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

Abstract

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.

Corneal protective effects of novel tear substitutes containing sodium hyaluronate and dodecahydrosqualene, squalane, in a porcine dry eye model

“…It is well known that SH is a mucinomimetic product, which is one of the main ingredients of TSs, and it provides good protective effects via its excellent viscoelastic and lubricating properties on the desiccated keratoconjunctiva of eyes with KCS or DES [6,7,23]. The concentrations of SH preparations are mainly 0.1-0.4% in current clinical practice [6,7,14,28], and 0.3% SH solution exhibited better corneal protective effects than 0.1% and 0.18% SH preparations in a murine dry eye model [30]. In addition, 0.4% SH artificial tears are recommended to be used in the treatment of KCS animals [14].…”

“…The higher viscosity of SH may induce blurred vision due to non-uniform distribution of SH on the corneal surface of the eye [23]. The clinically available and applicable SH concentration may be 0.3-0.4%, which is used in commercial products [7,14,28,30]. Therefore, SH at 0.3% or less was used in novel TS prescriptions established in this study.…”

“…1), and such long-lasting corneal protection was the goal of this study. The properties of the novel modified TS may be attributed to the additive effects of SH with viscoelastic and lubricating properties, and DHS having lubricating and cell-protective effects associated with cell-membrane stabilization [6,7,12,21,23,28]. This extended 3-hr protection was marked when compared with the saline/0.5% SH/1% CO solution having 60-min protection against the same corneal desiccation [10].…”

Effects of Topical Gabapentin on Ocular Pain and Tear Secretion

“…In fact, among the options available to treat patients suffering from DED, tear replacement is widely used to restore the original homeostasis of the ocular surface and to attenuate patient discomfort and pain, for instance by reducing the friction on the ocular surface, as attrition consequent to lubrication deficits has been recognized to impact on ocular pain ( van Setten, 2020 ). In this respect, artificial tears based on hyaluronic acid have been used since the early 1990 to alleviate dry eye signs and symptoms in DED patients thanks to its water retention and lubricant properties ( Yang et al, 2021 ). On the other hand, there is evidence that artificial tears that solely swell and absorb water show poor effects when applied to DED patients affected by neuropathic pain ( Galor et al, 2016 ), suggesting that those patients without neuropathic pain are more likely to benefit from tear replacement.…”

Potential Ophthalmological Application of Extracts Obtained from Tuna Vitreous Humor Using Lactic Acid-Based Deep Eutectic Systems

“…Its non-immunogenic and biocompatible effects have significantly increased its application in the pharmaceutical and medical fields, including joint injections, osteoarthritis treatment, ocular therapy, plastic surgeries, and skin treatments [16]. In recent years, HA has been increasingly used in formulations for patients suffering from dry eye disease, as it has been shown to improve the corneal epithelial barrier and the tear film stability [17][18][19][20]. Dry eye is a highly prevalent inflammatory disease in which ocular surface epithelia and the tear film are altered, leading to visual impairment, discomfort, eye dryness, burning, and pain [21][22][23].…”