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Staphylococcus aureus is a frequent cause of ocular surface infections worldwide. Of these surface infections, those involving the cornea (microbial keratitis) are most sight-threatening. S. aureus can also cause conjunctivitis and... more
Staphylococcus aureus is a frequent cause of ocular surface infections worldwide. Of these surface infections, those involving the cornea (microbial keratitis) are most sight-threatening. S. aureus can also cause conjunctivitis and contact lens-related non-infectious corneal infiltrative events (niCIE). The aim of this study was to determine the rates of resistance of S. aureus isolates to antibiotics and disinfecting solutions from these different ocular surface conditions. In total, 63 S. aureus strains from the USA and Australia were evaluated; 14 were from niCIE, 26 from conjunctivitis, and 23 from microbial keratitis (MK). The minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) of all the strains to ciprofloxacin, ceftazidime, oxacillin, gentamicin, vancomycin, chloramphenicol, azithromycin, and polymyxin B were determined. The MIC and MBC of the niCIE strains to contact lens multipurpose disinfectant solutions (MPDSs) was determined. All isolates were suscep...
To describe the usage patterns of steroids in bacterial keratitis and to analyze the effect of steroids on patients' visual outcomes. This was a single-center retrospective review of patients with culture-positive bacterial... more
To describe the usage patterns of steroids in bacterial keratitis and to analyze the effect of steroids on patients' visual outcomes. This was a single-center retrospective review of patients with culture-positive bacterial keratitis treated between 1999 and 2015 at Princess Alexandra Hospital (Brisbane, Australia). Patients with culture-positive bacterial keratitis were identified through the Queensland Pathology Database, and clinical information was gathered through a subsequent medical record review. High-dose steroid treatment was classified as 6 or more drops of a steroid a day started within 7 days of corneal scraping. The outcome of a patient's episode of keratitis was classified as good if their final visual acuity was 6/12 or better; poor if it was 6/60 or worse or required a corneal transplant, otherwise it was classified as average. Microbiological and clinical variables' association with outcomes was evaluated in univariate analyses. Variables significant at P < 0.1 were examined in a multivariate ordinal logistic regression analysis created with forward variable selection with forced inclusion of steroid treatment (high, regular, low dose, and none). A total of 328 patients were included from the 1002 reviewed charts. Of these patients, 164 (50.0%) were treated with steroids. Factors significantly associated with outcomes in the multivariate model were high-dose steroid treatment, visual acuity on presentation, age group, cause of keratitis, infiltrate size, and location. The odds ratio of better outcomes with high-dose steroids was 5.49 (confidence interval, 1.6-19.0, P = 0.007). High-dose steroid treatment is significantly associated with better visual outcomes in patients with culture-positive bacterial keratitis in this case series.
To survey the demographics, risk factors, microbiology and outcomes for infectious keratitis in Asia. Prospective, non-randomized clinical study METHODS: Thirteen study centers and 30 sub-centers recruited consecutive subjects over 12 -... more
To survey the demographics, risk factors, microbiology and outcomes for infectious keratitis in Asia. Prospective, non-randomized clinical study METHODS: Thirteen study centers and 30 sub-centers recruited consecutive subjects over 12 - 18 months, and performed standardized data collection. A microbiological protocol standardized the processing and reporting of all isolates. Treatment of the infectious keratitis was decided by the managing ophthalmologist. Subjects were observed for up to six months. Main outcome measures were final visual acuity and the need for surgery during infection. A total of 6626 eyes of 6563 subjects were studied. The majority of subjects were male (n=3992). Trauma (n=2279, 34.7%) and contact lens wear (n=704, 10.7%) were the commonest risk factors. Overall, bacterial keratitis was diagnosed in 2521 eyes (38.0%) and fungal keratitis in 2166 eyes (32.7%). Of the 2831 microorganisms isolated, the most common were Fusarium species (n=518, 18.3%), Pseudomonas a...
Patient-reported outcome measures (PROMs) are becoming increasingly recognised as a key component in assessing the relative effectiveness of cataract surgery. This manuscript presents the protocol methodology and baseline characteristics... more
Patient-reported outcome measures (PROMs) are becoming increasingly recognised as a key component in assessing the relative effectiveness of cataract surgery. This manuscript presents the protocol methodology and baseline characteristics of a prospective cohort study investigating patient-centred predictors of cataract surgery outcomes. Patients with bilateral cataract (aged ≥ 50 years) scheduled for their first eye cataract surgery were recruited at four public hospitals and three private ophthalmology clinics in Sydney, Australia. Participants underwent a comprehensive assessment of clinical measures of vision (for example, visual acuity, contrast sensitivity) and PROMs prior to first eye surgery and three months after first and second eye surgery. The PROMs of interest included health-related quality of life, visual disability and satisfaction with vision. The characteristics of the baseline cohort of 359 participants are reported in this manuscript. Enrolment occurred over a two...
It is critical to consult patients to develop patient-centred cataract surgery care. We aimed to identify attributes patients consider when making decisions about cataract surgery in an Australian context, where both publicly and... more
It is critical to consult patients to develop patient-centred cataract surgery care. We aimed to identify attributes patients consider when making decisions about cataract surgery in an Australian context, where both publicly and privately funded surgery are available. This is the first step in investigating how decisions are made about cataract surgery services. This observational qualitative study was undertaken in two public hospitals and one private practice in Sydney, Australia. The study involved 19 women and men with age-related cataracts and no previous cataract surgery, aged > 18 years, able to speak conversational English or Mandarin. A multi-stage attribute development process was followed, including: literature review, semi-structured interviews with surgery candidates in three eye clinics, and review by an expert panel. The main outcome measures were primary attributes for making choices about cataract surgery. Wait time, cost, institutional reputation, surgeon exper...
To clarify the effect of first-eye cataract surgery on the incidence of falls and identify components of visual function associated with fall risk. Eight public hospital eye clinics in Sydney, Melbourne, and Perth, Australia. Prospective... more
To clarify the effect of first-eye cataract surgery on the incidence of falls and identify components of visual function associated with fall risk. Eight public hospital eye clinics in Sydney, Melbourne, and Perth, Australia. Prospective cohort study. The study recruited patients who had bilateral cataract, were aged 65 years or older, and were on public hospital cataract surgery waiting lists. Comprehensive assessments of vision, physical function, and exercise activity were performed before and after first-eye cataract surgery. Falls were reported prospectively for up to 2 years and associations with falls were assessed using generalized linear mixed models. Of the 329 patients recruited, 196 (66.6%) completed first-eye surgery within the study period. First-eye cataract surgery reduced incident falls by 33% (adjusted incidence rate ratio 0.67; 95% confidence interval [CI], 0.49-0.92; P = .01). Poorer dominant-eye visual acuity was associated with falls during the study timeline (...
Importance Referral letters constitute the first step on the pathway to cataract surgery, however little is known on how effective referral letters are in providing adequate information to triage patients and inform surgical... more
Importance Referral letters constitute the first step on the pathway to cataract surgery, however little is known on how effective referral letters are in providing adequate information to triage patients and inform surgical prioritisation. Benchmarking exercises are important to document referral processes and to identify areas where improvements can be made. Design Cross-sectional study with longitudinal follow-up conducted at two metropolitan public hospitals in New South Wales, Australia. Samples 400 sequential cataract referral letters. An audit of cataract referral letters was performed and content benchmarked against international prioritisation tools. Medical records were reviewed one-year following referral. Main outcome measures referral quality; waiting times RESULTS: Two-thirds of patients referred for cataract surgery were yet to have their initial hospital appointment in the year following referral (65%, 245/376). One half of referrals seen in clinic (49%, 64/113) were...
The development of novel therapies for Dry Eye Disease (DED) is formidable, and relatively few treatments evaluated have been approved for marketing. In this report, the Subcommittee reviewed challenges in designing and conducting quality... more
The development of novel therapies for Dry Eye Disease (DED) is formidable, and relatively few treatments evaluated have been approved for marketing. In this report, the Subcommittee reviewed challenges in designing and conducting quality trials, with special reference to issues in trials in patients with DED and present the regulatory perspective on DED therapies. The Subcommittee reviewed the literature and while there are some observations about the possible reasons why so many trials have failed, there is no obvious single reason other than the lack of correlation between signs and symptoms in DED. Therefore the report advocates for conducting good quality studies, as described, going forward. A key recommendation for future studies is conduct consistent with Good Clinical Practice (GCP), including use of Good Manufacturing Practice (GMP) quality clinical trial material. The report also recommends that the design, treatments, and sample size be consistent with the investigationa...
This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of... more
This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org.
Contact lens-associated microbial keratitis poses a diagnostic dilemma for optometrists on two fronts. The distinction between sterile inflammation and microbial infection is often blurred. In addition, there is a requirement with nearly... more
Contact lens-associated microbial keratitis poses a diagnostic dilemma for optometrists on two fronts. The distinction between sterile inflammation and microbial infection is often blurred. In addition, there is a requirement with nearly 50 per cent of the Australian and New Zealand optometric profession being therapeutically endorsed, to distinguish between cases of infection that can be managed in the community verses those that require escalation to public hospitals that have access to laboratory diagnostic tools and advanced imaging techniques, such as in vivo confocal microscopy. Pattern recognition and incorporation of knowledge of aetiology and risk factors assists optometrists to decide on optimal management strategies. Skilled optometrists will utilise emerging diagnostic and therapeutic technologies to ensure safe management strategies and better outcomes for these cases.
The goals of the TFOS DEWS II Definition and Classification Subcommittee were to create an evidence-based definition and a contemporary classification system for dry eye disease (DED). The new definition recognizes the multifactorial... more
The goals of the TFOS DEWS II Definition and Classification Subcommittee were to create an evidence-based definition and a contemporary classification system for dry eye disease (DED). The new definition recognizes the multifactorial nature of dry eye as a disease where loss of homeostasis of the tear film is the central pathophysiological concept. Ocular symptoms, as a broader term that encompasses reports of discomfort or visual disturbance, feature in the definition and the key etiologies of tear film instability, hyperosmolarity, and ocular surface inflammation and damage were determined to be important for inclusion in the definition. In the light of new data, neurosensory abnormalities were also included in the definition for the first time. In the classification of DED, recent evidence supports a scheme based on the pathophysiology where aqueous deficient and evaporative dry eye exist as a continuum, such that elements of each are considered in diagnosis and management. Centr...
To review the effect of contact lens (CL) material, design, and fitting characteristics on CL discomfort. A PubMed search identified publications describing subjective comfort and CL material, fitting, and design parameters. The review... more
To review the effect of contact lens (CL) material, design, and fitting characteristics on CL discomfort. A PubMed search identified publications describing subjective comfort and CL material, fitting, and design parameters. The review included clinical signs associated with discomfort that may be a consequence of these parameters. Reduced lens movement or more CL tightness were associated with improved comfort. Increased lens-induced paralimbal conjunctival staining and indentation, considered as quasi-indicators of CL fitting or edge design, were also associated with better comfort. No recent studies have evaluated varying CL design parameters and subjective comfort. Silicone hydrogel CLs are no different in comfort compared with hydrogel CLs. Lower equilibrium water content is associated with improved comfort in hydrogel CL wear. Coefficient of friction shows promise as a material factor potentially associated with comfort. Lid wiper epitheliopathy and lid-parallel conjunctival folds have been linked with comfort in established wearers. Recent studies have confirmed the association between more mobile CLs and more discomfort, whereas closer conformity of the CL to the bulbar conjunctiva improved subjective comfort. There is no evidence to support the perceived comfort difference between silicone hydrogel and hydrogel CL. There has been limited progress in understanding the impact of varying specific CL design parameters. Although specific clinical signs may be predictive of discomfort, their role in the natural history of discomfort remains unclear. A better understanding of the relationship between coefficient of friction and comfort and strategies to improve lubricity may hold promise for limiting CL discomfort.
Sex hormones could provide a future treatment avenue for dry eye post menopause. However, there are few well-controlled studies. This study investigates the impact of testosterone and oestrogen on dry eye symptoms and signs in... more
Sex hormones could provide a future treatment avenue for dry eye post menopause. However, there are few well-controlled studies. This study investigates the impact of testosterone and oestrogen on dry eye symptoms and signs in postmenopausal women. A randomised double-blind placebo-controlled pilot study was conducted involving 40 women with dry eye (age 63.9±5.1 years, 13.2±6.3 years post menopause). Ten women were assigned to each of four treatment groups: transdermal testosterone, oestradiol, testosterone/oestradiol combination and placebo. Assessment at baseline and after 8 weeks: ocular symptoms, tear osmolarity, tear stability, tear secretion, meibomian gland assessment, corneal and conjunctival sensitivity, serum concentrations of 17β-oestradiol, 3-α-androstanediol-glucuronide and dehydroepiandrosterone sulfate. Differences from placebo were examined using one-way analysis of variance and Dunnett's t-test. Within-group analyses included paired t-tests and Spearman correlation. Dryness intensity after 8 weeks was significantly worse in the oestrogen group compared with placebo (p=0.04). No significant changes in other symptoms, tear function, meibomian gland function, lid morphology, corneal or conjunctival sensitivity were observed in any of the groups when compared with the change in placebo after 8 weeks. Within-group analyses showed increased tear secretion in the testosterone/oestradiol combination group (p=0.03) and a strong association between increased serum androgen and improved tear stability in the testosterone group (ρ=0.83,p=0.01). Oestrogen supplementation may worsen ocular symptoms in postmenopausal women with dry eye, whereas no impact of testosterone therapy on symptoms was apparent. The positive effects of oestrogen and testosterone on tear function require confirmation in a larger study, with sample size calculated from the data generated herein. Placebo control is essential in studies of dry eye therapies. ACTRN12612000281897.
Although cataract surgery can restore sight, lengthy waiting times are common in public hospitals in Australia. We investigated the driving status of older people during their surgical waiting period. Baseline, cross-sectional data from... more
Although cataract surgery can restore sight, lengthy waiting times are common in public hospitals in Australia. We investigated the driving status of older people during their surgical waiting period. Baseline, cross-sectional data from two prospective cohort studies of patients aged 50 years and older on Australian public hospital cataract surgery waiting lists were analysed. Participants underwent assessment of vision and completed the Driving Habits Questionnaire. The vision status was compared between current drivers and former drivers. Participants (n = 442) were on average 73 ± 8 years of age and approximately half were women (229/442, 52 per cent). Habitual vision was 6/12(+2) on average (0.26 ± 0.21 logMAR). There were 263 (60 per cent) current drivers, 110 (25 per cent) former drivers and 69 participants (16 per cent) who had never driven. Among the current drivers, 82/263 (31 per cent) failed visual acuity requirements for an unconditional drivers' license (6/12 acuity...
... Search for in All Fields. Advanced Search. « PreviousNext »Journal of The British Contact Lens Association Volume 15, Issue 1 , Pages 5-6, 1992. Microbial keratitis and contactlens wear. Fiona Stapleton: Affiliations. ...
To explore the relationship between serum concentration of sex hormones and dry eye symptoms and signs in postmenopausal women. A cross-sectional analysis was undertaken. Subjects were 46 postmenopausal women with dry eye (mean age... more
To explore the relationship between serum concentration of sex hormones and dry eye symptoms and signs in postmenopausal women. A cross-sectional analysis was undertaken. Subjects were 46 postmenopausal women with dry eye (mean age 64.4±5.2 years, 13.7±6.4 years since menopause; not undergoing hormone replacement therapy). Ocular symptoms (Ocular Surface Disease Index (OSDI) and Ocular Comfort Index (OCI)), tear function (tear osmolarity, non-invasive tear break-up time, tear secretion), corneal and conjunctival staining, and meibomian gland (MG) appearance, were recorded. Venous blood was collected and serum concentrations of 17β-oestradiol (E2), 3-α-androstanediol-glucuronide (3α-diol-G), and dehydroepiandrosterone sulfate (DHEA-S) were determined using ELISA. Multiple linear regression analysis was used to examine predictors of dry eye symptoms and signs. Mean serum concentration of E2, 3α-diol-G and DHEA-S was 9.02±13.40 pg/mL, 1.59±1.02 ng/mL and 0.74±0.53 μg/mL, respectively. Ocular symptoms were elevated (mean scores 27.0±18.1 (OSDI) and 40.3±8.4 (OCI)) but signs were within normal ranges. Higher serum E2 concentration along with capped glands, lid telangiectasia and older age was a significant predictor of worse MG secretion quality (p<0.001, R(2)adj=0.75). Serum hormones were not significant predictors of ocular symptoms in multivariate analysis (p>0.05). Serum oestrogen appears to be a key factor in MG signs. Although serum hormone levels did not contribute significantly to dry eye symptoms in this study, it is possible that oestrogen plays a role through its effect on meibum secretion. These findings suggest that MG dysfunction underpins dry eye symptoms in non-Sjögren's dry eye in postmenopausal women. ACTRN12612000281897.
A population based, cross-sectional telephone survey was conducted to estimate the total penetrance of contact lens wear in Australia. A total of 42,749 households around Australia were randomly selected from the national electronic... more
A population based, cross-sectional telephone survey was conducted to estimate the total penetrance of contact lens wear in Australia. A total of 42,749 households around Australia were randomly selected from the national electronic telephone directory based on postcode distribution. Before contact was attempted, letters of introduction were sent. The number of individuals and contact lens wearers in each household was ascertained and lens wearers were interviewed to determine details of lens type and mode of wear using a structured questionnaire. Of households contacted, 59.2% (19,171/32,405) agreed to participate. Response rates were only marginally higher amongst households that first received a letter of introduction. In these households, 35,914 individuals were identified, of which, 1,798 were contact lens wearers. The penetrance of contact lens wear during the study period was 5.01% (95% CI: 4.78-5.24). Soft hydrogel lenses had the largest penetrance in the community, (66.7% of all wearers), however, their market share decreased significantly over the study period with increased uptake of newly introduced lens types. The penetrance of contact lens wear concurs with market estimates and equates to approximately 680,000 contact lens wearers aged between 15 and 64 years in Australia. The low response rate obtained in this study highlights the difficulty in contemporary use of telephone survey methodology.
Purpose: To examine the role of Staphylococcus aureus alpha-toxin in contact lens-induced peripheral ulceration (CLPU). Materials and methods: Proteolytic enzyme, hyaluronidase, alpha-toxin, and beta-toxin production by S. aureus 8325-4... more
Purpose: To examine the role of Staphylococcus aureus alpha-toxin in contact lens-induced peripheral ulceration (CLPU). Materials and methods: Proteolytic enzyme, hyaluronidase, alpha-toxin, and beta-toxin production by S. aureus 8325-4 and its alpha-toxin-deficient mutant (S. aureus DU1090) were examined. Using a rabbit model of CLPU, animals were fitted with hydrogel contact lenses colonized by either S. aureus 8325-4 or the mutant strain. The clinical presentation, bacterial cultures, and histology of the ulceration were examined. Results: Both strains of S. aureus produced similar levels of caseinase, gelatinase, elastase, hyaluronidase, and beta-toxin. S. aureus DU1090 induced weaker haemolysis of rabbit blood cells than S. aureus 8325-4. Ulceration in the S. aureus DU1090 eye was less frequent and less severe than that caused by S. aureus 8325-4. Conclusions: The enzyme production profile of S. aureus DU1090 was similar to the parent strain. S. aureus strains may produce CLPU-like lesions irrespective of alpha-toxin production, but severe infectious lesions are produced only in the presence of alpha-toxin.
This study investigated changes in selected tear cytokine concentrations (IL-1β, IL-1Ra, IL-6, IL-10, IL-12 (p70), and TNF-α) after a 1-week washout from soft contact lens wear (CLW), and the repeatability of cytokine measurements using... more
This study investigated changes in selected tear cytokine concentrations (IL-1β, IL-1Ra, IL-6, IL-10, IL-12 (p70), and TNF-α) after a 1-week washout from soft contact lens wear (CLW), and the repeatability of cytokine measurements using custom multiplex assays. A total of 10 subjects completed this 6-visit (immediately following contact lens removal, and after 1, 2, 3, 4, and 7 [±1] days without CLW) pilot study. Approximately 20 to 30 μL of pooled basal tears were collected from both eyes at each visit. Two custom multiplex assays were used by two operators to quantify the concentration of tear cytokines. Tear samples from subjects 1 to 6 were analyzed using the first kit by operator 1. Tear samples from subject 7 to 10 plus additional tear samples from subjects 1 to 5, which were used to determine the between-kit per operator repeatability, were analyzed using the second kit by operator 2. Linear mixed models were used to determine changes in tear cytokine concentrations over time. Between-kit per operator and within-kit per operator repeatabilities were assessed using the Bland and Altman analysis. There were no significant changes in tear cytokine concentrations over a 1-week washout of CLW. More than 99% of the tear samples had detectable levels of cytokines using custom multiplex assays. Within-kit per operator repeatability was good, but between-kit per operator repeatability was poor; likely due to protein degradation, differences in operator experience, and operating procedures. A washout period may not be necessary when evaluating changes in tear cytokines with new contact lenses or lens care products. A well-trained operator using standardized operating procedures can produce repeatable measurements using custom multiplex assays.
The most likely etiology of post-LASIK dry eye is corneal nerve damage; however, no direct relationship between post-LASIK dry eye symptoms and nerve damage has been established, and limited information is available about the relationship... more
The most likely etiology of post-LASIK dry eye is corneal nerve damage; however, no direct relationship between post-LASIK dry eye symptoms and nerve damage has been established, and limited information is available about the relationship between dry eye signs and corneal reinnervation after LASIK. Tear neuropeptides (SP and CGRP) are important in the maintenance of corneal nerve health, but the impact of LASIK has not yet been studied. This study evaluated changes in nerve morphology, tear neuropeptide, and dry eye, so as to establish the relationship between reinnervation and dry eye and to assess the role of tear neuropeptides in reinnervation post-LASIK. Twenty non-dry eye volunteers who had undergone bilateral myopic-LASIK completed this study. Corneal nerve morphology (density, width, interconnections, and tortuosity), SP and CGRP concentration, and dry eye were monitored over time prior to, 1 day, 1 week, 1, 3, and 6 months post-LASIK. Dry eye symptoms and tear function, exce...
Defining the threshold for therapeutic and surgical intervention in patients with keratoconus presents a considerable challenge given the lack of clear, evidence-based data. Little is known about the patterns of practice and referral... more
Defining the threshold for therapeutic and surgical intervention in patients with keratoconus presents a considerable challenge given the lack of clear, evidence-based data. Little is known about the patterns of practice and referral criteria of optometrists within Australia. All members of the NSW branch of Optometrist Association Australia were invited to complete an online survey in January 2013. This survey was designed to elicit practice information regarding the evaluation and therapeutic treatment of patients with keratoconus in the optometric setting. Responses were received from 71 optometrists, of whom 65.2 per cent had 15 years or greater experience as an optometrist. Many (35.4 per cent) responded that they prescribed soft contact lenses daily. This percentage dropped to 9.2 per cent for rigid gas-permeable lenses (RGP), although 47.7 per cent said they would prescribe RGP lenses at least once per month. The main barriers to prescribing were experience with fitting RGP l...
Work-related musculoskeletal discomfort and injuries are reported by optometrists. The purpose of this paper is to describe the process used to investigate work-related discomfort in Australian optometrists. A multistage project was... more
Work-related musculoskeletal discomfort and injuries are reported by optometrists. The purpose of this paper is to describe the process used to investigate work-related discomfort in Australian optometrists. A multistage project was conducted which included questionnaires, interviews and onsite observations. Participants, with and without self-reported discomfort, included clinical optometrists, optometry students and clinical teachers. The various stages of the study developed over the course of the project, primarily in response to results collected at various stages. A multistage approach proved valuable for confirming results and testing hypotheses, and for investigating different groups of workers (clinicians, teachers and students). General guidelines to reduce the risk of work-related discomfort in optometrists can be developed from this project. Specific recommendations and teaching curricula have been identified in this project as areas of future research and development.
ABSTRACT The measurement of contact lens discomfort is complex; the sensation experienced is inherently variable, and existing measurement scales may not be optimal. This manuscript aims to review and describe instruments commonly used to... more
ABSTRACT The measurement of contact lens discomfort is complex; the sensation experienced is inherently variable, and existing measurement scales may not be optimal. This manuscript aims to review and describe instruments commonly used to measure contact lens discomfort. Appropriately designed questionnaires undergo a rigorous process of item development and validation. Interval scales (e.g. numerical rating scale and visual analogue scale) are frequently used to measure temporal characteristics of contact lens discomfort and remain useful in assessing qualities such as duration, onset and chronicity. The majority of studies of contact lens discomfort have used questionnaires designed and validated for use in dry eye patients, most commonly the ocular surface disease index. This practice is questionable as the characteristics, epidemiology and underlying mechanisms of the sensations of discomfort experienced by contact lens wearers differ from those reported by dry eye patients. There is a clear need for context specific validation of these instruments to occur. Improved instruments urgently need to be developed. Until then, interval scales and the CLDEQ-8, a short version of the contact lens dry eye questionnaire, represent the best-validated instruments currently available for measuring the temporal characteristics and the frequency and intensity of contact lens discomfort, respectively.
The tear film plays an important role in the defense of the external ocular surface. During sleep a number of changes take place, including increased production and release of various inflammatory mediators. We have studied the hypothesis... more
The tear film plays an important role in the defense of the external ocular surface. During sleep a number of changes take place, including increased production and release of various inflammatory mediators. We have studied the hypothesis that closed-eye tears contain proinflammatory cytokines and lipid inflammatory mediators, which serve to recruit polymorphonuclear leukocytes (PMNs) and regulate the function of PMNs and IgA during sleep. We investigated interleukin-1beta, interleukin-6, interleukin-8, monocyte chemotactic protein 1, granulocyte-macrophage colony stimulating factor (GM-CSF), leukotriene B4 (LTB4), and platelet activating factor (PAF) in open and closed-eye tears of normal healthy subjects. Results showed that IL-6, IL-8, GM-CSF, LTB4, and PAF were present in high levels in closed-eye tears compared to open-eye tears. Closed-eye tears were able to recruit neutrophils, with maximal recruitment after 8 hr of sleep, suggesting that chemokine IL-8 and the lipid chemoatt...
Bacterial colonization of the ocular surface and contact lens (CL) and recruitment of polymorphonuclear leucocytes (PMN) during overnight CL wear was examined in 11 asymptomatic wearers. The ocular surface was more frequently colonized... more
Bacterial colonization of the ocular surface and contact lens (CL) and recruitment of polymorphonuclear leucocytes (PMN) during overnight CL wear was examined in 11 asymptomatic wearers. The ocular surface was more frequently colonized than the CL, with commensal bacteria (P < 0.05). Following sleep, more bacteria were recovered from the CL compared with daily use (P < 0.05), and fewer PMN were recruited compared to sleep without CL wear (P < 0.05). Overnight CL wear may inhibit physiological PMN recruitment to the cornea by preventing their access, by modifying the chemotactic signal or by altering the activation state of the recruited cells.

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