Factors associated with acute care service use after epilepsy hospitalisation in people with intellectual disability.

BACKGROUND: This study aimed to identify factors associated with unplanned acute hospital readmission and emergency department (ED) presentation after hospitalisation for epilepsy in people with intellectual disability (ID). METHODS: This study is a retrospective cohort study using linked administrative datasets. We identified 3293 people with ID aged 5-64 years with a hospitalisation for epilepsy between 2005 and 2014 in New South Wales, Australia. We examined unplanned readmission and ED presentation within 30 or 365 days and associations with demographic, socio-economic and health status variables. Modified Poisson regression with robust estimation was used to model outcomes within 30 days. Negative binomial regression was used to account for the overdispersion of the data and to model 365-day outcome rates. RESULTS: Around half of the cohort had an unplanned readmission and ED presentation within 365 days of the index hospitalisation. In fully adjusted models, being female, being a young adult and having a longer or acute care index admission, mental and physical comorbidities and a history of incarceration were associated with an elevated risk of readmission or ED presentation. The strongest association was observed between history of self-harm and 365-day readmission (incidence rate ratio 2.15, 95% confidence interval 1.41-3.29). CONCLUSIONS: Socio-demographic, justice and health factors are associated with unplanned readmission and ED presentation risk after hospitalisation for epilepsy in people with ID. Interventions targeting improving continuity of care should be tailored for individuals and their support workers. The findings also emphasise the importance of person-centred multidisciplinary care across different health sectors.

Parity: A key measure of confounding in data-linkage studies of outcomes after medically assisted reproduction.

Parity is a potential confounder of the association between medically assisted reproduction (MAR) and health outcomes. This concept paper describes a population-based record linkage study design for selecting MAR-unexposed women matched to the parity of MAR-exposed women, at the time of the first exposure to MAR. Women exposed to MAR were identified from claims for government subsidies for relevant procedures and prescription medicines, linked to perinatal records. Women unexposed to MAR were identified from linked perinatal and death records, matched to exposed women by age, rurality, age of first child (if any) and parity at the date of first MAR. The availability of a longitudinal, whole-of-population dataset ("population spine") based on enrolments in Australia's universal health insurance scheme was a critical design element. The example application examines cancer risk in women after exposure to MAR. Parity is a confounder in this setting because it is associated with MAR and hormone-sensitive cancers.

Parental international migration is not associated with improved health care seeking for common childhood illnesses and nutritional status of young children left-behind in Nepal.

OBJECTIVE: To examine the impact of parental international migration on health care seeking for common childhood illnesses (diarrhoea, fever, and acute respiratory infections) and nutritional status (stunting, underweight and wasting) in young children in Nepal using the most recent nationally representative Multiple Indicator Cluster Survey. STUDY DESIGN: Nationally representative cross-sectional survey. METHODS: We used multiple logistic regression models to examine the association between parental international migration and the study outcomes adjusting for a range of potential confounders. RESULTS: Of 5310 children, 23.5% had at least one parent living abroad. Health care for common childhood illnesses was sought for 52.1% (95% confidence interval [CI]: 45.0%-59.2%) and 47.0% (95% CI: 42.7%-51.1%) of children from migrant and non-migrant families, respectively. The prevalence of stunting, underweight and wasting among left-behind children were 35.3% (95% CI: 31.5%-39.1%), 28.3% (95% CI: 24.2%-32.2%) and 11.8% (95% CI: 8.8%-14.7%), respectively. In adjusted analyses, there were no statistically significant differences in health care seeking or nutritional status by parent's migration status. CONCLUSIONS: Despite large economic benefits to Nepal due to international labour migration, we did not observe any apparent differences in young left-behind children in terms of seeking health care for common childhood illnesses or prevalence of under-nutrition. Longitudinal studies are needed to accurately measure whether migration has any substantial temporal effect on the nutritional status of young children or seeking for health care.

Health-related predictors of cancer registry-notified cancer of unknown primary site (CUP).

BACKGROUND: The relationship between comorbid disease and health service use and risk of cancer of unknown primary site (CUP) is uncertain. METHODS: A prospective cohort of 266,724 people aged 45 years and over in New South Wales, Australia. Baseline questionnaire data were linked to cancer registration, health service records 4-27 months prior to diagnosis, and mortality data. We compared individuals with incident registry-notified CUP (n = 327; 90% C80) to two sets of randomly selected controls (3:1): (i) incident metastatic cancer of known primary site (n = 977) and (ii) general cohort population (n = 981). We used conditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: In fully adjusted models incorporating sociodemographic and lifestyle factors, people with cancer registry-notified CUP were more likely to have fair compared with excellent self-rated overall health (OR 1.78, 95% CI 1.01-3.14) and less likely to self-report anxiety (OR 0.48, 95% CI 0.24-0.97) than those registered with metastatic cancer of known primary. Compared to general cohort population controls, people registered with CUP were more likely to have poor rather than excellent self-rated overall health (OR 6.22, 95% CI 1.35-28.6), less likely to self-report anxiety (OR 0.28, 95% CI 0.12-0.63), and more likely to have a history of diabetes (OR 1.89, 95% CI 1.15-3.10) or cancer (OR 1.62, 95% CI 1.03-2.57). Neither tertiary nor community-based health service use independently predicted CUP risk. CONCLUSION: Low self-rated health may be a flag for undiagnosed cancer, and an investigation of its clinical utility in primary care appears warranted.

Demographic, social and lifestyle risk factors for cancer registry-notified cancer of unknown primary site (CUP).

BACKGROUND: Little is known about the risk factors for cancer of unknown primary site (CUP). We examined the demographic, social and lifestyle risk factors for CUP in a prospective cohort of 266,724 people aged 45 years and over in New South Wales, Australia. METHODS: Baseline questionnaire data were linked to cancer registration, hospitalisation, emergency department admission, and mortality data. We compared individuals with incident cancer registry-notified CUP (n = 327) to two sets of controls randomly selected (3:1) using incidence density sampling with replacement: (i) incident cancer registry-notified metastatic cancer of known primary site (n = 977) and (ii) general cohort population (n = 981). We used conditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: In a fully adjusted model incorporating self-rated overall health and comorbidity, people diagnosed with CUP were more likely to be older (OR 1.05, 95% CI 1.04-1.07 per year) and more likely to have low educational attainment (OR 1.77, 95% CI 1.24-2.53) than those diagnosed with metastatic cancer of known primary. Similarly, compared to general cohort population controls, people diagnosed with CUP were older (OR 1.10, 95% CI 1.08-1.12 per year), of low educational attainment (OR 1.69, 95% CI 1.08-2.64), and current (OR 3.42, 95% CI 1.81-6.47) or former (OR 1.95, 95% CI 1.33-2.86) smokers. CONCLUSION: The consistent association with educational attainment suggests low health literacy may play a role in CUP diagnosis. These findings highlight the need to develop strategies to achieve earlier identification of diagnostically challenging malignancies in people with low health literacy.

Second cancers and late mortality in Australian children treated by allogeneic HSCT for haematological malignancy.

We examined risk of second cancer and late mortality in a population-based Australian cohort of 717 pediatric allogeneic stem cell transplant (HSCT) recipients treated for a malignant disease during 1982-2007. Record linkage with population-based death and cancer registries identified 17 second cancers at a median of 7.9 years post HSCT; thyroid cancer being the most common malignancy (n=8). The cumulative incidence of second cancer was 8.7% at follow-up, and second cancers occurred 20 times more often than in the general population (standardised incidence ratio 20.3, 95% confidence interval (CI)=12.6-32.7). Transplantation using radiation-based conditioning regimens was associated with increased second cancer risk. A total of 367 patients survived for at least 2 years post HSCT and of these 44 (12%) died at a median of 3.1 years after HSCT. Relapse was the most common cause of late mortality (n=32). The cumulative incidence of late mortality was 14.7%. The observed rate of late mortality was 36 times greater than in the matched general population (standardised mortality ratio 35.9, 95% CI=26.7-48.3). Recipients who relapsed or who had radiation-based conditioning regimens were at higher risk of late mortality. Second cancers and late mortality continue to be a risk for pediatric patients undergoing HSCT, and these results highlight the need for effective screening and survivorship programs.

Survival after cutaneous melanoma in kidney transplant recipients: a population-based matched cohort study.

Transplant recipients are at elevated risk of melanoma and may have poorer outcomes than nontransplant recipients. We conducted a national, population-based, matched cohort study of Australian kidney transplant recipients and randomly selected members of the general population matched for age, sex, state and year of diagnosis with invasive cutaneous melanoma (1982-2003). Melanoma histopathological characteristics were extracted from cancer registry notifications and death data were obtained from the National Death Index (1982-2011). Histopathology was compared using conditional logistic regression and overall survival analyzed using Cox proportional hazard models. Compared to melanomas in nontransplant recipients (n = 202), melanomas in transplant recipients (n = 75) had a higher Clark's level (p = 0.007) and higher American Joint Committee on Cancer pathologic stage (p = 0.002), but not Breslow thickness (p = 0.11). Posttransplant melanoma conferred higher risk of death (adjusted hazard ratio 4.26, 95% CI 2.71-6.72, p < 0.001) after adjustment for the matching variables, pathologic stage, histological type and anatomic site. This was not explained by transplantation alone. Melanomas in transplant recipients are more invasive than those in nonrecipients. More aggressive tumor behavior is also supported by a markedly poorer outcome. Treatment algorithms developed for the general population with melanoma may not apply to transplant recipients. A review of patient education and skin cancer screening guidelines is warranted.

Second cancer risk in adults receiving autologous haematopoietic SCT for cancer: a population-based cohort study.

Population-based evidence on second cancer risk following autologous haematopoietic SCT (HCT) is lacking. We quantified second cancer risk for a national, population-based cohort of adult Australians receiving autologous HCT for cancer and notified to the Australasian Bone Marrow Transplant Recipient Registry 1992-2007 (n=7765). Cancer diagnoses and deaths were ascertained by linkage with the Australian Cancer Database and National Death Index. Standardized incidence ratios (SIRs) were calculated and Cox regression models were used to estimate within-cohort risk factors treating death as a competing risk. During a median 2.5 years follow-up, second cancer risk was modestly increased compared with the general population (SIR 1.4, 95% confidence interval 1.2-1.6); significantly elevated risk was also observed for AML/myelodysplastic syndrome (SIR=20.6), melanoma (SIR=2.6) and non-Hodgkin lymphoma (SIR=3.3). Recipients at elevated risk of any second cancer included males, and those transplanted at a younger age, in an earlier HCT era, or for lymphoma or testicular cancer. Male sex, older age (>45 years) and history of relapse after HCT predicted melanoma risk. Transplantation for Hodgkin lymphoma and older age were associated with lung cancer risk. Second malignancies are an important late effect and these results inform and emphasize the need for cancer surveillance in autologous HCT survivors.

De novo cancer-related death in Australian liver and cardiothoracic transplant recipients.

Evidence is sparse on the relative mortality risk posed by de novo cancers in liver and cardiothoracic transplant recipients. A retrospective cohort study was conducted in Australia using population-based liver (n = 1926) and cardiothoracic (n = 2718) registries (1984-2006). Standardized mortality ratios (SMRs) were computed by cancer type, transplanted organ, recipient age and sex. During a median 5-year follow-up, de novo cancer-related mortality risk in liver and cardiothoracic recipients was significantly elevated compared to the matched general population (n = 171; SMR = 2.83; 95% confidence interval [95%CI], 2.43-3.27). Excess risk was observed regardless of transplanted organ, recipient age group or sex. Non-Hodgkin lymphoma was the most common cancer-related death (n = 38; SMR = 16.6; 95%CI, 11.87-22.8). The highest relative risk was for nonmelanocytic skin cancer (n = 23; SMR = 49.6, 95%CI, 31.5-74.5), predominantly in males and in recipients of heart and lung transplants. Risk of death from de novo cancer was high in pediatric recipients (n = 5; SMR = 41.3; 95%CI, 13.4-96.5), four of the five deaths were non-Hodgkin lymphoma. De novo cancer was a leading cause of late death, particularly in heart and liver transplantation. These findings support tailored cancer prevention strategies, surveillance to promote early detection, and guidelines for managing immunosuppression once cancer occurs.

Cancer, immunodeficiency and antiretroviral treatment: results from the Australian HIV Observational Database (AHOD).

OBJECTIVES: The objective of the study was to conduct a within-cohort assessment of risk factors for incident AIDS-defining cancers (ADCs) and non-ADCs (NADCs) within the Australian HIV Observational Database (AHOD). METHODS: A total of 2181 AHOD registrants were linked to the National AIDS Registry/National HIV Database (NAR/NHD) and the Australian Cancer Registry to identify those with a notified cancer diagnosis. Included in the current analyses were cancers diagnosed after HIV infection. Risk factors for cancers were also assessed using logistic regression methods. RESULTS: One hundred and thirty-nine cancer cases were diagnosed after HIV infection among 129 patients. More than half the diagnoses (n = 68; 60%) were ADCs, of which 69% were Kaposi's sarcoma and 31% non-Hodgkin's lymphoma. Among the NADCs, the most common cancers were melanoma (n = 10), lung cancer (n = 6), Hodgkin's lymphoma (n = 5) and anal cancer (n = 5). Over a total of 21021 person-years (PY) of follow-up since HIV diagnosis, the overall crude cancer incidence rate for any cancer was 5.09/1000 PY. The overall rate of cancers decreased from 15.9/1000 PY [95% confidence interval (CI) 9.25-25.40/1000 PY] for CD4 counts < 100 cells/µL to 2.4/1000 PY (95% CI 1.62-3.39/1000 PY) for CD4 counts > 350 cells/µL. Lower CD4 cell count and prior AIDS diagnoses were significant predictors for both ADCs and NADCs. CONCLUSIONS: ADCs remain the predominant cancers in this population, although NADC rates have increased in the more recent time period. Immune deficiency is a risk factor for both ADCs and NADCs.

Comparison of de novo cancer incidence in Australian liver, heart and lung transplant recipients.

Population-based evidence on the relative risk of de novo cancer in liver and cardiothoracic transplant recipients is limited. A cohort study was conducted in Australia using population-based liver (n = 1926) and cardiothoracic (n = 2718) registries (1984-2006). Standardized incidence ratios (SIRs) were computed by cancer type, transplanted organ and recipient age. Cox regression models were used to compare cancer incidence by transplanted organ. During a median 5-year follow-up, the risk of any cancer in liver and cardiothoracic recipients was significantly elevated compared to the general population (n = 499; SIR = 2.62, 95%CI 2.40-2.86). An excess risk was observed for 16 cancer types, predominantly cancers with a viral etiology. The pattern of risk by cancer type was broadly similar for heart, lung and liver recipients, except for Merkel cell carcinoma (cardiothoracic only). Seventeen cancers (10 non-Hodgkin lymphomas), were observed in 415 pediatric recipients (SIR = 23.8, 95%CI 13.8-38.0). The adjusted hazard ratio for any cancer in all recipients was higher in heart compared to liver (1.29, 95%CI 1.03-1.63) and lung compared to liver (1.65, 95%CI 1.26-2.16). Understanding the factors responsible for the higher cancer incidence in cardiothoracic compared to liver recipients has the potential to lead to targeted cancer prevention strategies in this high-risk population.

Governance approval for multisite, non-interventional research: what can Harmonisation of Multi-Centre Ethical Review learn from the New South Wales experience?

BACKGROUND: In 2007, New South Wales Health mandated the separation of ethical and scientific review from research governance at all New South Wales public health sites based on their distinction in the National Health and Medical Research Council National Statement. This separation allowed for single-site ethical review of multicentre studies. AIMS: To investigate the time taken for governance approval of multicentre studies through the site-specific approval (SSA) process. METHODS: A retrospective audit of the SSA process for five non-interventional studies proposed by a university cancer research unit. RESULTS: The median total governance approval time for all submissions (n= 28) was 12 weeks (range 2.5-64); median time from starting the SSA to submission was 8 weeks (range 1-48) and median time for governance approval was 5 weeks (range 0.3-40). Approval times were shorter for public compared to private institutions. Reasons for delays in finalising submissions for approval were the absence of institutional governance officers, lack of clarity regarding signatories, the need to identify a principal investigator employed by the institution, and lack of recognition of ethical approval by private institutions. The need to develop legal agreements between the university and hospital was the main reason for lengthy delays in obtaining approval. CONCLUSIONS: The advantages of a harmonised single ethical review process were undermined by the coexistence of a fragmented, complex and lengthy governance approval process. This experience has implications for the success of the national Harmonisation of Multi-Centre Ethical Review (HoMER) model. A harmonised and fully supported national approach to research governance should be developed contemporaneously with HoMER.

Anal human papillomavirus genotype diversity and co-infection in a community-based sample of homosexual men.

OBJECTIVES: To determine the prevalence and risk factors for anal human papillomavirus (HPV) infection in community-based cohorts of homosexual men in Sydney, Australia. METHODS: A cross-sectional study in consecutively presenting participants in the positive Health and Health in Men cohorts in 2005. HPV testing was performed on anal PreservCyt specimens collected from 316 homosexual men (193 HIV-negative, 123 HIV-positive) using the Digene Hybrid Capture 2 (HC-2) assay for detection of low-risk (LR) and high-risk (HR) genotypes. HPV genotype testing was also performed on a subset of 133 men (93 HIV-negative, 36 HIV-positive) using Roche Linear Array (LA) assay. RESULTS: HC-2 detected HPV infection in 79% of men (LR 55%, HR 69%). HIV-positive men were more likely than HIV-negative men to have LR-HPV (OR 3.5, 95% CI 2.1 to 5.7) and HR-HPV (OR 5.5, 95% CI 3.0 to 10.2). LA detected HPV infection in 95% of men (LR 85%, HR 77%). HIV-positive men had a mean of 7.1 HPV types compared to 4.2 in HIV-negative men; the difference was significant for both LR-HPV (p<0.001) and HR-HPV (p<0.001). HPV-16 was detected in 36% of HIV-positive and 27% of HIV-negative men. There was no consistent trend in HPV prevalence with increasing age. HR-HPV detection was associated with anal bleeding for HIV-positive men and anal warts for HIV-negative men. CONCLUSIONS: Anal HPV infection was nearly universal in this community-based sample of homosexual men. A wide variety of HPV genotypes were detected, and co-infection with multiple genotypes was common. Anal HPV infection is more prevalent and more diverse in HIV-positive than HIV-negative homosexual men.

Occupational exposure to power frequency magnetic fields and risk of non-Hodgkin lymphoma.

OBJECTIVES: To investigate the risk of non-Hodgkin lymphoma (NHL) using a job-exposure matrix (JEM) to assess exposure to occupational magnetic fields at the power frequencies of 50/60 Hz. METHODS: The study population consisted of 694 cases of NHL, first diagnosed between 1 January 2000 and 31 August 2001, and 694 controls from two regions in Australia, matched by age, sex and region of residence. A detailed occupational history was given by each subject. Exposure to power frequency magnetic fields was estimated using a population-based JEM which was specifically developed in the United States to assess occupational magnetic field exposure. The cumulative exposure distribution was divided into quartiles and adjusted odds ratios were calculated using the lowest quartile as the referent group. RESULTS: For the total work history, the odds ratio (OR) for workers in the upper quartile of exposure was 1.48 (95% CI 1.02 to 2.16) compared to the referent (p value for trend was 0.006). When the exposure was lagged by 5 years the OR was 1.59 (95% CI 1.07 to 2.36) (p value for trend was 0.003). Adjusting for other occupational exposures did not significantly alter the results. CONCLUSIONS: These findings provide weak support for the hypothesis that occupational exposure to 50/60 Hz magnetic fields increases the risk of NHL.

Blind sampling is superior to anoscope guided sampling for screening for anal intraepithelial neoplasia.

OBJECTIVES: Anal cytology smears are either collected "blind" (swab inserted 4 cm into anal canal and rotated) or guided through an anoscope (transformation zone visualised and then sampled). We compared these smear techniques with respect to sample quality and patient acceptability. METHODS: Using a paired, random sequence clinical trial, 151 homosexual men (n = 95 HIV positive) underwent both smear techniques at a single visit; smear order was randomised and specimens were read blind. Both techniques utilised a Dacron swab, with water lubrication. Cytological specimens were prepared using a liquid based collection method (ThinPrep). The outcome measures were cytological specimen adequacy, cytological classification, presence of rectal columnar, squamous and metaplastic cells, contamination, patient comfort and acceptability, and volume of fluid that remained after the ThinPrep procedure. RESULTS: Regardless of smear order, guided smears were less likely to detect higher grade abnormalities than blind smears (15 v 27 cases, p = 0.001). Controlling for smear order, guided smears were more likely to be assessed as "unsatisfactory" for cytological assessment (OR 6.93, 95% CI 1.92 to 24.94), and contain fewer squamous (OR 0.20, 95% CI 0.04 to 0.94) and metaplastic cells (OR 0.12, 95% CI 0.03 to 0.54) than blind smears; there were no other statistically significant differences between techniques. Regardless of smear technique, first performed smears were more likely to detect a higher grade abnormality than second performed smears (23 v eight cases, p < 0.001). CONCLUSIONS: Blind cytology smears are superior to anoscope guided smears for screening for anal neoplasia in homosexual men.

Occupational exposure to pesticides and risk of non-Hodgkin's lymphoma.

Pesticide exposure may be a risk factor for non-Hodgkin's lymphoma, but it is not certain which types of pesticides are involved. A population-based case-control study was undertaken in 2000-2001 using detailed methods of assessing occupational pesticide exposure. Cases with incident non-Hodgkin's lymphoma in two Australian states (n = 694) and controls (n = 694) were chosen from Australian electoral rolls. Logistic regression was used to estimate the risks of non-Hodgkin's lymphoma associated with exposure to subgroups of pesticides after adjustment for age, sex, ethnic origin, and residence. Approximately 10% of cases and controls had incurred pesticide exposure. Substantial exposure to any pesticide was associated with a trebling of the risk of non-Hodgkin's lymphoma (odds ratio = 3.09, 95% confidence interval: 1.42, 6.70). Subjects with substantial exposure to organochlorines, organophosphates, and "other pesticides" (all other pesticides excluding herbicides) and herbicides other than phenoxy herbicides had similarly increased risks, although the increase was statistically significant only for "other pesticides." None of the exposure metrics (probability, level, frequency, duration, or years of exposure) were associated with non-Hodgkin's lymphoma. Analyses of the major World Health Organization subtypes of non-Hodgkin's lymphoma suggested a stronger effect for follicular lymphoma. These increases in risk of non-Hodgkin's lymphoma with substantial occupational pesticide exposure are consistent with previous work.

Eye color and cutaneous nevi predict risk of ocular melanoma in Australia.

Ethnicity, cutaneous nevi and eye color are generally accepted risk factors for melanoma of the eye, although case-control studies have produced conflicting results. We sought to determine the constitutional risk factors for melanomas of the choroid, ciliary body, iris and conjunctiva in Australia. A population-based case-control study was conducted, with case ascertainment from a prospective national incidence survey and randomly selected community controls. Two hundred and ninety cases aged 18-79 years and diagnosed between 1st January 1996 and 31st July 1998 were enrolled with 916 controls frequency matched by age, sex and State or Territory of residence. Risk of choroidal and ciliary body melanoma (n = 246) was increased in people with grey (OR 2.9, 95% CI 1.5-5.5), hazel (OR 2.2, 95% CI 1.4-3.7) and blue eyes (OR 1.7, 95% CI 1.0-2.7) compared with brown eyes. Risk was also increased in those with 4 or more nevi on their back, those unable to tan, and those who squinted when outdoors as a child. Risk was reduced in people born other than in Australia and New Zealand (OR 0.7, 95% CI 0.5-1.0). Non-brown eye color was a risk factor for iris melanoma (n = 25). No risk factors were identified for conjunctival melanoma (n = 19). Eye color is the strongest constitutional predictor of choroidal and ciliary body melanoma, and may indicate a protective effect of melanin density at these sites. An independent association with cutaneous nevi suggests a role for other genetic factors.

Inter-ocular characteristics of the pre-contact lens tear film.

PURPOSE: To establish whether the status of the pre-contact lens tear film as indicated by standard, clinical observational techniques is affected by moderate stimulation of the contralateral eye. METHODS: Four indicators of tear film behavior, lipid layer appearance, amount of debris, inferior meniscus height and non-invasive tear break up time (NIBUT) were monitored in ten subjects before and during 30 minutes of monocular pHEMA contact lens wear. Concurrently, the contralateral eye was either subjected to moderate irritation by means of a silicone elastomer contact lens, or remained unstimulated. Data were compared, between the stimulated and unstimulated states to identify evidence of contralateral treatment effects. RESULTS: After 30 minutes, maximum contralateral differences between the unstimulated and stimulated conditions were 1 grade for both lipid layer appearance and debris, 0.1 mm for meniscus height and 4 secs for NIBUT. CONCLUSIONS: The magnitudes of contralateral effects induced by moderate, monocular irritation were comparable with the within-subject variabilities associated with these indicators of tear film behavior.

High-oxygen-transmissibility soft contact lenses do not induce limbal hyperaemia.

PURPOSE: To establish the temporal sequence of limbal hyperaemia in humans without contact-lens wear and during conventional and highly oxygen-permeable soft-contact-lens wear. METHODS: Two, 16-h, non-dispensing clinical studies were conducted, each incorporating 8 h of open eye with normal blinking, followed by 8 h of eye closure during sleep. In the first study, six non-habitual contact-lens wearers did not wear contact lenses. In the second study, the same subjects were each randomly assigned, in a double-masked fashion, to wear a conventional, thin, 38% water, pHEMA soft contact lens (SCL) in one eye and an experimental high Dk (EHD), 20%-water soft contact lens in the other. Limbal redness (LR) was graded, using a 0-4 scale with decimalised subdivisions, at baseline and after 4, 8 and 16 h. ANOVA was applied to the data, and the level for statistical significance was set at p < or = 0.005. RESULTS: In the non-wearing eye, LR changes averaged 0.2 +/- 0.2 and 0.4 +/- 0.2 grades at 4 and 16 h, respectively (inferior quadrant). The corresponding values for SCL wear were 1.0 +/- 0.6 and 1.1 +/- 0.6, while for EHD wear they were 0.2 +/- 0.4 and 0.5 +/- 0.5. Both for the normal eye and those wearing EHD lenses, increases in LR were significant only during eye closure (p < 0.005). During SCL wear, significant and larger LR increases were seen after 4 h open eye wear (p < 0.005), with only relatively small further changes being observed over the next 12 h. CONCLUSIONS: SCL wear induces a marked increase in limbal hyperaemia during open-eye wear, which is not seen either in the no lens situation or when EHD lenses are worn. The pattern of limbal hyperaemia for both the open and closed eyes during EHD lens wear is very similar to that for the no-lens situation. The mechanism whereby SCL induces excess limbal hyperaemia has not been absolutely established, but it may involve local hypoxia.

Examination of the conjunctival microbiota after 8 hours of eye closure.

We investigated the effect of overnight eye closure on the levels and types of microbiota in the external eye, the conjunctiva, and lid margins of 40 normal subjects during the day and immediately after eye opening following 8 hours of sleep over 3 consecutive days. Overall, clinically important levels of gram-positive bacteria were isolated from 22.1% of samples; 2.3% of samples yielded gram-negative bacterial growth. The incidence of clinically important levels of gram-positive bacteria was greater in closed-eye compared with open-eye samples. There was no significant increase in the incidence of gram-negative bacteria or fungi with eye closure. There was no difference between the open- and closed- eye samples with regard to types of microorganisms isolated. Our results suggest that eye closure may promote the growth of normal external ocular microbiota. These findings have implications for extended contact lens wear and ocular surgery.