To characterize hydrogel lens tear exchange and to apply an optimized method to compare tear exch... more To characterize hydrogel lens tear exchange and to apply an optimized method to compare tear exchange of a marketed hydrogel lens to that measured with a prototype silicone hydrogel lens. Fluorophotometry and a nonpenetrating tracer (70-kDa FITC-dextran) were used with a single extended-wear soft contact lens (EWSCL) material on 11 subjects to characterize tear-exchange kinetics. Twenty to 30 measurements were obtained over a 30-minute period to allow accurate modeling and estimation of the several tear-exchange parameters. Calculated values included tear-replenishment rate (TRR), elimination rate (ER), and the time for 95% of the signal to be eliminated (T(95)). Major experiments were (1) comparison of ER under controlled and physiological conditions, (2) comparison of right and left eyes, (3) repeatability of ER and T(95) on five occasions, and (4) comparison of a marketed lens (oxygen permeability [Dk] 28 x 10(-9) [cm/sec][ml O(2)/ml mm Hg]) to a prototype silicone hydrogel lens (Dk 140 x 10(-9) [cm/sec][ml O(2)/ml mm Hg]). Tracer elimination behind a hydrogel contact lens (CL), up to 30 minutes after insertion, was optimally described by double-exponential kinetics. Physiological ER (5-30 minutes after CL insertion) was optimally described by single-exponential kinetics. Overall, physiological ER was 8.8% +/- 3.8% per minute, and T(95) was 31.0 +/- 16.1 minutes (n = 76 and 72 determinations, respectively). Differences between right and left eyes in ER and T(95) were not significant at the 0.05 level. No difference in ER or T(95) was found between habitual and controlled blinking. Mean TRR was 0.67% +/- 0.26% per blink (n = 11 determinations). No differences were shown between ER or T(95) measurements over time. A prototype highly oxygen-permeable silicone hydrogel lens showed higher ER than did a marketed hydrogel lens (P < 0.01). Estimates of postlens tear exchange using a slit lamp fluorophotometer are similar to previously reported rates using similar fluorophotometric techniques. Fluorescent decay behind a hydrogel lens is most precisely described using a double-exponential curve equation and tear exchange may be described using ER, TRR and T(95), although the T(95) may be the least reliable of these measures. The technique appears capable of discriminating between lens types.
To explore and deepen understanding of factors influencing driving exposure for older drivers. Cr... more To explore and deepen understanding of factors influencing driving exposure for older drivers. Cross-sectional. Baseline data on function and driving exposure from 1 week of driving were evaluated. A convenience sample of 380 drivers aged 75 and older, residing in northwest Sydney, was recruited. Participants were required to be the primary drivers of their own vehicle. Driver function was evaluated using the DriveSafe and DriveAware clinic-based assessments to measure visual attention to the driving environment and awareness of driving ability. Demographic information was obtained through interview. An in-vehicle monitoring device with data logger and GPS receiver, was used to measure driving exposure in 362 of 380 participants' vehicles. Driving exposure outcomes were total distance driven, furthest distance traveled from home, and average trip length. Factors influencing these exposure outcomes were analyzed using generalized linear regression. Drivers typically drove 100 km ...
To report annualized adverse events (AEs) including corneal infiltrative events (CIEs) with use o... more To report annualized adverse events (AEs) including corneal infiltrative events (CIEs) with use of silicone hydrogel (SiHyDD) and hydrogel daily disposable (HydDD) soft contact lenses (SCLs) in the 1•DAY ACUVUE TruEye or 1•DAY ACUVUE MOIST Performance Overview (TEMPO) Registry (NCT01467557). Annualized incidence of symptomatic daily disposable (DD)-related AEs was calculated from 3064 surveys from 1171 subjects (601 SiHyDD and 570 HydDD, 31.8 ± 13.5 years, 68% female) during 1 year. Three independent experts adjudicated potential AE cases. Demographics were compared between wearers with and without AEs. The registry tracked 960.3 years of lens wear: SiHyDD 489.4 years and HydDD 470.9 years. In that period, the 601 SiHyDD wearers reported eight AEs with office visits (1.6%/y; 2 CIEs, 0.4%/y), eight (1.6%/y) without office visits, and four AEs unrelated to SCLs (0.8%/y) (SiHyDD wearers with AEs; 44.8 ± 12.5 years; 75% female). The 570 HyDD wearers reported three AEs with office visits...
To study the epidemiology, clinical observations, and microbiologic characteristics of fungal ker... more To study the epidemiology, clinical observations, and microbiologic characteristics of fungal keratitis at tertiary eye care centers in the United States. Retrospective multicenter case series. Fungal keratitis cases presenting to participating tertiary eye care centers. Charts were reviewed for all fungal keratitis cases confirmed by culture, histology, or confocal microscopy between January 1, 2001, and December 31, 2007, at 11 tertiary clinical sites in the United States. Frequency of potential predisposing factors and associations between these factors and fungal species. A total of 733 cases of fungal keratitis were identified. Most cases were confirmed by culture from corneal scraping (n = 693) or biopsies (n = 19); 16 cases were diagnosed by microscopic examination of corneal scraping alone; and 5 cases were diagnosed by confocal microscopy alone. Some 268 of 733 cases (37%) were associated with refractive contact lens wear, 180 of 733 cases (25%) were associated with ocular ...
Contact lens-related keratitis has been the subject of a number of rigorous epidemiologic studies... more Contact lens-related keratitis has been the subject of a number of rigorous epidemiologic studies over the past 20 years. This article summarizes data from such studies that address incidence and risk factors for this condition. Estimates of risk and associated predisposing factors have been quite consistent over time, geography and study design.
To examine predisposing factors, treatment costs, and visual outcome of microbial keratitis in an... more To examine predisposing factors, treatment costs, and visual outcome of microbial keratitis in an ophthalmic casualty and inpatient population. Retrospective medical records review. Fifteen- to 64-year-olds with microbial keratitis treated at the Royal Victorian Eye and Ear Hospital between May 2001 and April 2003 (n = 291). Risk factors were identified from patient files. Demographic, clinical, and microbiological data; severity; outpatient visits; hospital bed days; and vision loss were examined. Cost to treat (Australian dollars), vision loss, and factors influencing these outcomes. Ocular trauma (106/291 [36.4%]) and contact lens (CL) wear (98/291 [33.7%]) were the most commonly identified predisposing factors; 18 (6.1%) had multiple predisposing factors; 17 (5.8%), ocular surface disease; 20 (6.9%), herpetic eye disease; 4 (1.4%), systemic associations; 5 (1.7%), other; and 23 (7.9%), unknown cause. Of trauma cases, 90.6% involved males, compared with 44% to 57% for other group...
Our purpose was to determine visual and cognitive predictors for older drivers' failure to stop a... more Our purpose was to determine visual and cognitive predictors for older drivers' failure to stop at stopsigns. 1425 drivers aged between ages 67 and 87 residing in Salisbury Maryland were enrolled in a longitudinal study of driving. At baseline, the participants were administered a battery of vision and cognition tests, and demographic and health questionnaires. Five days of driving data were collected with a Driving Monitoring System (DMS), which obtained data on stop signs encountered and failure to stop at stop signs. Driving data were also collected one year later (Round two). The outcome, number of times a participant failed to stop at a stop sign at round two, was modeled using vision and cognitive variables as predictors. A Negative binomial regression model was used to model the failure rate. Of the 1241 who returned for Round two, 1167 drivers had adequate driving data for analyses and 52 did not encounter a stop sign. In the remaining 1115, 15.8% failed at least once to stop at stop signs, and 7.1% failed to stop more than once. Rural drivers had 1.7 times the likelihood of not stopping compared to urban drivers. Amongst the urban participants, the number of points missing in the bilateral visual field was significantly associated with a lower failure rate. In this cohort, older drivers residing in rural areas were less likely to stop at stop-sign intersections than those in urban areas. It is possible that rural drivers frequent areas with less traffic and better visibility, and may be more likely to take the calculated risk of not stopping. In this cohort failure to stop at
RESULTS. Of the 1425 enrolled, 1237 (87%) were followed up at 1 year. Excluding those who were al... more RESULTS. Of the 1425 enrolled, 1237 (87%) were followed up at 1 year. Excluding those who were already limiting their driving at baseline (n 35), 1.5% (18/1202) had stopped and 3.4% (41/1202) had restricted their driving. The women (odds ratio (OR), 4.01; 95% confidence interval (CI), 2.05-8.20) and those who prefer to be driven (OR, 3.91; 95% CI, 1.91-8.00) were
To examine factors influencing adherence to spectacle wear and perceived value within a prospecti... more To examine factors influencing adherence to spectacle wear and perceived value within a prospective 1-month trial of ready-made and custom spectacles in school-aged children with uncorrected refractive error in urban China. A total of 428 students aged 12 to 15 years with at least 1 diopter of uncorrected refractive error were given free spectacles and evaluated 1 month later at an unannounced visit. Demographic factors, vision, optical effects, and perceptions were modeled as predictors of observed use and perceived value using logistic regression adjusted for spectacle allocation. Of 415 students, 388 (93.5%) planned to use their spectacles, 227 (54.7%) valued their spectacles highly, 204 (49.2%) had their spectacles on hand, and 13 (3.0%) were lost to follow-up. Female students were 1.72 times (95% confidence interval [CI], 1.10-2.68), students from lower income households were 1.78 times (1.32-2.39), and those not concerned over appearance were 2.04 times (1.25-3.36) more likely...
BACKGROUND/AIMSCurrent contact lenses (CLs) when worn on an extended wear basis cause corneal epi... more BACKGROUND/AIMSCurrent contact lenses (CLs) when worn on an extended wear basis cause corneal epithelial alterations. The aim of this study was to evaluate changes in corneal epithelial cell morphology and physiology following short term (3 months) wear of highly oxygen permeable CLs and to compare this with disposable CLs.METHODSSubjects were wearers of highly oxygen permeable CLs (n=11, wearing CLs on
Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention, Jan 24, 2014
Cataract is one of the leading causes of visual impairment in Australia. As more older adults are... more Cataract is one of the leading causes of visual impairment in Australia. As more older adults are driving, the number of people with cataract on the roads will increase. A greater understanding of the effects of cataract and cataract surgery on driving performance and driver self-regulation is essential to improve road safety. This proposed study will examine the effects of bilateral cataract surgery on driving outcomes including driving performance and driver self-regulation. A 3-year prospective study will be undertaken in Western Australia (WA) and New South Wales (NSW). Three hundred participants (n=150 from WA and n=150 from NSW) aged >60 years with bilateral cataract will be assessed at three time points: the month before first-eye cataract surgery, 1-3 months after first-eye cataract surgery and 3 months after second-eye cataract surgery. Driving performance will be assessed using a driving simulator and driver self-regulation patterns measured using in-vehicle driver-moni...
PURPOSE. To determine whether intolerance to contact lens wear is attributable to clinical or pro... more PURPOSE. To determine whether intolerance to contact lens wear is attributable to clinical or protein characteristics of the tear film. METHODS. Thirty-eight subjects participated; 20 were success- ful contact lens wearers and 18 had discontinued contact lens wear because of discomfort. Baseline tear film (no lens wear) was analyzed with a range of clinical measurements and pro- tein analyses (lactoferrin,
To measure the change in quality of life and economic circumstances after cataract surgery and id... more To measure the change in quality of life and economic circumstances after cataract surgery and identify the predictors of an improvement in these outcomes. A multicenter, prospective, longitudinal cohort study. Participants aged ≥ 18 years were recruited to the study if the clinical assessment of their best-uncorrected vision was ≥ 6/18 in the better eye because of cataract. Cataract surgery. Data were collected on quality of life and a multidimensional assessment of household economic circumstances (work status, income, asset ownership, household economic hardship, and catastrophic health expenditure). At 12 months follow-up, 381 of 480 participants were re-interviewed, and all had undergone surgery. There was a significant improvement in quality of life. Household economic circumstances also improved (mean change paid work participation/month: 44.5 hours, P < 0.0001; mean change unpaid work participation/month: 89.5 hours, P < 0.0001; change in proportion with hardship: -17%...
Can exercise or physical training improve physical function and prevent falls in older adults wit... more Can exercise or physical training improve physical function and prevent falls in older adults with visual impairments? Systematic review of randomised controlled trials with meta-analysis. Older adults (≥ 60 years) with visual impairments. Individual or group exercise or physical training classes in any settings. Mobility, balance, strength and proprioception measured with performance tests or questionnaires and/or falls with calendars or incident reports. Four eligible trials with a total of 522 participants were identified. Multimodal group exercise (n = 50 and 41) and Tai Chi (n=40) improved physical function among residents of care settings. Meta-analysis of data from two trials indicated a significant positive impact of multimodal exercise on the Berg Balance Score (weighted mean difference 3.9 points, 95% CI 1.8 to 6.0), but not on the Timed Up and Go test (weighted mean difference 1.5seconds, 95% CI -1.7 to 4.6). One trial (n=41) found that multimodal exercise reduced the tim...
To conduct a process and impact evaluation of a multifaceted education-based pilot program target... more To conduct a process and impact evaluation of a multifaceted education-based pilot program targeting correct use of age-appropriate restraints in a regional setting with a high proportion of Aboriginal and Torres Strait Islander families. The program was delivered in 2010 in 3 early learning centers where 31 percent of the children were of Aboriginal and Torres Strait Islander descent. Each component of the program was assessed for message consistency and uptake. To measure program effectiveness, participating children were matched 1:1 by age, language spoken at home, and annual household income with 71 children from the control arm of a contemporaneous trial. The outcome measure in the control and program centers (a 4-category ordinal scale of restraint use) was compared using ordinal logistic regression accounting for age of the parent. Process evaluation found that though program components were delivered with a consistency of message, uptake was affected by turnover of all staff at one center and by parents experiencing difficulty in paying for subsidized restraints at each of the centers. Impact evaluation found that children from the centers receiving the program had nearly twice the odds of being in a better restraint category than children matched from the control group (adjusted odds ratio [ORadj] = 2.06, 95% confidence interval [CI], 1.09-3.90). This was a pragmatic study reflecting the real-life issues of implementing a program in preschools where 57 percent of families had a low income and turnover of staff was high. Despite these issues, impact evaluation showed that the integrated educational program showed promise in increasing correct use of age-appropriate restraints. The findings from this pilot study support the use of an integrated educational program that includes access to subsidized restraints to promote best practice child restraint use among communities that include a high proportion of Aboriginal and Torres Strait Islander families in New South Wales. Future trials in similar settings should consider offering more support in centers with high turnover of staff and offering alternative methods of payment when families experience financial difficulties in purchasing the subsidized restraints. If proven in larger trials, this approach could reduce death and injuries in child passengers in this vulnerable group.
This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone h... more This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone hydrogel lenses and low-Dk hydrogel lenses after 1 year of extended wear (EW). Ninety-two adult subjects were randomly assigned to a lens type. Subjective refraction and autokeratometry were performed at baseline and at 6 and 12 months. After 6 months of EW, myopia (spherical equivalent) regressed by 0.18 +/- 0.33 D (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in the high-Dk silicone hydrogel group and progressed by -0.23 +/- 0.36 D (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in the low-Dk hydrogel group. There were no further changes after 12 months. Previous lens wear history, baseline refractive error, and age and gender did not have an impact on the change in myopia, and only 35% of the variation could be accounted for by changes in corneal curvature and lens type. Soft contact lens type significantly affects the direction of change in myopia during EW. We hypothesize that these changes are driven by pressure-related redistribution of corneal tissue in high-Dk silicone hydrogel lens wearers and by hypoxia-associated corneal thinning in low-Dk hydrogel wearers. More long-term studies are required to confirm whether the effects of high-Dk silicone hydrogel lens wear on myopia are permanent.
The aim of this study was to characterize the clinical signs, symptoms, and ocular and systemic c... more The aim of this study was to characterize the clinical signs, symptoms, and ocular and systemic comorbidities in a large case series of contact lens-related microbial keratitis. Two hundred ninety-seven cases of contact lens-related microbial keratitis, aged between 15 and 64 years were detected through surveillance of hospital and community based ophthalmic practitioners in Australia and New Zealand. Full clinical data were available for 190 cases and 90 were interviewed by telephone. Clinical data included the size, location, and degree of anterior chamber response. Symptom data were available from the practitioner and from participant self-report. Associations between symptoms and disease severity were evaluated. Data on ocular and systemic disease were collected from participants and practitioners. The frequency of comorbidities was compared between the different severities of disease and to population norms. More severe disease was associated with greater symptom severity and pain was the most prevalent symptom reported. Ninety-one percent of cases showed progression of ocular symptoms after lens removal, and symptom progression was associated with all severities of disease. Twenty-five percent of cases reported prior episodes requiring emergency attention. Thyroid disease (p = 0.05) and self-reported poor health (p = 0.001) were more common in cases compared with age-matched population norms. Information on the signs, symptoms, and comorbidities associated with contact lens-related microbial keratitis may be useful in patient education and for practitioners involved in the fitting of lenses and management of complications. Although pain was the most common symptom experienced, progression of symptoms despite lens removal was close to universal. Poor general health, particularly respiratory disease and thyroid disease was more common in cases than in the general population, which may prompt practitioners to recommend flexibility in wear schedules when in poor health or the selection of a lower risk wear schedule in at risk patients.
To compare the frequency of mucin balls in subjects wearing conventional and high-Dk silicone hyd... more To compare the frequency of mucin balls in subjects wearing conventional and high-Dk silicone hydrogel lenses during 12 months of extended-wear and to determine whether mucin balls are associated with any lens or subject characteristics. This study used data from a clinical trial where subjects wore either conventional hydrogel (N = 69, 6-night extended-wear) or silicone hydrogel (N = 70, 30-night extended-wear) contact lenses for 12 months. The number of mucin balls and other physiological responses, lens fit and performance, and subjective patient responses to lens wear were rated at each scheduled visit. Subjects in the silicone hydrogel group had significantly greater numbers of mucin balls compared with subjects in the conventional hydrogel group over time (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), but there were no significant differences in the percentage of subjects with mucin balls between the two groups. Increasing lens wettability, back surface deposits, and time of lens wear were associated with higher numbers of mucin balls in the conventional hydrogel group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05); steeper corneal curvature and increasing lens wettability, back surface deposits, and number of microcysts were associated with higher numbers of mucin balls in the silicone hydrogel group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). This study indicates that a subset of the population is predisposed to develop mucin balls irrespective of the soft contact lens type worn, but lens type influences the degree of mucin ball formation. The relationship between lens wettability, back surface deposits, and steeper corneal curvature with mucin balls supports the hypothesis that the mechanical interaction of a lens with the surface layer of the epithelium and the tear film in association with the blinking forces of the lid is involved in mucin ball formation.
With estimated numbers of contact lens wearers worldwide exceeding 140 million, even complication... more With estimated numbers of contact lens wearers worldwide exceeding 140 million, even complications with a low incidence will affect a significant number of individuals. Although contact lenses clearly have many advantages for wearers, certain risks have been associated with their use. Differences in risk for different types of contact lenses and wearing patterns have been demonstrated for both rare and common lens related complications. This review particularly focuses on the incidence and etiology of contact lens related corneal infection and inflammation. An understanding of the risks and contributory factors to these conditions is important for practitioners and will enable an informed choice of safer lens wear modalities, wear schedules, and hygiene regimes to be made. (Optom Vis Sci 2007;84:257-272)
To characterize hydrogel lens tear exchange and to apply an optimized method to compare tear exch... more To characterize hydrogel lens tear exchange and to apply an optimized method to compare tear exchange of a marketed hydrogel lens to that measured with a prototype silicone hydrogel lens. Fluorophotometry and a nonpenetrating tracer (70-kDa FITC-dextran) were used with a single extended-wear soft contact lens (EWSCL) material on 11 subjects to characterize tear-exchange kinetics. Twenty to 30 measurements were obtained over a 30-minute period to allow accurate modeling and estimation of the several tear-exchange parameters. Calculated values included tear-replenishment rate (TRR), elimination rate (ER), and the time for 95% of the signal to be eliminated (T(95)). Major experiments were (1) comparison of ER under controlled and physiological conditions, (2) comparison of right and left eyes, (3) repeatability of ER and T(95) on five occasions, and (4) comparison of a marketed lens (oxygen permeability [Dk] 28 x 10(-9) [cm/sec][ml O(2)/ml mm Hg]) to a prototype silicone hydrogel lens (Dk 140 x 10(-9) [cm/sec][ml O(2)/ml mm Hg]). Tracer elimination behind a hydrogel contact lens (CL), up to 30 minutes after insertion, was optimally described by double-exponential kinetics. Physiological ER (5-30 minutes after CL insertion) was optimally described by single-exponential kinetics. Overall, physiological ER was 8.8% +/- 3.8% per minute, and T(95) was 31.0 +/- 16.1 minutes (n = 76 and 72 determinations, respectively). Differences between right and left eyes in ER and T(95) were not significant at the 0.05 level. No difference in ER or T(95) was found between habitual and controlled blinking. Mean TRR was 0.67% +/- 0.26% per blink (n = 11 determinations). No differences were shown between ER or T(95) measurements over time. A prototype highly oxygen-permeable silicone hydrogel lens showed higher ER than did a marketed hydrogel lens (P &lt; 0.01). Estimates of postlens tear exchange using a slit lamp fluorophotometer are similar to previously reported rates using similar fluorophotometric techniques. Fluorescent decay behind a hydrogel lens is most precisely described using a double-exponential curve equation and tear exchange may be described using ER, TRR and T(95), although the T(95) may be the least reliable of these measures. The technique appears capable of discriminating between lens types.
To explore and deepen understanding of factors influencing driving exposure for older drivers. Cr... more To explore and deepen understanding of factors influencing driving exposure for older drivers. Cross-sectional. Baseline data on function and driving exposure from 1 week of driving were evaluated. A convenience sample of 380 drivers aged 75 and older, residing in northwest Sydney, was recruited. Participants were required to be the primary drivers of their own vehicle. Driver function was evaluated using the DriveSafe and DriveAware clinic-based assessments to measure visual attention to the driving environment and awareness of driving ability. Demographic information was obtained through interview. An in-vehicle monitoring device with data logger and GPS receiver, was used to measure driving exposure in 362 of 380 participants' vehicles. Driving exposure outcomes were total distance driven, furthest distance traveled from home, and average trip length. Factors influencing these exposure outcomes were analyzed using generalized linear regression. Drivers typically drove 100 km ...
To report annualized adverse events (AEs) including corneal infiltrative events (CIEs) with use o... more To report annualized adverse events (AEs) including corneal infiltrative events (CIEs) with use of silicone hydrogel (SiHyDD) and hydrogel daily disposable (HydDD) soft contact lenses (SCLs) in the 1•DAY ACUVUE TruEye or 1•DAY ACUVUE MOIST Performance Overview (TEMPO) Registry (NCT01467557). Annualized incidence of symptomatic daily disposable (DD)-related AEs was calculated from 3064 surveys from 1171 subjects (601 SiHyDD and 570 HydDD, 31.8 ± 13.5 years, 68% female) during 1 year. Three independent experts adjudicated potential AE cases. Demographics were compared between wearers with and without AEs. The registry tracked 960.3 years of lens wear: SiHyDD 489.4 years and HydDD 470.9 years. In that period, the 601 SiHyDD wearers reported eight AEs with office visits (1.6%/y; 2 CIEs, 0.4%/y), eight (1.6%/y) without office visits, and four AEs unrelated to SCLs (0.8%/y) (SiHyDD wearers with AEs; 44.8 ± 12.5 years; 75% female). The 570 HyDD wearers reported three AEs with office visits...
To study the epidemiology, clinical observations, and microbiologic characteristics of fungal ker... more To study the epidemiology, clinical observations, and microbiologic characteristics of fungal keratitis at tertiary eye care centers in the United States. Retrospective multicenter case series. Fungal keratitis cases presenting to participating tertiary eye care centers. Charts were reviewed for all fungal keratitis cases confirmed by culture, histology, or confocal microscopy between January 1, 2001, and December 31, 2007, at 11 tertiary clinical sites in the United States. Frequency of potential predisposing factors and associations between these factors and fungal species. A total of 733 cases of fungal keratitis were identified. Most cases were confirmed by culture from corneal scraping (n = 693) or biopsies (n = 19); 16 cases were diagnosed by microscopic examination of corneal scraping alone; and 5 cases were diagnosed by confocal microscopy alone. Some 268 of 733 cases (37%) were associated with refractive contact lens wear, 180 of 733 cases (25%) were associated with ocular ...
Contact lens-related keratitis has been the subject of a number of rigorous epidemiologic studies... more Contact lens-related keratitis has been the subject of a number of rigorous epidemiologic studies over the past 20 years. This article summarizes data from such studies that address incidence and risk factors for this condition. Estimates of risk and associated predisposing factors have been quite consistent over time, geography and study design.
To examine predisposing factors, treatment costs, and visual outcome of microbial keratitis in an... more To examine predisposing factors, treatment costs, and visual outcome of microbial keratitis in an ophthalmic casualty and inpatient population. Retrospective medical records review. Fifteen- to 64-year-olds with microbial keratitis treated at the Royal Victorian Eye and Ear Hospital between May 2001 and April 2003 (n = 291). Risk factors were identified from patient files. Demographic, clinical, and microbiological data; severity; outpatient visits; hospital bed days; and vision loss were examined. Cost to treat (Australian dollars), vision loss, and factors influencing these outcomes. Ocular trauma (106/291 [36.4%]) and contact lens (CL) wear (98/291 [33.7%]) were the most commonly identified predisposing factors; 18 (6.1%) had multiple predisposing factors; 17 (5.8%), ocular surface disease; 20 (6.9%), herpetic eye disease; 4 (1.4%), systemic associations; 5 (1.7%), other; and 23 (7.9%), unknown cause. Of trauma cases, 90.6% involved males, compared with 44% to 57% for other group...
Our purpose was to determine visual and cognitive predictors for older drivers' failure to stop a... more Our purpose was to determine visual and cognitive predictors for older drivers' failure to stop at stopsigns. 1425 drivers aged between ages 67 and 87 residing in Salisbury Maryland were enrolled in a longitudinal study of driving. At baseline, the participants were administered a battery of vision and cognition tests, and demographic and health questionnaires. Five days of driving data were collected with a Driving Monitoring System (DMS), which obtained data on stop signs encountered and failure to stop at stop signs. Driving data were also collected one year later (Round two). The outcome, number of times a participant failed to stop at a stop sign at round two, was modeled using vision and cognitive variables as predictors. A Negative binomial regression model was used to model the failure rate. Of the 1241 who returned for Round two, 1167 drivers had adequate driving data for analyses and 52 did not encounter a stop sign. In the remaining 1115, 15.8% failed at least once to stop at stop signs, and 7.1% failed to stop more than once. Rural drivers had 1.7 times the likelihood of not stopping compared to urban drivers. Amongst the urban participants, the number of points missing in the bilateral visual field was significantly associated with a lower failure rate. In this cohort, older drivers residing in rural areas were less likely to stop at stop-sign intersections than those in urban areas. It is possible that rural drivers frequent areas with less traffic and better visibility, and may be more likely to take the calculated risk of not stopping. In this cohort failure to stop at
RESULTS. Of the 1425 enrolled, 1237 (87%) were followed up at 1 year. Excluding those who were al... more RESULTS. Of the 1425 enrolled, 1237 (87%) were followed up at 1 year. Excluding those who were already limiting their driving at baseline (n 35), 1.5% (18/1202) had stopped and 3.4% (41/1202) had restricted their driving. The women (odds ratio (OR), 4.01; 95% confidence interval (CI), 2.05-8.20) and those who prefer to be driven (OR, 3.91; 95% CI, 1.91-8.00) were
To examine factors influencing adherence to spectacle wear and perceived value within a prospecti... more To examine factors influencing adherence to spectacle wear and perceived value within a prospective 1-month trial of ready-made and custom spectacles in school-aged children with uncorrected refractive error in urban China. A total of 428 students aged 12 to 15 years with at least 1 diopter of uncorrected refractive error were given free spectacles and evaluated 1 month later at an unannounced visit. Demographic factors, vision, optical effects, and perceptions were modeled as predictors of observed use and perceived value using logistic regression adjusted for spectacle allocation. Of 415 students, 388 (93.5%) planned to use their spectacles, 227 (54.7%) valued their spectacles highly, 204 (49.2%) had their spectacles on hand, and 13 (3.0%) were lost to follow-up. Female students were 1.72 times (95% confidence interval [CI], 1.10-2.68), students from lower income households were 1.78 times (1.32-2.39), and those not concerned over appearance were 2.04 times (1.25-3.36) more likely...
BACKGROUND/AIMSCurrent contact lenses (CLs) when worn on an extended wear basis cause corneal epi... more BACKGROUND/AIMSCurrent contact lenses (CLs) when worn on an extended wear basis cause corneal epithelial alterations. The aim of this study was to evaluate changes in corneal epithelial cell morphology and physiology following short term (3 months) wear of highly oxygen permeable CLs and to compare this with disposable CLs.METHODSSubjects were wearers of highly oxygen permeable CLs (n=11, wearing CLs on
Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention, Jan 24, 2014
Cataract is one of the leading causes of visual impairment in Australia. As more older adults are... more Cataract is one of the leading causes of visual impairment in Australia. As more older adults are driving, the number of people with cataract on the roads will increase. A greater understanding of the effects of cataract and cataract surgery on driving performance and driver self-regulation is essential to improve road safety. This proposed study will examine the effects of bilateral cataract surgery on driving outcomes including driving performance and driver self-regulation. A 3-year prospective study will be undertaken in Western Australia (WA) and New South Wales (NSW). Three hundred participants (n=150 from WA and n=150 from NSW) aged >60 years with bilateral cataract will be assessed at three time points: the month before first-eye cataract surgery, 1-3 months after first-eye cataract surgery and 3 months after second-eye cataract surgery. Driving performance will be assessed using a driving simulator and driver self-regulation patterns measured using in-vehicle driver-moni...
PURPOSE. To determine whether intolerance to contact lens wear is attributable to clinical or pro... more PURPOSE. To determine whether intolerance to contact lens wear is attributable to clinical or protein characteristics of the tear film. METHODS. Thirty-eight subjects participated; 20 were success- ful contact lens wearers and 18 had discontinued contact lens wear because of discomfort. Baseline tear film (no lens wear) was analyzed with a range of clinical measurements and pro- tein analyses (lactoferrin,
To measure the change in quality of life and economic circumstances after cataract surgery and id... more To measure the change in quality of life and economic circumstances after cataract surgery and identify the predictors of an improvement in these outcomes. A multicenter, prospective, longitudinal cohort study. Participants aged ≥ 18 years were recruited to the study if the clinical assessment of their best-uncorrected vision was ≥ 6/18 in the better eye because of cataract. Cataract surgery. Data were collected on quality of life and a multidimensional assessment of household economic circumstances (work status, income, asset ownership, household economic hardship, and catastrophic health expenditure). At 12 months follow-up, 381 of 480 participants were re-interviewed, and all had undergone surgery. There was a significant improvement in quality of life. Household economic circumstances also improved (mean change paid work participation/month: 44.5 hours, P < 0.0001; mean change unpaid work participation/month: 89.5 hours, P < 0.0001; change in proportion with hardship: -17%...
Can exercise or physical training improve physical function and prevent falls in older adults wit... more Can exercise or physical training improve physical function and prevent falls in older adults with visual impairments? Systematic review of randomised controlled trials with meta-analysis. Older adults (≥ 60 years) with visual impairments. Individual or group exercise or physical training classes in any settings. Mobility, balance, strength and proprioception measured with performance tests or questionnaires and/or falls with calendars or incident reports. Four eligible trials with a total of 522 participants were identified. Multimodal group exercise (n = 50 and 41) and Tai Chi (n=40) improved physical function among residents of care settings. Meta-analysis of data from two trials indicated a significant positive impact of multimodal exercise on the Berg Balance Score (weighted mean difference 3.9 points, 95% CI 1.8 to 6.0), but not on the Timed Up and Go test (weighted mean difference 1.5seconds, 95% CI -1.7 to 4.6). One trial (n=41) found that multimodal exercise reduced the tim...
To conduct a process and impact evaluation of a multifaceted education-based pilot program target... more To conduct a process and impact evaluation of a multifaceted education-based pilot program targeting correct use of age-appropriate restraints in a regional setting with a high proportion of Aboriginal and Torres Strait Islander families. The program was delivered in 2010 in 3 early learning centers where 31 percent of the children were of Aboriginal and Torres Strait Islander descent. Each component of the program was assessed for message consistency and uptake. To measure program effectiveness, participating children were matched 1:1 by age, language spoken at home, and annual household income with 71 children from the control arm of a contemporaneous trial. The outcome measure in the control and program centers (a 4-category ordinal scale of restraint use) was compared using ordinal logistic regression accounting for age of the parent. Process evaluation found that though program components were delivered with a consistency of message, uptake was affected by turnover of all staff at one center and by parents experiencing difficulty in paying for subsidized restraints at each of the centers. Impact evaluation found that children from the centers receiving the program had nearly twice the odds of being in a better restraint category than children matched from the control group (adjusted odds ratio [ORadj] = 2.06, 95% confidence interval [CI], 1.09-3.90). This was a pragmatic study reflecting the real-life issues of implementing a program in preschools where 57 percent of families had a low income and turnover of staff was high. Despite these issues, impact evaluation showed that the integrated educational program showed promise in increasing correct use of age-appropriate restraints. The findings from this pilot study support the use of an integrated educational program that includes access to subsidized restraints to promote best practice child restraint use among communities that include a high proportion of Aboriginal and Torres Strait Islander families in New South Wales. Future trials in similar settings should consider offering more support in centers with high turnover of staff and offering alternative methods of payment when families experience financial difficulties in purchasing the subsidized restraints. If proven in larger trials, this approach could reduce death and injuries in child passengers in this vulnerable group.
This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone h... more This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone hydrogel lenses and low-Dk hydrogel lenses after 1 year of extended wear (EW). Ninety-two adult subjects were randomly assigned to a lens type. Subjective refraction and autokeratometry were performed at baseline and at 6 and 12 months. After 6 months of EW, myopia (spherical equivalent) regressed by 0.18 +/- 0.33 D (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in the high-Dk silicone hydrogel group and progressed by -0.23 +/- 0.36 D (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in the low-Dk hydrogel group. There were no further changes after 12 months. Previous lens wear history, baseline refractive error, and age and gender did not have an impact on the change in myopia, and only 35% of the variation could be accounted for by changes in corneal curvature and lens type. Soft contact lens type significantly affects the direction of change in myopia during EW. We hypothesize that these changes are driven by pressure-related redistribution of corneal tissue in high-Dk silicone hydrogel lens wearers and by hypoxia-associated corneal thinning in low-Dk hydrogel wearers. More long-term studies are required to confirm whether the effects of high-Dk silicone hydrogel lens wear on myopia are permanent.
The aim of this study was to characterize the clinical signs, symptoms, and ocular and systemic c... more The aim of this study was to characterize the clinical signs, symptoms, and ocular and systemic comorbidities in a large case series of contact lens-related microbial keratitis. Two hundred ninety-seven cases of contact lens-related microbial keratitis, aged between 15 and 64 years were detected through surveillance of hospital and community based ophthalmic practitioners in Australia and New Zealand. Full clinical data were available for 190 cases and 90 were interviewed by telephone. Clinical data included the size, location, and degree of anterior chamber response. Symptom data were available from the practitioner and from participant self-report. Associations between symptoms and disease severity were evaluated. Data on ocular and systemic disease were collected from participants and practitioners. The frequency of comorbidities was compared between the different severities of disease and to population norms. More severe disease was associated with greater symptom severity and pain was the most prevalent symptom reported. Ninety-one percent of cases showed progression of ocular symptoms after lens removal, and symptom progression was associated with all severities of disease. Twenty-five percent of cases reported prior episodes requiring emergency attention. Thyroid disease (p = 0.05) and self-reported poor health (p = 0.001) were more common in cases compared with age-matched population norms. Information on the signs, symptoms, and comorbidities associated with contact lens-related microbial keratitis may be useful in patient education and for practitioners involved in the fitting of lenses and management of complications. Although pain was the most common symptom experienced, progression of symptoms despite lens removal was close to universal. Poor general health, particularly respiratory disease and thyroid disease was more common in cases than in the general population, which may prompt practitioners to recommend flexibility in wear schedules when in poor health or the selection of a lower risk wear schedule in at risk patients.
To compare the frequency of mucin balls in subjects wearing conventional and high-Dk silicone hyd... more To compare the frequency of mucin balls in subjects wearing conventional and high-Dk silicone hydrogel lenses during 12 months of extended-wear and to determine whether mucin balls are associated with any lens or subject characteristics. This study used data from a clinical trial where subjects wore either conventional hydrogel (N = 69, 6-night extended-wear) or silicone hydrogel (N = 70, 30-night extended-wear) contact lenses for 12 months. The number of mucin balls and other physiological responses, lens fit and performance, and subjective patient responses to lens wear were rated at each scheduled visit. Subjects in the silicone hydrogel group had significantly greater numbers of mucin balls compared with subjects in the conventional hydrogel group over time (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), but there were no significant differences in the percentage of subjects with mucin balls between the two groups. Increasing lens wettability, back surface deposits, and time of lens wear were associated with higher numbers of mucin balls in the conventional hydrogel group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05); steeper corneal curvature and increasing lens wettability, back surface deposits, and number of microcysts were associated with higher numbers of mucin balls in the silicone hydrogel group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). This study indicates that a subset of the population is predisposed to develop mucin balls irrespective of the soft contact lens type worn, but lens type influences the degree of mucin ball formation. The relationship between lens wettability, back surface deposits, and steeper corneal curvature with mucin balls supports the hypothesis that the mechanical interaction of a lens with the surface layer of the epithelium and the tear film in association with the blinking forces of the lid is involved in mucin ball formation.
With estimated numbers of contact lens wearers worldwide exceeding 140 million, even complication... more With estimated numbers of contact lens wearers worldwide exceeding 140 million, even complications with a low incidence will affect a significant number of individuals. Although contact lenses clearly have many advantages for wearers, certain risks have been associated with their use. Differences in risk for different types of contact lenses and wearing patterns have been demonstrated for both rare and common lens related complications. This review particularly focuses on the incidence and etiology of contact lens related corneal infection and inflammation. An understanding of the risks and contributory factors to these conditions is important for practitioners and will enable an informed choice of safer lens wear modalities, wear schedules, and hygiene regimes to be made. (Optom Vis Sci 2007;84:257-272)
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