Lipid Layer Research Articles

Effect of cholesterol on the mechanical stability of gel-phase phospholipid bilayers studied by AFM force spectroscopy.

The remarkably low sliding friction of articular cartilage in the major joints such as hips and knees, which is crucial for its homeostasis and joint health, has been attributed to lipid bilayers forming lubricious boundary layers at its surface. The robustness of such layers, and thus their lubrication efficiency at joint pressures, depends on the lipids forming them, including cholesterol which is a ubiquitous component, and which may act to strengthen of weaken the bilayer. In this work, a systematic study using an atomic force microscope (AFM) was carried out to understand the effect of cholesterol on the nanomechanical stability of two saturated phospholipids, DSPC (1,2-distearoyl-sn-glycero-3-phosphatidlycholine) and DPPC (1,2-dipalmitoyl-sn-glycero- phosphatidylcholine), that differ in acyl chain lengths. Measurements were carried out both in water and in phosphate buffer solution (PBS). The nanomechanical stability of the lipid bilayers was quantitatively evaluated by measuring the breakthrough force needed to puncture the bilayer by the AFM tip. The molar fractions of cholesterol incorporated in the bilayers were 10% and 40%. We found that for both DSPC and DPPC, cholesterol significantly decreases the mechanical stability of the bilayers in solid-ordered (SO) phase. In accordance with the literature, the strengthening effect of salt on the lipid bilayers was also observed. For DPPC with 10mol % cholesterol, the effect of tip properties and the experimental procedure parameters on the breakthrough forces were also studied. Tip radius (2-42nm), material (Si, Si3N4, Au) and loading rate (40-1000nm/s) were varied systematically. The values of the breakthrough forces measured were not significantly affected by any of these parameters, showing that the weakening effect of cholesterol does not result from such changes in experimental conditions. As we have previously demonstrated that mechanical robustness improves the tribological performance of lipid layers, this study helps to shed light on the mechanism of physiological lubrication. Nanoindentation of SDPC bilayers.

Evolution of a fatty acyl-CoA elongase underlies desert adaptation in Drosophila.

Traits that allow species to survive in extreme environments such as hot-arid deserts have independently evolved in multiple taxa. However, the genetic and evolutionary mechanisms underlying these traits have thus far not been elucidated. Here, we show that Drosophila mojavensis, a desert-adapted fruit fly species, has evolved high desiccation resistance by producing long-chain methyl-branched cuticular hydrocarbons (mbCHCs) that contribute to a cuticular lipid layer reducing water loss. We show that the ability to synthesize these longer mbCHCs is due to evolutionary changes in a fatty acyl-CoA elongase (mElo). mElo knockout in D. mojavensis led to loss of longer mbCHCs and reduction of desiccation resistance at high temperatures but did not affect mortality at either high temperatures or desiccating conditions individually. Phylogenetic analysis showed that mElo is a Drosophila-specific gene, suggesting that while the physiological mechanisms underlying desert adaptation may be similar between species, the genes involved in these mechanisms may be species or lineage specific.

Relationship between ocular surface pain and corneal nerve loss in dry eye diabetics: a cross-sectional study in Shenyang, China

BackgroundDiabetes mellitus has been associated with increased dry eye disease (DED) and exacerbates DED pathology.ObjectiveTo investigate the potential relationship between corneal nerve loss and ocular pain among diabetic patients with...

The effects of chalazion and the excision surgery on the ocular surface

PurposeTo evaluate the effects of chalazion excision on the ocular surface, taking into account the subjective symptoms and the objective parameters of the tear film. MethodsThis prospective, interventional clinical study included 52 eyes from 26 patients with eyelid chalazion who underwent excision of the lesions between March and August 2022. Chalazion excision was performed on the patient's chalazion eye, and the contralateral eye served as the control. The following parameters were investigated both preoperatively and 1 week, 1 month, and 3 months postoperatively: the Ocular Surface Disease Index (OSDI), Schirmer I test, corneal fluorescein stain (CFS), tear meniscus height (TMH), noninvasive first breakup time (NifBUT), noninvasive average breakup time (NiaBUT), bulbar conjunctival redness score, the thickness of the lipid layer, and meibomian gland loss. ResultsBefore surgery, the OSDI score of the chalazion eye was significantly higher than the contralateral eye. The bulbar conjunctival redness score (p = 0.043) and the OSDI score (p = 0.004) improved significantly in the first month after surgery. In the third month after surgery, the objective parameters showed significant improvements, including TMH (p = 0.032), NiaBUT (p = 0.028), bulbar conjunctival redness score (p < 0.001), the thickness of the lipid layer (p = 0.021), and meibomian gland loss (p = 0.005). ConclusionsOur study revealed that chalazion excision can significantly improve the subjective symptoms and the objective tear film parameters of the ocular surface.

Rabbit models of dry eye disease: comparative analysis.

To report ocular changes in rabbits after the implementation of three different induction methods to create dry eye (DE) conditions and provides evidence of DE-related disease evolution. Experimental methods were divided into 3 models. The first model used involved triple injection of complete Freund's adjuvant, 50 µL each, also called the meibomian gland dysfunction (MGD) model. In the second model, DE conditions were created by the resection of nictitating membranes (NM), Harderian glands (HG), and main lacrimal glands (LG), also called the LGR model. The third model involved the topical administration of benzalkonium chloride (BAK) 0.1% solution. The Schirmer test, ocular surface staining with fluorescein, and tear break-up time tests were implemented before and after excision. After euthanasia, the ocular tissues were dissected. Cornea, conjunctiva, and meibomian glands were treated with periodic acid-Schiff (PAS) staining and haematoxylin-eosin staining. The MGD model triggered inflammation of meibomian glands. It detected changes in the lipid layer of the tear film. The bilateral resection of NM, HG, and LG reduced the watering layer of the tear film. The topical administration of BAK of 0.1% solution impacted the mucosal layer of the tear film. Different changes are observed with different DE syndrome models. The composition of the tear film differ depending on which part of the eye is targeted. More studies need to be done to confirm whether an increased thickness of the cornea has any impact on the DE disease.

The Combined Impact of Intense Pulsed Light Combined and 3% Diquafosol Ophthalmic Solution on Evaporative Dry Eye: A Randomized Control Study.

The primary objective of this study is to assess whether the combination of intense pulsed light (IPL) with 3% diquafosol (DQS) ophthalmic solution is more effective than intense pulsed light in alleviating signs and symptoms of dry eye disease (DED). This randomized study included 66 participants with evaporative dry eye (EDE) who received IPL + DQS therapy (n = 44 eyes), IPL therapy (n = 44 eyes), or sham therapy (n = 44 eyes). All participants were examined at baseline (D0), day14 (D14), and day28 (D28) for non-invasive break-up time (NITBUT), tear-film lipid layer (TFLL), corneal conjunctival staining (CS), meibomian gland quality (MGQ), meibomian gland expression (MGEx), and ocular surface disease index (OSDI). At day28, comparison among the IPL + DQS therapy, IPL therapy, and sham therapy found significant differences in the mean NITBUT (12.03 ± 1.27 versus 10.47 ± 3.48 versus 4.57 ± 0.46; p < 0.001), TFLL (2.09 ± 0.29 versus 2.27 ± 0.45 versus 2.89 ± 0.65; p < 0.001), CS (1.43 ± 0.82 versus 1.93 ± 1.32 versus 3.52 ± 1.00; p < 0.001), MGQ (1.55 ± 0.66 versus 1.91 ± 0.77 versus 2.66 ± 0.53; p < 0.001), MGEx (1.27 ± 0.45 versus 1.75 ± 0.44 versus 2.41 ± 0.50; p < 0.001), and OSDI score (19.36 ± 7.01 versus 24.77 ± 4.68 versus 42.61 ± 7.49; p < 0.001); significant improvements in NITBUT, TFLL, CS, MGQ, MGEx, and OSDI were found in the IPL + DQS therapy and IPL therapy, while the sham therapy had no significant improvements. Combining 3% diquafosol ophthalmic solution with intense pulsed light was superior to IPL therapy alone in relieving the signs and symptoms of patients with severe evaporative DED. Clinical Trials Identifier: NCT05694026.

Microscopic Analysis of E-Cigarette Vapors Effects on the Eyes

Recently, e-cigarettes or VAPE have become a new trend among smokers. Known as a modern cigarette with a wide selection of flavors and aromas such as vanilla, raspberry and spearmint as well as abundant steam, making vaping a favorite activity among teenagers. This research is a literature study on various medical research journal databases such as PubMed, Science Direct, Cochrane and Google Scholar. Based on research results, it is known that the vapor from vaping causes dryness, thickening and even damage to the cornea. The occurrence of lipid peroxidation by free radicals contained in vaping vapor causes the eye protective layer "tear film" consisting of lipid, aqueous, and mucin layers to be damaged. Dry eye syndrome and damage to the eye epithelium are characterized by a decrease in the number of goblet cells and inflammation of the corneal tissue, even an increased of potential for cataracts can occur either by direct exposure or by inhalation of vapors which causes a systemic increase in oxidant levels.

Modulation of Autophagy and Cell Death by Bacterial Outer-Membrane Vesicles.

Bacteria, akin to eukaryotic cells, possess the ability to release extracellular vesicles, lipidic nanostructures that serve diverse functions in host-pathogen interactions during infections. In particular, Gram-negative bacteria produce specific vesicles with a single lipidic layer called OMVs (Outer Membrane Vesicles). These vesicles exhibit remarkable capabilities, such as disseminating throughout the entire organism, transporting toxins, and being internalized by eukaryotic cells. Notably, the cytosolic detection of lipopolysaccharides (LPSs) present at their surface initiates an immune response characterized by non-canonical inflammasome activation, resulting in pyroptotic cell death and the release of pro-inflammatory cytokines. However, the influence of these vesicles extends beyond their well-established roles, as they also profoundly impact host cell viability by directly interfering with essential cellular machinery. This comprehensive review highlights the disruptive effects of these vesicles, particularly on autophagy and associated cell death, and explores their implications for pathogen virulence during infections, as well as their potential in shaping novel therapeutic approaches.

The blood-prostate barrier: an obstacle to drug delivery into the prostate.

The blood-prostate barrier (BPB), a non-static physical barrier, stands as an obstacle between the prostate stroma and the lumen of the prostate gland tube. The barrier has the ability to dynamically regulate and strictly control the mass exchange between the blood and the prostate, thereby limiting drug penetration into the prostate. The basement membrane, fibrous stromal layer, capillary endothelial cell, prostatic ductal epithelial cell, lipid layer, etc., have been confirmed to be involved in the composition of the barrier structure and altered membrane permeability mainly by regulating the size of paracellular ion pores. Various studies have been conducted to improve the efficiency of drug therapy for prostate diseases by changing the administration approaches, improving barrier permeability and increasing drug penetration. To gain a full understanding of BPB, the composition of BPB, the methodology for evaluating the permeability of BPB and alterations in barrier function under pathological conditions are summarized in this review. To find a shortcut for drug delivery across BPB, the biodistribution of drugs in the prostate and different methods of improving drug penetration across BPB are outlined. This review offers an applied perspective on recent advances in drug delivery across BPB.

Molecular dynamics of vegetable oil extraction and degumming: Analysis of micelles and phospholipid bilayers in different solvents

AbstractUnderstanding the molecular‐level mechanisms of vegetable oil extraction and degumming remains limited. This study aimed to investigate these processes using molecular dynamics (MD), with a focus on the challenges associated with replacing n‐hexane with ethanol. MD simulations with a coarse‐grained force field (Martini 3) were conducted to examine the behavior of phospholipid mono/bilayers with and without triacylglycerol in various solvents, including water, absolute and aqueous ethanol (with 0%–10% water content by weight), and n‐hexane. Trilinolein and phospholipids with 16–18 carbon tails and 0–2 unsaturations were considered. The degree of unsaturation and tail size of phospholipids did not significantly affect bilayer formation in water. However, they influenced bilayer organization, as measured by the order parameter, bilayer thickness, and area. The phospholipid bilayer, composed of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC), exhibited a well‐defined structure in water, partial disruption in ethanol, and complete disruption in n‐hexane. The presence of triacylglycerol had no effect on phospholipid monolayers in water but increased lipid disorder in ethanol. Minor amounts of water in ethanol did not significantly alter the behavior of the lipid layers. MD simulations, combined with artificial intelligence, identified and quantified the formation of micelles during the degumming process, both in conjunction with n‐hexane extraction and independently as a function of water concentration. The volume and number of micelles were strongly influenced by the water content. Molecular dynamics in food engineering is relatively limited and scarce because of the complex nature of the systems. However, this study successfully demonstrates its applicability in this context.

Effect of nano graphene oxide (nGO) incorporation on the lipophilicity of hydrophobic drugs

Lipophilicity is a measure of partitioning of an active pharmaceutical ingredient (API) in a lipophilic phase and has been shown to affect gastrointestinal absorption. If a hydrophobic API is completely water insoluble; it does not dissolve in the aqueous phase and is not available for absorption in the gastrointestinal (GI) lipid layer. Therefore, an optimum lipophilicity is important for enhanced bioavailability. It is typically measured as logP or log (Octanol-Water partition coefficient). While water soluble drugs tend to have negative values, high logP can be a problem with insoluble drugs. There are no strict guidelines on logP for hydrophobic drugs, but typically a logP between 0 and 2 is desirable. In this paper, we represent the lowering of logP of hydrophobic API via the successful incorporation of 0.5–2.0% of nanographene oxide (nGO). Four hydrophobic drugs namely Griseofulvin (GF), Dexamethasone (DXM), Apixaban (APX) and Megestrol Acetate (MA) were tested at physiological/intestine pH of 6.0, 7.0, and 8.0 to estimate partitioning behavior. The increased nGO incorporation led to the substantial decrease in logP of all the nGO formulated drugs at all pH as compared to pure drugs. In the cases of GF, APX and MA, the logP decreased from over 2.0 to somewhere between 1.0 and 2.0, and for DXM these decreased to negative values thus making it behave like a water soluble API. The maximum decrease in logP for DXM, GF, APX and MA were 157, 54, 61 and 64% respectively. In summary, the nGO incorporation is an effective means to lower logP and may significantly lead to improved biological absorption and therapeutic efficacy. We believe that current study is very promising for improving efficacy and potentially lowering drug dosage.

Alterations promoted by acid straightening and/or bleaching in hair microstructures.

Human hair is a biopolymer constituted mainly of keratin intermediate filaments, lipids, pigments and water. Cosmetic treatments usually interact with the hair at the molecular level, inducing changes in its components and modifying the physicochemical and mechanical properties of the fibers. Here, the effect of acid straightening on the morphology and ultrastructure of Caucasian hair was investigated by a group of complementary experimental methods: wide-, small- and ultra-small-angle X-ray scattering; high-resolution 3D X-ray microscopy; quasi-elastic neutron scattering and inelastic neutron scattering; thermogravimetry-mass spectrometry; and differential scanning calorimetry (DSC). X-ray diffraction patterns showed that acid straightening associated with a flat iron (∼180°C) changed the cortex of the fiber, shown by denaturation of the intermediate filaments (measured by DSC). The increase in the spacing of the lipid layers and the observation of the dehydration behavior of the fiber provided indications that water may be confined between these layers, while neutron spectroscopy showed alterations in the vibration mode of the CH2 groups of the lipids and an increase of the proton (H+) mobility in the hair structure. The latter may be associated with the extremely low pH of the formulation (pH ≃ 1). Additionally, this investigation showed that bleached hair (one-time bleached) is more damaged by the action of acid straightening than virgin hair, which was shown by a threefold increase in the percentage of total porosity of the tresses. The obtained results demonstrate that the investigation approach proposed here can provide very important thermodynamic and structural information on induced changes of hair structure, and certainly can be applied for the evaluation of the action mode and efficiency of cosmetic treatments.

Recent Advances in Messenger Ribonucleic Acid (mRNA) Vaccines and Their Delivery Systems: A Review.

Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.

Lipid based drug delivery systems for oral, transdermal and parenteral delivery: Recent strategies for targeted delivery consistent with different clinical application

Lipid-based drug delivery systems (LBDDS) are valuable and biocompatible nano-carriers for the vehiculation and potential delivery of various hydrophilic, hydrophobic, or amphiphilic compounds. LBDDS have the advantage of targeted drug delivery, as free drugs may have poor targeting, higher systemic toxicity, and possibilities of drug resistance. There is various type of lipid carrier systems for drug delivery based on the properties of drugs and clinical applications; nanoemulsion, microemulsion, lipid vesicles, and lipid nanoparticles. The era of targeted drug delivery is advancing from the superficial convention vesicles to the second generation of LBDDS by modulating the surface chemistry through modifying/surface functionalizing the lipid layer composition. The surfaces of lipid vehicles have been modified with small molecules, antibodies, peptides, and enzymes for targeted drug delivery and reduced toxicity. In this regard, polyethylene glycosylation (PEGylation) on the lipid surface was the first novel approach that improves blood circulation time and curtails opsonin resistance and clearance. However, multi-drug and multi-receptor strategies in the targeted-liposomal approach may be an innovative pathway to overcoming drug resistance while treating certain tumors. Several second-generation conventional drug delivery systems among liposomal formulations are at various stages of clinical trials. This review recapitulates the types of lipid formulations, characterization, and their applications in clinical aspects. Additionally, discuss the strategies for enhancement of disease targeting by surface functionalization with various entities to improve the drug delivery system.

Protocol for a parallel assignment prospective, randomised, comparative trial to evaluate the safety and efficacy of intense pulsed light (IPL) combined with 3% diquafosol (DQS) ophthalmic solution in dry eye syndrome

IntroductionEvaporative dry eye (EDE) is common and can lead to ocular pain, decreased visual quality and reduced quality of life. Intense pulsed light (IPL) and 3% diquafosol ophthalmic solution have...

Change in gastric-lipase adsorption on lipid layer by stigmasterols

Abstract Gastric-lipase (GL) binding to a lipid layer was investigated for the phase of the layer adjusted with the ratio of stigmasterol to the lipid using surface plasmon resonance. While the layer was formed on the hydrophobic surface, more stigmasterol led to lower surface density only in the dipalmitoylphosphatidylcholine (DPPC) layer. The addition of stigmasterol was believed to transform the phase (condensed liquid-phase) of DPPC layer closer to the phase (expanded liquid-phase) of dioleoylphosphatidylcholine (DOPC) layer. At a ratio greater than 15:85, the effect of the stigmasterol on the DPPC was saturated. The adsorption behavior of GL showed the similar trend with the lipid formation. The adsorption increased with the increase in the ratio of stigmasterol to lipid up to 15:85. On the DOPC layer of the expanded liquid-phase, the most adsorption seemed to occur and was indistinguishable from that in the DPPC layer of 15:85. The surface density of the adsorbed GL was interpreted into the fraction of the stigmasterol-dependent DPPC, 0.33, 0.67, and 1.00 for 10:90, 5:95, and 0:100 of DPPC. Furthermore, the equilibrium constant was between 1 × 1013 M−1 and 2 × 1013 M−1 and the kinetics of the adsorption showed an increase in the adsorption rate constant with the increase of the ratio up to 15:85.

The efficacy and safety of 0.01% atropine alone or combined with orthokeratology for children with myopia: A meta-analysis.

To evaluate the efficacy and safety of 0.01% atropine alone and in combination with orthokeratology for myopia control using a meta-analysis. PubMed, Cochrane Library, and EMBASE were searched. We included eligible randomized controlled trials (RCTs), non-RCTs, and retrospective cohort studies, published up to August 1, 2022. We calculated the weighted mean difference (WMD) and 95% confidence interval (CI) for all outcomes and plotted them in forest plots. Fourteen studies were included; 4 and 11 in the 0.01% atropine monotherapy and atropine-orthokeratology (AOK) groups, respectively. Compared with orthokeratology (OK) alone, 0.01% atropine alone had similar effects on slowing the axial elongation (WMD: -0.00 mm; 95% CI: -0.05-0.04, p<0.31), while AOK significantly lowered axial growth. Moreover, the baseline myopic degree and duration of treatment were influential for the change in axial elongation (WMD: -0.12 mm; 95% CI: -0.17--0.07, p = 0.00001 and WMD: -0.11 mm; 95% CI: -0.15--0.108, p<0.00001, respectively). Additionally, the AOK may reduce the change rate of the spherical equivalent refraction and the accommodation amplitude (WMD: -0.13 D; 95% CI: 0.07-0.19, p<0.001 and WMD: -1.08 mm; 95% CI: -1.73--0.43, p<0.0001, respectively), and cause a slight increase in the diameter of the pupil (WMD: 0.56 mm; 95% CI: 0.43-0.70, p = 0.007). No significant differences in the uncorrected distant visual acuity, best corrected visual acuity, intraocular pressure, tear film break-up time, lipid layer thickness, and corneal endothelial cell density were found between the OK and AOK groups. In slowing the axial elongation, 0.01% atropine alone and OK alone have similar effects, while AOK is more effective than OK alone in slowing down the axial elongation. Furthermore, the baseline degree of myopia and treatment duration may affect changes in axial elongation.

Ocular Surface Changes in Primary Open Angle Glaucoma Patients Treated With Topical Antihypertensive Drugs.

In this study, patients with glaucoma undergoing topical antihypertensive (TAH) drugs had changes in the ocular surface and more dry eye symptoms than controls. Clinicians should recognize the influence of TAH drops on exacerbating ocular surface disease. The purpose of this study was to evaluate the ocular surface of eyes with glaucoma treated with TAH drugs. Cross-sectional study that included eyes undergoing TAH drugs due to primary open angle glaucoma and controls. The parameters evaluated were: the basal tear flow (basic secretion test); the tear film osmolarity (TearLab); and the noninvasive break-up time, blink score, lipid layer thickness, tear meniscus height, and loss area of the meibomian glands, measured with the IDRA Ocular Surface Analyser. Presence of symptoms [Ocular Surface Disease Index (OSDI)], dry eye disease (DED, TFOS DEWS II criteria), and corneal fluorescein staining were assessed. We included 154 eyes (154 patients), 77 undergoing TAH drugs for glaucoma (group 1) and 77 of controls (group 2). The tear film osmolarity ( P =0.003) and the loss area of the meibomian glands ( P =0.004) were higher in group 1. The noninvasive break-up time ( P =0.005), lipid layer thickness ( P =0.006), and tear meniscus height ( P =0.001) were lower in group 1. The global OSDI score ( P <0.001), the proportion of eyes with severe disease ( P =0.002), according to the OSDI, and with DED ( P <0.001), according to the TFOS DEWS II criteria, were higher in group 1. The proportion of patients with corneal fluorescein staining was higher in group 1 ( P <0.001). There were no significant differences in eyes taking TAH drugs with and without preservatives ( P >0.127). DED, in patients with glaucoma, is a multifactorial disease, with a strong contribution from TAH drugs. These eyes had changes in almost every measured parameter, translating into the presence of more dry eye symptoms and corneal damage when compared with controls.

Lid scrubbing with a gel combining natural extracts for dry eye treatment.

To evaluate the effect of lid scrubbing using a gel combining different natural extracts on ocular signs and symptoms of dry eye patients. A retrospective study was performed on 19 dry eye patients (51.1±16.0y). Non-invasive tear break-up time, tear meniscus height, meibomian gland loss, lipid layer thickness, conjunctival redness, corneal staining, ocular surface disease index (OSDI), and ocular pain intensity were measured before (baseline), 1wk, and 2mo after lid scrubbing with a gel containing different natural extracts (okra extract, aloe vera leaf juice, hydrolysed soy protein, caffeine, citrus unshiu peel extract, and raspberry seed oil). Compared with the baseline, there was a statistically significant improvement in both first (P=0.048) and average (P=0.026) non-invasive tear break-up time 2mo after treatment, as well as in corneal staining (P=0.043, 0.012), OSDI (P<0.001), and ocular pain intensity (P<0.001) after 1wk and 2mo. In addition, there was no correlation between ocular signs and symptoms. The lid scrubbing with a gel combining different natural extracts show beneficial effects on tear film stability, corneal damage, and ocular symptoms, which is the reason why this therapeutic procedure is proposed as an alternative for dry eye management. However, it is not possible to attribute this beneficial effect solely to the presence of the natural extracts in the gel, primarily due to the absence of a negative control group.

Changes in Intraocular Pressure and Dry Eye Signs after Botulinum Toxin Injections to Treat Patients with Essential Blepharospasm

Purpose: This study investigates the intraocular pressures and dry eye signs before and after botulinum toxin (botox) injections for patients with essential blepharospasm.Methods: From November 2021 to July 2022, a prospective study examined 78 eyes of 39 patients diagnosed with essential blepharospasm. Before injection and 1 and 3 months after injection, intraocular pressures (IOPs) were measured using a Goldmann applanation tonometer. The noninvasive breakup time (NIBUT), lipid layer thickness (LLT), tear meniscus height (TMH), and meibomian gland clearance were assessed with the aid of the IDRA platform (SBM Sistemi, Turin, Italy).Results: The average IOPs were 14.33 ± 3.47 (7-21), 13.45 ± 3.54 (9-21), and 13.28 ± 2.98 (7-20) mmHg before, and 1 and 3 months after, botox injection respectively (p = 0.002 , p = 0.004). Twenty-four eyes of 12 patients with dry eye symptoms evidenced a significant difference in the NIBUT 1 month after Botox injection, but no significant difference in any of the LLT, TMH, or meibomian gland areal loss percentage (p = 0.007, 0.201, 0.586, and 0.435 respectively). After 3 months, no dry eye parameter change, including the NIBUT, was significant (p = 0.202, 0.542, 0.240, and 0.721 respectively).Conclusions: Botulinum toxin A injection temporarily relieved dry eye symptoms and reduced the IOP in patients with essential blepharospasm.