Risk Factors for Contact Lens Complications in US Clinical Practices

Goal framing of health promotion messages in contact lens wear

PURPOSE

Appropriate framing of health information influences the adoption of health behaviors. This study explored whether (1) gain- or loss-framed health promotion messages, emphasizing positive or negative consequences, respectively, were more persuasive in adult contact lens wearers and (2) approach-oriented participants (participants that tend to seek rewards or attain goals) were motivated by gain-framed messages while avoidance-oriented participants (those driven to avoid consequences such as disease or injury) were motivated by loss-framed messages, as postulated by the congruency hypothesis.

METHODS

Gain- and loss-framed health promotion messages were created for three healthy contact lens-wearing habits (avoiding sleeping in contact lenses unless instructed to by an eye care provider, replacing lenses according to the manufacturer's recommended replacement schedule, and avoiding water exposure with contact lenses). Following local pilot testing and revision of health messages, data from 300 soft contact lens wearers aged 18-33 years (2/3 female) were collected via an electronic survey and online survey platform. Message persuasiveness was assessed by the participants with a visual analog scale. Avoidance and approach motivations were evaluated using the Behavioural Inhibition System/Behavioural Activation System scale. A linear mixed-effect model explored factors that influenced the persuasive effect of messages. Independent variables included frame type, media (infographic versus text), and participant characteristics. Pairwise Pearson correlations were used to explore relationships between avoidance/approach mechanisms and persuasiveness.

RESULTS

Participants rated loss-framed messages as more persuasive than gain-framed messages across the three habits: overnight wear (P < 0.001), lens replacement (P < 0.001), and water exposure (P < 0.001). The motivational orientation of the participants was not significantly correlated with persuasiveness but varied significantly with participant sex and history of a contact lens-related red eye.

CONCLUSIONS

Loss-framing was more persuasive than gain-framing in this cohort. The results did not support the congruency hypothesis. Further study is needed to explore the clinical impact of these findings.

Scoping review: Reporting characteristics for the safety of contact lenses in the pediatric population

SIGNIFICANCE

Contact lenses are an increasingly popular option for correcting pediatric refractive error due to increased awareness of interventions to slow myopia progression. With limited information on the safety profiles of contact lenses in children, it is important to characterize the current understanding and promote this device's safe and effective use.

PURPOSE

This scoping review evaluates characteristics of the current literature that have examined the safety of contact lenses in pediatric patients. It provides future directions for systematic reviews and identifies any gaps in the current literature or areas for future research.

METHODS

Literature searches in MEDLINE via PubMed, EMBASE, The Cochrane Library, trial registries, and U.S. Food and Drug Administration clinical trial documentation were performed. Included studies (i.e., experimental and quasi-experimental studies; observational studies including prospective and retrospective cohort, case-control, and analytical cross-sectional studies, and case series of 30 or more participants) reported safety and/or complications of the use of any contact lens for correcting refractive error in children (0 to 18 years). Two independent reviewers first screened the titles and abstracts, and then full-text reports for eligibility. Conflicts in eligibility were resolved by discussions with a third reviewer. Two independent reviewers extracted data, including details about the participants, context, study methods, and key findings relevant to the review question.

RESULTS

This scoping review included 73 studies from 10 countries using different contact lens modalities, primarily orthokeratology and soft contact lenses, in children (6 to 18 years). The most common adverse event reported by the studies was corneal staining (60% orthokeratology, 45% soft contact lens).

CONCLUSIONS

The need for uniform reporting standards for adverse events poses challenges for comprehensive data synthesis. However, this scoping review identified a sufficient number of studies for a future systematic review to quantify the risks associated with orthokeratology and soft contact lens use in children.

A snap-shot of orthokeratology lens rinsing habits: An online survey in a major eye hospital in Shanghai

PURPOSE

A hospital-based survey to explore lens rinsing habits of orthokeratology (ortho-k) patients, including the solution used for rinsing.

METHODS

An anonymous survey, via an online questionnaire, was administered to ortho-k lens wearers or their parents when they attended Fudan University Eye and ENT Hospital for routine follow-up visits. Three major issues were investigated: basic demographics, lens rinsing solution used, and specific rinsing habits. Relationships between demographics and rinsing solution used and rinsing behaviours were explored.

RESULTS

Of the total of 541 online questionnaires delivered, 296 were completed and returned. The respondents were the person responsible for lens care, either the ortho-k users themselves, or their parents. The median age of the lens wearers was 12.0 years (range: 8-22 years), and the median period of ortho-k lens wear was 18.0 months (range: 1-109 months). The most common rinsing solutions reported were a particular brand of multidose preserved saline (28.4%), cooled boiled water (23.3%), and non-preserved multidose saline (16.2%). Overall, the main reason for choice of rinsing solution was recommendation of eye care practitioners (90.2%). The respondents with a longer lens wear history tended to use commercially available bottled water, drinking water, or cooled boiled water rather than non-preserved saline (unidose or multidose) (p ≤ 0.009) and were more likely to use the rinsing solution to soak their lenses (p = 0.009). Lens wearers who rinsed the lenses themselves tended to use tap water compared to those whose lenses were handled by parents (p = 0.040).

CONCLUSION

Inappropriate choice and usage of rinsing solution appeared to be a common issue among ortho-k lens wearers in Shanghai, China. The problem was more pronounced in long-term wearers and in those who performed rinsing themselves.

Examining daily disposable soft contact lens wearers' attitudes and beliefs using the Health Belief Model

PURPOSE

To use the Health Belief Model (HBM) to understand daily disposable (DD) soft contact lens (SCL) wearers' attitudes and beliefs.

METHODS

A convenience sample of DD SCL wearers (18-33 years) was enrolled at two sites. Participants were queried about demographics, SCL wear and HBM constructs. Rasch analysis was used to assess the psychometric properties of the survey instrument and generate scores for each HBM subscale. ANOVA was used to determine relationships among HBM constructs, subject demographics and DD SCL-related health behaviours.

RESULTS

One hundred people participated (mean ± SD), age = 24.2 ± 3.9 years, 76% female. Thirty-seven percent reported sleeping in DD SCLs and 25% reported reusing DD SCLs. Self-report of reusing DD SCLs was associated with scores on the benefits: reuse (p = 0.02) and barriers (p = 0.007) subscales, and sleeping in lenses was associated with scores on the susceptibility (p = 0.05), benefits: wear behaviours (p = 0.006) and barriers (p = 0.01) subscales. Rasch analysis showed some subscales demonstrated multidimensionality.

CONCLUSIONS

Selected health belief constructs were associated with DD SCL-related behaviours including reusing and overnight wear. Increased understanding of SCL attitudes and beliefs could inform patient education and interventions to decrease risks associated with improper SCL wear.

Contact Lens Safety for the Correction of Refractive Error in Healthy Eyes

ABSTRACT

Contact lenses are a safe and effective method for correction of refractive error and worn by an estimated 45 million Americans. Because of the widespread availability and commercial popularity of contact lenses, it is not well appreciated by the public that contact lenses are U.S. Food and Drug Administration (FDA)-regulated medical devices. Contact lenses are marketed in numerous hard and soft materials that have been improved over decades, worn in daily or extended wear, and replaced in range of schedules from daily to yearly or longer. Lens materials and wear and care regimens have impact on the risks of contact lens-related corneal inflammatory events and microbial keratitis. This article reviews contact lens safety, with specific focus on the correction of refractive error in healthy eyes.

OSDI Questions on Daily Life Activities Allow to Detect Subclinical Dry Eye in Young Contact Lens Users

Dry eye disease (DED) is difficult to detect in young contact lens (CL) wearers, who usually have no signs, mild symptoms and an ocular surface disease index (OSDI) below the DED diagnosis values (OSDI ≥ 13). We investigate if some of the 12 OSDI questions (OSDI A—ocular symptoms; OSDI B—vision-related functionality; OSDI C—environmental triggers) contribute the most to classify young CL as symptomatic. TBUT and tear volume are also measured. Age, gender and refraction error-matched eye glasses (EG) wearers participated as the control. CL and EG data were compared with t-test and z-test. Confusion matrices and logistic correlation analyses were performed to define the contribution of each OSDI question to classify symptomatic subjects. OSDI classified symptomatic CL better than the tear volume or TBUT values. In CL, only OSDI B and C values were significantly higher in symptomatic vs. asymptomatic subjects (p < 0.001), while values of all twelve OSDI questions were significantly higher in symptomatic vs. asymptomatic EG (p < 0.05−0.001). All OSDI questions contribute equally to identify symptomatic EG, while only OSDI B questions on daily life visual functions are significant to classify symptomatic CL wearers at risk to develop DED or at a subclinical stage. CL wearers scoring ≥ 2 on the OSDI B questions should be considered for preventive treatments, even if their clinical sings are scarce or absent.

Addressing common myths and misconceptions in soft contact lens practice

Advances in contact lens technology over the past 50 years since the commercialisation of the first soft lenses in 1971 have been incredible, with significant changes in contact lens materials, frequency of replacement, care systems and lens designs occurring. However, despite the widespread availability of contact lenses, penetration rates for those who need vision correction remain in the low single digits and many practitioners seem to hold on to concepts around the potential value of contact lenses that appear based in the dim and distant past and are certainly no longer valid today. This review addresses 10 common 'myths and misconceptions' around soft contact lenses using an evidence-based approach that can hopefully dispel some of these incorrect assumptions.

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.

The Risks and Benefits of Myopia Control

PURPOSE

The prevalence of myopia is increasing around the world, stimulating interest in methods to slow its progression. The primary justification for slowing myopia progression is to reduce the risk of vision loss through sight-threatening ocular pathologic features in later life. The article analyzes whether the potential benefits of slowing myopia progression by 1 diopter (D) justify the potential risks associated with treatments.

METHODS

First, the known risks associated with various methods of myopia control are summarized, with emphasis on contact lens wear. Based on available data, the risk of visual impairment and predicted years of visual impairment are estimated for a range of incidence levels. Next, the increased risk of potentially sight-threatening conditions associated with different levels of myopia are reviewed. Finally, a model of the risk of visual impairment as a function of myopia level is developed, and the years of visual impairment associated with various levels of myopia and the years of visual impairment that could be prevented with achievable levels of myopia control are estimated.

RESULTS

Assuming an incidence of microbial keratitis between 1 and 25 per 10 000 patient-years and that 15% of cases result in vision loss leads to the conclusion that between 38 and 945 patients need to be exposed to 5 years of wear to produce 5 years of vision loss. Each additional 1 D of myopia is associated with a 58%, 20%, 21%, and 30% increase in the risk of myopic maculopathy, open-angle glaucoma, posterior subcapsular cataract, and retinal detachment, respectively. The predicted mean years of visual impairment ranges from 4.42 in a person with myopia of -3 D to 9.56 in a person with myopia of -8 D, and a 1-D reduction would lower these by 0.74 and 1.21 years, respectively.

CONCLUSIONS

The potential benefits of myopia control outweigh the risks: the number needed to treat to prevent 5 years of visual impairment is between 4.1 and 6.8, whereas fewer than 1 in 38 will experience a loss of vision as a result of myopia control.

Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada

OBJECTIVES

To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS).

METHODS

This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures.

RESULTS

There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60).

CONCLUSIONS

No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

CLEAR - Evidence-based contact lens practice

Evidence-based contact lens -->practice involves finding, appraising and applying research findings as the basis for patient management decisions. These decisions should be informed by the strength of the research study designs that address the question, as well as by the experience of the practitioner and the preferences and environment of the patient. This reports reviews and summarises the published research evidence that is available to inform soft and rigid contact lens history and symptoms taking, anterior eye health examination (including the optimised use of ophthalmic dyes, grading scales, imaging techniques and lid eversion), considerations for contact lens selection (including the ocular surface measurements required to select the most appropriate lens parameter, lens modality and material selection), evaluation of lens fit, prescribing (teaching self-application and removal, adaptation, care regimen and cleaning instructions, as well as -->minimising risks of lens wear through encouraging compliance) and an aftercare routine.

Therapeutic Hydrogel Lenses and the Antibacterial and Antibiotic Drugs Release

The aim of this research was to evaluate the effects of different lens types on the availability and efficacy of anti-inflammatory and antibiotic drugs. Three lens types were examined: (1) nonionic hydrogel lenses; (2) ionic hydrogel lenses; and (3) silicone hydrogel lenses. The lenses were incubated with (a) dexamethasone; (b) betamethasone; (c) bromophenacyl bromide; and (d) chloramphenicol. Drug availability was quantified by gradient HPLC, and chloramphenicol antibacterial activity was quantified by testing the inhibition of Salmonella typhimurium growth on agar. The lens allowing the most abundant passage of betamethasone was the ionic hydrogel lens, followed by the silicone hydrogel lens and nonionic hydrogel lens. The lens allowing the most abundant passage of dexamethasone was the ionic hydrogel lens, but only at 0.5 h and 1 h. Regarding chloramphenicol, the ionic hydrogel lens and silicone hydrogel lens allowed more abundant passage than the nonionic hydrogel lens. These results highlight the relevance of adapting lenses to anti-inflammatory therapy, thus allowing a personalized medical approach.

Risk Factors for Contact Lens-Related Microbial Keratitis and Associated Vision Loss in a South Indian Population

OBJECTIVES

To identify risk factors associated with contact lens-related microbial keratitis (CL-MK) and subsequent vision loss in a south Indian population.

METHODS

A retrospective study of medical records at the LV Prasad Eye Institute in Hyderabad, India, of patients diagnosed with CL-MK and of controls who had no history of corneal inflammation during contact lens wear was undertaken. Variables such as demographic data, contact lens wear details, duration of the event, visual acuity, epithelial defect and infiltrate size, and microbiology of the cornea during the event were collected. Differences between cases and controls were analyzed using parametric and nonparametric tests. Logistic regression was used to calculate the odds ratio (OR) and associated 95% confidence intervals in univariate and multivariate analyses for cases vs. controls and for factors associated with vision loss.

RESULTS

One hundred sixty-seven cases of CL-MK and 153 controls were included in the analyses. Risk factors associated with the greatest increased OR for CL-related MK were: being in professional employment vs. a student (OR=3.9), disposing lenses yearly versus monthly or biweekly (OR=2.2), and any overnight wear (OR=2.8). Risk factors associated with vision loss were: high myopia (OR=3.6), severe vs. mild severity (OR=16.0), and hypopyon (OR=4.3).

CONCLUSIONS

Identification of these risk factors may help inform safe contact lens wear habits and management strategies.

Sol-Gel Nanocomposite Coatings for Preventing Biofilm Formation on Contact Lens Cases

Purpose

To evaluate the efficacy of a nanosilver-based sol–gel coating in preventing biofilm formation on contact lens cases.

Methods

An organic–inorganic hybrid silica–zirconia sol formulation with immobilized silver nanoparticles was deposited on contact lens case coupons. The coated and uncoated coupons were subjected to biofilm formation to Gram-negative and Gram-positive keratitis isolates and ATCC strains using a standard protocol. The biofilms were evaluated using crystal violet, MTT assay, and scanning electron microscope (SEM) examination. The duration of efficacy of the coating was evaluated by exposing the coated and uncoated coupons to a multipurpose lens cleaning solution for various durations up to 30 days and comparing their biofilm characteristics. The cytotoxicity of the coated surface was assessed using cell culture studies.

Results

Cross-hatch tests and SEM confirmed the presence of a uniform, well-adhered coating on the surface. The coating resulted in a nearly 95% reduction in biofilm formation of the tested bacteria and was effective despite exposures of up to 30 days to a multipurpose lens cleaning solution. The coating did not exhibit cytotoxicity to human corneal epithelial cells.

Conclusions

The silver nanoparticle-based coating exhibits a good antibiofilm property for both Gram-negative bacilli and Gram-positive cocci and is promising for commercial use in preventing contact lens-related infections.

Translational Relevance

Biofilm formation on lens cases continues to be an important concern. The proposed coating will help reduce such formations, thus reducing the risk of lens-associated microbial keratitis.

The contact Lens risk survey to assess risk of soft contact lens-related inflammatory events

PURPOSE

To test the Contact Lens Assessment in Youth Contact Lens Risk Survey (CLRS) scoring algorithm in soft contact lens (SCL) wearers presenting with SCL-related adverse events and healthy matched controls.

METHODS

This prospective case-control study compared CLRS responses in SCL wearers presenting with symptomatic red eyes (Cases) with age-, sex- and site-matched healthy SCL wearers (Controls) at six locations across North America. Responses to individual questions from Cases and Controls were analyzed using either the Pearson, Mantel-Haenszel chi-square, or Fisher's exact test. Differences in the CLRS scores were compared using t-tests.

RESULTS

A total of 171 SCL wearers were enrolled (n = 57 Cases, 114 Controls). Cases were adjudicated to consensus and classified as contact lens-related serious and significant (S&S) or non-serious events. S&S Cases scored significantly higher on the CLRS (56.1 ± 11.1) than either their matched Controls (44.3 ± 11.1) (P <  0.001) or the non-Serious Cases (44.8± 12.8 P =  0.002). Scores of non-serious Cases were not significantly different than scores of their Controls (43.4 ± 10.7, P = 0.33) CONCLUSIONS: The CLRS scoring algorithm discriminated between SCL wearers presenting with S&S CL-related adverse events from healthy SCL wearers and those with non-serious events. This survey and scoring system could help practitioners identify patients at greatest risk for CL-related adverse events and support targeted interventions aimed at reducing risk behaviors.

Development of a contact Lens risk survey

PURPOSE

To describe the development and report psychometric properties of the Contact Lens Risk Survey (CLRS) to identify patients at risk for soft contact lens-related complications.

METHODS

Psychometric properties of the CLRS, a web-based survey with branching logic, were determined using data from 5 multi-site fieldings (n = 1059), including re-fielding to sub groups. Responses from participants with and without an active red eye were used to identify risk factors of a red eye event and calculate an overall risk score. A 6th fielding of the CLRS (n = 171) was used to assess discriminate validity.

RESULTS

Participants needed 11-12 min to complete the survey with a negligible difference by age. Internal consistency was excellent (Cronbach's α ≥ 0.70) for 3 of the 5 constructs identified by factor analysis. Twelve of the 17 survey items exhibited excellent within-subject repeatability (Kappa ≥ 0.61). Between-subject agreement, assessed in 18-25 year olds, was high for the majority of items, suggesting good generalizability across different populations of SCL wearers. The ability of the model using individual items of the CLRS to discriminate Controls and participants with a red eye was good with an area under the curve of 0.779.

CONCLUSION

The CLRS tool is a repeatable and valid instrument to standardize documentation of demographic, behavior, and exposure factors which appear to drive the greatest risk of a contact lens related red eye event.

Adverse event rates in the retrospective cohort study of safety of paediatric soft contact lens wear: the ReCSS study

Purpose

To ascertain the safety of soft contact lens (SCL) wear in children through a retrospective chart review including real‐world clinical practice settings.

Methods

The study reviewed clinical charts from 963 children: 782 patients in 7 US eye care clinics and 181 subjects from 2 international randomised clinical trials (RCTs). Subjects were first fitted while 8–12 years old with various SCL designs, prescriptions and replacement schedules, and observed through to age 16. Clinical records from visits with potential adverse events (AEs) were electronically scanned and reviewed to consensus by an Adjudication Panel.

Results

The study encompassed 2713 years‐of‐wear and 4611 contact lens visits. The cohort was 46% male, 60% were first fitted with daily disposable SCLs, the average age at first fitting was 10.5 years old, with a mean of 2.8 ± 1.5 years‐of‐wear of follow‐up observed. There were 122 potential ocular AEs observed from 118/963 (12.2%) subjects; the annualised rate of non‐infectious inflammatory AEs was 0.66%/year (95% CI 0.39–1.05) and 0.48%/year (0.25–0.82) for contact lens papillary conjunctivitis. After adjudication, two presumed or probable microbial keratitis (MK) cases were identified, a rate of 7.4/10 000 years‐of‐wear (95% CI 1.8–29.6). Both were in teenage boys and one resulted in a small scar without loss of visual acuity.

Conclusion

This study estimated the MK rate and the rate of other inflammatory AEs in a cohort of SCL wearers from 8 through to 16 years of age. Both rates are comparable to established rates among adults wearing SCLs.

Soft contact lens wearers' compliance during the COVID-19 pandemic

Aim

Contact lens wearers need to maintain optimal hygiene practices during the COVID-19 pandemic to minimise contact-lens complications including microbial keratitis and corneal infiltrative events. This online survey (UK and Ireland) explored contact lens wearers’ compliance behaviours, attitudes and concerns during the pandemic.

Method

The 60-item anonymous online survey was distributed during a 1-month period via Qualtrics (starting on 14/04/20). The survey captured: a) demographic information, b) type of lenses worn and compliance with lens wear and care procedures, c) adherence to recommendations and d) concerns associated with contact lens wear during the pandemic.

Results

Two hundred and forty seven responses were received (34.3 ± 11.7 years old, 79% female). Seventy nine percent of participants reported that they were self-isolating or rigorously following social distance advice. Fifty-six percent of participants reported using their lenses less during the pandemic. Eighty-seven percent of respondents reported following the recommended 20-second rule most times/every time and 96% used soap and water during handwashing. Eleven percent of respondents admitted not following recommendations regarding disposal of lenses and 18% would not consider ceasing lens wear if unwell (with flu/cold) during the pandemic.

Conclusion

Respondents reported wearing their contact lenses less than usual. Good compliance with handwashing was observed but soft reusable lens wearers showed a statistically significant lower compliance with lens wear and care compared to daily disposable lens wearers (p=<0.001).

Tear Film Characteristics During Wear of Daily Disposable Contact Lenses

Purpose

To evaluate changes induced over time by three daily disposable (DD) contact lenses on tear meniscus height (TMH), pre-lens non-invasive break-up time (pre-lens NIBUT), tear film osmolarity (TO) and objective quality of vision (OQV).

Patients and Methods

Forty-six subjects enrolled in this prospective open-label unmasked non-randomized simultaneous comparative cross-over study. For the first week of the study, subjects wore a nesofilcon A lens in the right eye and a delefilcon A lens in the left eye. After 3 days of washout, for the second week, subjects wore a nesofilcon A lens in the left eye and a stenfilcon A lens in the right eye. TMH, pre-lens NIBUT, TO and OQV were measured before contact lens fitting and for each contact lens combination on day 1 at 20 minutes and on day 7 after ≥8 hours of wear. OQV measurement included the changes of objective scatter index (OSI), the stability index (SI) and the fluctuation index (FI) calculated in a range of time of 20 s from a blink.

Results

TMH was unchanged at 20 minutes wear of all lenses but was significantly reduced after 8 or more hours wear (on day 7) of delefilcon A and stenfilcon A, respectively. Pre-lens NIBUT was significantly reduced with all lenses, while no significant change in TO was observed with any lens. SI and FI increased significantly for all lenses at both wear times.

Conclusion

While the presence of any contact lens on the eye challenges the tear film, nesofilcon A contact lenses, despite their high water content, compared to delefilcon A and stenfilcon A contact lenses, showed a lower overall effect. We speculate that superior tear film behavior while wearing nesofilcon A lenses may translate to improved subjective comfort, but this remains to be evaluated.

The COVID-19 pandemic: Important considerations for contact lens practitioners

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). As information concerning the COVID-19 disease continues to evolve, patients look to their eye care practitioners for accurate eye health guidance. There is currently no evidence to suggest an increased risk of contracting COVID-19 through contact lens (CL) wear compared to spectacle lens wear and no scientific evidence that wearing standard prescription spectacles provides protection against COVID-19 or other viral transmissions. During the pandemic there will potentially be significant changes in access to local eyecare. Thus, it is imperative CL wearers are reminded of the steps they should follow to minimise their risk of complications, to reduce their need to leave isolation and seek care. Management of adverse events should be retained within optometric systems if possible, to minimise the impact on the wider healthcare service, which will be stretched. Optimal CL care behaviours should be the same as those under normal circumstances, which include appropriate hand washing (thoroughly with soap and water) and drying (with paper towels) before both CL application and removal. Daily CL cleaning and correct case care for reusable CL should be followed according to appropriate guidelines, and CL exposure to water must be avoided. Where the availability of local clinical care is restricted, practitioners could consider advising patients to reduce or eliminate sleeping in their CL (where patients have the appropriate knowledge about correct daily care and access to suitable lens-care products) or consider the option of moving patients to daily disposable lenses (where patients have appropriate lens supplies available). Patients should also avoid touching their face, including their eyes, nose and mouth, with unwashed hands and avoid CL wear altogether if unwell (particularly with any cold or flu-like symptoms).

A study of contact lens compliance in a non-clinical setting

PURPOSE

To evaluate soft contact lens replacement, overnight (ON) wear, and contact lens case compliance in a non-clinical sample.

METHODS

Subjects (n = 297) were recruited at the Center for Science and Industry (COSI) in Columbus, Ohio. Adult (≥ 18 years) soft contact lens wearers completed a survey about contact lens replacement, ON contact lens wear, and contact lens case replacement habits.

RESULTS

Two-week replacement lenses (according to the manufacturer's replacement schedule [MRS]) were most common (45.5%), followed by monthly (34.3%) and daily replacement (20.2%). Non-compliance with replacement schedule was reported in 38.7% of subjects. Age (p = 0.02), years of lens wear (p = 0.02), and MRS (p <0.0001) affected replacement compliance. Post-hoc analysis showed daily replacement wearers were more compliant than two-week (p <0.0001) and monthly (p <0.0001) replacement wearers with prescribed lens replacement. Non-compliance with prescribed ON wear was reported in 23.9% of subjects. Subjects who were non-compliant with lens replacement were more likely to be non-compliant with ON wear (p = 0.02) and had worn contact lenses for less time (p = 0.02). Of the subjects who used contact lens cases, 74.6% were unsure when they should replace their case. Frequency of case replacement was not associated with age (p = 0.5), gender (p = 0.5), years of contact lens wear (p = 0.7), MRS (p = 0.4), replacement compliance (p = 0.3), or ON wear compliance (p = 0.7).

CONCLUSIONS

Daily replacement wearers were most likely to be compliant with contact lens replacement, but all subjects, including daily replacement wearers, had similar ON wear non-compliance. Non-compliant lens replacement was associated with non-compliant ON wear, but contact lens case replacement was not related to either compliance category. The majority of subjects had no knowledge of proper contact lens case replacement, despite compliance in other categories.

The Development of an Antimicrobial Contact Lens - From the Laboratory to the Clinic

Contact lens wear is generally safe and provides excellent vision. However, contact lens wear is often associated with the risk of developing ocular surface infection and inflammation, and in severe cases, the infection can result in loss of vision. Antimicrobial peptide-coated contact lenses have been made to help reduce the incidence of infection and inflammation. This paper reviews the research progress from conception, through the laboratory and preclinical tests to the latest information on clinical testing of an antimicrobial contact lens. We provide insights into the pathways followed and pitfalls that have been encountered. The journey has not always been linear or smooth, but has resulted in some of the first published clinical testing of antimicrobial peptide-coated contact lenses in humans. We hope this may help lead to the development and commercialisation of antimicrobial contact lenses in the future.

IMI - Clinical Myopia Control Trials and Instrumentation Report

The evidence-basis based on existing myopia control trials along with the supporting academic literature were reviewed; this informed recommendations on the outcomes suggested from clinical trials aimed at slowing myopia progression to show the effectiveness of treatments and the impact on patients. These outcomes were classified as primary (refractive error and/or axial length), secondary (patient reported outcomes and treatment compliance), and exploratory (peripheral refraction, accommodative changes, ocular alignment, pupil size, outdoor activity/lighting levels, anterior and posterior segment imaging, and tissue biomechanics). The currently available instrumentation, which the literature has shown to best achieve the primary and secondary outcomes, was reviewed and critiqued. Issues relating to study design and patient selection were also identified. These findings and consensus from the International Myopia Institute members led to final recommendations to inform future instrumentation development and to guide clinical trial protocols.

Simulated optical performance of soft contact lenses on the eye

PURPOSE

To evaluate the impact of soft contact lens eye-fit on optical power by computational modelling and to produce correction maps for reversing this impact during the design process.

METHODS

Finite element models of spherical and toric hydrogel contact lenses at varying nominal powers of -20 D to +20 D, base curves radii (R1b) of 8.2, 8.5, 8.8 mm, and overall diameters (d3) of 14.5, 15.0, 15.5 mm were generated. Lenses were fitted to computational eye models generated with human eyes' topography data. Combined eye-lens simulations were run under the boundary conditions of the tears' surface tension between the contact lens and the eye in addition to the eyelid blink pressure. Lens optical zone power changes were calculated through computational light-ray tracing methods following each simulation.

RESULTS

Effective power changes (EPC) were affected negatively for all toric simulated lenses with power varying from -20 D to +20 D. Spherical lenses demonstrated similar behaviour, however with some positive EPC over the power range from -20 D to -10 D for spherical power (SPH) lenses. EPC assessment was between +0.25 D and -0.5 D for most lenses, however, lenses with prescriptions from +10 D to +20 D incurred EPC outside this range. The spherical lenses showed a maximum effective power change of +1.046 ± 0.338 D (Average Eye), and a minimum of -3.278 ± 0.731 D (Steep Eye). Similarly, the toric lenses showed a maximum of +1.501 ± 0.338 D (Average Eye), and a minimum of -3.514 ± 0.731 D (Steep Eye). EPC trends, along with minimum and maximum power, generally increased negatively as nominal lens prescription increased positively. Contact lens base curve selection affected the assessed effective power change for both spherical and toric lenses. The effect from lens total diameter for spherical lenses was less substantial than that for toric lenses.

CONCLUSIONS

This study considered the impact of soft contact lens design parameters on effective optical power changes (EPC) after eye-fit. Spherical lenses experienced more EPC of clinical significance (>0.25 D) than toric lenses. Both types of lenses, spherical and toric (simple astigmatism), demonstrated similar trends in EPC on fitting from -20 D to +20 D, with lenses in the extremely positive and the extremely negative prescriptions demonstrating the highest EPCs. The lens base curve impacted the extent of EPC observed, with flatter base curves experiencing less power change. Diameter proved to impact toric lenses more than spherical ones, however generally the diameter has less effect on power change than base curve selection.

Comparison of Silicone Hydrogel and Hydrogel Daily Disposable Contact Lenses

OBJECTIVE

To compare subjective, objective and safety performance of silicone hydrogel (SiHy) daily disposable (DD) with hydrogel (Hy) DD contact lenses.

METHOD

Retrospective analysis on approximately 40 participants (Px) each in 5 trials. Lenses grouped into SiHy (delefilcon A, somofilcon A, narafilcon A) and Hy (omafilcon A, nelfilcon A). Participants attended follow-up visits at baseline, 2 weeks, 1 and 3 months. Subjective ratings (1-10 scale), adverse events (percentage of Px), physiological variables (0-4 scale), and wearing time were collected at each visit and compared between groups.

RESULT

Trials enrolled 201 Px totally. No differences in age, sex, and lens wear experience were found between SiHy and Hy groups (P≥0.09). There was greater increase in limbal redness from baseline in Hy group (0.18±0.38 vs. 0.02±0.47, P<0.001), whereas conjunctival staining and indentation were less in Hy group (P<0.001). No differences in comfortable wearing time were found between groups (P=0.41), and comfort at insertion, during day, and end of day was also no different (P≥0.71). Incidence of corneal infiltrative events (SiHy vs. Hy: 6.7% vs. 2.5%; P=0.32) and mechanical adverse events (SiHy vs. Hy: 0.0% vs. 0.0%; P=1.00) were no different.

CONCLUSION

Though some statistical significance was found between the groups, these differences were within measurement error. Neither material types showed superiority in comfort, and adverse event rates were low with both material types. These findings suggest that choice of material is a patient and practitioner preference; however, for patients at risk of hypoxia-related complications, SiHy materials should be considered.

Consequences of Preservative Uptake and Release by Contact Lenses

OBJECTIVES

To assess contact lens preservative uptake and release from multipurpose solutions (MPS) and subsequent acquisition of lens antibacterial activity.

METHODS

Kinetics of uptake and release of poly (hexamethylene biguanide hydrochloride) (PHMB) or polyquaternium-1 (PQ-1) from various contact lenses were studied initially with the pure compounds and then after soaking in MPS containing these compounds. Lenses soaked in MPS were tested for antibacterial activity.

RESULTS

Only lenses with a negatively charged component absorbed these preservatives. For lenses containing methacrylic acid (MA), uptake of PHMB from preservative-only solution was fast, yet little was released, in contrast to its rapid release from lenses containing other anionic groups. This trend persisted with PHMB-containing MPS. PQ-1 from preservative-only solution was only absorbed by lenses containing MA and was released from MA-containing hydrogels, but not significantly from an MA-containing silicone hydrogel. Lens uptake of PQ-1 was much lower from MPS and release was essentially undetectable from all lenses evaluated. Antibacterial lens activity was acquired by lenses containing MA after an overnight soak in MPS containing PQ-1, and for balafilcon A and omafilcon A after 5 exchanges in PHMB-containing MPS. Acquired activity was maintained during cycling between artificial tear protein solution and MPS.

CONCLUSIONS

Lens preservative uptake and its subsequent release are dependent on lens chemistry, preservative nature, and other MPS components. A few lens/solution combinations acquired antibacterial activity after one or more overnight soaks in MPS, depending on the nature of the anionic lens component and the preservative. Uncharged lenses did not acquire antibacterial activity.

Epidemiology of contact lens-induced infiltrates: an updated review

Corneal infiltrative events (CIEs) are well established as a risk associated with soft contact lens wear. The incidence of symptomatic CIEs during extended soft lens wear ranges from 2.5 to six per cent; when asymptomatic CIEs are included, the incidence can be as high as 20-25 per cent. In daily soft lens wear, the annual incidence of symptomatic CIEs is about three per cent. There are various accepted methods of categorising CIEs, and a scoring system based on clinical signs and symptoms is a good approach to grade severity. Lens-related risk factors include extended wear, silicone hydrogel material, the use of multipurpose solutions, bacterial bioburden and reusable lenses. Recent studies report that daily disposable lenses reduce the risk of CIEs.

Risk Factors for Contact Lens-Related Microbial Keratitis: A Case-Control Multicenter Study

PURPOSE

The most feared complication of contact lens (CL) wear is microbial keratitis (MK), even though its incidence remains low. This study aimed to identify the risk factors of CL-related MK in a large, prospective, multicenter case-control study.

METHODS

A multicenter case-control study was designed. The CL-related MK subpopulation (Case) was compared with healthy CL wearers (Control) using a 52-item anonymous questionnaire designed to determine subject demographics and lens wear history. Univariate and multivariate logistic regression analyses were performed to compare both groups.

RESULTS

The study enrolled 499 cases and 508 controls. The risk factors associated with the greatest increased odds of CL-related MK were as follows: using disinfecting solution more than 3 months (odds ratio [OR]=1.94), cosmetic CL wear and use of multipurpose disinfection solution (1.37 each), overnight wear, and soft lens use (OR=1.24 each). The protective factors associated with the greatest reduction in OR were fitting by an ophthalmologist (OR=0.73) and hyperopia versus myopia (OR=0.75).

CONCLUSIONS

The infectious determinants were linked to the type of lenses, hygiene routine, CL handling, disinfecting solution, and storage case. This study aimed to highlight the increasingly CL-related MK, which likely occurs because of lack of patient information regarding basic rules of hygiene and CL care and handling.

Characterizing Contact Lens-Related Corneal Infiltrates: A Pilot Study

Purpose:

To document the time course and resolution of contact lens–related corneal infiltrative events (CIEs) comparing slit-lamp images with anterior segment ocular coherence tomography (AS-OCT) images.

Methods:

Six silicone hydrogel (SiHy) soft contact lens (SCL) wearers presenting with newly diagnosed symptomatic CIEs were monitored with slit-lamp images, detailed drawings, and AS-OCT until the resolution of the CIE. A final follow-up visit was completed 4 weeks after CIE resolution to determine whether scar formation was present. Positive controls were 2 SiHy SCL wearers with established (inactive) corneal scars, and negative controls were 2 SiHy SCL wearers with clear corneas. High- and low-contrast logMAR visual acuities were measured, and subjective symptom questionnaires were completed at all visits.

Results:

Clinical signs, vision, and symptoms improved in tandem with the resolution of the CIEs as measured by imaging methods. Calibrated measures of infiltrate width from a slit-lamp biomicroscope appear to be similar to calibrated images from AS-OCT.

Conclusions:

Although further studies are needed to develop standardized procedures, AS-OCT can be a useful tool to characterize the development, progression, and resolution of corneal infiltrates as an objective measure of resolution and scar formation.

Tear exchange and contact lenses: a review

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses.

Biometric risk factors for corneal neovascularization associated with hydrogel soft contact lens wear in Korean myopic patients

PURPOSE

To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea.

METHODS

This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups.

RESULTS

Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (≥2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV.

CONCLUSIONS

High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.

Age, behavior, environment, and health factors in the soft contact lens risk survey

PURPOSE

Previous studies have reported that the risk of corneal infectious and inflammatory events (CIEs) with soft contact lens (SCL) wear is highest in late adolescence and early adulthood. This study assesses the associations between patient age and other factors that may contribute to CIEs in young SCL wearers.

METHODS

After ethics approvals and informed consent, a nonclinical population of young SCL wearers was surveyed in five US cities. Data from 542 SCL wearers aged 12-33 years were collected electronically. Responses were analyzed by age bins (12-14, 15-17, 18-21, 22-25, 26-29, and 30-33 years) using chi-square test.

RESULTS

The cohort was 34% male and balanced across age bins. There were several significant associations between survey response and age (in bins). Wearers aged 18-21 years reported more recent nights with less than 6 hours of sleep (p < 0.001), more colds/flu (p = 0.049), and higher stress levels (p < 0.001). Wearers 18-21 and those 22-25 years were more likely to wear SCLs when showering (p < 0.001) and also reported more frequent naps with SCLs (p < 0.001). They reported sleeping in SCLs after alcohol use (p = 0.031), when traveling (p = 0.001), and when away from home (p = 0.024). Lower rates of regular hand washing before lens application (p = 0.054) was also associated with these groups. In addition, the relationship between reactive replacement and recommended replacement was dependent on age (p < 0.0001).

CONCLUSIONS

Patient age influences lens wearing behaviors, environmental exposures, and other determinants of health that may contribute to increased CIEs in younger wearers. Targeted, age-specific education should be considered for both new and established SCL wearers.

[Practical tips and tricks in fitting soft contact lenses]

This review is intended to give supportive information for beginners in contact lens fitting who are interested in providing a quality-related service to customers and patients. In Germany the proportion of contact lens wearers is significantly lower than in most other countries; therefore, there is a potentially fast growing market. The aim of this paper is to provide comprehensive guidelines for practitioners to develop and improve contact lens fitting practice and minimize unnecessary or preventable complications. The fundamental requirement for starting in contact lens fitting is to have correct education in the field and for the practice to be appropriately equipped. The key to providing a safe a reliable contact lens fitting practice is to continually update knowledge in the field and to maintain the practice to the highest professional standards.

Geographic and temporal risk factors for interruptions to soft contact lens wear in young wearers

OBJECTIVES

This was a secondary analysis of an existing dataset of soft contact lens wearers age 8-33 years, who received eye care outside of a clinical trial. The aim was to identify geographical and temporal factors associated with interruptions to contact lens wear.

METHODS

Data from six academic centers in North America captured 522 events in 3549 patients. Cases were analyzed overall and in subcategories of allergic, and serious and significant adverse events. General estimating equations were used to model the effect of geographic (Northwest, West, Central, Northeast, Southeast) and temporal (season, month, day of the week) factors, along with previously identified risk factors associated with interruptions in lens wear (patient age, contact lens material, overnight wear, lens care system, replacement schedule, and years of contact lens wear).

RESULTS

After controlling for established risk factors, both region and temporal factors disrupted the patients' ability to maintain contact lens wear. About 4% of all visits had complications that led to an interruption in wear. Allergic events were highest in the Central region. Serious and significant adverse events peaked in the Southeast during the Autumn and Winter months (September, October, December). Day of the week was not significant in any model.

CONCLUSIONS

This study provides evidence of seasonal and regional challenges to contact lens wear. As the use of soft contact lenses expands for both cosmetic and medical reasons, practitioners must examine ways to maintain continuous, safe, and healthy use of contact lenses across all patients.

Continuous 24-hour monitoring of intraocular pressure patterns with a contact lens sensor: safety, tolerability, and reproducibility in patients with glaucoma

OBJECTIVE To examine the safety, tolerability, and reproducibility of intraocular pressure (IOP) patterns during repeated continuous 24-hour IOP monitoring with a contact lens sensor. METHODS Forty patients suspected of having glaucoma (n = 21) or with established glaucoma (n = 19) were studied. Patients participated in two 24-hour IOP monitoring sessions (S1 and S2) at a 1-week interval (SENSIMED Triggerfish CLS; Sensimed AG). Patients pursued daily activities, and sleep behavior was not controlled. Incidence of adverse events and tolerability (visual analog scale score) were assessed. Reproducibility of signal patterns was assessed using Pearson correlations. RESULTS The mean (SD) age of the patients was 55.5 (15.7) years, and 60% were male. Main adverse events were blurred vision (82%), conjunctival hyperemia (80%), and superficial punctate keratitis (15%). The mean (SD) visual analog scale score was 27.2 (18.5) mm in S1 and 23.8 (18.7) mm in S2 (P = .22). Overall correlation between the 2 sessions was 0.59 (0.51 for no glaucoma medication and 0.63 for glaucoma medication) (P = .12). Mean (SD) positive linear slopes of the sensor signal from wake to 2 hours into sleep were detected in both sessions for the no glaucoma medication group (S1: 0.40 [0.34], P &lt; .001; S2: 0.33 [0.30], P &lt; .01) but not for the glaucoma medication group (S1: 0.24 [0.60], P = .06; S2: 0.40 [0.40], P &lt; .001). CONCLUSIONS Repeated use of the contact lens sensor demonstrated good safety and tolerability. The recorded IOP patterns showed fair to good reproducibility, suggesting that data from continuous 24-hour IOP monitoring may be useful in the management of patients with glaucoma. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01319617.

Dry eye disease and microbial keratitis: is there a connection?

Dry eye is a common ocular surface disease of multifactorial etiology characterized by elevated tear osmolality and inflammation leading to a disrupted ocular surface. The latter is a risk factor for ocular surface infection, yet overt infection is not commonly seen clinically in the typical dry eye patient. This suggests that important innate mechanisms operate to protect the dry eye from invading pathogens. This article reviews the current literature on epidemiology of ocular surface infection in dry eye patients and laboratory-based studies on innate immune mechanisms operating at the ocular surface and their alterations in human dry eye and animal models. The review highlights current understanding of innate immunity in dry eye and identifies gaps in our knowledge to help direct future studies to further unravel the complexities of dry eye disease and its sequelae.