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.

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.

Validation of an iPad test of letter contrast sensitivity.

PURPOSE: An iPad-based letter contrast sensitivity test was developed (ridgevue.com) consisting of two letters on each page of an iBook. The contrast decreases from 80% (logCS = 0.1) to 0.5% (logCS = 2.3) by 0.1 log units per page. The test was compared to the Pelli-Robson Test and the Freiburg Acuity and Contrast Test. METHODS: Twenty normally sighted subjects and 20 low-vision subjects were tested monocularly at 1 m using each test wearing their habitual correction. After a 5-minute break, subjects were retested with each test in reverse order. Two different letter charts were used for both the Pelli-Robson and iPad tests, and the order of testing was varied systematically. For the Freiburg test, the target was a variable contrast Landolt C presented at eight possible orientations and used a 30-trial Best PEST procedure. Repeatability and agreement were assessed by determining the 95% limits of agreement (LoA) ± 1.96 SD of the differences between administrations or tests. RESULTS: All three tests showed good repeatability in terms of the 95% LoA: iPad = ± 0.19, Pelli-Robson = ± 0.19, and Freiburg = ± 0.15. The iPad test showed good agreement with the Freiburg test with similar mean (± SD) logCS (iPad = 1.98 ± 0.11, Freiburg = 1.96 ± 0.06) and with narrow 95% LoA (± 0.24), but the Pelli-Robson test gave significantly lower values (1.65 ± 0.04). Low-vision subjects had slightly poorer repeatability (iPad = ± 0.24, Pelli-Robson = ± 0.23, Freiburg = ± 0.21). Agreement between the iPad and Freiburg tests was good (iPad = 1.45 ± 0.40, Freiburg = 1.54 ± 0.37), but the Pelli-Robson test gave significantly lower values (1.30 ± 0.30). CONCLUSIONS: The iPad test showed similar repeatability and may be a rapid and convenient alternative to some existing measures. The Pelli-Robson test gave lower values than the other tests.

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.

Vision performance with a contact lens designed to slow myopia progression.

PURPOSE: Recent research suggests multizone/dual-focus (DF) lens corrections may aid in controlling the progression of myopia. Recently, such a soft contact lens has become commercially available in Hong Kong (MiSight, CooperVision). The purpose of the current study was to evaluate the visual acceptability of this new lens design. METHODS: In a double-masked, randomized, crossover trial, 24 subjects (aged 18 to 25 years) wore MiSight contact lenses and Proclear Multifocal +2.00 diopters Add D (MF) soft contact lenses. Patient-reported outcomes (0 to 100 scale) and objective measures of visual performance were acquired for best-spectacle distance correction (BC) and with each contact lens after 1 week of daily use at HIHC (high illumination-high contrast) at distance and LILC (low illumination-low contrast) at distance, intermediate, and near. RESULTS: There were no significant differences in HIHC distance acuity between BC and either the DF or MF lens and no difference between the DF and MF lenses. However, when measured under LILC, there were significant mean differences between each study lens and BC viewed at distance and intermediate. The LILC logMAR visual acuity was not significantly different between the DF and MF lenses at any viewing distance. Although average visual quality and ghosting ratings for both DF and MF study lenses were significantly lower than habitual under all conditions, there were no significant differences between the DF and MF lenses (p = 0.448). CONCLUSIONS: Good acuity, similar to that attainable with typical MF lens correction, is attainable with a new contact lens designed to control myopia progression. However, like other contact lenses that contain multiple refractive zones, some decrease in visual performance may be experienced.

Factors influencing the electronic capture of patient-reported contact lens performance data.

PURPOSE: Electronic data capture is becoming increasingly common for collecting real-time patient responses. The purpose of this study was to investigate compliance with a daily electronic questionnaire regarding night-time contact lens visual performance. METHOD: Forty-eight subjects (34 females) were fit and dispensed two contralateral pairs of soft contact lenses (SCLs) for one week each. Subjects were sent a nightly e-mail at 8PM containing a secure, individualized link to an electronic questionnaire asking 30 questions of varying response styles (e.g., multiple choice, short answer, etc.) about SCL visual performance. Subjects were instructed to complete the questionnaire before going to bed. RESULTS: The overall completion rate based on 676 electronic questionnaires was 95.1%. Of these, only 3.6% were completed late (<24h). The percentage of subjects completing all questionnaires was significantly higher on weekdays (96.5%; Sunday through Thursday) than on weekends (91.1%; Friday and Saturday). Fisher exact tests indicated no significant association with gender for either weekday (p=0.25) or weekend (p=0.73). Although odds ratio estimates suggested that participants 23 and older were more likely to complete the questionnaire (weekday: OR=4.39, p=0.10; weekend: OR=2.93, p=0.19), these associations did not reach statistical significance. CONCLUSIONS: E-mail based questionnaires provide an effective method for acquiring time specific responses, making them a viable clinical and research tool. The day(s) of the week on which assessments occur need to be strongly considered, as on-time compliance may be affected on weekend evenings, or possibly situations in which a typical schedule may not be followed.

Quantification of ghosting produced with presbyopic contact lens correction.

OBJECTIVES: The defocused portion of the image obtained in wearers of bifocal and multifocal contact lenses often appears as a "ghost." Relatively few methods exist to quantify the ghosting perceived with lenses. The purpose of this study is to validate and implement a questionnaire to help patients quantify the ghost images perceived with bifocal or multifocal corrections. METHODS: Ten subjects viewed simulated bifocal vision images displayed on a monitor. Images contained a focused and a defocused (ghost) component of a specific dimension (direction, position offset, intensity, and focus). Using a test card, the subjects identified the ghosting dimension level displayed on the monitor. An additional 54 presbyopic subjects wearing a multifocal correction monocularly viewed a well-focused stimulus and then compared the perceived image to that of the other well-corrected eye looking at the ghosting test card to quantify their visual experience of the 4 proposed ghosting dimensions. RESULTS: Regardless of ghost letter size and orientation, subject responses were within 1 rating unit of expected on >95% of all trials for all 4 dimensions when asked to directly match a single dimension of ghosting. With bifocal images containing random amounts of these 4 dimensions most response errors were also within ± 1 unit. In presbyopes wearing a multifocal lens, the focus dimension was most strongly associated with overall ratings of ghosting. CONCLUSIONS: The subjects can accurately and reliably report on ghost intensity, focus, direction and position offset, and well-focused ghosts are most correlated with the overall perceptual saliency of ghosting.

Comparison of patient-reported visual outcome methods to quantify the perceptual effects of defocus.

PURPOSE: Patient-reported subjective responses have become increasingly popular in describing contact lens visual performance and discriminating between designs. The purpose of the current study is to evaluate the ability of patient-reported measures of vision to quantify the perceptual effects of defocus. METHODS: Ten young (18-35 years) subjects rated their subjective visual performance monocularly on 3 scales following wear of their optimal monocular distance correction and nine different blurring lenses (-0.50 to +1.50 in 0.25 D steps) in a trial frame. The three scales used were a 0-100 numeric rating scale (NRS), a 100 mm visual analog scale (VAS), and a 5 point ("Poor", "Fair", "Average", "Good", "Excellent") categorical rating scale (CRS). RESULTS: Mixed linear modeling results found no significant effects either for eye or trial number, but did find a significant effect due to blurring lens power (p<0.0001), with ratings decreasing with increasing levels of blur for all scales. Results were not significantly different between the NRS and VAS at any level of blur, with limits of agreement falling within 22% of the measurement scale. CRS ratings were about 15 units lower than the other scales on average, with limits of agreement that varied with lens power and were roughly 3 times as large. Across scale internal consistency was 0.94. CONCLUSIONS: The NRS and VAS yield virtually identical rating responses, but both differing slightly, however from the CRS. Each scale successfully discriminated levels of blur smaller than 0.25 D with only a single measurement.

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.

Effect of contact lens wear and a near task on tear film break-up.

PURPOSE: To study the effect of extrinsic controls on blinking by examining blink parameters and tear stability among adapted soft contact lens (CL) wearers performing tasks that require varying amounts of visual concentration. METHODS: The Demographic Questionnaire, Contact Lens Dry Eye Questionnaire, and Current Symptoms Questionnaire were completed by 15 adapted soft CL wearers (nine females). Three 55 s simultaneous measurements of tear film stability via retroillumination and blinking were obtained with a slit-lamp biomicroscope and 200 Hz video camera while subjects listened to music and played a video game with and without their habitual CLs. Interblink interval (IBI) and blink amplitude (BA) were calculated. The area of break-up (AB) was calculated for the retroillumination image before each blink. The Current Symptoms Questionnaire was completed four times throughout testing. RESULTS: With the game compared to music, IBI was significantly longer and BA significantly decreased without CLs (p < or = 0.001). With CLs, the IBI did not significantly change between tasks but the BA significantly decreased (p = 0.100). The AB significantly increased with CL and the game (paired t-test, p < or = 0.001). The BA was significantly correlated with self-reported severity of dry eye for all testing scenarios (Spearman r > or = 0.5579, p < 0.0001) and several symptom measures (Spearman r > or = 0.6262, p < 0.0001). The AB was significantly correlated with symptom measures including bothersome discomfort for the game with and without CLs (Spearman r > or = 0.5064, p < 0.0001). CONCLUSIONS: During tasks requiring concentration, the IBI increased (blink rate decreased) and many blinks were incomplete without CLs. With CLs, tear film instability increased. Blinking frequency also increased, but it remained high when subjects played the game, and symptoms of ocular irritation increased. This suggests that wearing soft CLs, even when fully adapted, provides enough extrinsic ocular surface stimulation to override internal controls and affect blink parameters.