Association Between Serratia marcescens Contamination and Hygiene Compliance in Orthokeratology.

BACKGROUND/AIM: Given the characteristics of Serratia marcescens (S. marcescens), this study aimed at investigating its presence in the hands and contact lens cases of orthokeratology wearers, along with the status of bacterial contamination. PATIENTS AND METHODS: The 39 patients received the questionnaires about the background of orthokeratology and hygiene habits. A total of 39 contact lens cases and 39 hand samples from the patients were collected at Show Chwan Memorial Hospital from June to August in 2020 and sent to National Chung Cheng University for DNA extraction and PCR identification. RESULTS: The results indicated a detection rate of 5.13% for S. marcescens in the contact lens cases and 12.82% in the hand samples. Additionally, 66.67% of contact lens case samples and 30.77% of hand samples found positive for 16s bacterial amplicons. The relationship between hand contamination and the duration of contact lens usage were revealed for both S. marcescens (p=0.021) and 16s bacterial amplicons (p=0.048). CONCLUSION: The results indicated that hand hygiene is more critical than focusing on contact lens hygiene when it comes to preventing S. marcescens infections. Nevertheless, both proper hand and contact lens hygiene practices can reduce the detection of bacterial eye pathogens, especially a common intestinal bacterium.

Current status of contact lenses usage in Korea: A population-based cohort study 2021.

PURPOSE: To investigate trends in contact lens usage in a nationally representative sample of the Korean population in 2021. METHODS: For this retrospective study, we analyzed data of 3,601 Korean participants aged 10-59 years, from the Korea National Health and Nutrition Examination Survey (KNHANES 2021 version), who underwent eye examination, of whom 1,136 individuals (274 men and 862 women) were contact lens users. The demographic trend among Korean contact lens wearers was examined using statistical analyses to investigate the changes in their contact lens-wearing experience, duration of lens use, type of lens used, location of purchase, presence of an Eye Care Practitioner(ECP)'s prescription, lens-related ophthalmic complications, and type of lenses worn at the time of complications, according to sex. Multivariable logistic regression analysis was conducted to examine the association of each variable with the rate of complications and use of soft lenses. RESULTS: The average age of the contact lens users was 33.42±0.33 years, with 70.36% (weighted percentage) of users being women who used contact lenses for significantly longer periods than men (p<0.001). Additionally, only wearing of cosmetic lenses was significantly correlated with the occurrence of complications (p = 0.006), and 6.76% of users purchased lenses without a prescription. Multivariate analysis among the contact lens users revealed a significant relationship between the complication rate and female sex (p = 0.002), pre-existing eye disease diagnosed by ECPs (p = 0.0288), and duration of contact lens use (p<0.0001). CONCLUSION: We identified sex differences in contact lens usage trends in Korea. The main changes observed were an increase in middle-aged lens users and a decrease in female users compared to that in the early 2000s. In addition, contact lens complications were significantly associated with sex and pre-existing eye disease. Therefore, those wearing contact lenses for extended periods should exercise caution and consult eye care specialists in the presence of any symptoms.

Differentiation of acanthamoeba keratitis from other non-acanthamoeba keratitis: Risk factors and clinical features.

INTRODUCTION: Infectious Keratitis is one of the most common ocular emergencies seen by ophthalmologists. Our aim is to identify the risk factors and clinical features of Acanthamoeba Keratitis (AK). METHODS: This retrospective chart review study was conducted at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, and included all the microbial keratitis cases, male and female patients of all ages. The main outcome is the differentiation between various microbial keratitis types. RESULTS: We included 134 consecutive eyes of 126 persons. We had 24 cases of acanthamoeba keratitis, 22 bacterial keratitis, 24 fungal keratitis, 32 herpetic keratitis, and 32 bacterial co-infection. Contact lens wear was found in 33 eyes (24.6%). Among acanthamoeba keratitis patients, 73% were ≤ 39 years of age, and 73% were females (P <0.001). Also, in AK cases, epithelial defect was found in all cases (100%), endothelial plaques were found in 18 eyes (69.2%), 12 cases had radial keratoneuritis (46.2%), and ring infiltrate was found in 53.8% of AK cases. CONCLUSIONS: We determined the factors that increase the risk of acanthamoeba infection and the clinical characteristics that help distinguish it from other types of microbial keratitis. Our findings suggest that younger females and patients who wear contact lenses are more likely to develop acanthamoeba keratitis. The occurrence of epitheliopathy, ring infiltrate, radial keratoneuritis, and endothelial plaques indicate the possibility of acanthamoeba infection. Promoting education on wearing contact lenses is essential to reduce the risk of acanthamoeba infection, as it is the most significant risk factor for this infection.

Persistence of Contact Lens-Induced Corneal Parainflammation Following Lens Removal.

Purpose: Contact lens wear induces corneal parainflammation involving increased immune cell numbers after 24 hours' (CD11c+, Lyz2+, γδ-T cells) and six days' (Ly6G+ cells) wear. We investigated the time course of onset and resolution of these responses. Methods: LysMcre or C57BL/6J mice were fitted with a contact lens (four to 48 hours). Contralateral eyes did not wear lenses. After lens removal, Lyz2+, MHC-II+ or Ly6G+ cells were examined by quantitative imaging. RT-qPCR determined cytokine gene expression. Results: Lens wear for 24 hours increased corneal Lyz2+ cells versus contralateral eyes approximately two-fold. Corneas remained free of visible pathology. The Lyz2+ response was not observed after four or 12 hours' wear, nor after 12 hours' wear plus 12 hours' no wear. Lens removal after 24 hours' wear further increased Lyz2+ cells (∼48% after one day), which persisted for four days, returning to baseline by seven days. Lyz2+ cells in contralateral eyes remained at baseline. MHC-II+ cells showed a similar response but without increasing after lens removal. Lens wear for 48 hours showed reduced Lyz2+ cells versus 24 hours' wear with one day discontinuation, correlating with reduced IL-1ß and IL-18 gene expression. Lens wear for 24 hours did not induce Ly6G+ responses six days after removal. Conclusions: Lens-induced corneal parainflammation involving Lyz2+ cells requires 24 hours' wear but persists after lens discontinuation, requiring seven days for reversal. Lens wear for 48 hours may suppress initial Lyz2+ cell and cytokine responses. The significance of parainflammation during and after lens wear remains to be determined.

Efficacy and Safety of Artificial Tears Containing Lipidure and Hypromellose for the Treatment of Moderate Dry Eye Disease in Contact Lens Wearers.

Background and Objectives: Dry eye disease (DED) affects 5-50% of the global population and deeply influences everyday life activities. This study compared the efficacy, tolerability, and safety of novel Respilac artificial tears containing lipidure and hypromellose (HPMC) with the widely used Nextal artificial tears, which are also HPMC-based, for the treatment of moderate DED in contact lenses (CL) wearers. Materials and Methods: In a prospective, single-center, randomized investigation, 30 patients aged ≥18 years, diagnosed with moderate DED, and wearing CL were randomly assigned to the Respilac (n = 15) or Nextal group (n = 15). Patients self-administrated one drop of Respilac or Nextal in both eyes three times daily for 21 days. Changes in the endpoint (visual analogue scale (VAS) score for ocular tolerability, symptom assessment in dry eye (SANDE) score, non-invasive first break-up time (NIF-BUT) results, tear analysis value, meibography results, and CL tolerability results were assessed, comparing treatment groups and time-point evaluations. Adverse events (AEs) were also recorded and evaluated. Results: VAS scores decreased with time (p < 0.001) in both groups, showing no statistically significant difference among them (p = 0.13). Improvements were also detected from screening to end-of-treatment, which were indicated by the SANDE scores for severity and frequency (p < 0.001) and by tear analysis results (p < 0.001) with no observed difference between the Nextal and Respilac arms. NIF-BUT, meibography, and CL tolerability values were shown to be non-significantly affected by treatment and time. There were no AEs detected in this study cohort. Conclusions: Respilac was confirmed to be effective, safe, and well-tolerated. Lipidure-based ophthalmic solution was shown not to be inferior to the currently used Nextal, however, showing improvements in DED symptoms. Within the existing literature, our study is one of the first to report that MPC plus HPMC-containing eye drops are an effective option for the treatment of moderate dry eye disease and desiccation damage prevention in contact lens wearers.

Lens and solution properties in patients with and without midday fogging.

INTRODUCTION: Midday fogging is a complication of scleral lens (SL) wear that interrupts clear vision during the course of wear. SLs can be made with a variety of gas permeable materials, sizes and surface treatments, and various solutions are available for storing the lenses and for filling them before application on the eye. Many of these factors have been implicated as possible contributors to midday fogging. This study explored the lens and solution properties in habitual SL wearers with and without midday fogging. METHODS: In this prospective study, 48 habitual SL wearers were evaluated and asked to report whether they experienced midday fogging and if they removed their lenses during the day. They completed the Ocular Surface Disease Index (OSDI), which is a validated tool for dry eye assessment. Lens parameters (material, coatings and diameter) and lens storage and filling solutions were documented. Backward elimination of regression terms evaluated the lens and solution properties in those with and without fogging. OSDI scores were compared using the Mann-Whitney analysis. RESULTS: Collectively, the lens properties and solutions accounted for 27.7% of the variance related to midday fogging. None of the factors alone had a significant impact upon midday fogging. The median (interquartile range) OSDI score for those with fogging [37 (35)] was significantly different from those without fogging [10 (15)], with the scores corresponding to severe dry eye and normal eyes, respectively. CONCLUSION: SL wearers with midday fogging exhibited similar symptoms to patients with severe dry eye. Lens and solution characteristics may play a small role in patients with midday fogging, although changing just a single factor is not likely to impact its presence.

[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.

Multi-Target Effect of Aloeresin-A against Bacterial and Host Inflammatory Targets Benefits Contact Lens-Related Keratitis: A Multi-Omics and Quantum Chemical Investigation.

Contact lens-mediated microbial keratitis caused by Pseudomonas aeruginosa and Streptococcus pneumoniae provokes corneal damage and vision loss. Recently, natural phytochemicals have become complementary medicines for corneal destruction. Herein, we aimed to identify multi-targeting Aloe vera-derived phytochemicals capable of inhibiting bacterial and host targets of keratitis through ADME (absorption, distribution, metabolism, and excretion), docking, molecular dynamics (MD) simulation, MMGBSA (molecular mechanics generalized Born surface area) and density functional theory (DFT) investigations. An extensive literature search revealed ExoU, ExoS, ExoT, ExoY, and PLY as virulent bacterial targets. Simultaneously, differential gene expression (DGE) and pathway enrichment analysis-specified host transcription factor (SPI1) influences keratitis pathogenesis. Molecular docking analysis uncovered aloeresin-A as a promising inhibitor against bacterial and host targets, demonstrating strong binding energies ranging from -7.59 to -6.20 kcal/mol. Further, MMGBSA and MD simulation analysis reflect higher binding free energies and stable interactions of aloeresin-A with the targets. In addition, DFT studies reveal the chemical reactiveness of aloeresin-A through quantum chemical calculations. Hence, our findings show aloeresin-A to be a promising candidate for effectively inhibiting keratitis. However, additional research is imperative for potential integration into lens care solutions.

Lentes de contacto y disbiosis ocular, de lo transitorio a lo patológico / Contact lenses and ocular dysbiosis, from the transitory to the pathological

La microbiota ocular normal está compuesta por diferentes comunidades bacterianas Gram negativas y positivas que actúan en la superficie ocular como comensales. Un desequilibrio en la homeostasis de las especies nativas o disbiosis desencadena alteraciones funcionales que eventualmente pueden conllevar afecciones oculares, señalándose al uso de lentes de contacto como el factor predisponente más relevante. Mediante una revisión bibliográfica que incluyó artículos científicos publicados entre el año 2018 y 2022, se analizó la relación entre la microbiota ocular sana, la disbiosis asociada al uso de lentes de contacto que desencadena afecciones oculares. La microbiota ocular en individuos sanos, se compone principalmente por bacterias de los filos: proteobacterias, actinobacteria y firmicutes. Estas comunidades bacterianas al verse asociadas al uso de lentes de contacto desarrollaron disbiosis, observándose un aumento de ciertos géneros como Staphylococcus spp. y Pseudomonas spp., que en condiciones normales son comensales de la superficie ocular, pero al estar aumentada su abundancia condicionan la aparición de diversas afecciones oculares como eventos infiltrativos corneales, queratitis y úlcera corneal bacterianas. Dichas patologías tienden a evolucionar de manera rápida, lo que, sumado a una detección y tratamiento tardíos, puede determinar un pronóstico visual deficiente. Se sugiere que, frente a diversas afecciones de la superficie ocular, los profesionales en el área de oftalmología conozcan la composición de las comunidades de microorganismos que conforman esta microbiota ocular, de manera de distinguir e identificar correctamente el agente causal y, con ello, brindar un tratamiento adecuado y efectivo al usuario (AU)

Normal ocular microbiota is composed of different Gram-negative and positive bacterial communities that act as commensals on the ocular surface. An imbalance in the homeostasis of the native species or dysbiosis triggers functional alterations that can eventually lead to ocular conditions, indicating the use of contact lenses as the most relevant predisposing factor. Through a bibliographic review that added scientific articles published between 2018 and 2022, the relationship between healthy ocular microbiota and dysbiosis associated with the use of contact lenses that trigger ocular conditions was analyzed. The ocular microbiota in healthy individuals is mainly composed of bacteria from the phyla: proteobacteria, actinobacteria and firmicutes. These bacterial communities associated with the use of contact lenses develop dysbiosis, observing an increase in certain genera such as Staphylococcus spp. and Pseudomonas spp., which under normal conditions are commensals of the ocular surface, but as their abundance is increased, they condition the appearance of various ocular conditions such as corneal infiltrative events, bacterial keratitis and corneal ulcer. These pathologies tend to evolve rapidly, which, added to late detection and treatment, can lead to a poor visual prognosis. It is suggested that professionals in the ophthalmology area learn about the composition of the communities of microorganisms that make up this ocular microbiota, in order to correctly distinguish and identify the causative agent, thereby providing a adequate and effective treatment to the user (AU)

Behaviour of hTERT in the tears of neophyte contact lens wearers during the sleep/wake cycle.

PURPOSE: To investigate the behaviour of telomerase reverse transcriptase (hTERT) in the tears of healthy neophyte contact lenses-wearing individuals during the sleep/wake cycle. A subsequent aim was to investigate whether hTERT behaviour was associated with inflammatory mediators interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in tears. METHODS: Flush tears were collected from 19 healthy, non-contact lens-wearing participants (11 males, 8 females, mean age 31.9 ± 5.7 years), before and during contact lens wear. Tears were collected at noon, before sleep and upon awakening and levels of hTERT, IL-6 and TNF-α, were determined using enzyme-linked immunosorbent assays (ELISA). RESULTS: hTERT levels (median [interquartile range]) during contact lens wear were significantly higher before sleep (436.5 (263.9 - 697.7) ng/ml compared to the same time point without contact lenses (256.1 (0.0 - 590.9) ng/ml (p = 0.01). There was no difference between contact lens wear (851.3 [353.2 - 2109.9]) ng/ml, and no wear (1091.0 [492.3 - 3045.4]) ng/ml, upon awakening (p = 0.94). A significant increase was found upon awakening compared to before sleep, irrespective of the presence of a contact lens (p = 0.02). IL-6 and TNF-α levels in tears were below the limit of detection. CONCLUSIONS: The study showed that hTERT increases after a contact lens is placed on the eye, but this change is small, compared to the impact of overnight eye closure. Taken together with the lack of responses of the inflammatory markers monitored at the same time points, this may suggest that hTERT can respond both to low-level stress stimuli acting on the ocular surface, and to situations where inflammation is a likely factor.

High Astigmatism Secondary to Peripheral Ectasia Recurrence in Postpenetrating Keratoplasty Eyes Managed With Miniscleral Contact Lenses.

OBJECTIVES: After penetrating keratoplasty (PK) for keratoconus, vision can be impaired by high-degree astigmatism, particularly in those patients with recurrent peripheral ectasia. Scleral contact lenses (CLs) have long been used in the management of keratoconus both in treatment-naive corneas and those postcorneal transplants. We report the use of miniscleral CLs and their related visual and clinical outcomes in a series of patients with post-PK peripheral rim ectasia. METHODS: In this retrospective case series, 5 patients (7 eyes) presented because of reduced visual acuity with their spectacles/CLs and/or reduced comfort with their existing rigid gas-permeable lenses. All patients in this series underwent PK more than two decades ago for keratoconus (mean 28.7 years±7.2). All patients demonstrated characteristic thinning at the graft-host junction, with anterior chamber deepening. Central corneas had remained clear in all patients inferring high visual potential. Contact lenses used were No 7 Comfort 15 miniscleral and the Onefit MED scleral with 14.5 mm and 15.6 mm diameters, respectively. RESULTS: All eyes achieved a best-corrected visual acuity of 6/9 or greater. One case had difficulty with insertion and removal and has since discontinued wearing lens at this time. All others are successfully wearing the lenses regularly. CONCLUSION: Despite advances in CL design, surgical management is still required in some patients. Miniscleral CLs are effective in the refractive management of peripheral ectasia in keratoconic post-PK eyes and should be considered in such eyes before proceeding with repeat surgical intervention.

Contact lenses and ocular dysbiosis, from the transitory to the pathological.

Normal ocular microbiota is composed of different Gram-negative and positive bacterial communities that act as commensals on the ocular surface. An imbalance in the homeostasis of the native species or dysbiosis triggers functional alterations that can eventually lead to ocular conditions, indicating the use of contact lenses as the most relevant predisposing factor. Through a bibliographic review that added scientific articles published between 2018 and 2022, the relationship between healthy ocular microbiota and dysbiosis associated with the use of contact lenses that trigger ocular conditions was analyzed. The ocular microbiota in healthy individuals is mainly composed of bacteria from the phyla: Proteobacteria, Actinobacteria and Firmicutes. These bacterial communities associated with the use of contact lenses develop dysbiosis, observing an increase in certain genera such as Staphylococcus spp. and Pseudomonas spp., which under normal conditions are commensals of the ocular surface, but as their abundance is increased, they condition the appearance of various ocular conditions such as corneal infiltrative events, bacterial keratitis and corneal ulcer. These pathologies tend to evolve rapidly, which, added to late detection and treatment, can lead to a poor visual prognosis. It is suggested that professionals in the ophthalmology area learn about the composition of the communities of microorganisms that make up this ocular microbiota, in order to correctly distinguish and identify the causative agent, thereby providing a adequate and effective treatment to the user.

Clinical comparative analysis of bacterial keratitis according to contact lens use: a retrospective study in a tertiary referral center of South Korea.

PURPOSE: To compare the clinical aspects and treatment outcomes of contact lens-related bacterial keratitis (CLBK) and non-CLBK patients. METHODS: Altogether 217 patients of bacterial keratitis (CLBK; 62, non-CLBK; 155) hospitalized between January 2012 and December 2020 were retrospectively analyzed for epidemiology, microbiological profiles, predisposing factors, clinical characteristics, and treatment outcomes. Poor treatment outcomes (PTO) were defined as a final BCVA < 0.3 (Snellen), a decreased visual acuity after treatment, complications, or surgical intervention. Relative importance of the initial clinical features leading to PTO was assessed using the random forest model and two-proportion Z-test. RESULTS: The most common predisposing factors were sleeping with wearing CL (51.6%) in the CLBK group and trauma (55.5%) in the non-CLBK group. There were significant differences between the two groups in mean age (35.1:55.1 years, p < 0.001), female sex (56.5:34.8%, p = 0.003), symptom duration (6.2:6.9 days, p = 0.019), gram-negative organisms (83.3:48.3%, p = 0.008), epithelial healing time (8.5:14.1 days, p = 0.004), final BCVA (0.15:0.46 logMAR, p = 0.015), and PTO (9.7:21.9%, p = 0.035). For the entire group, the initial BCVA < 0.1 (27.9%), symptom duration ≥ 5 days (19.4%), age ≥ 60 years (16.4%), and hypopyon (14.0%) were important initial clinical features leading to PTO in the random forest model. In CLBK group, the type of CL or CL-related history was not significantly related to PTO. CONCLUSION: CLBK patients had a higher proportion of females, younger age, gram-negative bacteria, and better treatment outcomes than those of non-CLBK patients. There were no significant risk factors leading to PTO in either the type of CL or CL-related history.

Visual discomfort and contact lens wear: A review.

The purpose of this manuscript is to describe how vision influences contact lens discomfort and review the evidence supporting the hypothesis that contact lens discomfort can be caused by vision and vision-related disorders. Contact lens discomfort is a misunderstood and difficult to manage clinical condition. Most treatments and strategies aimed at alleviating discomfort focus on optimizing the contact lens fit and its relationship with the ocular surface, but these strategies commonly fail at relieving discomfort symptoms. Many vision and vision-related disorders share symptoms with those reported by uncomfortable contact lens wearers. This paper will review evidence and literature that describes how these vision and vision-related disorders may influence comfort in contact lens wearers. Acknowledging how vision influences contact lens discomfort will improve future research intended to better understand the condition, allow for more effective clinical management, and reduce rates of discontinuation.

Nutrient Supplementation Improves Contact Lens-Induced Corneal Cell Damage Based on a SIRC Cellular Model.

OBJECTIVES: The long-term use of contact lenses may damage the structure of the ocular surface and cause metabolic disorders in corneal cells. Vitamins and amino acids help maintain the physiological function of the eye. In the present study, the effects of nutrient (vitamin and amino acid) supplementation on corneal cell repair after contact lens-induced damage was investigated. METHODS: High-performance liquid chromatography was used to quantify the nutrient contents of minimum essential medium, and the MTT assay was used to measure the viability of corneal cells. A Statens Seruminstitut rabbit cornea cellular model was established to simulate contact lens-induced keratopathy and investigate the effects of vitamin and amino acid supplementations on corneal cell repair. RESULTS: The high water content lens group (78%) has a cell viability as high as 83.3%, whereas the cell viability of the low water content lens group (38%) is only 51.6%. The 32.0% difference between the two groups confirms the correlation between water content of lens and corneal viability. CONCLUSIONS: Vitamin B2, vitamin B12, asparagine, and taurine supplementation may help improve contact lens-induced damage.

Corneal oedema during reverse piggyback scleral lens wear.

PURPOSE: One clinical approach to address poor front surface wettability during scleral lens wear is the use of a "reverse piggyback" system (a soft contact lens applied to the anterior surface of a scleral lens). The aim of this study was to compare the magnitude of corneal oedema induced following short-term reverse piggyback scleral lens wear and standard scleral lens wear. METHODS: Ten young (mean age 22 ± 6 years) healthy participants with normal corneas were recruited. On separate days, central corneal thickness and fluid reservoir thickness were measured using optical coherence tomography before and after 90 min of standard scleral lens wear (Kerectasia Alignment Tangent Torus diagnostic lenses, hexafocon A, Dk 100 × 10-11 (cm2 /s)(ml O2 /ml × mmHg), Capricornia Contact Lenses, capcl.com.au) and reverse piggyback scleral lens wear (the same scleral lens with a Dailies Total 1®, delefilcon A, Dk 140 × 10-11 (cm2 /s)(ml O2 /ml × mmHg), Alcon, alcon.com, applied to the anterior scleral lens surface). RESULTS: After correcting for small variations in the initial central fluid reservoir thickness, central corneal oedema was similar between the reverse piggyback (2.32 ± 1.15%) and standard scleral lens conditions (2.02 ± 0.76%; p = 0.45). CONCLUSIONS: Following 90 min of lens wear, the highly oxygen-permeable reverse piggyback system did not induce a clinically or statistically greater magnitude of central corneal oedema compared with standard scleral lens wear in young adults with healthy corneas. This approach may be suitable to address poor front surface scleral lens wettability or to correct residual refractive error during diagnostic scleral lens fitting.

Norepinephrine as the Intrinsic Contributor to Contact Lens-Induced Pseudomonas aeruginosa Keratitis.

Purpose: Contact lens wear (CLW) is one of the leading risk factors for Pseudomonas aeruginosa keratitis (PAK). However, the intrinsic factors that contribute to the high susceptibility to keratitis during CLW remain to be elucidated. CLW over an extended period can elevate corneal norepinephrine (NE) concentration. In this study, we investigated the role of NE in promoting PAK. Methods: We constructed an injury-induced PAK model and a CLW-induced PAK model to confirm the impact of NE during corneal infection. Pharmacological blockage of NE and gene knockdown mouse were used to investigate the downstream effector of NE. RNA sequencing was performed to explore the cellular alterations during NE treatment. Non-parametric Mann-Whitney U test or Kruskal-Wallis test were used to ascertain the significance (P < 0.05). Results: Supplementation of NE led to PAK even without artificial corneal injury during CLW. The effect was mediated by the ß2-adrenergic receptor (ß2-AR) in the corneal epithelium. The ß2-AR blockage by the NE antagonist ICI118,551 (ICI) or by deleting of its encoding gene Adrb2 significantly alleviated infection during CLW. Conversely, ß2-AR activation compromised the integrity of the epithelium and significantly increased the cortical plaque marker ezrin. Transcriptome analysis identified that the protective effect of ICI on the keratitis was mediated by dual-specificity phosphatases. Suramin, a Dusp5 antagonist, abrogated the protective effect of ICI. Conclusions: These data reveal a new mechanism by which NE acts as an intrinsic factor that promotes CLW-induced PAK and provide novel therapeutic targets for treating keratitis by targeting NE-ß2-AR.

Long-term effect of using hard contact lenses on corneal endothelial cell density and morphology in ophthalmologically healthy individuals in Japan.

The adverse effects of hard contact lenses (HCL) on the corneal endothelium have been studied in the short term; however, long-term effects remain still unclear. In this study, we analyzed the effect of long-term HCL use on corneal endothelial cell density (ECD) and morphology in healthy Japanese individuals. This cross-sectional observational study included individuals using HCL for refractive errors examined at a single specialty eye hospital. Patient age, duration of HCL usage, ECD, coefficient of variation of the cell area (CV), and rate of appearance of hexagonal cells (6A) obtained via non-contact specular microscopy were assessed. We analyzed 8604 eyes (mean age: 35.6 ± 10.0 years, 837 males, 3465 females). The mean duration of HCL usage was 14.7 ± 9.1 (range, 1-50) years. Multivariate analysis revealed that ECD significantly correlated with age (P < 0.001) but not with duration of usage; however, CV and 6A significantly correlated with both factors (P < 0.001). Univariate analysis revealed that CV and 6A correlated with duration of usage (all, P < 0.001). According to our results, CV and 6A correlated with the duration of HCL usage in ophthalmologically healthy Japanese individuals. Therefore, it is important to monitor corneal endothelial morphology in long-term HCL wearers.