Contact Lens Wear Research Articles

Self-assembled micelles loaded with itraconazole as anti-Acanthamoeba nano-formulation.

Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB2 miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and CuI catalyzed azide-alkyne cycloaddition. Characterization by 1H and 13C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB2 miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG2) and blank micelles (PCL-PEG2) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG2) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG2) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG2 and ITZ-PCL-PEG2 inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG2 revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG2 micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus shouldbe investigated further in vivo to determine its clinical potential.

Refitting contact lens dropouts into a modern daily disposable contact lens.

To determine the number of previous contact lens (CL) wearers who could be comfortably refitted into delefilcon A (DAILIES TOTAL1®) CLs. This was a 6-month, three-visit study that recruited subjects who discontinued CLs within the past 2 years because of discomfort or dryness symptoms. Subjects were required to have Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire scores ≤3 and to be able to wear spherical study CLs. Subjects were asked to complete a ±50 comfort visual analogue scale (VAS) at 1 month and a Likert questionnaire after 1 and 6 months of CL wear to understand the subjects' CL experience. All 60 subjects who were fitted with the study CLs were still wearing them after 1 month, while one subject had dropped out by 6 months. Subjects had a median (interquartile range) age of 24.0 (7.0) years (71.7% female). They reported a median VAS score of 44.0 (8.0) units at the 1-month visit, with all reporting a comfortable score. At the 1-month/6-month visits, 98.3%/93.2%, 86.5%/78.0% and 93.2%/91.5% of subjects responded that they were very satisfied or satisfied with their vision, their end-of-day CL comfort and overall CL comfort, respectively. The same subjects responded that they were very likely or likely to continue to wear the study CLs at 1 (89.6%) and 6 months (80.7%) and to recommend the study CLs to a friend at 1 (98.3%) and 6 months (93.2%). The results suggest that when encountering a CL dropout, a practitioner could educate a patient about trying an alternative CL and consider delefilcon A lenses as an option.

Scaling-up laser cladding of rails

With rail travel getting more popular more demands are being put on rail infrastructure. The wheel/rail contact is the one of the main parameters that is key to maintaining a high performing network. With increasing demands for higher loads and higher speeds, wear and rolling contact fatigue (RCF) are the main two problems.New maintenance techniques can overcome some problems, but new solutions that reduce the damage are needed. Laser cladding is one of the best methods for improving wear and RCF of rail steels by adding layers of more durable materials to the rail.In this article full-scale tests of clad layers have been carried out at realistic contact conditions to verify outcomes seen in twin-disc testing to see if the results can be scaled to predict field performance of clad layers. Martensitic Stainless Steel (MSS) and Stellite 6 were used for the clad layers and R260 was used as the base material. Un-clad R260 was used as reference material.Results of full-scale tests in terms of wear rates, sub-surface deformation, hardness and roughness evolution were comparable. This showed that the clad layers deposited on actual rail performed very well compared to un-clad rail and that the tests run at the small-scale were appropriate for predicting full-scale behaviour.

Study on laser processing of medical polyether ether ketone surface texture and its improvement on service performance

Polyether ether ketone (PEEK) has excellent chemical stability, x-ray transmittance, and elastic modulus close to human cortical bone, which can effectively reduce the stress shielding effect. Therefore, PEEK can be used as a commonly used medical bone implant material to repair damaged bones. However, due to its low surface free energy, PEEK has a certain degree of biological inertness. Surface modification methods are urgently needed to improve this problem. Laser surface texturing is expected to improve the biological inertia of PEEK materials. In this study, an ultraviolet laser with a wavelength of 355 nm was used to construct textures on the surface of PEEK materials. By biomimetic design on the surface of PEEK materials, textures similar in depth and width to the surface topography of natural bones were processed. We explore the specific improvement of corrugated texture, single line texture, and orthogonal texture on PEEK material performance, aiming at improving the service performance of PEEK material and creating conditions for better service of PEEK material in vivo. Through the evaluation of PEEK surface contact angle, friction and wear properties, and biocompatibility, the research results show that laser surface texture treatment can improve many service properties of PEEK materials.

CPD: Neurodevelopmental disorders and contact lenses

Neil Retallic and Dr Ketan Parmar highlight key considerations for the eye care professional when fitting and managing contact lens wear in patients with neurodevelopmental conditions such as ADHD and autism. The authors focus on the importance of communication and offer practical steps for the ECP

The association between participant-reported ratings of comfort, dryness and vision quality in soft contact lens wearers.

Previous literature has indicated an association between participant-reported perceptions (e.g., ratings) of comfort, dryness and vision quality during soft contact lens wear. However, these reports do not account for participant- and lens-specific factors which may impact the interpretation of these results. The purpose of this project was to quantify the association between these participant-reported ratings while accounting for both participant- and lens-specific factors. Participant-reported ratings (scale 0-100) of comfort, dryness and quality of vision for 675 soft contact lens wearers (1207 eyes) were aggregated across 31 studies completed at Indiana University. Linear mixed-effects regression modelling was performed on each outcome rating individually. Covariate-adjusted models incorporated both participant- (e.g., age, sex) and lens-related (e.g., lens material, edge and optics) factors. The models were statistically adjusted for the duration of lens wear in hours and cumulative days of exposure. Consistent with estimates from covariate-adjusted regression models, pairwise Spearman correlations [95% CI] between dryness and comfort (rs = 0.71,[0.69, 0.74]), vision quality and comfort (rs = 0.53, [0.49, 0.57]) and vision quality and dryness (rs = 0.49, [0.42, 0.54]) were all positive and had p < 0.001. Average participant-reported ratings of comfort, dryness and vision quality decreased by (bs [95% CI]) = -0.81 [-1.15, -0.46] -0.34 [-0.67, 0.0005] and -0.90 [-1.19, -0.60] rating units, respectively, for each hour of lens wear. Significant positive associations were found between participant-reported measures of comfort, dryness and vision quality during soft contact lens wear. The associations between these ratings and the participant- and lens-related factors that drive them should be considered by clinicians and manufacturers when fitting and designing soft contact lenses.

Influence of sliding wear on contact characteristics based on 3-D wheel/rail contact model

During the process of starting, braking and running of the train, sliding contact between wheel and rail occurs. The wear caused by sliding contact exerts a noteworthy influence on the contact characteristics of wheel/rail. To analyze these characteristics, a three-dimensional wheel/rail contact wear model is established, and the contact characteristics at different wear depths are studied. The results indicate that at initial contact, the wheel/rail contact patch is approximately elliptical in shape and its area is 122.5 mm2. The von Mises stress of the wheel and rail is maximum in the subsurface at a distance of 2 mm from the contact interface, with maximum values of 559 MPa and 628 MPa respectively. When the wear depth is less than 0.5 mm, the wear depth, contact area and size increase quickly. As the amount of wheel contact wear increases, the maximum contact stress gradually decreases and the contact stress becomes uniform. In addition, the calculation results indicate that the contact patch shape does not always remain elliptical, the shape can change from elliptical to rectangular as the wear depth increases. As the increasing of wear amount, the contact stress gradient on the inner side of wheel contact surface increases.

Awareness and Hygiene Practices Among Contact Lens Wearers: A Population-Based Cross-Sectional Survey.

Background More than 150 million individuals worldwide wear contact lenses (CL) for therapeutic as well as cosmetic purposes. Researchers have linked failure to adhere to CL care instructions with outbreaks of serious eye infections. In the current study, we assess the consequences of inadequate cleanliness as well as awareness of and adherence to appropriate CL hygiene. Methods This is a cross-sectional descriptive study conducted in the Jazan region, southwest Saudi Arabia, during the period between October 2022 and April 2023. Results Out of a total of 718 participants, 391 (54.4%) were wearing CL. Of these, 318 (81.33%) CL wearers were female, while 73 (18.67%) were male. Among the CL wearers, 196 (50%) were aged 24 and younger. The overall knowledge was higher in females, with 320 (74.6%) having a high level of knowledge, compared to 195 (67.5%) males (p-value = 0.044). The level of knowledge was higher in those who had had an eye examination before using CL. Regarding practice, 202 (63.5%) females demonstrated better practices, while only 32 (43.8%) males did (p-value = 0.002). Variations in the adequacy of practice regarding CLs were identified according to the duration of CL use and the risk of suffering from eye dryness (p-values <0.05). Conclusions The participants' overall knowledge and practices were good. This should be encouraged by performing an eye examination before wearing CL and demonstrating good wearing habits in terms of hygiene behavior.

HUBUNGAN ANTARA PEMAKAIAN LENSA KONTAK DAN RISIKO BLEFAROPTOSIS DIDAPAT

Objectives: Contact lenses (CL) wear has been reported to be associated with acquired blepharoptosis. This literature review aims to summarize and evaluate the risk of acquired blepharoptosis in contact lens wearers. Methods: Literature searching was conducted using three online databases including PubMed, Cochrane Library, and Embase. Search terms such as “contact lens”, “ptosis”, and “blepharoptosis” were included. Reference lists of each study were also assessed for potentially relevant sources. Results: Using relevant search terms in various databases, a total of three articles were included in this review. All studies reviewed were single-center retrospective studies. The three studies suggested that wearing contact lens was significantly associated with blepharoptosis. Long-term contact lens wear, ranging from 15 to 34 years, seemed to have a significant effect on the incidence of blepharoptosis. Hard contact lens (HCL) wear has a greater risk for ptosis to occur than soft contact lens (SCL) wear. Conclusion: There is evidence of a clear association between hard or soft contact lens wear and an increased risk of blepharoptosis. Patients wearing contact lenses should be informed of the risk of blepharoptosis, and a history of contact lens wear should be sought in all patients who have acquired blepharoptosis.

Relationship Between Contact Lens Wear and the Risk of Acquired Blepharoptosis

Abstract&#x0D; Introduction &amp; Objectives : Contact lens wear has been reported to be associated with acquired blepharoptosis. This literature review aims to summarize and evaluate the risk of acquired blepharoptosis in contact lens wearers.&#x0D; Methods : Literature searching was conducted using three online databases including PubMed, Cochrane Library, and Embase. Search terms such as “contact lens”, “ptosis”, and “blepharoptosis” were included. Reference lists of each study were also assessed for potentially relevant sources. Prospective and retrospective studies as well as meta-analyses and systematic reviews were included.&#x0D; Results : Using relevant search terms in various databases, a total of five articles were included in this review. Four studies suggested that wearing hard or soft contact lenses was significantly associated with blepharoptosis. One study indicated hard contact lens wearers presented blepharoptosis 17.38 times more frequently than non-wearers (OR, 17.38, 95% CI=3.71–81.29), while soft contact lens wearers had 8.12 times more risk of presenting blepharoptosis than non-wearers (OR, 8.12, 95% CI=2.68–24.87). Furthermore, long-term contact lens wear, which was 20 years or more, seemed to have a significant effect on the incidence of blepharoptosis. There was only one study which stated that hard contact lens wear did not lead to acquired blepharoptosis in this review.&#x0D; Conclusion : There is evidence of a clear association between hard or soft contact lens wear and an increased risk of blepharoptosis. Patients wearing contact lenses should be informed of the risk of blepharoptosis, and a history of contact lens use should be sought in all patients who have acquired blepharoptosis.

Rolling contact fatigue and wear behavior of a vanadium microalloyed railway wheel steel under dry rolling/sliding condition

This study aims to evaluate the effect of vanadium microalloying on rolling contact fatigue (RCF) and wear behavior of railway wheel steels. It involves microstructural analysis and mechanical testing, including hardness, tensile, and rolling/sliding tests on the test steels, followed by electron backscatter diffraction, residual stress, and microhardness analyses after rolling/sliding tests. The findings demonstrate that vanadium microalloying leads to the alleviation of dynamic recrystallization, strain hardening, and compressive residual stress within the outermost layer beneath the worn surface, indicating a reduction in the plastic deformation capacity during dry rolling/sliding conditions. RCF resistance of railway steel can be enhanced through vanadium microalloying, as it simultaneously delays crack initiation by increasing yield strength and restricts crack growth by reducing plastic deformation capacity. While vanadium microalloying enhances the matrix hardness of wheel steel, it concurrently diminishes its strain hardening ability, potentially compromising its wear resistance. In addition, this study found that the yield ratio, being indicative of plastic deformation capacity and strain hardening ability, can serve as a suitable parameter for characterizing the RCF and wear resistances of tested steels. It exhibits a positive correlation with RCF resistance and a negative correlation with wear resistance.

Chinese expert consensus on the diagnosis and treatment of contact lens-associated dry eye (2024)

The number of contact lens wearers in China is increasing rapidly. Long-term contact lens wearing may induce or exacerbate tear film instability, and consequently affect the visual quality, ocular surface safety, and compliance of the wearers. To promote the safety and effectiveness of contact lens fitting, and to improve the visual quality and satisfaction of contact lens wearers, the Society of Contact Lens Safety Monitoring & Vision Health of Chinese Health Association has targeted to develop an expert consensus on the diagnosis and treatment of contact lens-associated dry eye. By referring to relevant literature and summarizing clinical experience, the clinical experts in corneal disease, pediatric ophthalmology and optometry have made repeated discussions to form this consensus, including the definition, pathological mechanisms, influencing factors, evaluation, prevention and treatment of contact lens-associated dry eye, for the reference of optometrists and ophthalmologists.

FEA-Based Stress-Strain Barometers as Forecasters for Corneal Refractive Power Change in Orthokeratology.

To improve the effectivity of patient-specific finite element analysis (FEA) to predict refractive power change (RPC) in rigid Ortho-K contact lens fitting. Novel eyelid boundary detection is introduced to the FEA model to better model the effects of the lid on lens performance, and stress and strain outcomes are investigated to identify the most effective FEA components to use in modelling. The current study utilises fully anonymised records of 249 eyes, 132 right eyes, and 117 left eyes from subjects aged 14.1 ± 4.0 years on average (range 9 to 38 years), which were selected for secondary analysis processing. A set of custom-built MATLAB codes was built to automate the process from reading Medmont E300 height and distance files to processing and displaying FEA stress and strain outcomes. Measurements from before and after contact lens wear were handled to obtain the corneal surface change in shape and power. Tangential refractive power maps were constructed from which changes in refractive power pre- and post-Ortho-K wear were determined as the refractive power change (RPC). A total of 249 patient-specific FEA with innovative eyelid boundary detection and 3D construction analyses were automatically built and run for every anterior eye and lens combination while the lens was located in its clinically detected position. Maps of four stress components: contact pressure, Mises stress, pressure, and maximum principal stress were created in addition to maximum principal logarithmic strain maps. Stress and strain components were compared to the clinical RPC maps using the two-dimensional (2D) normalised cross-correlation and structural similarity (SSIM) index measure. On the one hand, the maximum principal logarithmic strain recorded the highest moderate 2D cross-correlation area of 8.6 ± 10.3%, and contact pressure recorded the lowest area of 6.6 ± 9%. Mises stress recorded the second highest moderate 2D cross-correlation area with 8.3 ± 10.4%. On the other hand, when the SSIM index was used to compare the areas that were most similar to the clinical RPC, maximum principal stress was the most similar, with an average strong similarity percentage area of 26.5 ± 3.3%, and contact pressure was the least strong similarity area of 10.3 ± 7.3%. Regarding the moderate similarity areas, all components were recorded at around 34.4% similarity area except the contact pressure, which was down to 32.7 ± 5.8%. FEA is an increasingly effective tool in being able to predict the refractive outcome of Ortho-K treatment. Its accuracy depends on identifying which clinical and modelling metrics contribute to the most accurate prediction of RPC with minimal ocular complications. In terms of clinical metrics, age, Intra-ocular pressure (IOP), central corneal thickness (CCT), surface topography, lens decentration and the 3D eyelid effect are all important for effective modelling. In terms of FEA components, maximum principal stress was found to be the best FEA barometer that can be used to predict the performance of Ortho-K lenses. In contrast, contact pressure provided the worst stress performance. In terms of strain, the maximum principal logarithmic strain was an effective strain barometer.

Clinical correlations and ımpact of conjunctivochalasis in soft contact lens wearers.

To evaluate the correlation between clinical tests, patient symptoms, and conjunctivochalasis in contact lens wearers and non-wearers. This study comprised 40 eyes of 40 current soft contact lens users and 40 eyes of 40 control subjects. Cross-sectional areas of conjunctivochalasis at three locations (nasal, central, temporal) during straight and downward gazes were determined using anterior segment optical coherence tomography in all participants. Tear film break up time test and Schirmer test with anesthesia were performed and for evaluation of symptoms, the participants completed ocular surface disease index questionnaire. During straight gaze, the mean cross-sectional areas of conjunctivochalasis were 0.0112 ± 0.009 and 0.006 ± 0.005 mm2 at nasal, 0.0096 ± 0.007 and 0.002 ± 0.004 mm2 at central, 0.0176 ± 0.014 and 0.008 ± 0.009 mm2 at temporal in contact lens and control groups, respectively. Regardless of location and gaze direction, the mean cross-sectional conjunctivachalasis areas of the contact lens group were significantly higher than those of the controls (all, p < 0.05). Significant positive correlations between ocular surface disease index score and measured conjunctivachalasis areas (in all sites) during straight gaze and downward gaze were observed in the contact lens group (all, p < 0.05 and r > 0.450). Wearing soft contact lenses is associated with increased conjunctivochalasis areas. Anterior segment optical coherence tomography determined conjunctivochalasis area is an objective clinical measurement value that is positively correlated with patients' symptoms in soft contact lens wearers.

Content development for a new item-bank for measuring multifocal contact lens performance

BackgroundPresbyopia is an age-related condition that causes a decreased ability to focus on nearby objects. Multifocal contact lenses are commonly used to address this issue. However, there seems to be a notable dissatisfaction among multifocal contact lens wearers. The absence of a reliable instrument to measure the patient’s perspective, despite the widespread use of this method, highlights the need for further research in this area.ObjectiveThe objective of this study is to develop an item-bank integrating all domains necessary to assess the patient’s perspective on multifocal contact lens performance, offering a comprehensive measure. The item-bank will ensure a high level of content validity, be self-administered, and will initially be available in Spanish. The aim of this tool is to serve as a valuable resource for research and optometric clinics, facilitating the follow-up of patients with presbyopia who wear multifocal contact lenses or those who are newly starting to use them.MethodologyThe MCL-PRO item bank, followed a systematic and step-wise inductive approach to gather information, following the recommendations outlined in the COSMIN guidelines and similar studies. The process involved the following steps: (1) Literature review and relevant existing items identification (2) Social media review, (3) Semi-structured focus groups, (4) performing qualitative analysis, (5) refining and revising the items, and (6) generating the content of the item bank.ResultsA total of 575 items were included in the item-bank hosted under 8 different domains that were found to be important for presbyopic population: visual symptoms (213), activity limitation (111), ocular symptoms (135), convenience (36), emotional well-being (33), general symptoms (16), cognitive issues (21) and economic issues (10).ConclusionThe item-bank created has followed standardised methodology for its development and encloses all the aspects for MCL performance evaluation from patients perspective.

Analysis of Coil Systems with Non-Symmetrical Fe Backings for Electrical Vehicle Wireless Charging Applications

Wireless power transfer is a widely applied technology whose market and application areas are growing rapidly. It is considered to be a promising supplement to the conductive charging of electrical vehicles (EVs). Wireless charging provides safety, convenience, and reliability in terms of mitigating issues related to wiring, risk of tearing, trip hazards, and contact wear inherent to the conductive charging. A variety of coil structures have been researched for EV charging applications; however, most of them were of the symmetrical type. This work analyzes systems of coils possessing ferromagnetic backing with non-symmetrical geometries and compares them with the conventional symmetrical ones. Numerical FEM simulation was applied in the research. The numerical models were verified analytically and experimentally. The impact of air-gap length, longitudinal displacement, number of turns, and width of the ferrite bars on coupling factor was investigated. The results suggest that coil systems with non-symmetrical structures of ferromagnetic backings are a good alternative to the conventional symmetrical structures for wireless electrical vehicle charging applications.

COMPARISON OF KNOWLEDGE, ATTITUDE, AND PRACTICES TOWARDS CL USAGE AMONGST MEDICAL AND NON-MEDICAL STUDENTS

Background and Objective: Amidst the myopia epidemic, the number of contact lens (CL) users is steadily increasing, especially youngsters. Many CL practitioners presume optimum knowledge and good practice of CL usage by medical professionals. With rising complications and a significant dropout rate, there is a need to investigate the knowledge (K), attitudes (A), and practices (P) among CL users. This study aimed to assess the K, A, and P in CL users registered in various programs in a university. We hypothesized no difference between K, A, and P in CL users with medical (M) and non-medical (N) academic backgrounds.&#x0D; Methods and Materials: A pre-validated questionnaire, consisting of 19 questions on knowledge, 9 questions on attitude, and 30 questions on practice, was distributed among the university students admitted to various programs, excluding optometry, through an online survey tool. Inferences were drawn using a Chi-square test and Mann-Whitney U test to compare the M and N groups, with a predetermined significance of 0.05. Spearman’s correlation gave a relationship between the K, A, and P of CL users.&#x0D; Results: Out of 1041 (M=146 and N=895) valid responses, 476 (45.7%) respondents had prior experience or were CL users. The prevalence of CL users was a little higher in the N group (M=39.0%; N=46.8%) but statistically not significant (χ2=3.057, df=1, p&lt;0.05). The knowledge about CL hygiene and complications was not significantly different between the two groups (U=10370, z=–1.645, p&lt;0.05). However, there was a significant difference in the attitude towards CL wear and care (U=9268, z= –2.751, p&gt;0.05) and practice of lens wear and care (U=8770, z=–3.318, p&gt;0.05). For all the respondents, a weak correlation between knowledge and practice was observed (r=0.137, p&lt;0.05), and a fair to strong correlation in medical respondents (r=0.465, p&lt;0.05). For the non-medical student group, a statistically significant weak correlation was found between attitude and practice (r=0.110, p&lt;0.05).&#x0D; Conclusion: Medical students exhibited a slightly better attitude and practice toward CL use than non-medical students. However, knowledge scores in both groups were similar. The results of this survey disrupted the presumption that CL users with medical backgrounds possess better K, A, and P toward CL usage. This study highlights the need to be proactive in educating young CL wearers, irrespective of their academic background, providing them with optimum knowledge and skill, and nurturing their right attitude towards CL usage, which will ultimately contribute to the optimization of eye health outcomes and prevention of complications associated with CL wear. This will help the CL industry overcome growth challenges, providing safe opportunities for vision correction to the increasingly prevalent myopic population at large.

LipiFlow for the treatment of dry eye disease.

Meibomian gland dysfunction (MGD) is the most common underlying cause of dry eye disease (DED). MGD leads to pathological alteration of the composition or quantity of meibum, or both, which subsequently results in tear evaporation and the typical signs and symptoms associated with DED. The LipiFlow Thermal Pulsation System (LipiFlow) is a medical device used to treat MGD in office; however, it is unclear if LipiFlow can outperform other DED treatments. To evaluate the effectiveness of LipiFlow for treating DED signs and symptoms and the safety of LipiFlow compared with sham or other available treatments for MGD in adults. The Cochrane Eyes and Vision Information Specialist searched the electronic databases for randomized controlled trials. There were no restrictions on language or date of publication. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, including the Cochrane Eyes and Vision Trials Register; 2022, Issue 6), MEDLINE Ovid, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Science Information database), ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) electronic databases. We also examined the reference lists of identified trials, review articles, and guidelines for information about relevant trials that may not have been identified by our search strategy. We contacted investigators regarding ongoing trials. The last database search was performed on 24 October 2022. We included studies conducted in adults (over 18 years of age) with DED or MGD as defined by the primary trial investigators. We imposed no restrictions on race, ethnicity, or sex. We considered trials involving contact lens wearers if they were equally represented between groups. We applied standard Cochrane methodology. We included 13 trials that randomized a total of 1155 participants (28 to 236 participants randomized per study). Six trials were conducted in the USA, three in China, two in Thailand, one in France, and one in Italy. Eight trials were of single-center design, while four trials were of multicenter design; one trial did not report the number of participating centers. Study characteristics The study population of the included trials was 66% female (range 48% to 80%), with an age range of 19 to 86 years. LipiFlow, used as a stand-alone intervention, was compared with basic warm compresses in five studies, thermostatic device in five studies, oral intervention in one trial, and topical dry eye medications in one trial. LipiFlow was also evaluated together with eyelid hygiene product versus eyelid hygiene products alone in one trial. Findings Five trials compared LipiFlow with a basic warm compress applied for varying durations and frequencies during the trial period; only one of these trials combined a warm compress with eyelid massage. Analyzing symptom scores by different questionnaires (Ocular Surface Disease Index [OSDI] and Standard Patient Evaluation of Eye Dryness [SPEED]) yielded conflicting evidence of a difference in symptoms between LipiFlow and basic warm compresses after four weeks. There was no evidence of a difference in meibomian gland expression, meibum quality, or tear breakup time when comparing LipiFlow with basic warm compresses. Another five trials compared LipiFlow with thermostatic devices. Analysis of symptom scores at four weeks showed that thermostatic devices had reduced OSDI scores by a mean difference (MD) of 4.59 (95% confidence interval [CI] 1.23 to 7.95; I2 = 0, P = 0.007; 553 participants; very low certainty evidence) as compared with LipiFlow. When we compared LipiFlow plus eyelid hygiene with eyelid hygiene alone, there was no evidence of difference in signs or symptoms at any time point evaluated. Only one trial compared LipiFlow with a topical DED medication (lifitegrast 5%). The single-trial estimate suggested that 5% lifitegrast may increase meibomian gland expression scores compared with LipiFlow at day 42 (MD -1.21, 95% CI -2.37 to -0.05; 50 participants; low certainty evidence) by using a meibomian gland expression scale of 0 to 8. One trial compared LipiFlow with an oral intervention (doxycycline), finding that LipiFlow may result in significantly better SPEED scores than doxycycline at three months (MD -4.00, 95% CI -7.33 to -0.67; 24 participants; very low certainty evidence). No other significant differences in signs or symptoms were found between LipiFlow and doxycycline at three months. We did not find any other statistically significant differences in symptoms or signs for any other analysis performed in this review at the one- to four-week time point. Adverse events No trial reported any intervention-related, vision-threatening adverse events. LipiFlow performs similarly to other commonly used DED treatments with regard to DED signs and symptoms. The best available evidence was deemed to have a high level of bias, leading to low or very low certainty evidence. Additional research with adequate masking, a standardized testing methodology, and a sample representative of the MGD population is therefore needed before any firm conclusions can be drawn regarding comparative benefits and harms.

Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis.

Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.

Numerical simulation on the effect of current intensity on electrical contact performance of electrical connectors subject to micro-slip wear

This article aims to develop a wear simulation method considering thermal-electrical- mechanical coupling to obtain the evolutions of contact variables and electrical resistance. Then, the influence mechanism of current intensity on the electrical contact performance subject to micro-slip wear is revealed. The maximum wear depth exhibits an increasing and then decreasing trend with the electric current, and the wear profile shows a W-shape at the start and then evolves into a U-shape under 15 A/mm. Meanwhile, a greater contact half-width is observed under a larger current condition to maintain a stable and low electrical resistance. Furthermore, experimental results are obtained confirming the potential of this numerical approach to simulate the wear of electrical contact.