Multicenter Testing of a Risk Assessment Survey for Soft Contact Lens Wearers With Adverse Events: A Contact Lens Assessment in Youth Study.

PURPOSE: To test the ability of responses to the Contact Lens Assessment in Youth (CLAY) Contact Lens Risk Survey (CLRS) to differentiate behaviors among participants with serious and significant (S&S) contact lens-related corneal inflammatory events, those with other events (non-S&S), and healthy controls matched for age, gender, and soft contact lens (SCL) wear frequency. METHODS: The CLRS was self-administered electronically to SCL wearers presenting for acute clinical care at 11 clinical sites. Each participant completed the CLRS before their examination. The clinician, masked to CLRS responses, submitted a diagnosis for each participant that was used to classify the event as S&S or non-S&S. Multivariate logistic regression analyses were used to compare responses. RESULTS: Comparison of responses from 96 participants with S&S, 68 with non-S&S, and 207 controls showed that patients with S&S were more likely (always or fairly often) to report overnight wear versus patients with non-S&S (adjusted odds ratio [aOR], 5.2; 95% confidence interval [CI], 1.4-18.7) and versus controls (aOR, 5.8; CI, 2.2-15.2). Patients with S&S were more likely to purchase SCLs on the internet versus non-S&S (aOR, 4.9; CI, 1.6-15.1) and versus controls (aOR, 2.8; CI, 1.4-5.9). The use of two-week replacement lenses compared with daily disposables was significantly higher among patients with S&S than those with non-S&S (aOR, 4.3; CI, 1.5-12.0). Patients with S&S were less likely to regularly discard leftover solution compared with controls (aOR, 2.5; CI, 1.1-5.6). CONCLUSIONS: The CLRS is a clinical survey tool that can be used to identify risky behaviors and exposures directly associated with an increased risk of S&S events.

Water Exposure is a Common Risk Behavior Among Soft and Gas-Permeable Contact Lens Wearers.

PURPOSE: To understand soft contact lens (SCL) and gas-permeable (GP) lens wearers' behaviors and knowledge regarding exposure of lenses to water. METHODS: The Contact Lens Risk Survey (CLRS) and health behavior questions were completed online by a convenience sample of 1056 SCL and 85 GP lens wearers aged 20 to 76 years. Participants were asked about exposing their lenses to water and their understanding of risks associated with these behaviors. Chi-square analyses examined relationships between patient behaviors and perceptions. RESULTS: GP lens wearers were more likely than SCL wearers to ever rinse or store lenses in water (rinsing: 91% GP, 31% SCL, P < 0.001; storing: 33% GP, 15% SCL P < 0.001). Among SCL wearers, men were more likely to store (24% vs. 13%, P = 0.003) or rinse (41% vs. 29%, P = 0.012) their lenses in water. Showering while wearing lenses was more common in SCL wearers (86%) than GP lens wearers (67%) (P < 0.0001). Swimming while wearing lenses was reported by 62% of SCL wearers and 48% of GP lens wearers (P = 0.027). Wearers who rinsed (SCL; P < 0.0001, GP; P = 0.11) or stored lenses in water (SCL; P < 0.0001, GP P = 0.007) reported that this behavior had little or no effect on their infection risk, compared with those who did not. Both SCL (P < 0.0001) and GP lens wearers (P < 0.0001) perceived that distilled water was safer than tap water for storing or rinsing lenses. CONCLUSIONS: Despite previously published evidence of Acanthamoeba keratitis' association with water exposure, most SCL, and nearly all GP lens wearers, regularly expose their lenses to water, with many unaware of the risk.

Case-Control Pilot Study of Soft Contact Lens Wearers With Corneal Infiltrative Events and Healthy Controls.

PURPOSE: The purpose of this study was to assess risk factors associated with soft contact lens (SCL)-related corneal infiltrative events (CIEs). METHODS: This was a single-visit, case-control study conducted at five academic centers in North America. Cases were defined as current SCL wearers with a symptomatic CIE. For each case, three age- and sex-matched controls were enrolled. Subjects completed the Contact Lens Risk Survey (CLRS), a standardized scripted medical interview, supplied a recent health history, and underwent an ocular examination. Microbial culturing of the ocular surface, SCL, and lens storage case was conducted for all cases and one of the three matched controls. Univariate and multivariate logistic regression modeling were used to assess the risk of developing a CIE. RESULTS: Thirty cases and 90 controls 13 to 31 years of age completed the study. Corneal infiltrative event diagnosis included contact lens-associated red eye, infiltrative keratitis, and contact lens peripheral ulcer. Subjects with symptomatic CIEs were more likely to harbor substantial levels of gram-negative bioburden on the ocular surface and contact lens. Significant risk factors for developing a CIE were overnight wear of SCLs, use of multipurpose solution, rinsing SCLs with water, lens storage case older than 6 months, previous "red eye" event, use of ocular drops in the past week, and illness during the past week. CONCLUSIONS: This pilot study demonstrated feasibility of enrolling a representative pool of SCL wearers with an untreated, symptomatic CIE and assessing CIE risk factors by using standardized methods. A larger sample size is needed to determine relationships between patient-reported behaviors and exposures, microbial bioburden, and CIE development.

Contact Lens Wearer Demographics and Risk Behaviors for Contact Lens-Related Eye Infections--United States, 2014.

Contact lenses provide safe and effective vision correction for many Americans. However, contact lens wearers risk infection if they fail to wear, clean, disinfect, and store their contact lenses as directed. Over the past decade, CDC has investigated several multistate outbreaks of serious eye infections among contact lens wearers, including Acanthamoeba keratitis. Each investigation identified frequent contact lens hygiene-related risk behaviors among patients. To guide prevention efforts, a population-based survey was used to estimate the number of contact lens wearers aged ≥18 years in the United States. A separate online survey of contact lens wearers assessed the prevalence of contact lens hygiene-related risk behaviors. Approximately 99% of wearers reported at least one contact lens hygiene risk behavior. Nearly one third of contact lens wearers reported having experienced a previous contact lens-related red or painful eye requiring a doctor's visit. An estimated 40.9 million U.S. adults wear contact lenses, and many could be at risk for serious eye infections because of poor contact lens wear and care behaviors. These findings have informed the creation of targeted prevention messages aimed at contact lens wearers such as keeping all water away from contact lenses, discarding used disinfecting solution from the case and cleaning with fresh solution each day, and replacing their contact lens case every 3 months.

Rate of change and predictive factors for increasing minus contact lens powers in young myopes.

BACKGROUND: Understanding the factors associated with myopic progression is critical to properly recruit subjects into clinical trials for control of myopia. The purpose of this study is to describe the rate of change in soft contact lens (SCL) power and the associated predictive factors in a young clinical population from the Contact Lens Assessment in Youth study. METHODS: Data from a retrospective chart review of myopic SCL wearers aged eight to 22 years were analysed for rate of progression of myopia and associated characteristics using multivariate methods. RESULTS: Myopic subjects (n = 912) with at least six months of follow-up were observed (4,341 visits, mean follow-up 25 months, 37 per cent hydrogel and 63 per cent silicone hydrogel SCLs). During observation, 36 per cent of subjects experienced a change in soft contact lens power of -0.50 D or more. Significant predictors of future increase in minus lens power were: ages eight to 13 years, shorter time to the first increase in minus power and hydrogel soft contact lens material. The mean annualised increase in minus decreased with age (-0.31D per year for eight to 13 year olds to -0.10 D per year for 20 to 22 year olds, p < 0.0001). Increases in minus were less common among users of silicone hydrogel materials than hydrogel daily disposable lenses after controlling for age (p = 0.039). CONCLUSION: In this retrospective chart review of young soft contact lens wearers, the mean annualised rate of increase in minus soft contact lens power decreased with age, longer time to first increase in power and was greater with hydrogel soft contact lenses. The rates observed were similar to progression rates in prospective myopia clinical trials that employed cylcoplegic autorefraction.

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.

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.

Risk factors for interruption to soft contact lens wear in children and young adults.

PURPOSE: The purpose of this study was to describe age and other risk factors for ocular events that interrupt soft contact lens (SCL) wear in youth. METHODS: A retrospective chart review of SCL wearers aged 8 to 33 years at the first observed visit was conducted at six academic eye care centers in North America. Data were extracted from all visits during the observation period (>3 years). Clinical records that documented conditions resulting in an interruption of SCL wear "events" were scanned, masked for age and SCL parameters, and then adjudicated to consensus diagnosis. Generalized estimating equations were used to examine the effect of selected covariates, including age, on the risk of an event. RESULTS: Chart review of 3549 SCL wearers yielded 522 events among 426 wearers (12%). The risk of an event increased from ages 8 to 18 years, showed modest increases between ages 19 and 25 years, and then began to decline after age 25 years. New lens wearers (<1 year) were less likely to experience events (p = 0.001). Lens replacement schedule and material were also predictive of interruptions to SCL wear with the lowest risk in daily replacement and hydrogel lens wearers (both p < 0.0001). CONCLUSIONS: These results suggest that the risk of events that interrupt SCL wear peaks in late adolescence and early adulthood and reflects risk factors identified in prospective contact lens studies. Relative to older teens and young adults, patients younger than 14 years presented with significantly fewer events resulting in interrupted lens wear.

Age and other risk factors for corneal infiltrative and inflammatory events in young soft contact lens wearers from the Contact Lens Assessment in Youth (CLAY) study.

PURPOSE: To describe age and other risk factors for corneal infiltrative and inflammatory events (CIEs) in young, soft contact lens (SCL) wearers and to model the age-related risk. METHODS: A multicenter, retrospective chart review of 3549 SCL wearers (8-33 years at first observed visit, +8.00 to -12.00D, oversampling <18 years) captured CIEs from January 2006 to September 2009. The review noted age, sex, SCL worn, use of lens care products, and SCL wearing history. Event diagnoses were adjudicated to consensus by reviewers masked to wearer identity, age, and SCL parameters. Significant univariate risk factors for CIEs were subsequently tested in multivariate generalized estimating equations. RESULTS: Charts from 14,305 visits observing 4,663 SCL years yielded 187 CIEs in 168 wearers. Age was a significant nonlinear risk factor, peaking between 15 and 25 years (P < 0.008). Less than 1 year of SCL use was protective versus longer years of wear (P < 0.0003). Use of multipurpose care products (2.86×), silicone hydrogels (1.85×), and extended wear (2.37×) were significantly associated with CIEs in the multivariate model (P < 0.0001 each). CONCLUSIONS: Patient age, years of lens wear, use of multipurpose care products, silicone hydrogels, and extended wear were all significantly associated with CIEs with SCL wear. Use of SCLs in young patients aged 8 to 15 years was associated with a lower risk of infiltrative events compared with teens and young adults. In terms of safety outcomes, SCLs appear to be an acceptable method of delivering optics designed to manage myopia progression in children and young teens in the future.

Contact lens assessment in youth: methods and baseline findings.

PURPOSE: To describe the Contact Lens Assessment in Youth (CLAY) Study design and report baseline data for a multicenter, retrospective, observational chart review of children, teenagers, and young adult soft contact lens (SCL) wearers. METHODS: Clinical charts of SCL wearers aged 8 to 33 years were reviewed at six colleges of optometry. Data were captured retrospectively for eye care visits from January 2006 through September 2009. Patient demographics, SCL parameters, wearing schedules, care systems, and biomicroscopy findings and complications that interrupted SCL wear were entered into an online database. RESULTS: Charts from 3549 patients (14,276 visits) were reviewed; 78.8% were current SCL wearers and 21.2% were new fits. Age distribution was 8 to <13 years (n = 260, 7.3%), 13 to <18 years (n = 879, 24.8%), 18 to <26 years (n = 1,274, 36.0%), and 26 to <34 years (n = 1,136, 32.0%). The sample was 63.2% females and 37.7% college students. At baseline, 85.2% wore spherical SCLs, 13.5% torics, and 0.1% multifocals. Silicone hydrogel lenses were worn by 39.3% of the cohort. Daily wear was reported by 82.1%, whereas 17.9% reported any or occasional overnight wear. Multipurpose care systems were used by 78.1%, whereas another 9.9% indicated hydrogen peroxide solutions use. CONCLUSIONS: This data represent the SCL prescribing and wearing patterns for children, teenager, and young adult SCL wearers who presented for eye care in North American academic clinics. This will provide insight into SCL utilization, change in SCL refractive correction, and risk factors for SCL-related complications by age group.

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 8-33yrs, SCL power +8.00 to -12.00D) 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 18-25yrs), males, smokers, myopes, silicone hydrogel lens wearers and patients with >1yr 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.

Effects of head tilt on stereopsis.

PURPOSE: Depth perception is an important part of many everyday tasks such as driving, catching a ball, and threading a needle. Binocular cues such as horizontal retinal image disparity (HRID) are significant cues to depth and play an important role in overall depth perception. Stereoscopic threshold (stereoacuity) is directly proportional to the interpupillary distance (IPD). Therefore, decreasing the IPD would predictably decrease streoacuity. Tilting the head toward one shoulder or the other will decrease the horizontal separation between the eyes thereby decreasing the IPD. This results in a decrease in stereoacuity. Although this has been demonstrated mathematically it has yet to be shown to have clinical significance. METHODS: All subjects had normal vision, eye alignment, and ocular health. Stereoacuity was evaluated using the BVAT distance stereoacuity test with the subject's head upright as well as when tilted to the right and left at 10, 20 and 30 degrees. A digital potograph verified the head tilt and IPD. The median stereoacuity for each head position was analyzed using the Friedman Test and pair-wise comparisons were made between different head positions using the Paired T-Test. RESULTS: 77.2% (44/57) of subjects exhibited a decrese in stereoacuity of at least 15 arc-sec with head tilt. The median change in stereoacuity from the upright was 22.5 to 45 arc-sec for the 6 head tilt positions (P 0.001). Although statistically the decrease in stereoacuity was not linear with regard to head tilt, there was an almost linear correlation between increasing head tilt and decreasing stereoacuity. CONCLUSIONS: Head tilt to either the left or right creates a relative decrease in interpupillary distance with regards to the horizontal plane. This effective decrease in IPD results in a decrease in a subject's stereoacuity. Additionally, the greater the head tilt, the greater the loss of stereoacuity. This information is useful in counseling individuals, especially those engaged in activities where stereoacuity is critical to performance, to make a special effort to maintain a straight head position.

Neurochemical correlates of cortical plasticity after unilateral elevated intraocular pressure in a primate model of glaucoma.

PURPOSE: To examine the time course of changes in the expression patterns of several synaptic plasticity markers in the primary visual cortex after unilateral elevated intraocular pressure (IOP) in a primate model of glaucoma. METHODS: A monkey model of experimental glaucoma was combined with immunohistochemical and histochemical methods to assess changes in expression patterns and metabolic activity of cortical neurons in V1. RESULTS: Experimental unilateral glaucoma altered the spatial and temporal distribution of several neurochemicals associated with cortical plasticity in V1 of the primate. Within-animal comparisons of immunohistochemical studies revealed that GABAa receptor protein and GAP-43 were significantly lower in glaucomatous versus normal eye bands after 2, 4, and 7 months of elevated IOP. SYN immunoreactivity was also lower in the glaucomatous versus the normal eye bands but only at 4 months of elevated IOP. CAMKIIalpha immunoreactivity levels were higher in the glaucomatous versus the normal eye bands. Between-animal comparisons revealed that the levels of GAP-43 and SYN were upregulated, whereas levels of GABAa receptor protein were downregulated, in glaucomatous eyes when compared with levels in the visual cortex of normal animals. CONCLUSIONS: Unilateral elevation of IOP affects both the metabolic activity of cortical neurons and the expressed levels of GAP-43, SYN, GABAa receptor protein, and CAMKIIalpha, as measured immunohistochemically in the primary visual cortex of adult monkeys. Because these neurochemicals are thought to be necessary for synaptic plasticity, their redistribution may support functional recovery of cortical neurons after damage to retinal ganglion cells induced by elevated IOP.