Contact Lens Wear Research Articles

Study on the effect of magnetic needle grinding process on the service properties of medical Mg-1.6Ca-2.0Zn alloy

Magnesium alloy, valued for its superior mechanical properties and biocompatibility in biomaterials, faces limitations such as rapid corrosion, poor wear resistance, and unfavorable cell adhesion. To address these challenges and enhance medical magnesium alloy development, this study investigates a magnetic needle grinding process on magnesium alloy. Mg-1.6Ca-2.0Zn alloy, prepared through powder metallurgy and T6 aging treatment, undergoes milling, and magnetic grinding using various needle sizes. The impact is assessed through Vickers hardness, residual stresses, surface roughness, friction and wear tests, electrochemical assessments, and contact angle tests. Results indicate a 22.59% microhardness increase, 30.43 MPa residual compressive stress, increased surface roughness, improved wear and corrosion resistance, and improved hydrophilia after magnetic needle grinding. This research provides a theoretical foundation for advancing medical magnesium alloy industrially.

Fault Diagnosis of Dry Gas Seal Operation Status Based on Acoustic Emission Monitoring

A dedicated test bench is employed to record acoustic emission signals from dry gas seals under various operating conditions. Time-domain and frequency-domain analysis methods are utilized to process and analyze the acoustic emission signals during start/stop, stable operation, and two common fault states (end-face defects and compensation spring failure). Furthermore, feature recognition research is conducted. A method for identifying the operational states of seals (low-speed friction, gradual detachment, stable operation) based on the root mean square (RMS) was established, with transition points at speeds of 100 and 1000 RPM, respectively. Additionally, spectral analysis is conducted using Fourier transform to determine the frequency band of acoustic emission signals (240–320 kHz) generated during contact wear of dry gas seals. Investigation into two typical faults of dry gas seals reveals that the RMS value of the acoustic emission signal gradually increases with the rotational speed during the operation of dry gas seal end-face defects. This is attributed to the insufficient dynamic pressure effect on the end face, resulting in long-term wear and tear. When the dry gas seal compensates for spring failure, the RMS value of the acoustic emission signal initially increases, then decreases, and finally increases again as the speed increases. It reaches the stable operating inflection point when the end-face speed is 800 r/min.

Overview of the Knowledge Level and Behavior of Contact Lens Use among Medical Students of Universitas Kristen Krida Wacana

<p class="AbstractNormal"><strong>Introduction: </strong>Contact lenses are intended to treat refractive errors in the eye, as a diagnostic aid, and to support the personal appearance. A case study suggested that contact lenses cause eye diseases due to less knowledge and misbehavior when wearing contact lenses. This study was conducted to know the level of knowledge and behavior of using contact lenses among medical students of Universitas Kristen Krida Wacana (UKRIDA), intake 2016.</p><p class="AbstractNormal"><strong>Methods: </strong>It employed a descriptive analysis with a cross-sectional study. A total of 97 students who use contact lenses filled out a questionnaire in Google form.</p><p class="AbstractNormal"><strong>Results: </strong>The result demonstrated that 91 respondents (94%) had good knowledge about using contact lenses. Regarding behavior, 80 (93%) belonged to a good category.</p><p class="AbstractNormal"><strong>Conclusion: </strong>Their good knowledge and behavior towards using soft contact lenses might minimize their risk of red eye incidence upon using them.</p><p class="Keywords"> </p>

Theoretical study on wheel wear mechanism of high-speed train under different braking modes

The high-speed train wheel wear problem persists throughout the whole service cycle, including the traction-braking stage, constant-speed stage, acceleration and deceleration stage, and so on. This article focuses on the wheel wear of high-speed trains under various braking modes. Firstly, high-speed motor cars and trailers are created, and the two are linked by the coupler buffer device, and the former considers detailed gear transmission system. A comprehensive wheel wear prediction process is then established based on the vehicle model, wheel-rail contact model, wear model, and wheel tread update strategy. Secondly, vehicle model and wheel wear prediction procedure are validated using the measured dynamic data and worn wheel profile. Thirdly, common braking modes and emergency braking modes are used for the braking process of high-speed trains. Finally, wheel wear and wear mechanism of high-speed trains during braking process is revealed. The results demonstrate that with the increase of braking mode level, the amplitude of longitudinal creepage also increases synchronously, while lateral creepage and spin creepage do not change significantly. According to wheel wear depth under different braking processes, the order from large to small is emergency braking mode >8-level common braking mode >6-level common braking mode >4-level common braking mode >3-level common braking mode >B1-level common braking mode. Furthermore, with the increase of rail slope, wheel wear is increasing during braking process. With the increase of friction coefficient, wheel wear depth decreases gradually during braking process.

Safety, Efficacy, and Visual Performance of an Orthokeratology Lens with Increased Compression Factor.

The aim was to evaluate the safety, efficacy, and visual performance of an orthokeratology lens with an increased compression factor (ICF) of 1.25 D in a 3-month follow-up. Thirty-six myopic patients (5 males and 31 females; 24.2 ± 5.8 years) were fitted with Alexa AR (Tiedra Farmacéutica S.L., Madrid, Spain) contact lenses (CLs) and twenty participants finished the follow-up. Visual acuity (VA), subjective refraction, primary spherical and primary coma aberrations, keratometry, central pachymetry, and ocular surface evaluation were performed at baseline and after 1 night, 1 week, 1 month, and 3 months of CL wear. The differences among visits were analyzed using a repeated-measures analysis of variance or the Friedman test. The spherical equivalent decreased (p ≤ 0.005), and the uncorrected VA improved (p < 0.001) until the first week. Corneal and ocular aberrations showed a significant increase (p ≤ 0.02). A significant decrease (p < 0.001) was found for keratometry values. No significant changes were observed in either central pachymetry or ocular surface parameters among study visits. In conclusion, an orthokeratology CL with an ICF of 1.25 D provides good safety, efficacy, and visual performance in a 3-month follow-up. Seven days of orthokeratology wear are enough to achieve the full myopic compensation, resulting in satisfactory VA.

Patient Satisfaction and Tear Film Break-Up Time After First-Time Wearing of Silicone Hydrogel Contact Lenses.

The dryness and discomfort associated with soft contact lenses (SCLs) prevent their continued use. Recently, verofilcon A, a new daily disposable silicone hydrogel material SCL, was introduced, which has a high water content (surface water content of 80% or more) that overcomes the low water content drawback of silicone hydrogels. In this study, we evaluated the non-invasive tear break-up time (NIBUT) and comfort level in individuals wearing verofilcon A SCL for the first time. We enrolled 42 first-time SCL wearers, comprising 84 eyes. NIBUT was measured using the DR-1α® dry eye observation device at the state of the naked eye before SCL wear (baseline) and at one and four weeks after the first SCL wear. Additionally, we conducted a questionnaire survey during the fourth week to assess the comfort level (0-10) of SCL wear. Results:The NIBUT values were significantly higher at one week (10.8 ± 2.2 s, p<0.01) and four weeks (11.4 ± 2.2 s, p<0.01) after the first SCL wear than those at baseline (5.9 ± 2.0 s). Comfort level in SCL use was significantly higher at one week (9.0 ± 1.1, p<0.01) and four weeks (8.7 ± 1.2, p<0.01) than that at baseline (7.8 ± 1.8), and this level was higher regardless of the baseline NIBUT value. Prolonged BUT and increased comfort levels were observed in individuals wearing verofilcon A SCLs. Improvement in tear fluid retention was found to alleviate dry eye and discomfort, suggesting that verofilcon A may be a beneficial introductory lens for first-time SCL wearers.

The Influence of Lid-Parallel Conjunctival Folds and Conjunctivochalasis on Dry Eye Symptoms with and Without Contact Lens Wear: A Review of the Literature.

Lid-parallel conjunctival folds (LIPCOF) and conjunctivochalasis (CCH) are similar conditions that seem to be related to dry eye severity. In addition, there is a lack of studies on the topic of LIPCOF and CCH on dry eye symptoms in non-contact lens and contact lens (CL) wearers. Therefore, the aim of this study is to review the relationship of LIPCOF and CCH with dry eye symptoms in non-CL and CL wearers, as well as to report the treatment of dry eye disease (DED) in non-CL and CL wearers who present LIPCOF or CCH. A literature review of full-length original studies in two databases, PubMed and Scopus, was performed. The search period included observational studies in humans published between April21, 2009 and March20, 2023. A total of 26 studies were included. The studies suggest that LIPCOF and CCH are significantly related to dry eye symptoms in non-CL and CL wearers. However, the impact of CL wear on LIPCOF and CCH may be complex and may vary depending on individual factors such as lens type, lens care regimen, and pre-existing ocular conditions. Regarding LIPCOF management, tear substitutes seem to significantly reduce LIPCOF and dry eye symptoms in non-CL wearers, while vectored thermal pulsation (VTP) and microblepharoexfoliation (MBE) are suggested as promising treatment for LIPCOF and dry eye symptoms in CL wearers. Regarding CCH management, surgical interventions may be effective in reducing CCH when medical treatments have no response. In addition, an ocular examination by slit lamp is necessary to distinguish both conditions. Tear substitutes, VTP, MBE, and fitting CLs with low coefficient of friction (CoF) seem to reduce and prevent LIPCOF. However, surgical treatment options seem to be more effective in the complete elimination of CCH. An adequate evaluation and differentiation between LIPCOF and CCH are important, and they should be considered by practitioners in managing dry eye symptoms in non-CL and CL wearers.

Paying attention to the application of contact lenses in the treatment of special types of refractive abnormalities in children

Childhood vision is in the stage of development, and the incidence of ametropia is high. For special types of refractive abnormalities such as ultra-high myopia, ultra-high anisometropia and aphakia, conventional wearing of frame glasses can easily cause aberrations and peripheral visual deformations, affect the visual development of children, and even cause refractory amblyopia. In this article, the benefits of contact lenses are discussed from perspectives of ultra-high refractive error, refraction-related refractory amblyopia, and photosensitivity-related refractive error, so as to attract the attention of clinical physicians, expand the application scope of contact lens wear, give full play to the role of contact lenses, and improve the diagnosis and treatment of refractive abnormalities in children.

Prediction of contact resistance of electrical contact wear using different machine learning algorithms

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission, and has excellent performance in all aspects. Since the wear behavior of electrical contact pairs is particularly complex when they are in service, we evaluated the effects of load, sliding velocity, displacement amplitude, current intensity, and surface roughness on the changes in contact resistance. Machine learning (ML) algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact resistance. Random forest (RF), support vector regression (SVR) and BP neural network (BPNN) algorithms were used to establish RF, SVR and BPNN models, respectively, and the experimental data were trained and tested. It was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after wear. Characteristic analysis shows that the load and current have great influence on the predicted electrical contact properties. The wear behavior of electrical contacts is influenced by factors such as load, sliding speed, displacement amplitude, current intensity, and surface roughness during operation. Machine learning algorithms can predict the electrical contact performance after wear caused by these factors. Experimental results indicate that an increase in load, current, and surface roughness leads to a decrease in stable mean resistance, while an increase in displacement amplitude and frequency results in an increase in stable mean resistance, leading to a decline in electrical contact performance. To reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors, three algorithms (random forest (RF), support vector regression (SVR), and BP neural network (BPNN)) were used to train and test experimental results, resulting in a machine learning model suitable for predicting the stable mean resistance of H62 brass alloy after wear. The prediction results showed that the BPNN model performed better in predicting the electrical contact performance compared to the RF and SVR models.

A case study of the economic reprofiling method for a high-speed train's wheel tread in the frequent contact area

The wheel-rail contact geometry strongly affects the dynamic running behavior of a railway vehicle, so it is a key factor for its operational safety. Although wear in the wheel-rail contact is generally inevitable, a particular problem is the occurrence of nonuniformly distributed wear, which changes the wheel profile and thereby often leads to a deterioration of the vehicle's running behavior. Therefore, the restoration of the wheel profile, known as reprofiling, is an important maintenance action for ensuring operational safety. The exact restoration of the original wheel profile, however, often requires the removal of a high volume of material, which can drastically shorten the service life of the wheel. An incomplete restoration of the wheel profile, which requires the removal of less material, extends the wheel's service life and is therefore also known as “economic reprofiling”. Nevertheless, an incompletely restored wheel profile, too, must still fulfill the same requirements as the original profile with respect to the vehicle's running behavior and thereby to its operational safety. While previous work mainly dealt with the impact of flange wear, the present study focuses on the wheel tread frequent contact area (WTFCA). This study presents a long-term wheel wear prediction model for a high-speed train and proposes a design method for the wheel profile in the WTFCA for economic reprofiling. After optimizing the key factors, the utilization of the wheel profile for economic reprofiling can comprehensively consider the dynamic performance, wear behavior, and economic performance of the vehicle, which can be applied to guide the maintenance of the wheel profile.

Assessment of the prevalence and risk factors for dry eye symptoms among Romanian medical students using the ocular surface disease index – a cross-sectional study

BackgroundThis study aims to assess how Romanian medical students suffer from dry eye disease symptoms, establish the prevalence and severity of dry eye (DE) symptoms and identify potential risk factors.MethodsAn analytical, cross-sectional study was conducted on students from “Carol Davila” University of Medicine, Romania, after the final examination period of July 2022. The OSDI score (Ocular Surface Disease Index©) was applied in an online survey. The study adopted the standards used by other authors, who defined symptomatic DED as an OSDI score greater than 12. The chi-square test was used to establish statistical significance at a cutoff value of p < 0.05. The predictive model was created using linear logistic regression analysis. The goodness of fit of the logistic regression model was assessed using the Hosmer-Lemeshow test. When the severity outcome had a nominal categorical form, multinomial regression analysis with normal subjects as a reference was performed. The distribution of the severe type of symptomatology across sex categories and years of study was analyzed using a nonparametric test (Independent-Samples Kruskal-Wallis Test).ResultsA total of 274 answers were received from 81.4% females and 18.6% males with a response rate of 35.58%. The mean age was 22.7 years ± 1.66 with an age range between 20 and 25 years old. Using the OSDI score, we established that the overall prevalence of DE symptoms was 83.6% (95%CI: 79.6%, 88%), with an 85.2% (95%CI: 80.5%, 89.8%) prevalence in females and 76.5% (95%CI: 65%,88%) in males. The severe form of DE was the most prevalent, regardless of the study year or sex. Increased screen time (p-value < 0.05) and non-smokers (p-value < 0.05) were proven risk factors. The predictive model which includes the explanatory variables (sex, contact lens wearers, smoking, oral contraceptives, screen time) proved an 84.7% predictability for symptomatic DE and was able to better predict the dependent variable than the intercept model only (p-value < 0.05). Smoking (p = 0.002) and screen time (p = 0.009) preserved their significance in the multinominal regression as well.ConclusionsThis is the first study to report the epidemiology of DE symptoms among Romanian medical students. OSDI revealed a high prevalence of symptomatic DE in medical students. Screen time, although not the only factor, likely plays a role in exacerbating the disease. This information can be used to inform healthcare policies, establish occupational health guidelines, and implement preventive measures for individuals in similar high-stress academic or professional environments.

Analysis of rolling contact fatigue and wear characteristics of aging-treated laminar plasma strip quenching rails

The application of laminar plasma discrete quenching (LPQ) technology to enhance the wear resistance of railway tracks has been a notable advancement. Nonetheless, it has been observed that LPQ-treated rails experience a reduction in rolling contact fatigue (RCF) resistance. Our previous study found that aging treatment can improve the toughness of laminar plasma spot quenched rails. However, the microstructure as well as the mechanical properties of strip quenching are significantly different from those of spot quenching. To tackle this concern, the study delves into the wear and RCF damage mechanisms of aging-treated laminar plasma strip quenching (ALPQ) rails. The findings reveal that the aging process induces the precipitation of supersaturated solid solutions within the hardened layer, consequently elevating the RCF resistance of ALPQ rails. Following appropriate aging treatment, nearly complete elimination of fatigue cracks on the rail surface is achieved.

Factors Associated With Laboratory Test Negativity Following a Transition in Specimen Collection in Microbial Keratitis Cases

Purpose Negative laboratory results make targeting microbial keratitis treatment difficult. We investigated factors associated with laboratory negativity in patients with microbial keratitis in the context of a transition to a new specimen collection method. Methods Microbial keratitis patients with associated laboratory tests were identified in the electronic health record of a tertiary care facility from August 2012 to April 2022. Patient demographics and laboratory results were obtained. Random sampling of 50% of charts was performed to assess the impact of the ocular history and pretreatment measures. The relationship between probability of negative laboratory results with demographics, ocular history, pretreatment measures, and utilization of a new specimen collection method (i.e. ESwab) was evaluated by multivariable logistic regression. Results Of 3395 microbial keratitis patients identified, 31% (n = 1051) had laboratory tests. Laboratory testing increased over time (slope = 2.5% per year, p < 0.001; 19.6% in 2013 to 42.2% in 2021). Laboratory negative rate increased over time (slope = 2.2% per year, p = 0.022; 48.5% in 2013 to 62.3% in 2021). Almost one-third of patients (31.2%, n = 164) were pretreated with steroids. Over two-thirds of patients were pretreated with antibiotics (69.5%, n = 367). 56.5% (n = 297) of patients were outside referrals. In multivariable regression, patients with corticosteroid pretreatment had lower odds of negative laboratory results (odds ratio [OR] = 0.49, p = 0.001). There were higher odds of negative laboratory results for every additional antibiotic prescribed to a patient prior to presentation (OR = 1.30, p = 0.006) and for specimens collected using ESwabs (OR = 1.69, p = 0.005). Age, prior eye trauma, outside referrals, and contact lens wear were not significantly associated with negative laboratory results. Conclusion More microbial keratitis associated laboratory tests are being taken over time. Over 60% of tests were negative by 2022. Factors associated with negative laboratory test results included pretreatment with antibiotics and specimens collected with the new collection method.

Evaluation of Perfluorohexyloctane Eyedrops in Habitual Contact Lens Wearers.

Dry eye disease is one of the most common disorders we see in practice today. Perfluorohexyloctane (PFHO) ophthalmic solution (MIEBO®) (©Bausch + Lomb) is a novel, non-aqueous, single entity, preservative-free ophthalmic drop recently approved by the FDA for treatment of the signs and symptoms of dry eye disease. While the safety and efficacy of PFHO has been demonstrated in non-contact lens wearers, its safety and potential benefits in habitual contact lens wearers have not been explored. This report presents the results of a trial designed to evaluate the safety of PFHO and its effect on contact lens comfort, specifically in established contact lens wearers. The study included 47 patients who were adjusted contact lens wearers with a best corrected visual acuity of 20/25 or better at distance. All the patients were healthy contact lens wearers with no dry eye symptoms. A significant improvement in comfort scoring was observed without any significant changes in osmolarity, meibography scores, and total fluorescein staining. These findings suggest that PCHO is safe for contact lens wearers to use and shows promise to reduce contact lens dropout.

TFOS lifestyle report: Effects of contact lenses on the ocular surface and adnexa

This presentation summarizes the evidence‐based findings of the Contact Lens Subcommittee of the recent Workshop of the Tear Film &amp; Ocular Surface Society, entitled “A Lifestyle Epidemic: Ocular Surface Disease” (www.tearfilm.org).Several risk factors can increase the potential for complications associated with contact lens wear, such as ignoring appropriate contact lens care, disregarding an ocular or systemic disease (especially if associated with an unhealthy ocular surface), reduced clinical surveillance and the simultaneous use of excessive alcohol, tobacco, or recreational drugs. The recent pandemic has introduced novel challenges to the wear of contact lenses, including mask associated dry eye, discomfort and fatigue with digital devices, accidental exposure to hand sanitizers and a decreased duration of contact lens wear. Adverse environments for lens wearers, such as pollution, dust, smoke, and sport or work accidents determining ocular trauma, can represent challenges for the use of contact lens, though protective in some cases. To ensure the best outcomes for contact lens wearers in adverse situations, prescription choice should consider several factors, including night driving, sports, wear at high altitude, military application, and outer space environments.This presentation synthetises the lifestyle‐related choices made by both clinicians and contact lens wearers, and underlines that, if appropriately undertaken, these can positively impact contact lens wearers quality of life. A systematic review and meta‐analysis highlight the need to better understand the influence of lifestyle factors on contact lens dropout.

Microbial keratitis in Sao Paulo, Brazil: a 10-year review of laboratory results, epidemiological features, and risk factors.

To study epidemiological data, laboratory results, and risk factors associated with microbial keratitis. We conducted a retrospective study of corneal sample cultures from patients with microbial keratitis from January 2010 to December 2019. Results were analyzed according to the etiological diagnosis of bacterial, mycotic, or parasitic infection and were associated with related risk factors. We analyzed 4810 corneal samples from 4047 patients (mean age 47.79 ± 20.68 years; male 53.27%). The prevalence of bacterial, fungal, and Acanthamoeba infections were 69.80%, 7.31%, and 3.51%, respectively. The most frequently isolated bacteria were coagulase-negative Staphylococcus (CoNS) (45.14%), S. aureus (10.02%), Pseudomonas spp. (8.80%), and Corynebacterium spp. (6.21%). Among CoNS, the main agent was S. epidermidis (n=665). For mycotic keratitis, Fusarium spp. (35.42%) and Candida parapsilosis (16.07%) were the most common agents among filamentous and yeasts isolates, respectively. Contact lens use was associated with a positive culture for Acanthamoeba spp. (OR = 19.04; p < 0.001) and Pseudomonas spp. (OR = 3.20; p < 0.001). Previous ocular trauma was associated with positive fungal cultures (OR = 1.80; p = 0.007), while older age was associated with positive bacterial culture (OR = 1.76; p = 0.001). Our findings demonstrated a higher positivity of corneal sample cultures for bacteria. Among those, CoNS was the most frequently identified, with S. epidermidis as the main agent. In fungal keratitis, Fusarium spp. was the most commonly isolated. Contact lens wearers had higher risks of positive cultures for Acanthamoeba spp. and Pseudomonas spp. Ocular trauma increased the risk of fungal infection, while older age increased the risk of bacterial infection.

In vitro compatibility study of a new preservative‐free multidose 0.6% bilastine eye drop formulation containing sodium hyaluronate with soft and gas rigid permeable contact lenses

Aims/Purpose: Despite many patients with allergic conjunctivitis are contact lens wearers, research on the physical compatibility of antihistamine eye drops and contact lenses is lacking. The aim of this work was to evaluate the in vitro compatibility of a new preservative‐free bilastine eye drops with the main types of contact lenses.Methods: The physical compatibility of a new preservative‐free bilastine eye drops in comparison with an isotonic saline solution, was evaluated in three types of contact lenses: hydrogel, silicone hydrogel and gas rigid permeable. Physical properties evaluated: diameter of the lens, posterior vertex power, radius of curvature, physical appearance, and spectral transmittance were characterized. For initial characterization, the lenses (n = 60) were equilibrated in a saline solution at 20–25°C for 24 h. After, 10 lenses of each type were separately immersed in either the saline solution or the bilastine formulation, both at 20–25°C, for 1 h, and then subjected to 30 wash cycles. The physical characterization was carried out after 1, 15 and 30 wash cycles, measurements performed in triplicate. Measurement methods and tolerance limits of the physical properties and general procedure and performance criteria for assessing the physical compatibility of contact lens were conducted in accordance with the guidelines (UNE‐EN ISO 18369‐3:2007; UNE‐EN ISO 18369‐2:2007; UNE‐EN ISO 11981:2013).Results: The incubation of contact lenses with the new preservative‐free bilastine eye drop formulation did not affect any of the physical properties of the lenses and the results were comparable to those exposed to the control saline solution. The physical properties of all the contact lenses tested in both conditions complied with the manufacturer's specifications and tolerance limits stablished.Conclusion: These results indicate that the new preservative‐free bilastine eye drop is physically compatible with soft and rigid gas permeable contact lens.

Ocular pathogens and antibiotic susceptibility patterns in bacterial keratitis during 2010–2019 in the county of Östergötland, Sweden, a retrospective study

Aim/Purpose: The aim of this study was to identify causative bacterial species, aetiology of infection and determine antibiotic susceptibility in bacterial keratitis in the county of Östergötland, Sweden.Methods: We performed a retrospective search in the regional Electronic Health Record, period 2010–2019, for patients diagnosed with keratitis according to the codes of the International Classification of Disease.Results: One‐hundred and ninety patients with lab culture‐confirmed bacterial keratitis were included in the final analysis. Antimicrobial susceptibility tests were available for all confirmed bacterial keratitis. Laboratory tests revealed a total of 188 (84%) Gram‐positive and 36 (16%) Gram‐negative pathogens. The most frequently reported bacterial species were coagulase‐negative staphylococci (CoNS) (39%), Staphylococcus aureus (17%) and Cutibacterium acnes (10%). Pseudomonas spp. was the most frequently reported Gram‐negative bacterial species (7%). Contact lens wear and severely ill/blind eye were the top two aetiological factors associated with bacterial keratitis. Most of the isolates (157 out of 173) were reported susceptible to first line antibiotics, which are fluoroquinolones, and nearly all (145 out of 155) isolates were susceptible to chloramphenicol ‐ that is the recommended treatment in combination with fluoroquinolones. We did not detect any cases of methicillin‐resistant Staphylococcus aureus. The type of treatment and the outcome of the treatment including visual acuity were assessed in the cohort.Conclusions: Our results revealed a positive rate of bacterial keratitis of 59% for the samples sent to the laboratory. The bacterial species causing keratitis in the current study were consistent over time and the species were susceptible to the recommended antibiotics. These findings indicate patients are receiving the correct treatment.

Changes in corneal sensory nerves activity and the protective mechanisms during ocular surface pathologies

The prevalence of dry eye complaints due to tear production disorders is steadily increasing, mainly due to increased life expectancy and changes in lifestyle (contact lens wear, increased time spent in front of computer screens). However, the prevalence of subjective complaints and clinical symptoms of tear production disorders is variable, with only 10%–30% of the population having both subjective complaints and clinical symptoms. A number of in vivo confocal corneal microscopy (IVCM) studies have been performed to qualitatively and quantitatively examine the corneal nerve network in patients with dry eye disease in an attempt to elucidate the changes in corneal innervation and their clinical significance in the disease. Most studies have reported a decrease in nerve density, which may lead to nerve damage, followed by altered sensitivity of the regenerated nerves in patients with dry eye disease, resulting in hyperalgesia or allodynia. This presentation will summarize the role of corneal sensory nerves in the control of tear secretion in healthy eyes and the changes in some pathologies, particularly in dry eye disease. The changes in corneal sensory function in dry eye disease will be described in detail based on animal and human clinical studies. Knowledge of these changes will help to understand the contradictory relationship between objective symptoms and subjective complaints in dry eye patients.

Long-term Prognosis of Pediatric Ocular Disease.

Several problems differentiate the treatment of children, especially those with congenital ocular disease, from adults, including the absence of complaints and the complication of systemic diseases. However, the most challenging is the continuing developing anatomical and functional development and immaturity in children. Consequently, the timing of disease onset and treatment can greatly affect the prognosis, and the prognosis cannot be confirmed without long-term follow-up periods. The prognosis for unilateral congenital cataract is very poor. However, some cases achieved good vision with successful refractive correction and amblyopia therapy, suggesting that long-term parental enthusiasm and adherence are important for the visual prognosis. Penetrating keratoplasty is rarely performed in children, and outcomes at our hospital have been extremely poor for congenital corneal opacity over the past 28 years. The visual prognosis is also poor for large limbal dermoids approaching the center of the cornea, which did not respond to preoperative amblyopia therapy. Consequently, early excision, lamellar keratoplasty, wearing of hard contact lenses, and amblyopia therapy were considered necessary. Treatment of pediatric ocular disease should consider the pros and cons, methods, and timing, especially the development of the pediatric eye and the time of onset of the disease.