Jami Kern

The TFOS International Workshop on Contact Lens Discomfort: Report of the Subcommittee on Epidemiology

This report characterizes the neurobiology of the ocular surface and highlights relevant mechanisms that may underpin contact lens-related discomfort. While there is limited evidence for the mechanisms involved in contact lens-related discomfort, neurobiological mechanisms in dry eye disease, the inflammatory pathway, the effect of hyperosmolarity on ocular surface nociceptors, and subsequent sensory processing of ocular pain and discomfort have been at least partly elucidated and are presented herein to provide insight in this new arena. The stimulus to the ocular surface from a contact lens is likely to be complex and multifactorial, including components of osmolarity, solution effects, desiccation, thermal effects, inflammation, friction, and mechanical stimulation. Sensory input will arise from stimulation of the lid margin, palpebral and bulbar conjunctiva, and the cornea.

Soft contact lens-related dryness with and without clinical signs.

Purpose. To report demographics, wearing patterns, and symptoms from soft contact lens (SCL) wearers with significant SCL-related dryness symptoms with and without significant ocular signs of dryness. Methods. In a multicenter, prospective observational clinical trial, symptomatic SCL wearers reported significant SCL-related dryness via self-administered questionnaire of frequency and intensity of dryness after a dry eye (DE) examination. DE etiology was assigned post hoc by an expert panel, and those with and without significant DE-related signs were analyzed by univariate logistic regression. Possible DE etiologies were aqueous tear deficiency, SCL-induced tear instability, meibomian gland dysfunction, or “other.” Wearers without signs that qualified for any DE etiology were designated as No DE Signs (NDES). Results. Of the 226 SCL symptomatic wearers examined, 23% were without signs, 30% had aqueous tear deficiency, 25% had SCL-induced tear instability, 14% had meibomian gland dysfunction, and 8% had “other” diagnoses. The NDES wearers had significantly longer pre-lens break-up time (9.8 vs. 6.6 s, p < 0.0001), better lens wetting (3.4 vs. 2.4 0 to 4 scale, p < 0.0001), lower levels of film deposits on lenses (0.45 vs. 0.92, 0 to 4 scale, p < 0.0001), and of most slit lamp signs. The NDES wearers were significantly more likely to be male (36% vs.19%, p = 0.013), were less likely to have deteriorating comfort during the day (81% vs. 97%, p = 0.001), reported longer average hours of comfortable wear (11 ± 3 vs. 9 ± 4 h, p = 0.014), had older contact lenses (18 ± 14 vs. 13 ± 12 days, p = 0.029), and greater intensity of photophobia early and late in the day (p = 0.043 and 0.021). Conclusions. Symptoms of dryness in SCL wearers stem from a variety of underlying causes. However, nearly one-quarter of these symptomatic SCL wearers appear to be free of signs of dryness. The effective management of CL-related dryness requires a comprehensive range of clinical assessments and the use of a diverse range of management strategies.

Corneal inflammatory events with daily silicone hydrogel lens wear

Purpose This study aimed to determine the probability and risk factors for developing a corneal inflammatory event (CIE) during daily wear of lotrafilcon A silicone hydrogel contact lenses. Methods Eligible participants (n = 218) were fit with lotrafilcon A lenses for daily wear and followed up for 12 months. Participants were randomized to either a polyhexamethylene biguanide-preserved multipurpose solution or a one-step peroxide disinfection system. The main exposures of interest were bacterial contamination of lenses, cases, lid margins, and ocular surface. Kaplan-Meier (KM) plots were used to estimate the cumulative unadjusted probability of remaining free from a CIE, and multivariate Cox proportional hazards regression was used to model the hazard of experiencing a CIE. Results The KM unadjusted cumulative probability of remaining free from a CIE for both lens care groups combined was 92.3% (95% confidence interval [CI], 88.1 to 96.5%). There was one participant with microbial keratitis, five participants with asymptomatic infiltrates, and seven participants with contact lens peripheral ulcers, providing KM survival estimates of 92.8% (95% CI, 88.6 to 96.9%) and 98.1% (95% CI, 95.8 to 100.0%) for remaining free from noninfectious and symptomatic CIEs, respectively. The presence of substantial (>100 colony-forming units) coagulase-negative staphylococci bioburden on lid margins was associated with about a five-fold increased risk for the development of a CIE (p = 0.04). Conclusions The probability of experiencing a CIE during daily wear of lotrafilcon A contact lenses is low, and symptomatic CIEs are rare. Patient factors, such as high levels of bacterial bioburden on lid margins, contribute to the development of noninfectious CIEs during daily wear of silicone hydrogel lenses.

Risk factors for microbial bioburden during daily wear of silicone hydrogel contact lenses

Purpose: To assess risk factors associated with substantial microbial bioburden of lids, conjunctivae, contact lenses, and storage cases during daily wear of silicone hydrogel contact lenses. Methods: Two hundred eighteen patients were fit to lotrafilcon A lenses, randomized to use either a multipurpose solution or a hydrogen peroxide care system, and followed up for 1 year. Lenses, lens transport saline, lids, conjunctivae, and storage cases were cultured and considered to have substantial microbial bioburden when they harbored high levels of commensal or pathogenic organisms. Univariate and multivariate logistic regression analyses were conducted to examine which demographic covariates were associated with significant bioburden at each location while controlling for solution use. Results: In multivariate analyses, smoking trended toward an association with lens bioburden (odds ratio [OR]=2.15, 95% confidence interval [CI]: 0.95–4.88). Clerical occupations were found to be associated with more frequent overall storage case contamination (OR=3.51, 95% CI: 1.15–10.70) and, specifically, higher gram-positive storage case contamination (OR=5.57, 95% CI: 1.82–17.06). The peroxide system was associated with more frequent storage case contamination (OR=7.6, 95% CI: 3.79–15.19). Coagulase-negative staphylococci (CNS) were the most frequently cultured organisms within storage cases, and in multivariate analyses, CNS were more frequently found in storage cases of peroxide users (OR=6.12, 95% CI: 2.91–13.09). Conclusions: Clerical occupations were associated with increased microbial bioburden of storage cases during daily wear of silicone hydrogel lenses. Smoking may increase the risk of lens contamination. Storage cases are most frequently contaminated with normal skin flora, and peroxide cases were associated with more frequent contamination. However, the solution type was not associated with lid or lens contamination nor with corneal infiltrative events in this study.

Daily disposable contact lenses versus spectacles in teenagers.

Purpose To compare clinical and subjective quality-of-life (QoL) data for teenagers wearing daily disposable contact lenses or spectacles. Methods This open-label study randomized subjects (aged 13 to 19 years) with no previous contact lens wear experience to nelfilcon A (DAILIES AquaComfort Plus) contact lenses or spectacles for 6 months. A full clinical workup, as well as subjective QoL measures using the Pediatric Refractive Error Profile and Quality of Life Impact of Refractive Correction questionnaires, was conducted at baseline and at week 4 and months 3 and 6, with an additional study visit at week 2 for subjects randomized to wear contact lenses. Results A total of 110 teenagers were enrolled in the study; 13 discontinued before study completion, 10 (17.5%) from the contact lens group and 3 (5.7%) from the spectacle group (p = 0.04). Visual acuity was good for both groups at all study visits. Biomicroscopy assessments were similar at baseline for both groups. Significant differences in Pediatric Refractive Error Profile responses were noted between vision correction groups across visits for appearance (p < 0.001), satisfaction (p < 0.001), activities (p < 0.001), peer perception (p = 0.003), and overall score (p < 0.001). For Quality of Life Impact of Refractive Correction, the contact lens group gave more favorable responses than the spectacle group (p = 0.02). After 6 months of wearing contact lenses, teenagers had a more positive attitude toward comfort, vision, and safety with contact lenses. No serious adverse events were reported during the study. Conclusions The daily disposable lenses used in this study are suitable for vision correction for teenagers, offering improvements in QoL measures during the first month of wear, including appearance, satisfaction, activities, and peer perceptions, without negatively impacting vision or eye health. Teenagers were able to handle contact lenses with the same amount of confidence as spectacles.

The impact of lens care solutions on corneal epithelial changes during daily silicone hydrogel contact lens wear as measured by in vivo confocal microscopy

PURPOSE To assess corneal epithelial microstructure via confocal microscopy and determine if cellular changes are associated with lens care solutions during daily wear of silicone hydrogel contact lenses. METHODS Corneal in vivo confocal microscopy with the Nidek ConfoScan4 was performed at baseline and after 5 months of lotrafilcon A daily contact lens wear. Enrolled participants were randomized to use either a polyhexamethylene biguanide (PHMB) preserved multipurpose care solution (MPS) or a peroxide based solution system. Lens and storage case bioburden were assessed with aerobic culture methods. Univariate and multivariable analyses were done to evaluate the association between solution use, or solution-related clinical covariates, and morphologic differences (hyper-reflectivity) in the superficial epithelial cells and epithelial basal cell density. RESULTS Data on 139 participants were available for analysis of superficial epithelial cells while data on 92 participants were available for epithelial basal cell density. Five months after randomization to the solution groups, 33% of participants had visible hyper-reflective cells. More participants using MPS had ≥1 hyper-reflective cells compared to peroxide users at 5 months (44% vs. 22%; p=0.006). Similarly at 5 months, more participants with solution-induced corneal staining (SICS) had ≥1 hyper-reflective cells compared to non-SICS participants (57% vs. 29%; p=0.010). The adjusted odds ratios (ORs) for risk of presenting with hyper-reflective cells in MPS users or SICS participants was 2.7 (95% CI; 1.27-5.65) and 3.4 (95% CI; 1.29-8.97), respectively. Basal cell density decreased by over 350 cells/mm2 over time (about 6%) in participants who had substantial bioburden on their lenses or in their storage case. CONCLUSION The confocal microscope can detect epithelial cellular changes in vivo during contact lens wear. Hyper-reflective superficial epithelial cells are associated with a PHMB preserved solution and decreases in basal epithelial cell density may be associated with bacterial bioburden.

Soft Contact Lens-Related Symptoms in North America and the United Kingdom.

Purpose To characterize and compare the prevalence of soft contact lens-related (SCL) dryness symptoms in large populations of SCL wearers in North America (NAm) and the United Kingdom (UK). Methods SCL wearers from NAm (n = 1443) and UK (n = 932) sites completed self-administered questionnaires on SCL symptoms and wearing experiences. A categorization for contact lens-related dry eye (CL-DE) was applied that combined Contact Lens Dry Eye Questionnaire (CLDEQ) items on dryness frequency and intensity at the end of the day (CL-DE+ = constantly/frequently/sometimes plus intensity = 3–5, and CL-DE- = never/rarely plus intensity = 0–1, Marginal = all other ratings). Data were analyzed across regions and categories, with p-values <0.05 significant. Results Compared to UK wearers, those in NAm wore fewer toric and multifocal designs, and reported significantly longer average and comfortable wearing times (p < 0.001) but similar levels of general and end-of-day comfort. The prevalence of CL-DE+ differed between the UK and NAm: CL-DE+: 31 vs. 39%, Marginal CL-DE: 13 vs. 14%, and CL-DE−: 56 vs. 47%, p = 0.0001. Although daily disposable (DD) lenses were worn more commonly in the UK than NAm (33 vs. 10%, p < 0.0001), their use did not impact the overall prevalence of dryness symptoms. Between regions, NAm wearers reported significantly more frequent and intense end-of-day discomfort and dryness (p < 0.0001) and were significantly more likely to use treatments for CL-related symptoms yet experienced a lower degree of relief. Conclusions SCL wearers in NAm reported longer hours of wear with significantly more symptoms of dryness and discomfort. NAm wearers used dryness treatments more often, but experienced less relief than UK wearers. In both regions, the CL-DE categorization was useful to predict poorer comfort, shorter comfortable wearing time, and increased use of treatments. These results highlight the need to benchmark SCL performance locally or regionally to understand and focus on the challenges to the lens wearing experience.

55 Antimicrobial properties of a novel contactions disinfecting solution, OPTI-FREE EverMoist

Purpose: To evaluate the efficacy of a new contact lens disinfecting solution. Method: The efficacy of a new contact lens disinfecting solution with a dual disinfection system was assessed against standard challenge microorganisms and clinical isolates of Acanthamoeba castellanii, Acanthamoeba polyphaga, Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Candida albicans, and Fusarium solani using stand-alone microbiological test methodology. Additionally, the efficacy of recently marketed contact lens care solutions, including Revitalens and Biotrue, was tested against standard challenge microorganisms. The stand-alone test is a time kill study designed to qualify individual solutions with a suitable level of antimicrobial activity as contact lens disinfection products. Results: After six hours of disinfection time, the OPTI-FREE EverMoist showed ∼2 logs kill against cysts of A. castellanii ATCC30234 and A. polyphaga ATCC 30871. OPTI-Free EverMoist met the primary Stand-alone criteria with efficacies of more than 4 log reductions for each of the three standard bacteria and each standard yeast and mold. All tested marketed contact lens care solutions showed efficacy against standard challenge microorganisms. Clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, and Candida albicans were reduced by approximately 4 logs or greater after six hours of exposure to OPTI-FREE EverMoist. Conclusions: OPTI-FREE EverMoist MPDS provides broad spectrum antimicrobial activity against a variety of challenge ATCC and clinical microorganisms. OPTI-FREE EverMoist leverages the proven PolyQuad® and Aldox® dual disinfection system to provide excellent antimicrobial efficacy.

Results from a global survey of contact lens-wearer satisfaction with OPTI-FREE ® PureMoist ® Multi-Purpose Disinfecting Solution

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Clinical Optometry 2013:5 39–46 Clinical Optometry Dovepress