Open evaluation of a new non-preserved artificial tear

Review of Hydroxypropyl Methylcellulose in Artificial Tears for the Treatment of Dry eye disease

Dry eye disease (DED) is a highly prevalent condition, resulting in reduced quality of life, lower participation in social life and impaired work efficiency. Hydroxypropyl methylcellulose (HPMC) is a cellulose-based viscosity-enhancing agent and is one of the most popular therapeutic ingredients in artificial tears. This review aims to evaluate the literature on the efficacy and safety of HPMC used in the treatment of DED. Literature searches were conducted in PubMed and Cochrane CENTRAL. A total of 28 clinical trials from 26 publications are included in this review, including 21 clinical intervention studies evaluating the effect of HPMC treatment over time and seven single instillation studies evaluating the short-term physical and symptomatic effects of HPMC after drop-instillation. The duration of clinical intervention studies ranged from 2 weeks to 5.5 months. DED severity ranged from mild to severe. Drop frequency ranged from two to up to 16 drops per day. HPMC concentration in artificial tears ranged from 0.2% to 0.5%. No major complications or adverse events were reported. Artificial tears containing HPMC were effective at improving symptoms and some signs of DED. However, combination drops with HPMC plus other therapeutic ingredients seem more effective than HPMC alone. HPMC appears to be equally effective or inferior to hyaluronic acid (HA). There is no evidence of superiority or inferiority to either carboxymethylcellulose (CMC) or polyethylene glycol 400/propylene glycol (PEG/PG). No single study explained the choice of drop frequency or HPMC concentration. More well-designed studies are needed to determine an evidence-based standard for HPMC treatment, including drop frequency, concentration and molecular weight for different DED severity and subgroups.

Over the counter (OTC) artificial tear drops for dry eye syndrome

BACKGROUND

Over the counter (OTC) artificial tears historically have been the first line of treatment for dry eye syndrome and dry eye-related conditions like contact lens discomfort, yet currently we know little regarding the overall efficacy of individual, commercially available artificial tears. This review provides a much needed meta-analytical look at all randomized and quasi-randomized clinical trials that have analyzed head-to-head comparisons of OTC artificial tears.

OBJECTIVES

To evaluate the effectiveness and toxicity of OTC artificial tear applications in the treatment of dry eye syndrome compared with another class of OTC artificial tears, no treatment, or placebo.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to December 2015), EMBASE (January 1980 to December 2015), Latin American and Caribbean Health Sciences (LILACS) (January 1982 to December 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) and the US Food and Drugs Administration (FDA) website (www.fda.gov). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 4 December 2015. We searched reference lists of included trials for any additional trials not identified by the electronic searches.

SELECTION CRITERIA

This review includes randomized controlled trials with adult participants who were diagnosed with dry eye, regardless of race and gender. We included trials in which the age of participants was not reported, and clinical trials comparing OTC artificial tears with another class of OTC artificial tears, placebo, or no treatment. This review did not consider head-to-head comparisons of artificial tears with another type of dry-eye therapy.

DATA COLLECTION AND ANALYSIS

We followed the standard methodological procedures expected by Cochrane. Two authors independently screened the search results, reviewed full-text copies for eligibility, examined risk of bias, and extracted data. We performed meta-analysis for trials that compared similar interventions and reported comparable outcomes with sufficient data. We summarized all other included trial results in the text.

MAIN RESULTS

We included 43 randomized controlled trials (3497 participants with dry eye). Due to the heterogeneity of study characteristics among the included trials with respect to types of diagnostic criteria, interventions, comparisons, and measurements taken, our ability to perform meta-analyses was limited. The review found that, in general, there was uncertainty whether different OTC artificial tears provide similar relief of signs and symptoms when compared with each other or placebo. Nevertheless, we found that 0.2% polyacrylic acid-based artificial tears were consistently more effective at treating dry eye symptoms than 1.4% polyvinyl alcohol-based artificial tears in two trials assessing this comparison (175 participants). All other included artificial tears produced contradictory between-group results or found no between-group differences. Our review also found that OTC artificial tears may be generally safe, but not without adverse events. Overall, we assessed the quality of evidence as low due to high risks of bias among included trials and poor reporting of outcome measures which were insufficient for quantitative analysis. Furthermore, we identified an additional 18 potentially eligible trials that were reported only in clinical trial registers with no associated results or publications. These trials reportedly enrolled 2079 total participants for whom no data are available. Such lack of reporting of trial results represents a high risk of publication bias.

AUTHORS' CONCLUSIONS

OTC artificial tears may be safe and effective means for treating dry eye syndrome; the literature indicates that the majority of OTC artificial tears may have similar efficacies. This conclusion could be greatly skewed by the inconsistencies in study designs and inconsistencies in reporting trial results. Additional research is therefore needed before we can draw robust conclusions about the effectiveness of individual OTC artificial tear formulations.

Ocular surface disease in patients with ocular hypertension and glaucoma

PURPOSE

To review the prevalence, diagnosis, causes, and treatment of ocular surface disease (OSD) in patients with ocular hypertension or primary open-angle glaucoma.

METHODS

A review of the literature pertaining to OSD and glaucoma.

RESULTS

Recent studies indicate that OSD demonstrates an overall prevalence in glaucoma of 42% (range 20-59%) and is severe in 36% (range 14-66%). Further, the prevalence appears to increase with the greater the number of glaucoma drugs prescribed. Symptoms and signs are non-specific to the anterior surface of the eye and are thought to result from allergic, toxic, or pro-inflammatory conditions. However, the specific causes remain incompletely described, but may result from the benzalkonium chloride (BAK) preservative or occasionally the ocular hypotensive active molecule itself. Additionally, anterior segment ocular diseases might be causative, such as allergy, blepharitis, dry eye, and eyelid anatomical abnormalities. Treatment may consist of using preservative-free or non-BAK preserved glaucoma medications. Also, although unproven specifically in glaucoma patients, treatment of associated diseases of the anterior surface might reduce signs and symptoms.

CONCLUSIONS

OSD is common in treated glaucoma patients causing symptoms and signs that may impact on a patient's quality of life. Treatment is directed towards any underlying disease process and the use of preservative-free or non-BAK-preserved glaucoma preparations.

The efficacy of eye care for ventilated patients: outline of an experimental comparative research pilot study

The aim in this study was to investigate the efficacy of eye care given to mechanically ventilated and unconscious patients in an intensive care unit; and to answer the research question: "Is eye surface integrity maintained after the application of a "Geliperm" dressing to the closed eye of a ventilated patient?' Six patients formed the sample group. In each patient one eye received standard eye care, forming the control group, and the other eye received a 'geliperm' dressing, forming the treatment group. Tear production, using the Schirmer test, and the degree of eye surface staining by rose bengal were used as the measurement indicators. As a pilot study this project was primarily concerned with establishing a sound methodology for further enquiry. There were some difficulties in validating the degree of rose bengal staining; no statistically significant difference could be demonstrated between outcomes of the two forms of eye care after a 24-hour test period, with a P = 0.05 significance level, using the Mann-Whitney-U test. It should be noted, however, that the sample size was too small to measure a statistically significant change or its absence, in either the treatment or control eye between pre- and post-test results, with the same significance level, and using the Wilcoxon signed rank test. This study does provide evidence to support the need for eye care for critically ill patients. The methodology may offer a way forward for future investigation in the search for optimal eye surface preservation.