Comfort Response of Three Silicone Hydrogel Daily Disposable Contact Lenses

Subjective Wearing Experience of Lehfilcon A Among Satisfied Comfilcon A Toric Lens Wearers

Purpose

To evaluate the subjective wearing experience of lehfilcon A toric lenses among subjects who were already satisfied with their comfilcon A toric lenses.

Methods

This was an open-label, single arm study of currently satisfied comfilcon A soft toric contact lens (Biofinity Toric, CooperVision, Pleasanton, CA) wearers that were refit with lehfilcon A soft toric lenses (Total30® for Astigmatism; Alcon Vision LLC, Fort Worth, TX). Subjects were administered a questionnaire about satisfaction with comfort, visual performance, end of day comfort, and ease of handling with lehfilcon A toric lenses.

Results

A total of 40 subjects completed the study. After one month of wear the median and interquartile range (IQR) was 8 (2) for overall satisfaction with lehfilcon A comfort, 8 (1.25) for visual performance, 7 (3.25) for end of day comfort, 9 (2) for ease of handling, and finally 8 (2) for overall satisfaction.

Conclusion

A high proportion of subjects were satisfied with the subjective wearing experience with lehfilcon A toric lenses, including satisfaction with comfort, visual performance, end of day comfort, and ease of handling.

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.

Comfort After Refitting Symptomatic Habitual Reusable Toric Lens Wearers with a New Daily Disposable Contact Lens for Astigmatism

Purpose

To subjectively evaluate comfort with a daily disposable (delefilcon A for astigmatism) contact lens compared to other common weekly/monthly soft toric contact lenses in symptomatic wearers.

Methods

This open-label, single arm study enrolled current reusable soft toric lens wearers with minimum score of 12 on the contact lens dry eye (CLDEQ-8) questionnaire. Subjects were also administered the CLDEQ-8 after 1 replacement schedule of their optimized habitual toric lenses (2 to 4 weeks), and after 2 weeks of wear with delefilcon A toric daily disposable lenses (Dailies Total1 for Astigmatism; Alcon Vision LLC, Fort Worth, Texas).

Results

A total of 85 subjects completed the study. Mean total CLDEQ-8 score was 16.8 ± 8.1 for subjects refit with their optimized habitual toric lenses and 12.4 ± 7.5 for subjects refit with delefilcon A toric lenses, a difference of 4.3 ± 10.4 (p < 0.001). With delefilcon A toric lenses, 78.9% of subjects reported little to no intensity of eye discomfort, compared to 51.7% for the habitual toric lenses (p = 0.005). In addition, 77.7% of subjects reported little to no intensity of dryness for delefilcon A toric lenses, compared to 50.6% for the habitual toric lenses (p = 0.001).

Conclusion

The subjective comfort in symptomatic habitual reusable toric contact lens wearers was improved by refitting with delefilcon A toric lenses.

Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety

BACKGROUND

Ocular discomfort is the leading cause of permanent discontinuation of soft contact lens (SCL) wear. Silicone hydrogel and hydrogel materials are the two major categories of SCLs, with silicone hydrogel materials being newer and more breathable than hydrogel materials. Whether comfort is associated with SCL material is controversial despite numerous studies. Similarly, the difference between these materials in terms of safety outcomes (e.g. frequency of microbial keratitis) is unclear.

OBJECTIVES

To evaluate the comparative effectiveness and safety of silicone hydrogel compared with hydrogel SCLs on self-reported comfort, dry eye test results, and adverse events in SCL-wearing adults 18 years of age or older.

SEARCH METHODS

The Cochrane Eyes and Vision Information Specialist searched the electronic databases for randomized controlled trials (RCTs). There were no restrictions on language or date of publication. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, including the Cochrane Eyes and Vision Trials Register; 2022, Issue 6), MEDLINE Ovid, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Science Information database), ClinicalTrials.gov, and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We also searched the reference lists of identified studies, review articles, and guidelines for information about relevant studies that may not have been identified by our search strategy. Furthermore, we contacted investigators regarding ongoing trials. The most recent database search was conducted on 24 June 2022.

SELECTION CRITERIA

Our search selection criteria included RCTs, quasi-RCTs, and cross-over RCTs.

DATA COLLECTION AND ANALYSIS

We applied standard Cochrane methodology.

MAIN RESULTS

We included seven parallel-group RCTs conducted in the USA, the UK, Australia, Germany, India, and Turkey. A total of 1371 participants were randomized. The duration of SCL wear ranged from one to 52 weeks. Study characteristics and risk of bias The median number of participants per trial was 120 (interquartile range: 51 to 314), and the average age ranged from 20.7 to 33.0 years. Women represented the majority of participants (range 55% to 74.9%; 5 RCTs). Collectively, the included trials compared eight different silicone hydrogel SCLs with three different hydrogel SCLs. Five trials compared daily disposable SCLs, and two compared extended wear SCLs (worn for seven days and six nights). New SCL wearers were enrolled in three trials. Two trials included both new and established SCL wearers, and two trials did not report participants' history of SCL use. Five trials were sponsored by industry. We judged the overall risk of bias to be 'high' or 'some concerns' for the safety and efficacy outcomes. Findings One trial reported Ocular Surface Disease Index (OSDI) results, with the evidence being very uncertain about the effects of SCL material on OSDI scores (mean difference -1.20, 95% confidence interval [CI] -10.49 to 8.09; 1 RCT, 47 participants; very low certainty evidence). Three trials reported visual analog scale comfort score results, with no clear difference in comfort between materials, but the evidence was of very low certainty; trial results could not be combined because the three trials reported results at different time points. The evidence is very uncertain about the effect of SCL material on discontinuation of contact lens wear (risk ratio [RR] 0.64, 95% CI 0.11 to 3.74; 1 RCT, 248 participants). None of the included trials reported Contact Lens Dry Eye Questionnaire (CLDEQ-8) or Standard Patient Evaluation of Eye Dryness (SPEED) scores. There was no evidence of a clinically meaningful difference (> 0.5 unit) between daily disposable silicone hydrogel and hydrogel SCLs in corneal staining, conjunctival staining, or conjunctival redness (very low certainty evidence). Adverse events Very low certainty evidence from two trials comparing daily disposable SCLs suggested no evidence of a difference between lens materials in the risk of vision-threatening adverse events at one to four weeks (RR 0.68, 95% CI 0.08 to 5.51; 2 RCTs, 368 participants). Two trials comparing extended wear SCLs indicated that hydrogel SCLs may have a 2.03 times lower risk of adverse events at 52 weeks compared with silicone hydrogel SCLs (RR 2.03, 95% CI 1.38 to 2.99; 815 participants), but the certainty of evidence was very low.

AUTHORS' CONCLUSIONS

The overall evidence for a difference between all included silicone hydrogel and hydrogel SCLs was of very low certainty, with most trials at high overall risk of bias. The majority of studies did not assess comfort using a validated instrument. There was insufficient evidence to support recommending one SCL material over the other. For extended wear, hydrogel SCL may have a lower risk of adverse events at 52 weeks compared to silicon hydrogel. Future well-designed trials are needed to generate high certainty evidence to further clarify differences in SCL material comfort and safety.

Physical Properties and Interaction With the Ocular Surface of Water-Gradient Contact Lenses

ABSTRACT

Since the introduction of silicone hydrogel contact lenses, many silicone-hydrogel materials have been produced, including water-gradient contact lenses with a silicone hydrogel core and a thin hydrogel outer layer (e.g., delefilcon A, verofilcon A, and lehfilcon A). Their properties have been investigated in various studies assessing both the chemical-physical characteristics and the comfort, but the overall picture is not always consistent. In this study, water-gradient technology is reviewed by looking at basic physical properties both in vitro and in vivo and at the interaction with the human ocular surface. Surface and bulk dehydration, surface wetting and dewetting, shear stress, interaction with tear components and with other environmental compounds, and comfort are discussed.

Short-Term Fit Assessment of a Novel Daily Disposable, Toric, Silicone Hydrogel Contact Lens

Purpose

The development of new contact lens materials and designs are necessary to minimise patient dropout. A lens material with water surface technology was recently developed to incorporate toric design. The on-eye stability of a toric contact lens is critical to a successful toric lens fitting. In an effort to establish if the new daily disposable verofilcon A toric silicone hydrogel lens provides fast stability for ease of fit, this study assessed the initial and short-term on-eye stability of this new lens.

Patients and Methods

Habitual full-time wearers of soft contact lenses, aged 18 or over, were enrolled and fit with the verofilcon A toric lens. Study endpoints included lens settling time, axis orientation at specific time-points within 10 minutes after insertion, lens oscillation with blink, lens movement and centration, and scribe mark visibility.

Results

Thirty-nine subjects completed the study; 67% were female and mean age was 34.1 ± 10.8 years (range 18 to 61). The majority of verofilcon A toric lenses (98.7%) settled on average within 60 seconds. Average lens orientation was 3° from six o’clock position within two minutes of insertion. The lenses showed minimal oscillation with blink; 98.7% of the eyes demonstrated ≤5° oscillation with blink. All lenses showed optimal/acceptable lens movement and centration and the scribe mark was reported as easily visible in 96% of eyes. Practitioners reported a 99% first lens fit success rate.

Conclusion

The novel verofilcon A toric lens was highly successful with the first lens, had excellent on-eye stability and good fit characteristics. These qualities make this new lens a good option for lens wearers. Furthermore, it fulfills the needs of practitioners who want a toric lens that is easy and predictable to fit.

All soft contact lenses are not created equal

Soft contact lenses that have been prescribed by eye care practitioners are sometimes substituted for alternative lenses by unqualified, unregulated and sometimes even fully regulated lens suppliers, in the mistaken belief that there is essentially no difference between different soft lens types. This review considers the implications of inappropriately substituting soft contact lens types in terms of (a) lens properties: surface treatment, internal wetting agents, material, total diameter, back optic zone radius, thickness, edge profile, back surface design, optical design, power, colour (tint) and ultraviolet protection; and (b) lens usage: wearing modality (daily versus overnight wear) and replacement frequency. Potential aspects of patient dissatisfaction and adverse events when prescribed soft lenses are substituted for lenses with different properties or intended usage are considered. Substitution of 15 of the 16 lens properties considered (i.e. except for back surface design) was found to be related to at least one - and as many as six - potential sources of patient dissatisfaction and adverse ocular events. Contact lens are medical devices which are prescribed and fitted; they should never be substituted for another lens type in the absence of a new prescription further to a full finalised fitting, for the simple reason that all soft contact lenses are not created equal. A substituted lens may have properties that results in undesirable consequences in respect of vision, ocular health, comfort and cosmetic appearance, and may be incompatible with the lifestyle of the patient.

Role of the Water Gradient Structure in Inhibiting Thin Aqueous Layer Break in Silicone Hydrogel-Soft Contact Lens

Purpose

Soft contact lenses (SCLs) are effective for refractive error correction, but prolonged wear triggers discomfort and discontinuation. This study investigates whether water gradient technology of delefilcon A-based SCLs improve tear film dynamics.

Methods

This retrospective observational study included 50 asymptomatic delefilcon A or narafilcon A users. Data on thin aqueous layer break (TALB; %), noninvasive tear break-up time (NIBUT), tear meniscus height (TMH; mm), subjective dryness, and higher-order aberrations (HOAs) were collected. Measurements of the bare eye, the SCL-worn eye after 15 minutes (visit 1 [v1]) and 30 ± 5 days after v1 after SCL was worn for ≥5 hours (visit 2 [v2]) were recorded.

Results

TALB was significantly reduced in the delefilcon A group compared to the narafilcon A group (33.3% vs. 85.5% at v1; P < 0.0001 and 31.7% vs. 80.4% at v2; P < 0.0001). The NIBUT was also significantly higher in the former (4.2 ± 2.1 seconds vs. 2.9 ± 1.5 at v1; P < 0.01 and 4.1 ± 2.3 seconds vs. 2.7 ± 1.6 seconds at v2; P < 0.01) across both visits. The TMH was significantly reduced in the former in both v1 and v2. The total ocular HOAs were significantly lower in the former at v1 (P < 0.001) and v2 (P < 0.05) compared to the bare eye.

Conclusions

The water gradient technology of delefilcon A reduces TALB and increases NIBUT.

Translational Relevance

The use of water gradient technology improves tear film dynamics and alleviate pathological break-up pattern, improving lens performance.

Stabilization of comfort and visual quality after the insertion of soft contact lenses

PURPOSE

To evaluate comfort, visual function, and in vivo wettability after the insertion of hydrogel and silicone hydrogel contact lenses for a better understanding of how long practitioners should wait for the initial evaluation of soft contact lenses.

METHODS

A short-term prospective, contralateral, randomized, and participant-masked study was carried out. Twenty healthy participants (25.4 ± 2.6 years) were evaluated after the insertion of two different soft contact lenses at different times (1, 5, 10, 20, 30 min). Ocufilcon D (hydrogel) and Somofilcon A (silicone hydrogel) contact lenses were randomly assigned to both eyes of the same participant. Comfort, visual function under photopic conditions in terms of high-contrast visual acuity, low-contrast visual acuity, contrast sensitivity, and in vivo wettability were measured.

RESULTS

There was an increase in comfort (p < 0.001), high-contrast visual acuity (p < 0.05), and contrast sensitivity (p < 0.001, only with silicone hydrogel) directly related to time after contact lens insertion. Besides, in vivo wettability suffered a statistically significant deterioration directly related to time with both contact lenses (p < 0.05). Except for comfort and contrast sensitivity, all the parameters stabilized their values 10 min after the insertion of both soft contact lenses. Additionally, in vivo wettability and visual acuity differences were found between hydrogel and silicone hydrogel contact lenses (p < 0.05).

CONCLUSIONS

It would be possible to properly evaluate high-contrast visual acuity, low-contrast visual acuity, and in vivo wettability 10 min after the insertion of both soft contact lenses.

Changes in the geometry of modern daily disposable soft contact lenses during wear

The geometry of contact lenses can be altered by wear but determining the changes that occur in soft contact lenses (SCLs) is challenging. This study aimed to investigate the shape alterations of daily disposable SCLs after wear using swept-source optical coherence tomography (SS-OCT). Forty-five eyes with myopia of − 3.00 diopters (D) were enrolled. The participants wore three types of SCLs: hydrogel lens (nesofilcon A) and silicone hydrogel lenses (delefilcon A and stenfilcon A). The SCLs were scanned 3–6 min after lens removal. We found a significant decrease in the SCL anterior curvature: 0.24 ± 0.17 mm for nesofilcon A, 0.44 ± 0.21 mm for delefilcon A, and 0.53 ± 0.29 mm for stenfilcon A. The changes in the anterior curvature of SCLs correlated moderately with the mean corneal keratometry; Pearson’s correlation coefficients for nesofilcon A and delefilcon A were 0.57 and 0.52, respectively (P < 0.001). A statistically significant change in the total diameter was observed in SCL made of stenfilcon A (0.39 mm, P < 0.001). To conclude, the central radii of curvature decreased after a wearing period for all three types of daily disposable SCLs to imitate the anterior corneal surface, however, the changes in other geometrical parameters measured with SS-OCT were lens-specific.

Daily Disposable Contact Lens use in Adolescents and its Short-term Impact on Self-Concept

OBJECTIVE

To determine the short-term effect of contact lens (CL) wear on the self-concept of adolescents.

METHODS

In this open-label trial, first-time CL wearing adolescents were prescribed Delefilcon A (DAILIES TOTAL1,® Alcon, USA) daily disposable CL. To determine the self-concept level of the subjects at dispensing and after one month, the Turkish adapted version of the Piers-Harris Children's Self-Concept Scale (PHCSCS) was used. The subject-reported outcomes included lens wettability, vision quality, comfort, and overall satisfaction. Self-concept was evaluated under six categories.

RESULTS

The mean age of the 21 subjects was 16.5 ± 1.5 years. All subjects had normal biomicroscopic assessments and best corrected visual acuity was 20/20. The mean spherical equivalent was -2.90 ± 1.18 (range, -4.75 to -1.75). Spectacle use was causing dissatisfaction with their appearance in 90% of subjects (n = 19), the others defined it as uncomfortable. Most subjects had acquired information about CLs from their peers and friends (57%, n = 12). Most of the subscales in the PHCSCS showed increased but statistically insignificant scores after one month. The mean overall satisfaction was 95%.

CONCLUSION

Prescription of CLs may be a good option in adolescents even if the self-concept did not show significant improvement in the short term.

Cost-Efficient Printing of Graphene Nanostructures on Smart Contact Lenses

Smart contact lenses have been put forward for years, but there is still no commercial product in the market; the high cost due to expensive fabrication techniques could be one of the reasons. In this paper, first, a cost-efficient and reliable route to fabricate graphene grating on contact lens was designed and demonstrated based on the direct laser interference patterning graphene film on commercial contact lenses using an Nd:YAG laser. The thickness of the film and the interference angle have been taken into consideration. Optical characterization and simulation have been applied to evaluate the quality of our final achieved grating patterns with a grating size from 0.92 to 3.04 μm. Two-dimensional (2D) patterns could also be obtained through double-time laser interference. Contact angles for samples with different interference angles were presented considering the service environment of smart contact lenses. Of course, the conductivity of the samples was evaluated using a four-probe method. The most conductive sample had the sheet resistance lower than 30 Ω/sq. This research study highlighted the possibility of patterning graphene with the laser ablation method and provided a candidate solution for the fabrication of smart contact lenses under controlled cost.

Objective Evaluation Of On-Eye Optical Quality Of Daily Disposable Silicone Hydrogel Contact Lens With Internal Wetting Agents

Purpose

To investigate the on-eye optical quality of a daily disposable silicone hydrogel contact lens with internal wetting agent.

Patients and methods

Study subjects were daily disposable soft contact lens wearers (N=20) who were instructed to wear daily disposable hydrogel etafilcon A lens (without added wetting agent) or daily disposable silicone hydrogel senofilcon A lens (with an internal wetting agent), for a week. Subjects wore their respective lenses bilaterally and disposed of the pair of lenses daily. At the end of the 1-week test-wear period, the on-eye visual performances of the lens and the ocular surfaces were evaluated. A wavefront sensor measured sequential ocular higher-order aberrations (HOAs) for 10 s after the blink. The aberration data were analyzed in the central 4-mm diameter up to the sixth-order Zernike polynomials. Total HOAs, fluctuation index (FI), and stability index (SI) of the total HOAs over time were compared between the two lenses. Ocular surface evaluation with fluorescein was performed following the wavefront measurement.

Results

The senofilcon A lens had significantly lower average total HOAs, FI, and SI (p<0.001, p=0.001, p=0.007, respectively) than the etafilcon A lens. After 1-week wear of each lens, corneal staining was observed in eight subjects (40%) with the etafilcon A lens and in two subjects (10%) with the senofilcon A lens. The senofilcon A lens had significantly lower incidence of corneal staining than the etafilcon A lens (p=0.041).

Conclusion

Quantitative sequential measurement of HOAs objectively showed the possibility of better and more stable optical quality with silicone hydrogel daily disposable contact lens with the internal wetting agent than with hydrogel lens without the added wetting agent.

Hydrogels Based Drug Delivery Synthesis, Characterization and Administration

Hydrogels represent 3D polymeric networks specially designed for various medical applications. Due to their porous structure, they are able to swollen and to entrap large amounts of therapeutic agents and other molecules. In addition, their biocompatibility and biodegradability properties, together with a controlled release profile, make hydrogels a potential drug delivery system. In vivo studies have demonstrated their effectiveness as curing platforms for various diseases and affections. In addition, the results of the clinical trials are very encouraging and promising for the use of hydrogels as future target therapy strategies.

Novel in vitro method to determine pre-lens tear break-up time of hydrogel and silicone hydrogel contact lenses

PURPOSE

To develop an in vitro model to determine pre-lens non-invasive break-up time (NIBUT) and to subsequently use this method to compare the NIBUT over contemporary daily disposable (DD) contact lenses (CL).

METHODS

Three silicone hydrogel (SH) and two conventional hydrogel (CH) DD CLs were incubated in an artificial tear solution (ATS). A model blink cell (MBC) was utilised to mimic intermittent air exposure. CLs were repeatedly submerged for 3 seconds (s) and exposed to air for 10 s over periods of 2, 6, 12, and 16 hours (h). NIBUTs (n = 4) were determined out of the blister pack (T₀) and at the end of each incubation period.

RESULTS

Overall, nesofilcon A showed the longest NIBUTs (p < 0.001). At T₀, CHs revealed significantly longer NIBUTs (p ≤ 0.001) than SHs. After 2 h, nesofilcon A showed the longest NIBUT, however, this was only statistically significant compared with delefilcon A (p ≤ 0.001). After 6 h, nesofilcon A NIBUT was significantly longer than all other CLs (p ≤ 0.001). Etafilcon A showed a significantly longer NIBUT (p ≤ 0.001) after 12 h and delefilcon A had the longest NIBUT (p ≤ 0.001) after 16 h. Statistically significant (p ≤ 0.05) changes of NIBUT within the lens materials varied between time points. After 16 h, all CLs showed significant reductions in NIBUTs (p ≤ 0.001) in comparison to T₀.

CONCLUSION

NIBUT values reduced gradually over time and varying levels of deposition impacted measured pre-lens NIBUTs. While NIBUT of CH materials are longer immediately out of the blister pack, after tear film exposure, the NIBUTs obtained using this methodology became very similar.

Direct Laser Writing of Nanophotonic Structures on Contact Lenses

Contact lenses are ubiquitous biomedical devices used for vision correction and cosmetic purposes. Their application as quantitative analytical devices is highly promising for point-of-care diagnostics. However, it is a challenge to integrate nanoscale features into commercial contact lenses for application in low-cost biosensors. A neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (1064 nm, 3 ns pulse, 240 mJ) in holographic interference patterning mode was utilized to produce optical nanostructures over the surface of a hydrogel contact lens. One-dimensional (925 nm) and two-dimensional (925 nm × 925 nm) nanostructures were produced on contact lenses and analyzed by spectroscopy and angle-resolve measurements. The holographic properties of these nanostructures were tested in ambient moisture, fully hydrated, and artificial tear conditions. The measurements showed a rapid tuning of optical diffraction from these nanostructures from 41 to 48°. The nanostructures were patterned near the edges of the contact lens to avoid any interference and obstruction to the human vision. The formation of 2D nanostructures on lenses increased the diffraction efficiency by more than 10%. The versatility of the holographic laser ablation method was demonstrated by producing four different 2D nanopattern geometries on contact lenses. Hydrophobicity of the contact lens was characterized by contact angle measurements, which increased from 59.0° at pristine condition to 62.5° at post-nanofabrication. The holographic nanostructures on the contact lens were used to sense the concentration of Na⁺ ions. Artificial tear solution was used to simulate the conditions in dry eye syndrome, and nanostructures on the contact lenses were used to detect the electrolyte concentration changes (±47 mmol L^-1). Nanopatterns on a contact lens may be used to sense other ocular diseases in early stages at point-of-care settings.

Performance evaluation of delefilcon a water gradient daily disposable contact lenses in first-time contact lens wearers

PURPOSE

To evaluate the tolerability of and subject and investigator satisfaction with delefilcon A (DAILIES TOTAL1^®) daily disposable contact lenses in first-time contact lens wearers.

METHODS

This European multicenter, open-label, single-arm, two-week trial enrolled first-time contact lens wearers and fitted them with delefilcon A contact lenses. Assessments were made at dispensing and at Weeks 1 and 2. Subject-reported outcomes included comfort, quality of vision, convenience, and intent to purchase, which were ranked by agreement responses. Investigator-reported outcomes included slit-lamp biomicroscopy findings and lens fit satisfaction.

RESULTS

Ninety-two subjects were included in the per protocol dataset. Mean scores at Weeks 1 and 2 for subject-reported quality of vision and ocular comfort were significantly higher with delefilcon A contact lenses than with the subjects' habitual spectacles during the day, at the end of the day, and overall (all p ≤ 0.02). Ninety-one percent of subjects reported that their study lenses were more comfortable than expected, 98% agreed that they were convenient to use, and 92% were interested in purchasing the lenses (all p < 0.001). Investigators reported that study lenses had an acceptable fit in at least 97% of subjects.

CONCLUSIONS

Practitioners can expect favorable outcomes when transitioning first-time contact lens wearers from spectacles to delefilcon A daily disposable contact lenses.

Corneal Swelling with Cosmetic etafilcon A Lenses versus No Lens Wear

Purpose

To determine if the use of pigments or adding polyvinyl pyrrolidone during the fabrication of 1-DAY ACUVUE DEFINE (AD) brand contact lenses impacts open-eye corneal swelling compared with no lens wear (NLW).

Methods

A partial double-masked, randomized, bilateral crossover study was conducted in 24 Asian subjects using AD, 1-DAY ACUVUE DEFINE with Lacreon (ADL), NLW, and a control lens with no tint (1-DAY ACUVUE MOIST [AM]). Central corneal thickness was measured before insertion and immediately after removal after 8 ± 1 h of open-eye wear using an optical pachymeter in one eye. Corneal thickness along a 10-mm cord was measured in the contralateral eye using the Visante optical coherence tomographer (OCT). Corneal swelling was tested for noninferiority using a 5% margin. The endothelial bleb response was measured at baseline and 20 min after lens insertion using specular microscopy. Subjective grading of corneal staining and limbal/bulbar hyperemia were also monitored.

Results

After 8 ± 1 h of open-eye wear, central corneal swelling across the study lenses with either optical pachymeter or OCT methods was negligible. Peripheral corneal swelling least-square mean differences with OCT were −0.03% (95% confidence interval [95% CI], −0.65 to 0.58%) and −0.26% (95% CI, −0.87 to 0.36%) between AD and ADL and the control lens (AM), respectively, and 1.67% (95% CI, 1.06 to 2.29%) and 1.45% (95% CI, 0.84 to 2.06%) between AD and ADL and NLW, respectively. No endothelial blebs were observed. No clinically significant differences were distinguished between the lenses and NLW for corneal staining and limbal/bulbar hyperemia.

Conclusions

After 8 ± 1 h of open-eye wear, central and peripheral corneal swelling along the horizontal meridian with AD, ADL, AM, and NLW were equivalent. These results confirm that the addition of polyvinyl pyrrolidone or pigments to etafilcon A to obtain a limbal ring design have no impact on corneal swelling or limbal/bulbar hyperemia during normal open-eye wear.

Raman imaging of layered soft contact lenses

BACKGROUND

Daily disposable contact lenses are gaining in popularity among practitioners and wearers for the improved ocular health and subjective outcomes they offer. Recently a novel daily disposable contact lens material with water gradient technology was introduced. Delefilcon A lenses consist of a 33% water content silicone hydrogel core and an outer hydrogel layer which is totally free of silicone and contains 80% water.

METHODS

The aim of the present study was to confirm the layered structure of delefilcon A contact lenses. Thickness of hydrogel coating on the silicone hydrogel core was assessed using Raman spectroscopy. To investigate the layered structure of the material, depth spectra of the lenses were recorded.

RESULTS

The results obtained suggest that at about 6 μm a boundary between the hydrogel layer and silicone hydrogel core exists, which is in good agreement with the manufacturer's data.

CONCLUSIONS

Data collected in this experiment confirm a water gradient at the delefilcon A lens surface.

Effect of Three Interventions on Contact Lens Comfort in Symptomatic Wearers: A Randomized Clinical Trial

Purpose

To investigate whether carrying out various interventions part way through the day influences comfort in symptomatic daily disposable (DD) contact lens wearers.

Methods

A subject-masked, randomized, controlled clinical trial was conducted in thirty symptomatic soft lens wearers who wore their habitual DD contact lenses bilaterally for 12 h on two separate days. Five hours after lens application, one of the following three interventions or a control was performed on each eye: replacing the existing lens with a new lens; removing and reapplying the same lens; performing a ‘scleral swish’; and no action (control). Comfort scores were recorded using SMS text messages every hour following lens application using a 0 (causes pain) to 100 (excellent comfort) scale. Comfort scores before lens application, at 6 mins post-application, and at 6 mins post-intervention were also recorded.

Results

There was a significant reduction in comfort from pre-lens application to 6 mins post-application for all groups (all p<0.05). Comfort gradually decreased from 6 mins to 5 h after lens application for each group (p<0.0001) with no significant difference between groups over the 5-h period (p = 0.09). There was no significant difference in comfort 6 mins post-intervention for any group (all p>0.05). After the intervention, comfort continued to decline (p<0.0001) with slightly lower mean scores for the control group compared to the new lens group (p = 0.003). Change in comfort relative to pre-intervention (5 h) was similar for all groups (p = 0.81). There was no difference in comfort at 12 h between groups (p = 0.83).

Conclusion

This work has confirmed that comfort shows a continual and significant decline over a 12-h wearing period in symptomatic DD contact lens wearers. None of the interventions investigated had any significant impact on end-of-day comfort. These data suggest discomfort in lens wearers is more heavily influenced by changes to the ocular environment rather than to the lens itself.

Trial Registration

Controlled-Trials.com ISRCTN10419752 http://www.controlled-trials.com/ISRCTN10419752