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.

Spherical aberration in contact lens wear

INTRODUCTION: The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control. METHODS: A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses. The first study evaluated residual spherical aberration with a standard lens (Focus Dailies Disposable, Ciba Vision) and with an aberration controlled contact lens (ACCL) (Definition AC, Optical Connection Inc.). The second study evaluated the residual spherical aberrations with a monthly disposable silicone hydrogel lens with aberration reduction (PureVision, Bausch & Lomb). RESULTS: Uncorrected spherical aberration was positive for all pupil sizes in both studies. In the first study, residual spherical aberration was close to zero with the standard lens for all pupil sizes whereas the ACCL over-corrected spherical aberration. The results of the second study showed that the monthly disposable lens also over-corrected the aberration making it negative. The changes in aberration were statistically significant (p<0.05) with all lenses. CONCLUSION: Since the amount of aberration varies individually we suggest that aberrations should be measured with lenses on the eye if the aim is to change spherical aberration in a certain direction.     

Synthesis and characterization of nanosilver-silicone hydrogel composites for inhibition of bacteria growth

Purpose

Nanosilver-silicone hydrogel (NAgSiH) composites for contact lenses were synthesized to asses the antimicrobial effects.

Does placebo effect exist in contact lens discomfort management?

PurposeTo study the effect of daily disposable contact lens (DDCL) refitting in monthly contact lens (CL) wearers suffering from contact lens discomfort (CLD), and to assess if there is a placebo effect associated with this CLD intervention.MethodsSymptomatic CL wearers, according to the Contact Lens Dry Eye Questionnaire 8 (CLDEQ-8 ≥ 12 points), were divided into two groups. The study group was provided with DDCLs (delefilcon A) and the control group with a masked pair of their habitual monthly CLs (placebo effect) and were assessed after one month. Then, the control group was provided with the same DDCLs and evaluated one month later. The symptoms were recorded with the CLDEQ-8 and global rating of change scale (GRCS). Non-invasive tear break-up time (NITBUT), conjunctival hyperaemia, fluorescein staining, and lid wiper epitheliopathy (LWE) were evaluated. Changes between visits, groups, and the effect of each intervention were analysed.ResultsThirty-one participants (mean age: 23.2 ± 5.3 years) were recruited. The study group (n = 14) showed an improvement of -39.6 ± 25.8 % (p < 0.001) in CLDEQ-8 and 31.3 ± 14.6 points in GRCS (p < 0.001) after one month of DDCL use, while no changes in clinical tests were found. In the control group (n = 17), symptoms improved significantly after wearing the masked monthly CL (CLDEQ-8: -26.1 ± 31.0 %, p = 0.03; GRCS: 14.9 ± 17.0, p = 0.002), however a worsening in bulbar (26.5 ± 40.0 %; p = 0.02) and limbal hyperaemia (21.6 ± 34.7 %, p = 0.02) and an improvement of -19.1 ± 37.0 % (p = 0.049) in LWE was found. When the control group was fitted with the DDCL, improvements in GRCS (20.5 ± 25.5, p = 0.02), NITBUT (37.9 ± 42.3 %, p = 0.002), and conjunctival staining (-47.1 ± 59.9 %, p = 0.005) were noted.ConclusionsRefitting symptomatic monthly CL wearers with Delefilcon A DDCL is effective in reducing symptoms related to CLD. However, clinicians and researchers must be aware of the existence of a placebo effect when assessing the effectiveness of any CL refitting.     

Eye care professionals’ perceptions of the benefits of daily disposable silicone hydrogel contact lenses

PurposeTo gain a better understanding of eye care professionals’ (ECPs) perceptions regarding the benefits of silicone hydrogel (SiH) daily disposable contact lenses (DDCL), particularly with respect to health, comfort and patient satisfaction.MethodsA survey was conducted with 300 ECPs in the United States, United Kingdom and Japan during November 2017. The survey comprised 34 statements relating to SiH DDCLs, to which the ECPs provided their level of agreement using a 6 point Likert scale. A minimum of 70% agreement was set to define majority agreement. Categories of statements included Health, Comfort, Patient Experience, and Standard of Care.ResultsECPs rated the highest levels of agreement to perceptions within the Patient Experiences and Health categories. The six statements receiving the highest ratings were “Silicone hydrogel 1 day lenses satisfy today’s patients’ demanding lifestyles” (93% agreement); “Silicone hydrogel 1 day lenses are the best choice to safeguard my patients’ eye health related to contact lens wear” (92%); “Silicone hydrogel 1 day lenses provide the best benefits to my patients” (92%); “Silicone hydrogel 1 day lenses provide better long term eye health for my patients than hydrogel 1 day lenses” (91%); “Silicone hydrogel is the healthiest lens material for my daily disposable patients” (90%); and “Silicone hydrogel 1 day lenses provide a better wearing experience for my patients than hydrogel 1 day lenses” (90%).ConclusionECPs perceive that SiH DDCLs offer long-term eye health and comfort for the patient and although the ECPs surveyed would not necessarily prescribe SiH DDCLs to all their patients, they would prescribe them to most of their patients. The results support the premise that while ECPs consider SiH 1 day contact lenses as the current “standard of care”; the principal barrier continues to be the perceived higher cost of these lenses.     

Trends in the use of silicone hydrogel contact lenses for daily wear

Although the first silicone hydrogel contact lenses introduced onto the world contact lens market in 1999 held approval for both daily wear and extended wear use, the latter modality was promoted much more heavily by the manufacturers. The first silicone hydrogel lenses specifically promoted for daily wear were introduced in 2003. Data that we have gathered from annual contact lens fitting surveys demonstrate an immediate increase in market share whereby this lens type now represents more than one-third of soft lens fits in the United Kingdom. The success of this lens category is attributed to the health and safety benefits of silicone hydrogel materials and the positive impact of lens manufacturers by way of the effective marketing and distribution of these products.     

A novel in-vitro method for assessing contact lens surface dewetting: Non-invasive keratograph dry-up time (NIK-DUT)

Purpose

This study was designed to develop a novel technique called non-invasive keratograph dry-up time (NIK-DUT), which used an adapted corneal topographer, to analyse in-vitro contact lens surface dewetting and the effects of combinations of lenses and lens care solutions on dewetting.

Health beliefs affect the correct replacement of daily disposable contact lenses: Predicting compliance with the Health Belief Model and the Theory of Planned Behaviour

Purpose

To assess the compliance of Daily Disposable Contact Lenses (DDCLs) wearers with replacing lenses at a manufacturer-recommended replacement frequency. To evaluate the ability of two different Health Behavioural Theories (HBT), The Health Belief Model (HBM) and The Theory of Planned Behaviour (TPB), in predicting compliance.

Struggle with hydrogel CL wear increases with age in young adults

Purpose

To report the symptoms and experiences associated with habitual hydrogel (Hyd) and silicone hydrogel (SiHy) contact lenses (CLs) among young adults and measure their association with age.

Methods

Questionnaire responses from 699 Hyd and 183 SiHy wearers were analyzed to test the association of age with features indicating struggle with CL wear. Prevalence by age was compared between groups with Pearson's chi-square and within groups with Spearman's correlation coefficient.

Results

Hyd and SiHy groups were similar for sex and age distribution. Diagnosis of dry eye increased with age in the Hyd wearers from 10.6% to 21.1% (18-24 vs. 30-35 years), but was approximately 19% in the SiHy wearers across age. Adverse environments caused more discomfort with Hyd than SiHy lenses and Hyd wearers’ discomfort increased with age (smoky (p = 0.0001), dry air environments (p = 0.002), after napping or sleeping (p = 0.004). More Hyd wearers considered discontinuation of CL wear with age, from 4.6% to 14.2% (18-24 vs. 30-35 years, p < 0.04), but the proportion remained steady at 9% across age for SiHy wearers (p = 0.46).

Conclusions

From 18 to 35 years, hydrogel CL wearers reported increasing struggle with CL wear and more negative ratings compared to SiHy wearers. Older hydrogel CL wearers were also more likely to consider discontinuing CL wear compared with younger hydrogel or silicone hydrogel CL wearers in general. Young adult CL wearers should be routinely queried directly about specific aspects of CL wear in order to determine whether different lens types should be prescribed to avoid abandonment of CL wear.     

Characterization of patients who report compliant and non-compliant overnight wear of soft contact lenses

Purpose

To describe compliant and non-compliant overnight wear (EW) of soft contact lenses from a large observational study.

Methods

A retrospective chart review of 3211 SCL patients with known EW status (aged 8–33 yrs, SCL power +8.00 to −12.00 D) captured data from 10,516 clinical visits (2006–2009). Status of EW was either daily wear (DW), compliant EW (overnight wear of US Food & Drug Administration (US FDA) EW-approved lenses), non-compliant EW (overnight wear of DW-approved lenses). The effect of demographic and clinical characteristics on the likelihood of reporting EW was examined using logistic regression. Additionally, the effect of these same characteristics on the likelihood of non-compliant EW was assessed with logistic models.

Results

Eight-hundred and eight patients (25.2%) reported EW. Non-compliant EW was reported by 6% of wearers (13 hydrogel, 2 silicone hydrogel brands) In multivariate models, patient age and lens replacement schedule were significant factors for EW (vs. DW) and for non-compliant (vs. compliant) EW (p < 0.0001). Other factors significantly related to EW were gender, smoking, lens material, sphere power, and years of CL wear (p ≤ 0.007, all).

Conclusions

Young people (ages 18–25 yrs), males, smokers, myopes, silicone hydrogel lens wearers and patients with >1 yr of CL wear were significantly more likely to report EW. Non-compliant EW occurred often in young people and daily disposable wearers, though many brands had non-compliant EW use. Understanding who is likely to wear EW and non-compliant EW will help clinicians pointedly counsel patients more at risk on best practices with EW.     

Patterns of prescribing extended wear contact lenses

Patterns of prescribing extended wear contact lenses in the UK were determined by mining through data gathered from annual contact lens fitting surveys conducted over the past 12 years. The increased rate of extended wear prescribing this century - which in 2007 had reached 7% and 19% of all soft lens new fits and refits, respectively - probably reflects the superior clinical performance of silicone hydrogel lenses for this purpose.     

Development and evaluation of evidence-based guidelines on contact lens-related microbial keratitis.

PURPOSE: To assess the response to clinical guidelines based on recent epidemiological studies of contact lens-related microbial keratitis. METHODS: Incidence rates for silicone hydrogel extended wear were summarized from recent studies. Risk factors were listed and two key factors identified: overnight wear and poor hygiene accounting for 43% and 33% of risk, respectively. A pre-guidelines, web-based survey was conducted to assess the need for information and level of knowledge on CL-related microbial keratitis (n=162). Comparisons to a post-guidelines survey (n=51) measured whether new information was acquired through an educational brochure posted to the membership. RESULTS: In the pre- and post-guidelines surveys, 52% (85/162) vs. 43% (22/51, p=0.3) indicated they did not have enough information on CL-related microbial keratitis. The importance attached to risk factors was generally reflective of the magnitude of risk and practitioners made appropriate recommendations about low risk modalities. Hygiene practices were rated as highly important in both surveys (>90%) with increased awareness of handwashing (p=0.03). Overnight wear of hydrogel lenses was considered highly important in 94% (201/213). However, despite evidence to the contrary, only 53% in the pre-guidelines and 58% in the post-guidelines surveys indicated that silicone hydrogel overnight wear was a highly important risk factor. CONCLUSIONS: Research evidence has been disseminated to the BCLA membership and responses gathered via a web survey. There are some areas of disconnect between practitioner opinion, as gauged in this survey, and the evidence from the research, particularly with regards to increased risk with overnight wear.     

The influence of lens care systems on eyelid tissue changes during silicone hydrogel contact lens wear

Purpose

To compare the effects of a hydrogen peroxide (H₂O₂)-based lens care solution and a polyhexamethylene biguanide (PHMB) multi-purpose solution on the eyelids when used with silicone hydrogel (SiHy) contact lenses.

Prescribing daily disposable contact lenses in the UK.

Patterns of prescribing daily disposable contact lenses in the UK were determined by mining through data gathered from annual contact lens fitting surveys conducted over the past 12 years. Spherical, toric and multifocal design daily disposable lenses represent a substantial proportion of all contact lenses prescribed, reflecting the significant ocular health and lifestyle advantages offered by this lens category.     

The effect of hydrogel and silicone hydrogel contact lenses on the measurement of intraocular pressure with rebound tonometry

Purpose

To assess the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over disposable hydrogel (etafilcon A) and silicone hydrogel (senofilcon A) contact lenses (CLs) of different powers.

Methods

The experimental group comprised 36 subjects (19 male, 17 female). IOP measurements were undertaken on the subject's right eyes in random order using a rebound tonometer (ICare). The CLs had powers of +2.00D, −2.00D and −6.00D. Six measurements were taken over each contact lens and also before and after the CLs had been worn.

Results

A good correlation was found between IOP measurements with and without CLs (all r ≥ 0.80; p < 0.05). Bland Altman plots did not show any significant trend in the difference in IOP readings with and without CLs as a function of IOP value. A two-way ANOVA revealed a significant effect of material and power (p < 0.01) but no interaction. All the comparisons between the measurements without CLs and with hydrogel CLs were significant (p < 0.01). The comparisons with silicone hydrogel CLs were not significant.

Conclusions

Rebound tonometry can be reliably performed over silicone hydrogel CLs. With hydrogel CLs, the measurements were lower than those without CLs. However, despite the fact that these differences were statistically significant, their clinical significance was minimal.