An Ultrasensitive Ti3C2Tx MXene-based Soft Contact Lens for Continuous and Nondestructive Intraocular Pressure Monitoring.

Wearable soft contact lens sensors for continuous and nondestructive intraocular pressure (IOP) monitoring are highly desired as glaucoma and postoperative myopia patients grow, especially as the eyestrain crowd increases. Herein, a smart closed-loop system is presented that combines a Ti3C2Tx MXene-based soft contact lens (MX-CLS) sensor, wireless data transmission units, display, and warning components to realize continuous and nondestructive IOP monitoring/real-time display. The fabricated MX-CLS device exhibits an extremely high sensitivity of 7.483 mV mmHg-1, good linearity on silicone eyeballs, excellent stability under long-term pressure-release measurement, sufficient transparency with 67.8% transmittance under visible illumination, and superior biocompatibility with no discomfort when putting the MX-CLS sensor onto the Rabbit eyes. After integrating with the wireless module, users can realize real-time monitoring and warning of IOP via smartphones, the demonstrated MX-CLS device together with the IOP monitoring/display system opens up promising platforms for Ti3C2Tx materials as the base for multifunctional contact lens-based sensors and continuous and nondestructive IOP measurement system.

Polyhexanide based contact lens storage fluids frequently exhibit insufficient antifungal activity against Fusarium species.

PURPOSE: Fusarium keratitis is a severe infection of the anterior eye, frequently leading to keratoplasty or surgical removal of the affected eye. A major risk factor for infection is the use of contact lenses. Inadequate hygiene precautions and mold-growth permissive storage fluids are important risk factors for fungal keratitis. The aim of this study was to comparatively analyze contact lens storage fluids disinfection efficacy against Fusarium species. METHODS: Eleven commercially available storage fluids were tested. The storage fluids were classified according to their active ingredients myristamidopropyldimethylamine (Aldox), polyhexanide and hydrogen peroxide. Efficacy was tested against isolates belonging to the Fusarium solani and Fusarium oxysporum species complexes as the most common agents of mould keratitis. Tests were carried out based on DIN EN ISO 14729. RESULTS: All Aldox and hydrogen peroxide (H2O2) based fluids were effective against Fusarium spp., while the majority of polyhexanide based storage fluids showed only limited or no antifungal effects. Efficacy of polyhexanide could be restored by the addition of the pH-regulating agent tromethamine - an additive component in one commercially available product. CONCLUSIONS: In summary, the use of Aldox- or hydrogen peroxide-based storage fluids may reduce the risk of Fusarium keratitis, while polyhexanide-based agents largely lack efficacy against Fusarium.

Raman spectroscopy assisted tear analysis: A label free, optical approach for noninvasive disease diagnostics.

In recent times, tear fluid analysis has garnered considerable attention in the field of biomarker-based diagnostics due to its noninvasive sample collection method. Tears encompass a reservoir of biomarkers that assist in diagnosing not only ocular disorders but also a diverse list of systemic diseases. This highlights the necessity for sensitive and dependable screening methods to employ tear fluid as a potential noninvasive diagnostic specimen in clinical environments. Considerable research has been conducted to investigate the potential of Raman spectroscopy-based investigations for tear analysis in various diagnostic applications. Raman Spectroscopy (RS) is a highly sensitive and label free spectroscopic technique which aids in investigating the molecular structure of samples by evaluating the vibrational frequencies of molecular bonds. Due to the distinct chemical compositions of different samples, it is possible to obtain a sample-specific spectral fingerprint. The distinctive spectral fingerprints obtained from Raman spectroscopy enable researchers to identify specific compounds or functional groups present in a sample, aiding in diverse biomedical applications. Its sensitivity to changes in molecular structure or environment provides invaluable insights into subtle alterations associated with various diseases. Thus, Raman Spectroscopy has the potential to assist in diagnosis and treatment as well as prognostic evaluation. Raman spectroscopy possesses several advantages, such as the non-destructive examination of samples, remarkable sensitivity to structural variations, minimal prerequisites for sample preparation, negligible interference from water, and the aptness for real-time investigation of tear samples. The purpose of this review is to highlight the potential of Raman spectroscopic technique in facilitating the clinical diagnosis of various ophthalmic and systemic disorders through non-invasive tear analysis. Additionally, the review delves into the advancements made in Raman spectroscopy with regards to paper-based sensing substrates and tear analysis methods integrated into contact lenses. Furthermore, the review also addresses the obstacles and future possibilities associated with implementing Raman spectroscopy as a routine diagnostic tool based on tear analysis in clinical settings.

Co-delivery of Brinzolamide and Timolol from Micelles-laden Contact Lenses: In vitro and In Vivo Evaluation.

PURPOSE: Traditional eye drops exhibit a modest bioavailability ranging from 1 to 5%, necessitating recurrent application. Thus, a contact lens-based drug delivery system presents substantial benefits. Nonetheless, pharmaceutical agents exhibiting poor solubility may compromise the quintessential characteristics of contact lenses and are, consequently, deemed unsuitable for incorporation. To address this issue, the present study has engineered a novel composite drug delivery system that amalgamates micellar technology with contact lenses, designed specifically for the efficacious conveyance of timolol and brinzolamide. METHODS: Utilizing mPEG-PCL as the micellar material, this study crafted mPEG-PCL micelles loaded with brinzolamide and timolol through the film hydration technique. The micelle-loaded contact lens was fabricated employing the casting method; a uniform mixture of HEMA and EGDMA with the mPEG-PCL micelles enshrouding brinzolamide and timolol was synthesized. Following the addition of a photoinitiator, 50 µL of the concoction was deposited into a contact lens mold. Subsequently, the assembly was subjected to polymerization under 365 nm ultraviolet light for 35 min, resulting in the formation of the micelle-loaded contact lenses. RESULTS: In the present article, we delineate the construction of a micelle-loaded contact lens designed for the administration of brinzolamide and timolol in the treatment of glaucoma. The study characterizes crucial properties of the micelle-loaded contact lenses, such as transmittance and ionic permeability. It was observed that these vital attributes meet the standard requirements for contact lenses. In vitro release studies revealed that timolol and brinzolamide could be gradually liberated over periods of up to 72 and 84 h, respectively. In vivo pharmacodynamic evaluation showed a significant reduction in intraocular pressure and a relative bioavailability of 10.84 times that of commercially available eye drops. In vivo pharmacokinetic evaluation, MRT was significantly increased, and the bioavailability of timolol and brinzolamide was 2.71 and 1.41 times that of eye drops, respectively. Safety assessments, including in vivo irritation, histopathological sections, and protein adsorption studies, were conducted as per established protocols, confirming that the experiments were in compliance with safety standards. IN CONCLUSION: The manuscript delineates the development of a safe and efficacious micelle-loaded contact lens drug delivery system, which presents a novel therapeutic alternative for the management of glaucoma.

Contact lens fitting and changes in the tear film dynamics: mathematical and computational models review.

PURPOSE: This review explores mathematical models, blinking characterization, and non-invasive techniques to enhance understanding and refine clinical interventions for ocular conditions, particularly for contact lens wear. METHODS: The review evaluates mathematical models in tear film dynamics and their limitations, discusses contact lens wear models, and highlights computational mechanical models. It also explores computational techniques, customization of models based on individual blinking dynamics, and non-invasive diagnostic tools like high-speed cameras and advanced imaging technologies. RESULTS: Mathematical models provide insights into tear film dynamics but face challenges due to simplifications. Contact lens wear models reveal complex ocular physiology and design aspects, aiding in lens development. Computational mechanical models explore eye biomechanics, often integrating tear film dynamics into a Multiphysics framework. While different computational techniques have their advantages and disadvantages, non-invasive tools like OCT and thermal imaging play a crucial role in customizing these Multiphysics models, particularly for contact lens wearers. CONCLUSION: Recent advancements in mathematical modeling and non-invasive tools have revolutionized ocular health research, enabling personalized approaches. The review underscores the importance of interdisciplinary exploration in the Multiphysics approach involving tear film dynamics and biomechanics for contact lens wearers, promoting advancements in eye care and broader ocular health research.

The analysis of tear meniscus parameters during daily soft contact lens wear using optical coherence tomography.

PURPOSE: To evaluate tear meniscus parameters in soft contact lens wearers (SCL) using optical coherence tomography (OCT) and ImageJ software. METHODS: This prospective study included 50 soft contact lens wearers (group 1: 25 symptomatic SCL wearers (SCLW), group 2: 25 asymptomatic SCL wearers (ASCW)) and 25 healthy non-CL wearers (group 3 (NCLW)). SCLs were fitted on each eye of CL wearers, and the lower tear meniscus was imaged using OCT before CL insertion, immediately afterward, and reimaged 2, 5 and 10 h after insertion. Tear meniscus parameters, including tear meniscus height (TMH), depth (TMD), turbidity, and percentage area occupied by particles (PAOP) were measured in all groups. RESULTS: Turbidity and PAOP measurements at baseline in SCLW were significantly higher than in other groups (p < 0.05). There was no significant difference between TMH, TMD, turbidity, and PAOP parameters calculated at baseline visit and two hours after SCL insertion in all groups (p > 0.05 for 2 comparisons). The symptomatic SCL users had a significant decrease in TMH and TMD in the fifth hour. The turbidity and PAOP measurements of SCLW and ASCW at the fifth and tenth hours were significantly higher than those of NCLW (p < 0.05). CONCLUSION: TMD and height TMH decrease throughout the day in all participants; however, a significant decrease in these parameters was observed only in symptomatic SCL users at the fifth hour, at the earliest. As the duration of CL wear increases, turbidity and PAOP even in asymptomatic SCL wearers become significantly higher than those in healthy non-CL wearers. KEY MESSAGES: What Is Known • Contact lens wear is associated with an increased risk of dry eye. • Tear volume decreases gradually during contact lens wear. What Is New • Tear meniscus turbidity and particle area occupied by particles (PAOP) were higher in symptomatic contact lens wearers and they increase gradually during contact lens wear. • Tear meniscus turbidity and PAOP may be measures of how well the tear film and meniscus are functioning in contact lens wearers.

Efficacy and adverse reactions of peripheral add multifocal soft contact lenses in childhood myopia: a meta-analysis.

OBJECTIVES: This study aims to compare the efficacy of peripheral add multifocal soft contact lenses (SCLs) (excluding bifocal SCLs) with single vision contact lenses or spectacles in controlling myopia progression. METHOD: A comprehensive literature search was conducted in the Pubmed, EMBASE, Web of Science, and Cochrane Library databases until October 2023. The literature was thoroughly screened based on predetermined eligibility criteria. Pooled odds ratios (ORs) were calculated for dichotomous data and weighted mean differences (WMD) for continuous data. RESULTS: A total of 11 articles comprising 787 participants were included in this meta-analysis. Our pooled results demonstrated that the peripheral add multifocal SCLs groups exhibited significantly reduced refraction progression (MD = 0.20; 95%CI, 0.14 ∼ 0.27; P<0.001) and less axial length elongation (MD=-0.08; 95%CI, -0.09∼-0.08; P<0.001) compared to the control group. There was no significant difference in high-contrast logMAR distance visual acuity between the two groups (MD = 0.01; 95%CI, -0.00 ∼ 0.02; P = 0.19). However, the group using single-vision lenses had better low-contrast logMAR distance visual acuity compared to those using peripheral add multifocal SCLs (MD = 0.06; 95%CI, 0.02 ∼ 0.10; P = 0.004). Data synthesis using a random-effects model indicated an incidence of contact lens-related adverse events of 0.065 (95%CI, 0.048 ∼ 0.083). CONCLUSIONS: The present meta-analysis signifies that peripheral defocus modifying contact lenses are effective in slowing down the progression of myopia and reducing axial elongation.

The efficacy of bandage contact lens in relieving the aggravation of dry eye disease after complicated cataract or/and IOL surgery.

PURPOSE: In the present study, we aimed to evaluate the efficacy of the bandage contact lens (BCLs) in the treatment of dry eye disease (DED) after complicated cataract or/and intraocular lens (IOL) surgery. METHODS: In this retrospective, single-centered, observational study, we collected data from 69 patients who underwent complicated cataract or/and IOL surgery. Of these, 35 cases wore their own BCLs immediately after the operation, while the other 34 cases did not have their own BCLs and were instead covered with gauze. The Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp microscope examination, keratograph analysis, and Schirmer I test were measured at baseline, 1 week and 1 month postoperatively. RESULTS: In the BCL group, the score of the OSDI questionnaire was significantly decreased at 1 week and 1 month postoperatively compared with baseline levels (P = 0.000, collectively). Moreover, the fluorescein staining score of the BCL group was remarkably decreased 1-week and 1-month postoperatively compared with the non-BCL group (P = 0.000 and P = 0.000, respectively). Furthermore, the redness score of the BCL group was also better compared with the non-BCL group at 1 week and 1 month postoperatively (P = 0.014 and P = 0.004, respectively). CONCLUSIONS: Complicated cataract or/and IOL surgery would intensify the DED. Early application of BCLs postoperatively improved patients' comfort and alleviated dry eye-related symptoms and signs. Furthermore, this mechanism might involve the acceleration of corneal epithelial healing, the alleviation of ocular stress response and the stabilization of the tear film. TRIAL REGISTRATION: Trial registration ClinicalTrials, NCT04120389. Registered 10 October 2019-retrospectively registered.

You've got to hide your myopia away: John Lennon's contact lenses.

John Lennon has an enduring, instantly recognisable, iconic, spectacle look. However, prior to 1966, he was rarely seen wearing glasses in public. From ages 7 to 26, he effectively hid his myopia away, including a period of unsuccessful contact lens wear during Beatlemania. This narrative review examines John's experience with contact lenses from 1963 to 1966 when he wore corneal rigid lenses made from polymethylmethacrylate, which regularly fell out. This frequent lens ejection was most likely due to the interaction between his upper eyelid and a spherical back surface rigid lens fitted to his right eye, which had a moderate degree of with-the-rule corneal astigmatism. John's recollection that his contact lenses stayed in place while 'stoned' supports this hypothesis, as a cannabis-induced upper eyelid ptosis would reduce the likelihood of lens ejection.

Refractive power profiles of commercially available soft multifocal contact lenses for myopia control.

PURPOSE: Lens power profiles can provide valuable insights on the imposed optical defocus and visual experience of contact lens wearers, especially in the context of myopia control. This study measured the refractive power profiles of multifocal soft contact lenses (MFCLs) currently used or that have the potential for use in myopia control using high spatial resolution aberrometry. The instrument's repeatability for determining MFCLs power profiles was also assessed. METHOD: The power profiles of 10 MFCLs of various designs (centre-distance, centre-near and extended depth of focus) were measured using the Lambda-X NIMOEVO, a phase shifting Schlieren-based device. Power profiles were graphically expressed as measured power at each chord position and the maximum add power was calculated. The repeatability of the NIMOEVO was expressed as the within-subject standard deviation at each chord position for a subset of five MFCLs. RESULTS: The measured distance powers differed from nominal powers for more than half of the MFCLs with a definable distance zone. There were variations in the chord position of the distance and near correction zones, rate of power transitions and calculated maximum add between the MFCLs which did not depend on lens design. For half of the MFCLs, the power profile shape was inconsistent between different nominal back vertex powers of the same design. The repeatability of the NIMOEVO was dependent on the lens design, with designs featuring faster rates of power change exhibiting worse repeatability. CONCLUSIONS: Significant differences in MFCL power profiles were found which were not adequately represented in labelling. This is likely due to the small number of parameters used to define lens power characteristics. Eye health care practitioners should be aware of potential differences in power profiles between different MFCLs, which will impact the retinal defocus introduced during lens wear and the wearer's visual experience.

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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Ocular effects of exposure to low-humidity environment with contact lens wear: A pilot study.

PURPOSE: To compare the ocular effects of exposure to a low-humidity environment with and without contact lens (CL) wear using various non-invasive tests. METHODS: Fourteen habitual soft CL wearers were exposed to controlled low humidity (5% relative humidity [RH]) in an environmental chamber for 90 min on two separate occasions. First, when wearing their habitual spectacles and then, on a separate visit, when wearing silicone hydrogel CLs that were fitted specifically for this purpose. All participants had adapted to the new CL prior to data collection. Three non-invasive objective measurements were taken at each visit: blinking rate, objective ocular scatter (measured using the objective scatter index) and ocular surface cooling rate (measured using a long-wave infrared thermal camera). At each visit, measurements were taken before the exposure in comfortable environmental conditions (RH: 45%), and after exposure to environmental stress (low humidity, RH: 5%). RESULTS: CL wearers showed increased blinking rate (p < 0.005) and ocular scatter (p = 0.03) but similar cooling rate of the ocular surface (p = 0.08) when compared with spectacle wear in comfortable environmental conditions. The exposure to low humidity increased the blinking rate significantly with both types of corrections (p = 0.01). Interestingly, ocular scatter (p = 0.96) and cooling rate (p = 0.73) were not significantly different before and after exposure to low humidity. There were no significant two-way interactions between correction and exposure in any of the measurements. CONCLUSIONS: CLs significantly increased the blinking rate, which prevented a quick degradation of the tear film integrity as it was refreshed more regularly. It is hypothesised that the increased blinking rate in CL wearers aids in maintaining ocular scatter quality and cooling rate when exposed to a low-humidity environment. These results highlight the importance of blinking in maintaining tear film stability.

Assessing the rebound phenomenon in different myopia control treatments: A systematic review.

PURPOSE: To review the rebound effect after cessation of different myopia control treatments. METHODS: A systematic review that included full-length randomised controlled studies (RCTs), as well as post-hoc analyses of RCTs reporting new findings on myopia control treatments rebound effect in two databases, PubMed and Web of Science, was performed according to the PRISMA statement. The search period was between 15 June 2023 and 30 June 2023. The Cochrane risk of bias tool was used to analyse the quality of the selected studies. RESULTS: A total of 11 studies were included in this systematic review. Unifying the rebound effects of all myopia control treatments, the mean rebound effect for axial length (AL) and spherical equivalent refraction (SER) were 0.10 ± 0.07 mm [-0.02 to 0.22] and -0.27 ± 0.2 D [-0.71 to -0.03] after 10.2 ± 7.4 months of washout, respectively. In addition, spectacles with highly aspherical lenslets or defocus incorporated multiple segments technology, soft multifocal contact lenses and orthokeratology showed lower rebound effects compared with atropine and low-level light therapy, with a mean rebound effect for AL and SER of 0.04 ± 0.04 mm [0 to 0.08] and -0.13 ± 0.07 D [-0.05 to -0.2], respectively. CONCLUSIONS: It appears that the different treatments for myopia control produce a rebound effect after their cessation. Specifically, optical treatments seem to produce less rebound effect than pharmacological or light therapies. However, more studies are required to confirm these results.

Contact lens wear and follow-up and its association with signs and symptoms of meibomian gland dysfunction.

INTRODUCTION: This study investigated the equivocal association between contact lens (CL) wear and meibomian gland dysfunction (MGD) by comparing the morphological, functional and subjective outcomes of CL wearers versus control, non-CL wearers. CL wearers were examined as two cohorts based on the annual attendance of follow-up visits (FLU-attended these visits, whereas non-FLU did not). METHODS: Habitual logMAR visual acuity, invasive and non-invasive tear break-up time, Schirmer test, Efron grading scales, meibum quality score (MQS), meibum expressibility score (MES), meibomian gland (MG) loss, lid margin abnormalities and subjective dry eye (DE) symptoms were assessed. RESULTS: Of the 128 participants, 31 were in the FLU cohort, 43 were in the non-FLU cohort and 54 were controls (mean ages: 22.2 ± 3.1, 23.0 ± 4.6 and 22.3 ± 3.5, respectively). Non-FLU CL wearers had more symptoms than controls (3.7 ± 2.4 vs. 2.3 ± 2.1, p < 0.01). Morphologically, FLU (16.9 ± 8.8%, p = 0.02) and non-FLU (18.6 ± 11.3%, p = 0.001) had more MG loss than controls (11.2 ± 6.8%). Functionally, FLU (0.6 ± 0.7, p = 0.01) and non-FLU (0.8 ± 0.9, p = 0.001) had worse MES than controls (0.2 ± 0.5). FLU and non-FLU were both associated with corneal staining (odds ratio [OR] = 3.42, 95% CI: 1.16-10.11, p = 0.03 and OR = 5.23, 95% CI: 1.89-14.48, p = 0.001, respectively) and MG loss (OR = 10.47, 95% CI: 1.14-96.29, p = 0.04 and OR = 16.63, 95% CI: 1.96-140.86, p = 0.01, respectively). Non-FLU CL wear was also associated with abnormal MQS (OR = 12.87, 95% CI: 1.12-148.41, p = 0.04), conjunctival staining (OR = 12.18, 95% CI: 3.66-40.51, p < 0.001) and lid margin telangiectasia (OR = 3.78, 95% CI: 1.55-9.21, p = 0.003). MGD was three times more prevalent in CL wearers (12%) than in controls (4%). CONCLUSIONS: Both CL-wearing cohorts demonstrated significantly more MG abnormalities than controls though the difference was not clinically significant. Non-FLU CL wearers had more DE symptoms. Non-FLU CL wear is an independent predictor for more abnormalities than FLU CL wear, emphasising the importance of follow-ups.

Reliability and agreement of subjective and objective non-invasive break-up time measurements in contact lens wearers.

PURPOSE: To assess the reliability and agreement of non-invasive break-up time (NIBUT) in symptomatic and asymptomatic contact lens (CL) wearers using automatic objective and conventional subjective techniques. METHODS: In this prospective cross-sectional study, soft CL wearers, classified into symptomatic and asymptomatic based on the Contact Lens Dry Eye Questionnaire-8, underwent NIBUT assessment with the CL in situ. The CA-800 Corneal Analyzer and the EasyTear® VIEW+ Tearscope were used for objective and subjective evaluation, respectively. The within-subject repeatability and intraclass correlation coefficient (ICC) were calculated. The agreement between the devices was compared using the Bland-Altman method. RESULTS: A total of 141 CL wearers (51 male and 90 female) with a mean age of 33.6 (SD = 12.2) years were included. The repeatability and ICC values obtained with the CA-800 device when measuring NIBUT were 5.4 s and 58.6% across the whole sample, 4.2 s and 48.8% for the asymptomatic group and 7.1 s and 68.4% for the symptomatic group. When using the subjective method (EasyTear®), the respective repeatability and ICC values were 7.3 s and 32.7% for the whole sample, 6.5 s and 30.4% for the asymptomatic group and 8.6 s and 35.9% for the symptomatic group. The CA-800 device provided significantly (p < 0.001) shorter NIBUT values compared with EasyTear® for the whole sample (3.3 [2.9] vs. 8.1 [3.4] s), the asymptomatic (3.3 [3.0] vs. 7.7 [3.6] s) and the symptomatic (3.8 [2.9] vs. 8.6 [3.0] s) groups. CONCLUSION: Objective (CA-800) NIBUT assessment provides more reliable measurements than the conventional subjective technique using the EasyTear® device. However, CL practitioners should also be aware that the objective method indicates shorter NIBUT values. Symptomatic CL wearers may also need a higher number of NIBUT measurements to obtain reliable estimations.

Allowable movement of wavefront-guided contact lens corrections in normal and keratoconic eyes.

PURPOSE: The goal was to use SyntEyes modelling to estimate the allowable alignment error of wavefront-guided rigid contact lens corrections for a range of normal and keratoconic eye aberration structures to keep objectively measured visual image quality at or above average levels of well-corrected normal eyes. Secondary purposes included determining the required radial order of correction, whether increased radial order of the corrections further constrained the allowable alignment error and how alignment constraints vary with keratoconus severity. METHODS: Building on previous work, 20 normal SyntEyes and 20 keratoconic SyntEyes were fitted with optimised wavefront-guided rigid contact lens corrections targeting between three and eight radial orders that drove visual image quality, as measured objectively by the visual Strehl ratio, to near 1 (best possible) over a 5-mm pupil for the aligned position. The resulting wavefront-guided contact lens was then allowed to translate up to ±1 mm in the x- and y-directions and rotate up ±15°. RESULTS: Allowable alignment error changed as a function of the magnitude of aberration structure to be corrected, which depends on keratoconus severity. This alignment error varied only slightly with the radial order of correction above the fourth radial order. To return the keratoconic SyntEyes to average levels of visual image quality depended on maximum anterior corneal curvature (Kmax). Acceptable tolerances for misalignment that returned keratoconic visual image quality to average normal levels varied between 0.29 and 0.63 mm for translation and approximately ±6.5° for rotation, depending on the magnitude of the aberration structure being corrected. CONCLUSIONS: Allowable alignment errors vary as a function of the aberration structure being corrected, the desired goal for visual image quality and as a function of keratoconus severity.

End-of-day assessment of asymptomatic versus highly symptomatic soft contact lens wearers.

PURPOSE: To investigate differences in key clinical parameters between asymptomatic and highly symptomatic soft contact lens (CL) wearers after 14 h of wear. METHODS: In this pilot investigation, Phase 1 identified asymptomatic (CLDEQ-8 score ≤ 7) and highly symptomatic (CLDEQ-8 score ≥ 20) subjects after fitting with nelfilcon A CLs. Phase 2 investigated the following over a single nelfilcon A CL-wearing day (14 ± 2 h): blinking characteristics, tear meniscus height (TMH), non-invasive tear break-up time (NIBUT), tear film osmolarity and eyelid margin staining. Parameters for the two groups were compared using linear mixed models and post-hoc testing. The relationship between comfort scores and the clinical parameters was also investigated. RESULTS: Overall, 161 and 42 subjects were enrolled into Phase 1 and 2, respectively. Twenty-five asymptomatic and 17 symptomatic subjects completed Phase 2. Lower eyelid TMH was decreased after 14 h in symptomatic compared with asymptomatic subjects (least square mean [LSM] difference -0.04 mm, 95% CI: -0.07, -0.01). Osmolarity was lower in symptomatic than in asymptomatic subjects at fitting (LSM difference -9.89, 95% CI: -18.91, -0.86). Upper eyelid margin staining was greater after 14 h in symptomatic than in asymptomatic subjects (LSM difference 0.53, 95% CI: 0.01, 1.05) and greater after 14 h than baseline in the symptomatic group (LSM difference 0.61, 95% CI: 0.16, 1.07). There was a significant relationship between comfort and upper eyelid margin staining (r = -0.40, 95% CI: -0.63, -0.11) and blink rate (r = -0.31, 95% CI: -0.57, -0.003). CONCLUSION: The potential parameters most effective in differentiating asymptomatic from symptomatic wearers were upper eyelid margin staining and lower TMH. The parameter with the strongest relationship to comfort was upper eyelid margin staining, where higher comfort scores were associated with lower levels of staining.

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

PURPOSE: To determine the number of previous contact lens (CL) wearers who could be comfortably refitted into delefilcon A (DAILIES TOTAL1®) CLs. METHODS: 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. RESULTS: 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%). CONCLUSIONS: 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.

Synergistic Effect of Nilavembu Choornam-Gold Nanoparticles on Antibiotic-Resistant Bacterial Susceptibility and Contact Lens Contamination-Associated Infectious Pathogenicity.

Antibiotic-resistant bacterial colonies mitigate rapid biofilm formation and have complex cell wall fabrications, making it challenging to penetrate drugs across their biofilm barriers. The objective of this study was to investigate the antibacterial susceptibility of antibiotic-resistant bacteria and contact lens barrenness. Nilavembu Choornam-Gold Nanoparticles (NC-GNPs) were synthesized using NC polyherbal extract and characterized by UV-visible spectrophotometer, SEM-EDX, XRD, Zeta sizer, FTIR, and TEM analysis. Contact lenses with overnight cultures of antibiotic-resistant bacteria K. pneumoniae and S. aureus showed significant differences in growth, biofilm formation, and infection pathogenicity. The NC-GNPs were observed in terms of size (average size is 57.6 nm) and surface chemistry. A zone of inhibition was calculated for K. pneumoniae 18.8 ± 1.06, S. aureus 23.6 ± 1.15, P. aeruginosa 24.16 ± 0.87, and E. faecalis 24.5 ± 1.54 mm at 24 h of NC-GNPs alone treatment. In electron microscopy studies, NC-GNP-treated groups showed nuclear shrinkage, nuclear disintegration, degeneration of cell walls, and inhibited chromosomal division. In contrast, normal bacterial colonies had a higher number of cell divisions and routinely migrated toward cell multiplications. NC-GNPs exhibited antibacterial efficacy against antibiotic-resistant bacteria when compared to NC extract alone. We suggest that NC-GNPs are highly valuable to the population of hospitalized patients and other people to reduce the primary complications of contact lens contamination-oriented microbial infection and the therapeutic efficiency of antibiotic-resistant bacterial pathogenicity.

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.