Bilberry-containing supplements on severe dry eye disease in young and middle-aged adults: A 3-month pilot analysis

A narrative literature review about alpha-lipoic acid role in dry eye and ocular surface disease

Ocular surface diseases (OSD) include various conditions that affect the eye's surface, causing discomfort and pain. One such condition, dry eye disease (DED), is a multifactorial disorder that significantly impacts patients' quality of life, with prevalence rates ranging from 5% to 50% and higher incidence in women. DED involves tear film instability, inflammation and neurosensory abnormalities, making its management challenging due to diverse underlying mechanisms. Conventional treatments typically focus on symptom relief, but new approaches targeting the disease's pathogenesis are emerging. Alpha-lipoic acid (ALA) is gaining attention for its potential in treating OSD and DED. ALA acts as a potent antioxidant, neutralizing reactive oxygen species. It protects cell membranes by interacting with vitamin C and glutathione, potentially recycling vitamin E. Its antioxidative properties are particularly relevant in meibomian gland dysfunction, a condition implicated in DED. By scavenging free radicals and modulating redox status in the meibomian glands, ALA can reduce oxidative damage, preserve glandular function and decrease inflammation. In diabetic patients with DED, ALA administration has been found to improve tear film parameters, reduce corneal defects, enhance antioxidant status and potentially prevent diabetic retinopathy and keratopathy. Its therapeutic effects on neurosensory abnormalities, especially in diabetic polyneuropathy and other neuropathies, are primarily due to its antioxidant, anti-inflammatory and metal-chelating properties. In summary, ALA holds promise as a therapeutic agent for DED and OSD and could be a promising treatment option for diabetic retinopathy and keratopathy, although further research is needed to confirm its efficacy.

Protective effects of docosahexaenoic acid combined with bilberry extract on myopic Guinea pigs

This study aims to investigate the protective effects of docosahexaenoic acid (DHA) combined with bilberry extract (BE) on myopic guinea pigs. In total, 105 healthy pigmented guinea pigs aged 2 weeks were selected and randomly divided into five groups. The normal control (NC) group received no treatment, while the experimental groups wore -6.0D lenses on the right eye to establish an animal model of lens-induced myopia (LIM). These groups were further divided based on different treatments: normal feeding, DHA treatment, BE treatment, and combined DHA + BE treatment. Refractive error and axial length for both eyes were measured before modeling, after 4 weeks of modeling, and after 8 weeks of treatment. Fundus examination was performed, and choroidal thickness, choroidal vascularity index (CVI), maximal mixed response in dark adaptation (Max-ERG), and cone cell response in light adaptation (Cone-ERG) were measured. After 8 weeks of treatment, we observed a significant reduction in refractive error and shortening of axial length, improvement in fundus condition, and increased choroidal thickness and CVI in the LIM + DHA + BE group. Electroretinogram (ERG) showed that the amplitudes of a-wave and b-wave were enhanced in both Max-ERG and Cone-ERG tests. The LIM + DHA + BE group exhibited superior effects compared to the LIM + DHA group and the LIM + BE group. The combination of DHA and BE delayed the progression of LIM in guinea pigs and was more effective than DHA or BE alone. The synergistic effect of DHA and BE offers a new approach to the prevention and treatment of myopia.

Extract from Aronia melanocarpa, Lonicera caerulea, and Vaccinium myrtillus Improves near Visual Acuity in People with Presbyopia

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision. Our previous experience on a rabbit model proved the positive effect of taking an oral extract of Cornus mas in stabilizing the intraocular pressure of the eye. The purpose of this study was to evaluate the effect of an orally administered ternary compound preparation on the status of physiological parameters of the ocular organ. The preparation contained an extract of the chokeberry Aronia melanocarpa, the honeysuckle berry Lonicera caerulea L., and the bilberry Vaccinium myrtillus (hereafter AKB) standardized for anthocyanins and iridoids, as bioactive compounds known from the literature. A randomized, double-blind, cross-over study lasting with a "wash-out" period of 17 weeks evaluated a group of 23 people over the age of 50, who were subjects with presbyopia and burdened by prolonged work in front of screen monitors. The group of volunteers was recruited from people who perform white-collar jobs on a daily basis. The effects of the test substances contained in the preparation on visual acuity for distance and near, sense of contrast for distance and near, intraocular pressure, and conjunctival lubrication, tested by Schirmer test, LIPCOF index and TBUT test, and visual field test were evaluated. Anthocyanins (including cyanidin 3-O-galactoside, delphinidin 3-O-arabinoside, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-arabinoside) and iridoids (including loganin, sweroside, loganic acid) were identified as substances present in the extract obtained by HPLC-MS. The preliminary results showed that the composition of AKB applied orally does not change visual acuity in the first 6 weeks of administration. Only in the next cycle of the study was an improvement in near visual acuity observed in 92.3% of the patients. This may indicate potential to correct near vision in presbyopic patients. On the other hand, an improvement in conjunctival wetting was observed in the Schirmer test at the beginning of week 6 of administration in 80% of patients. This effect was weakened in subsequent weeks of conducting the experiment to 61.5%. The improvement in conjunctival hydration in the Schirmer test shows the potential beneficial effect of the AKB formulation in a group of patients with dry eye syndrome. This is the first study of a preparation based on natural, standardized extracts of chokeberry, honeysuckle berry, and bilberry. Preliminary studies show an improvement in near visual acuity and conjunctival hydration on the Schirmer test, but this needs to be confirmed in further studies.