Search Results (82)

Objectives: The aim was to present the complicated diagnostic and therapeutic process of atypical, painless keratitis caused by a cosmopolitan protozoan of the genus Acanthamoeba. Methods: This Case Report describes a medical case involving a 48-year-old woman who occasionally wears soft contact lenses and was referred to our hospital for treatment due to deteriorating visual acuity in her left eye. The diagnostic process included the isolation of amoebae from corneal scrapings and the morphological and molecular identification of the etiological agent of the infection. Results: After examination, painless atypical keratitis was diagnosed, initially considered recurrent herpetic keratitis. However, antiviral treatment did not bring about any improvement. Further observation revealed a dense, central, annular infiltrate on the periphery of the cornea. Despite treatment, the corneal infiltrate did not improve and the patient required therapeutic penetrating keratoplasty. Ultimately, the patient underwent combined surgery: corneal transplantation with cataract phacoemulsification and intraocular lens implantation. The postoperative course was uneventful. Conclusions: Acanthamoeba keratitis should be included in the differential diagnosis of keratitis, even in the absence of its characteristic feature of severe ocular pain, especially in contact lens wearers and patients who have had herpetic keratitis. Infection of the cornea with the Herpes simplex type 1 virus causes nerve degeneration, which probably translates into a painless course of Acanthamoeba castellanii infection. Full article

Background: The World Health Organization defines myopia as a global epidemic. Its growing prevalence and the increasingly early age onset all raise a major concern for public health due to the elevated risk of loss and deterioration of visual function as a result of myopia-related ocular pathological complications. However, it remains unclear whether the vision-related quality of life of patients with myopia is the same as in healthy individuals. The aim of the present study is to assess the quality of life in children and adolescents with myopia between the ages of 8 and 16 years, who underwent observation at USBOBAL-Varna. Methods: This study prospectively included 190 patients with myopia between −1.00 and −5.50 D, corrected with different optical aids. After a thorough physical ocular examination and inquiry into the best visual acuity with and without distance correction, specially designed questionnaires were completed by the patients and their parents/guardians for the purpose of the study. The data from the questionnaires was statistically processed. The mean age of the patients in the study was 11.65 years, 101 were female and 89 were male. Of these, 83 wore monofocal glasses, 50 were monofocal and 47 were multifocal contact lenses, and 10 wore ortho-K lenses. Results: No significant difference in best corrected visual acuity (BCVA) was found among the three types of optical correction (p-value > 0.05). Cronbach’s alpha of the questionnaire for all 10 factors was higher than 0.6, indicating acceptable internal consistency. Significantly higher scores were reported for overall, near, and distance vision, symptoms, appearance, attitude, activities and hobbies, handling, and perception for soft contact lens wearers than for spectacle wearers (p-value < 0.05). Ortho-K wearers performed better than spectacle wearers in all aspects except for pronounced symptoms (p = 0.74). No significant difference was found between ortho-K wearers and soft contact lens wearers for any factor (p > 0.05). Conclusions: Patients wearing spectacles and with myopia above −5.00 D had the highest anxiety scores and lower quality of life among all myopic participants. The research on the quality of life in children with myopia with different refractive errors and optical correction devices is crucial for improving corrective devices and meeting the needs of patients. Full article

Pseudomonas aeruginosa (P. aeruginosa) is a common antibiotic-resistant pathogen, posing significant public health threats worldwide. It is a major cause of ocular infections, mostly linked to contact lens wear. P. aeruginosa often produces biofilm during infections, and these are also associated with antibiotic resistance. Bacteriophage (phage) therapy is emerging as a promising approach for treating multidrug-resistant P. aeruginosa. Objective: This study aimed to assess the antibiofilm effects of six phages against P. aeruginosa biofilms isolated from patients with corneal infections. Method: This study examined P. aeruginosa strains for their ability to form biofilms using crystal violet assay. Six P. aeruginosa bacteriophages (DiSu1 to DiSu6) were used, which were isolated from sewage water in Melbourne, Australia. Spot tests were used to assess phage sensitivity. The effect of phages against P. aeruginosa strains was determined using time–kill assay and efficiency of plating. The ability of phage to inhibit biofilm formation over 24 h or reduce preformed biofilms was also studied and confirmed using confocal laser scanning microscopy with Live/Dead staining. Result: After 24 h of incubation, all tested P. aeruginosa strains formed moderate to strong biofilms. All P. aeruginosa strains were sensitive to at least four of the six phages. The highest level of bacterial growth inhibition in the liquid infection model was observed when phages were applied at a multiplicity of infection (MOI) of 100. Certain bacteria/phage combinations were able to inhibit biofilm formation over 24 h, with the combination of strain PA235 and phage DiSu3 producing the highest inhibition (83%) at a MOI of 100. This was followed by the combinations of PA223/DiSu3 (56%), and PA225/DiSu5 (52%). For the reduction in preformed biofilms, the best combinations were PA235 (90%), PA221 (61%), and PA213 and PA225 (57% each), all with DiSu3 after 3 h. However, exposing the biofilm with phages for over 24 h appeared to promote phage resistance as there was evidence of biofilm growth, with the only combination still showing a significant reduction being PA221/DiSu3 (58%) at MOI of 100. Conclusions: This study showed that the effect of phages against P. aeruginosa is concentration (MOI) dependent. Phages at higher MOI have the ability to disrupt, inhibit, and reduce P. aeruginosa biofilms. However, prolonged exposure of the biofilm with phages appeared to promote phage resistance. To enhance phage efficacy and address this form of resistance, further studies utilizing phage cocktails or a combination of phages and antibiotics is warranted. Full article

Dry eye disease (DED) is a common, multifactorial disorder of the ocular surface. Although DED can affect individuals at any age, its prevalence, clinical manifestations, underlying mechanisms, and optimal management strategies differ considerably across the lifespan. In children, symptoms are frequently associated with atopy and allergic disorders and environmental factors, whereas in young adults, digital device usage and contact lens wear are the predominant contributors. In older adults, systemic diseases and polypharmacy significantly elevate the risk of DED. Across all age groups, tear film instability, decreased tear production, and chronic inflammation are central pathogenic features. Key tear biomarkers, such as pro-inflammatory cytokines, have been widely linked to disease development. Cathepsin S and tumor necrosis factor-alpha have recently been implicated in age-related DED. A nuanced understanding of these age-related differences is crucial for improving diagnostic accuracy and tailoring interventions to specific patient populations. This review synthesizes current evidence on DED across age groups, focusing on prevalence, risk factors, pathophysiology, molecular mechanisms, coexisting conditions, biomarkers, and treatment options. Finally, it highlights critical unmet clinical needs in the management of age-related DED. Full article

Myopia patients wear rigid gas-permeable contact lenses during the day to achieve normal vision, but they might feel uncomfortable, since they are made of hard materials that can cause inappropriate friction and adhesion. These forces affect the biological tissues of the cornea and eyelid. In this study, an in vitro rigid gas-permeable contact lens friction testing method was established to mimic the friction between the eyelid and the rigid contact lens. The lens was rubbed against a gelatin membrane to investigate the tribological properties of artificial tear, saline, and two kinds of care solutions using a dedicated experimental setup. The viscosity, pH value, and surface tension of each lubricant was also analyzed. The friction coefficient of the artificial tear solution was the highest: 0.18 for its static friction and 0.09 for its dynamic friction. In contrast, polysaccharide-containing care solution demonstrated the lowest friction coefficient. The viscosity of artificial tear solutions ranged from 0.97 ± 00 to 1.15 ± 0.16 mPa·s, when the shear rate was increased from 19.2 to 192 1/s, while it ranged from 2.26 ± 1.12 to 2.91 ± 0.00 for polysaccharide-containing care solution. Although the physical–chemical properties of various lubricants could not explain the distinct tribological outcomes, the in vitro tribological testing method for rigid gas-permeable lenses was successfully established in this study. Full article

Swimming goggles still face numerous challenges in practical use, including deterioration and failure of anti-fog coatings, residual water marks on lens surfaces, and relatively short service life in complex environments. When swimming outdoors during winter, goggles also present an icing problem. To address these problems and enhance the performance of swimming goggles, this study employs a combination of plasma cleaning and mechanical spraying methods, utilizing HB-139 SiO₂ to modify the surface of goggle lenses, thereby fabricating lenses with superhydrophobic properties. The changes in lens surfaces before and after friction and immersion treatments were characterized using three-dimensional profilometry and scanning electron microscopy, further investigating the hydrophobic, drag-reducing, wear-resistant, and anti-icing properties of the lenses. Experimental results demonstrate that SiO₂ can enhance the hydrophobic, drag-reducing, durability, and anti-icing performance of the lenses. Under standard conditions, the contact angle of modified samples reached 162.33 ± 3.15°, representing a 48.77 ± 2.15% improvement over original samples. Under friction conditions, modified samples exhibited a 45.86 ± 2.53% increase in contact angle compared to original samples, with Sa values decreasing by 58.64 ± 3.21%. Under immersion conditions, modified samples showed a 54.37 ± 2.44% increase in contact angle relative to original samples. The modified samples demonstrated excellent droplet bouncing performance at temperatures of −10 °C, 10 °C, and 30 °C. De-icing efficiency improved by 14.94 ± 2.37%. Throughout the experimental process, SiO₂ demonstrated exceptional hydrophobic, drag-reducing, durability, and anti-icing capabilities. This establishes a robust foundation for the exemplary performance of swimming goggles in both training and competitive contexts. Full article

The biomechanical and optical properties of the cornea are responsible for its functional response, structural integrity and refractive function. Corneal viscoelasticity is the cornea’s ability to absorb transient increases in intraocular pressure (IOP) and constitutes a biomarker of glaucoma. The use of silicone hydrogel soft contact lenses (SiH-SCLs) can affect both corneal viscoelasticity and IOP. However, the behavior of the pure elastic and viscous components remains hidden within viscoelastic properties, and their influence and relationship with IOP in the biomechanical changes observed with short-term SiH-SCL use remains unknown. This study investigates the effects of silicone hydrogel soft contact lenses (SiH-SCLs) on corneal elasticity and viscosity and their influence on IOP over different lens wear periods: 10 or 20 consecutive days. Ocular Response Analyzer (ORA) measurements were combined with a biomechanical Standard Linear Solid Model (SLSM) to differentiate and calculate the elastic and viscous components of the cornea. The results showed that after 10 days of lens wear, elasticity and viscosity increased, with a significant reduction in IOP. After 20 days, elasticity and viscosity decreased, with a further reduction in IOP, reflecting a time-dependent effect of SiH-SCLs on corneal biomechanics. The study indicates the potential protective role of corneal viscosity against changes in IOP, which may be used for glaucoma treatment. Full article

Laparoscopic lens fogging and contamination pose significant challenges, leading to a reduced surgical field of view. Intraoperative cleaning to address these issues extends the surgical duration and elevates the risk of surgical site infections. The authors propose that a hydrophilic diamond-like carbon (DLC) coating would effectively mitigate fogging and fouling, thereby eliminating the requirement for intraoperative cleaning, while the scratch-resistant nature of DLC would provide additional benefits. The present study investigates the efficacy of aluminum oxide (Al₂O₃) as a dopant in diamond-like carbon (DLC) films for antifogging applications. The authors hypothesized that adding oxygen to the DLC matrix would increase surface energy by increased hydrogen bonding, resulting in a highly hydrophilic coating. Varying dopant concentrations were tested to observe their effects on hydrophilicity, transparency, biocompatibility, and wear properties. The doped films displayed a notable improvement in transparency throughout the visible spectrum. Plasma-cleaned samples demonstrated a substantial reduction in contact angles, achieving values less than 8°. The biocompatibility of these films was analyzed with CellTiter-Glo assays; the films demonstrated statistically similar levels of cell viability when compared to the control media. The absence of adenosine triphosphate released by blood platelets in contact with the DLC coatings suggests in vivo hemocompatibility. These films, characterized by high transparency, biocompatibility, and biostability, could be valuable for biomedical applications necessitating transparent coatings. Full article

Discomfort is one of the leading causes associated with contact lens dropout. This study investigated changes in the tear film parameters induced by lens wear and their relationship with ocular symptomology. Thirty-four lens wearers (32.9 ± 9.1 years, 7 men) and thirty-three non-lens wearers (29.4 ± 6.8 years, 12 men) participated in this clinical setting. Subjects were categorised into asymptomatic (n = 11), moderate (n = 15), or severe symptomatic (n = 8). Clinical evaluations were performed in the morning, including blink frequency and completeness, pre-corneal (NIBUT) and pre-lens non-invasive break-up (PL-NIBUT), lipid interference patterns, and tear meniscus height. Contact lens wearers had a higher percentage of incomplete blinks (37% vs. 19%, p < 0.001) and reduced tear meniscus height compared to controls (0.24 ± 0.08 vs. 0.28 ± 0.10 mm, p = 0.014). PL-NIBUT was shorter than NIBUT (7.6 ± 6.2 vs. 10.7 ± 9.3 s. p = 0.002). Significant statistical differences between the groups were found in the PL-NIBUT (p = 0.01) and NIBUT (p = 0.05), with asymptomatic recording higher times than symptomatic. Long-term use of silicone–hydrogel lenses can affect tear stability, production, and adequate distribution through blinking. Ocular symptomology correlates with tear stability parameters in both lens wearers and non-wearers. Full article

Background/Objectives: In glaucoma patients, the fluctuation in intraocular pressure during the day seems to have an influence on the progression of the disease. The contact lens sensor (CLS) Triggerfish^® from the company SENSIMED records ocular dimensional changes for 24 h. The aim was to determine the amplitude of the measurements with a contact lens sensor before and after trabeculectomy (TE) in glaucoma patients. Methods: Twelve patients with glaucoma were included in this prospective, single-arm, single-center, interventional study. All patients received a CLS measurement for 24 h 8 ± 2 days before and 12 weeks (±1 week) after surgery. The raw data of the measurements were modeled using a double-harmonic cosine function. Fluctuation in the raw CLS data, amplitude, and the MESOR (midline estimating statistic of rhythm, rhythm-adjusted mean) of the modeled data were investigated. The safety and feasibility of the CLS measurements were evaluated. Results: Nine patients underwent the complete 24-h wearing period before and after surgery. Whereas the MESOR changed significantly before and after surgery (p = 0.04), the amplitude of the modeled data did not change significantly and the daytime fluctuation and circadian rhythm also did not vary significantly. The CLS could be safely removed from all study eyes after surgery. Conclusions: The non-significant change in amplitude suggests that diurnal fluctuations persist after TE. This contrasts with reports in the literature that show that TE reduces diurnal fluctuations. It can be assumed that the significant reduction in the MESOR represents the reduction in the average intraocular pressure over 24 h. The CLS can be used safely three months after TE. Full article

Background/Objectives: Preceding studies have reported the efficacy of multifocal contact lenses (MFCLs) in slowing myopia progression. Recently, a novel type of MFCL, i.e., extended depth-of-focus (EDOF) contact lens (CL), was designed. Here, we retrospectively investigated myopia progression associated with EDOF CL wear. Methods: Twenty-four consecutive myopic children (24 eyes; mean age, 13.9 years) received EDOF CLs to control myopia progression and participated in the study. We measured the axial length (AL), spherical equivalent (SE), and choroidal thickness (CT) at baseline and after 1 year of lens wear and compared the changes. Results: The mean baseline AL, SE, and CT were, respectively, 26.31 mm, −6.38 diopter (D), and 235 μm, and at 1 year 26.40 mm (p = 0.03), −6.61 D (p = 0.05), and 244 μm (p = 0.18). The AL decreased in 20.8% of cases (≧−0.05 mm/year), whereas 20.8% and 58.4% of cases had stabilization of the AL or an increased AL (≧+0.05 mm/year), respectively. The patients with a decreased AL engaged in a mean outdoor activity time of 200.6 min/day, the patients with an increased AL (≧+0.05 mm/year) engaged in a mean outdoor activity time of 126.7 min/day. The change in the AL was correlated significantly with the change in the CT (β = −0.46, p < 0.05), and 80% of patients with a shortened AL had increased CT (≧+20 μm/year). Conclusions: Our data showed that the AL stabilized or decreased in over 40% of myopic patients wearing EDOF CLs. Full article

Purpose: To evaluate how Video Display Terminal (VDT) use, Contact Lens (CL) wear, and eyedrop use affect ocular surface parameters in participants with ocular discomfort and how these factors may vary across different age groups. Methods: The current cross-sectional study initially involved a total of 252 participants who completed a self-administered survey to collect information about ocular discomfort and lifestyle factors. This online survey was composed of an Ocular Surface Disease Index (OSDI) questionnaire and three extra questions regarding lifestyle factors (VDT use, CL wear, and eyedrop use). Only 185 symptomatic participants, those with OSDI values > 12, were scheduled to undergo a comprehensive ocular examination that included tear film osmolarity, Fluorescein Break-Up Time (FBUT), Maximum Blink Interval (MBI), and corneal staining. Results: Differences in ocular parameters and lifestyle factors across age groups (<40 years, 40–60 years, >60 years) were analyzed, along with their correlations and regression. Significant age group differences were found in OSDI, osmolarity, FBUT, and MBI (One-way ANOVA, all p ≤ 0.029). Correlations were observed between CL wear and osmolarity and MBI (Pearson’s correlation, both p ≤ 0.049). Multiple regression confirmed age associations with OSDI, osmolarity, FBUT, and MBI (Multiple linear regression, all p ≤ 0.040) and found links between VDT use and osmolarity and MBI (Multiple linear regression, both p ≤ 0.038) and between eyedrop use and OSDI (Multiple linear regression, p = 0.040). Conclusion: Aging is a primary factor affecting ocular homeostasis, with older adults showing lower FBUT and MBI values and higher osmolarity. Prolonged use of VDTs exacerbates this effect, further contributing to ocular discomfort and destabilized tear film. No associations between CL wear and any of the ocular parameters were found. Eyedrop use shows varied effects on ocular comfort across age groups, emphasizing the need for age-specific ocular care. Overall, these findings confirm that aging and extended VDT use play a significant role in ocular surface discomfort. Full article

Contact lens (CL) wear is a safe method for the correction of refractive errors. However, rare, severe ocular complications may occur which may lead to visual loss. As most of these complications are related to poor patient compliance with care and maintenance instructions, resulting in the contamination of hands, CLs and accessories, it was the purpose of this study to assess hand-washing habits in a sample of Spanish soft CL wearers. Hand hygiene was explored through a self-reported online survey and via an in-office practical demonstration in a subset of those users answering the survey. A total of 198 surveys were analyzed, and 18 CL users participated in the practical demonstration. Overall, hand-washing habits were not adequate, with 35 (17.8%) and 103 (52.2%) participants reporting not always washing their hands prior to CL or storage case manipulation, respectively. While 161 (81.3%) participants dried their hands after washing, 132 of these (82.1%) used non-disposable cloth towels. Participants receiving specific hand-washing information from their practitioners (141, or 71.1%) had better hand hygiene (p < 0.05). During the practical demonstration, 13 (72.2%) participants used water and soap to wash their hands, but only 3 (16.7%) displayed correct hand washing routines. Complete patient education, as well as practical reminders at all follow-up visits, are essential to ensure better hand hygiene in order to reduce the probability of ocular complications and to guarantee safe and satisfactory CL use. Full article

Acanthamoeba keratitis (AK) is a rare but serious infection of the cornea, typically associated with contact lens wear. Here, we present a case of AK caused by the Acanthamoeba genotype T4D/T4e in a patient without identifiable risk factors: a 34-year-old woman who initially presented with signs and symptoms suggestive of herpetic keratitis, and who did not respond to conventional treatment. Corneal culture and targeted metagenomic analysis (18S rRNA, 16S-like rRNA) revealed the presence of an Acanthamoeba species closely related to the ‘Nagington’ strain. Despite intensive anti-Acanthamoeba therapy, complications arose necessitating penetrating keratoplasty. In conclusion, this case underscores the importance of considering Acanthamoeba as a causal agent of keratitis in non-contact-lens wearers. The identification of Acanthamoeba genotype T4D/T4e challenges the previous understanding of its pathogenic potential. Furthermore, it emphasizes the need for ongoing research into the pathogenicity of different Acanthamoeba subtypes. Early diagnosis and treatment are essential for preventing vision-threatening complications associated with AK. Full article

Background: Sudden volcanic eruptions can lead to volcanic ash entering the eyes, causing severe discomfort and complicating evacuation efforts. The specific effects of volcanic ash on ocular tissues, especially when wearing soft contact lenses (SCLs), are not well documented, prompting this experimental investigation. Methods: White rabbits with normal eyes were randomly divided into three groups: (1) a bare eye group: bare eye + volcanic ash exposure + eye washing, (2) an SCL group: SCL-wearing eye + volcanic ash exposure + eye washing, and (3) a control group: eye washing only. In groups 1 and 2, volcanic ash was applied to one eye under topical anesthesia, followed by immediate saline rinsing. Slit-lamp microscopy and histopathological analysis were conducted after euthanasia. Results: Slit-lamp and histopathological examinations revealed more significant corneal and conjunctival erosion in the bare eye group compared to the SCL group, which showed limited damage. The control group displayed no ocular damage. Conclusions: Guidelines from the “Volcanic Ash Health Effects: A Guide for the Public” by the National Research Institute for Earth Science and Disaster Resilience recommend removing SCLs during ashfall. Our findings suggest that the damage to the corneal and conjunctival epithelium is less severe in SCL-wearing eyes than in bare eyes, recommending that SCL wearers prioritize evacuation over lens removal during sudden ashfall. Full article