeling of dryness. At the 3^rd visit (after 8 weeks) the frequency of symptoms were: 45.3% foreign body sensation, 30.6% itching, 45.9% burning, 40% watering, 24.7% photophobia and 13.5% feeling of dryness.

Conclusion: Sodium Hyaluronate can provide a suitable alternate in the treatment of dry eye disease due to its reported efficacy on foreign body sensation, itching, burning, watering, photophobia and feeling of dryness,