Extending the Duration of Tear Film Protection in Dry Eye Syndrome: Review and Retrospective Case Series Study of the Hydroxypropyl Cellulose Ophthalmic Insert

Variability in the substitution pattern of hydroxypropyl cellulose affects its physico-chemical properties

Hydroxypropyl cellulose (HPC) is a water-soluble polymer with many applications in food, pharmaceutical, medical, or paints industries. Past studies have reported that differences in functionality can occur between products of similar pharmaceutical grades. Understanding the origin of these differences is a major challenge for the industry. In this work, the structure and physico-chemical properties of several HPC samples of the same commercial grade were studied. Structural analysis by NMR and enzymatic hydrolysis were performed to study molar substitution and distribution of substituents along the polymer chain respectively. Water-polymer interactions, surface properties as well as rheological and thermal behavior were characterized to tentatively correlate them with the structure, and gain new insights into the structure-function relationship of this polymer. The differences in structure revealed between the samples affect their properties. The unexpected behavior of one sample was attributed to a more heterogeneous substitution pattern, with the coexistence of highly and weakly substituted regions along the same polymer chain. The more block-like distribution of substituents has a great effect on the clouding behavior and surface tension reduction ability of the polymer.

Enhanced topical corticosteroids delivery to the eye: A trade-off in strategy choice

Topical corticosteroids are the primary treatment of ocular inflammation caused by surgery, injury, or other conditions. Drug pre-corneal residence time, drug water solubility, and drug corneal permeability coefficient are the major factors that determine the ocular drug bioavailability after topical administration. Although growing research successfully enhanced local delivery of corticosteroids utilizing various strategies, rational and dynamic approaches to strategy selection are still lacking. Within this review, an overview of the various strategies as well as their performance in retention, solubility, and permeability coefficient of corticosteroids are provided. On this basis, the tradeoff of strategy selection is discussed, which may shed light on the rational choice and application of ophthalmic delivery enhancement strategies.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.

Artificial tears potpourri: a literature review

Numerous brands and types of artificial tears are available on the market for the treatment of dysfunctional tear syndrome. Past literature has focused on comparing the components of these products on patient’s clinical improvement. The wide array of products on the market presents challenges to both clinicians and patients when trying to choose between available tear replacement therapies. Different formulations affect patients based on etiology and severity of disease. In order to provide an unbiased comparison between available tear replacement therapies, we conducted a literature review of existing studies and National Institutes of Health clinical trials on commercially available, brand name artificial tears. Outcomes evaluated in each study, as well as the percent of patients showing clinical and symptomatic improvement, were analyzed. Fifty-one studies evaluating different brands of artificial tears, and their efficacy were identified. Out of the 51 studies, 18 were comparison studies testing brand name artificial tears directly against each other. Nearly all formulations of artificial tears provided significant benefit to patients with dysfunctional tear syndrome, but some proved superior to others. From the study data, a recommended treatment flowchart was derived.

Changes in functional visual acuity and ocular wavefront aberration after administration of eye ointment

PURPOSE

To investigate the influence of an eye ointment on functional visual acuity (FVA) and ocular wavefront aberration.

METHODS

In 11 healthy volunteers (6 men and 5 women), visual function parameters, such as FVA, visual maintenance ratios (VMR), and minimal visual acuity (minVA), were assessed by the FVA measurement system before and 2, 5, 10, 20, 30, 40, 50, 60, 90, 120, 180, and 240 min after administration of ofloxacin eye ointment. Ocular aberration was also measured, and the root mean square (RMS) of second-, third-, fourth-, and total higher-order aberrations was determined. The time course of changes in each parameter was statistically analyzed by using repeated-measures analysis of variance and the Dunnett post hoc test, and relationships between visual function and ocular aberration parameters were also analyzed by the Pearson correlation test.

RESULTS

FVA, VMR, and minVA showed significant deteriorations at 2-, 5-, 10-, and 20 min after administration of eye ointment compared with the baseline values (P<0.05). All components of ocular wavefront aberration such as second-, third-, fourth-, and total higher-order RMS significantly increased at 2- and 5 min after the administration of eye ointment compared with the baseline values (P<0.05). In addition, deteriorations of these visual function parameters were significantly correlated with reduced blink numbers (Pearson's correlation coefficient; r=- 0.76, P=0.017 for FVA, r=0.79, P=0.013 for VMR, and r=-0.62, P=0.040 for minVA), and VMR was significantly related with changes in second-order RMS (r=-0.60, P=0.049).

CONCLUSIONS

Eye ointment significantly reduced visual function for at least 20 min. Especially, minVA was worse than 0.155 logMAR, which is legally required for driving, for 3 h after the administration. In addition, increases in lower-order aberration and low blink rates were associated with the degradation of visual function.

Review of hydroxypropyl cellulose ophthalmic inserts for treatment of dry eye

Dry eye syndrome is a prevalent disease that affects visual acuity, activities of daily living, and quality of life. A number of contributory factors affect the severity of dry eye syndrome, including autoimmune disease, environmental surroundings, contact lens use, hormonal changes, anatomical features, chronic inflammation, infections, and iatrogenic factors, such as medications or surgery. Symptoms may include intermittent or constant blurry vision, discomfort, burning, foreign body sensation, hyperemia, dryness, and photophobia. The severity of dry eye syndrome can range from very mild disease to extremely severe cases with vision-threatening consequences. A variety of dry eye treatment modalities exist to address the different causes, symptoms, and consequences of ocular surface disease, including artificial tears, lubricating gels, ophthalmic inserts, anti-inflammatory drops, and surgical procedures. In this paper, an assortment of literature pertaining to the treatment of dry eye syndrome, in particular hydroxypropyl cellulose ophthalmic inserts, is reviewed. These inserts can be used effectively as monotherapy, or in conjunction with other therapies, and should be considered in the treatment of dry eye syndrome.

Impact of dry eye disease and treatment on quality of life

PURPOSE OF REVIEW

Recent increased awareness of dry eye disease (DED) by both clinicians and patients has been accompanied by improved recognition that it is a chronic disorder often requiring long-term management. DED, frequently associated with symptoms of discomfort and visual disturbance, also impairs quality of life (QoL), including aspects of physical, social, and psychological functioning. This review summarizes the available research on the impact of DED and its treatment on measures of QoL.

RECENT FINDINGS

A relative dearth of data supporting the effectiveness of DED treatments as assessed by QoL measures exists. Both cyclosporine ophthalmic emulsion 0.05% and hydroxypropyl cellulose ophthalmic inserts have been associated with improvements in Ocular Surface Disease Index scores, a disease-specific measure of QoL, and with enhancement of patients' ratings regarding their ability to perform activities of daily living.

SUMMARY

Because there is a lack of concordance between symptoms and diagnostic measures of DED, QoL measures provide clinicians a valuable tool for assessing the burden of disease as well as response to treatment. Such measures should be employed in clinical practice and in future trials of treatment modalities.

Improved signs, symptoms, and quality of life associated with dry eye syndrome: hydroxypropyl cellulose ophthalmic insert patient registry

OBJECTIVES

To evaluate the acceptability, ease of use, and efficacy of hydroxypropyl cellulose ophthalmic inserts in reducing signs and symptoms of moderate-to-severe dry eye syndrome (DES), and improving quality of life (QoL) and activities of daily living (ADL).

METHODS

The multicenter, prospective, open-label, 4-week registry comprised 520 patients with bilateral DES and a history of artificial tear use, or a desire to use artificial tears within the previous week. Visit 1 encompassed a clinical evaluation and symptom and QoL questionnaires, including the Ocular Surface Disease Index. Patients were trained to use inserts, which were used once daily, thereafter, as monotherapy or with existing therapy. At visit 2, clinical evaluation and questionnaires evaluated changes in signs, symptoms, ADL, and QoL. Adverse events were monitored throughout the registry.

RESULTS

There were 418 (80.4%) completers. Statistically significant improvements in discomfort, burning, dryness, grittiness, stinging, and light sensitivity, as well as clinical signs of keratitis, conjunctival staining, and tear volume were seen (P<0.05). Mean Ocular Surface Disease Index total scores improved by 21.3% (P<0.05). Blurred vision, affecting 8.7% of patients, was the most commonly reported adverse event leading to discontinuation.

CONCLUSIONS

Hydroxypropyl cellulose ophthalmic inserts significantly improved signs and symptoms of moderate-to-severe DES, as well as ADL and QoL. Benefits were additive to those seen with patients' existing care.