Consequences of changing Canadian activity patterns since the COVID-19 pandemic include increased residential radon gas exposure for younger people

The COVID-19 pandemic has produced widespread behaviour changes that shifted how people split their time between different environments, altering health risks. Here, we report an update of North American activity patterns before and after pandemic onset, and implications to radioactive radon gas exposure, a leading cause of lung cancer. We surveyed 4009 Canadian households home to people of varied age, gender, employment, community, and income. Whilst overall time spent indoors remained unchanged, time in primary residence increased from 66.4 to 77% of life (+ 1062 h/y) after pandemic onset, increasing annual radiation doses from residential radon by 19.2% (0.97 mSv/y). Disproportionately greater changes were experienced by younger people in newer urban or suburban properties with more occupants, and/or those employed in managerial, administrative, or professional roles excluding medicine. Microinfluencer-based public health messaging stimulated health-seeking behaviour amongst highly impacted, younger groups by > 50%. This work supports re-evaluating environmental health risks modified by still-changing activity patterns.

Tailored Sun Safety Messages for Outdoor Workers

Background

Messaging surrounding skin cancer prevention has previously focused on the general public and emphasized how or when activities should be undertaken to reduce solar ultraviolet radiation (UVR) exposure. Generic messages may not be applicable to all settings, and should be tailored to protect unique and/or highly susceptible subpopulations, such as outdoor workers. The primary objective of this study was to develop a set of tailored, practical, harm-reducing sun safety messages that will better support outdoor workers and their employers in reducing the risk of solar UVR exposure and UVR-related occupational illnesses.

Methods

We adapted a core set of sun safety messages previously developed for the general population to be more applicable and actionable by outdoor workers and their employers. This study used an integrated knowledge translation approach and a modified Delphi method (which uses a survey-based consensus process) to tailor the established set of sun safety messages for use for outdoor worker populations.

Results

The tailored messages were created with a consideration for what is feasible for outdoor workers, and provide users with key facts, recommendations, and tips related to preventing skin cancer, eye damage, and heat stress, specifically when working outdoors.

Conclusion

The resulting tailored messages are a set of evidence-based, expert- approved, and stakeholder-workshopped messages that can be used in a variety of work settings as part of an exposure control plan for employers with outdoor workers.

Characterizing occupational radon exposure greater than 100 Bq/m3 in a highly exposed country

Radon is an established lung carcinogen concentrating in indoor environments with importance for many workers worldwide. However, a systematic assessment of radon levels faced by all workers, not just those with direct uranium or radon exposure, has not previously been completed. The objective of this study was to estimate the prevalence of workers exposed to radon, and the level of exposure (> 100-200 Bq/m³, 200-400 Bq/m³, 400-800 Bq/m³, and > 800 Bq/m³) in a highly exposed country (Canada). Exposures among underground workers were assessed using the CAREX Canada approach. Radon concentrations in indoor workplaces, obtained from two Canadian surveys, were modelled using lognormal distributions. Distributions were then applied to the susceptible indoor worker population to yield the number of exposed workers, by occupation, industry, province, and sex. In total, an estimated 603,000 out of Canada's 18,268,120 workers are exposed to radon in Canada. An estimated52% of exposed workers are women, even though they comprise only 48% of the labour force. The majority (68%) are exposed at a level of > 100-200 Bq/m³. Workers are primarily exposed in educational services, professional, scientific and technical services, and health care and social assistance, but workers in mining, quarrying, and oil and gas extraction have the largest number of exposed workers at high levels (> 800 Bq/m³). Overall, a significant number of workers are exposed to radon, many of whom are not adequately protected by existing guidelines. Radon surveys across multiple industries and occupations are needed to better characterize occupational exposure. These results can be used to identify exposed workers, and to support lung cancer prevention programs within these groups.

Prevalence and Level of Occupational Exposure to Asbestos in Canada in 2016

Objective

Asbestos use has decreased over time but occupational exposure still exists today due to the presence of asbestos in older buildings. The objective of this study was to update CAREX Canada’s prevalence of exposure estimate from 2006 to 2016, and to assess the level of occupational exposure by industry, occupation, province/territory, and sex.

Methods

Estimates by occupation, industry, province/territory, and sex were calculated using labor force data from the 2016 Census of Population and proportions of workers exposed by occupation and industry, which were previously developed for the 2006 estimates and updated here to reflect new knowledge and changes in exposures. Statistics Canada concordance tables were used to account for changes between the 2006 and 2016 job and industry coding systems. Expert assessment was used to qualitatively assign levels of exposure (low, moderate, or high) for each occupation and industry, with consideration of workers’ proximity and access to asbestos-containing material, and the condition and content of asbestos.

Results

Approximately 235 000 workers are exposed to asbestos on the job in Canada. The majority of Canadian workers exposed to asbestos are male (89%). Only 5% of all exposed workers are in the high-exposure category, while most workers are in the low (49%) or moderate (46%) exposure categories. The construction sector and associated jobs (e.g. carpenters, trades helpers and laborers, electricians) accounted for the majority of exposed workers.

Conclusions

Occupational exposure to asbestos continues to occur in Canada. Updating the prevalence of exposure estimate and adding exposure levels highlights the shift from high to lower-lever exposures associated with asbestos-containing materials remaining in the built environment.

A media surveillance analysis of COVID-19 workplace outbreaks in Canada and the United States

A media surveillance analysis was conducted to identify COVID-19 workplace outbreaks and associated transmission risk for new and emerging occupations. We identified 1,111 unique COVID-19 workplace outbreaks using the Factiva database. Occupations identified in the media articles were coded to the 2016 National Occupational Classification (V1.3) and were compared and contrasted with the same occupation in the Vancouver School of Economics (VSE) COVID Risk/Reward Assessment Tool by risk rating. After nurse aides, orderlies, and patient service associates ( n = 109, very high risk), industrial butchers and meat cutters, and poultry preparers and related workers had the most workplace outbreaks reported in the media ( n = 79) but were rated as medium risk for COVID-19 transmission in the VSE COVID Risk Tool. Outbreaks were also reported among material handlers ( n = 61) and general farm workers ( n = 28), but these occupations were rated medium–low risk and low risk, respectively. Food and beverage services ( n = 72) and cashiers ( n = 60) were identified as high-risk occupations in the VSE COVID Risk Tool. Differences between the media results and the risk tool point to key determinants of health that compound the risk of COVID-19 exposure in the workplace for some occupations and highlight the importance of collecting occupation data during a pandemic.

COVID-19 and Vitamin D Misinformation on YouTube: Content Analysis

Background

The “infodemic” accompanying the SARS-CoV-2 virus pandemic has the potential to increase avoidable spread as well as engagement in risky health behaviors. Although social media platforms, such as YouTube, can be an inexpensive and effective method of sharing accurate health information, inaccurate and misleading information shared on YouTube can be dangerous for viewers. The confusing nature of data and claims surrounding the benefits of vitamin D, particularly in the prevention or cure of COVID-19, influences both viewers and the general “immune boosting” commercial interest.

Objective

The aim of this study was to ascertain how information on vitamin D and COVID-19 was presented on YouTube in 2020.

Methods

YouTube video results for the search terms “COVID,” “coronavirus,” and “vitamin D” were collected and analyzed for content themes and deemed useful or misleading based on the accuracy or inaccuracy of the content. Qualitative content analysis and simple statistical analysis were used to determine the prevalence and frequency of concerning content, such as confusing correlation with causation regarding vitamin D benefits.

Results

In total, 77 videos with a combined 10,225,763 views (at the time of data collection) were included in the analysis, with over three-quarters of them containing misleading content about COVID-19 and vitamin D. In addition, 45 (58%) of the 77 videos confused the relationship between vitamin D and COVID-19, with 46 (85%) of 54 videos stating that vitamin D has preventative or curative abilities. The major contributors to these videos were medical professionals with YouTube accounts. Vitamin D recommendations that do not align with the current literature were frequently suggested, including taking supplementation higher than the recommended safe dosage or seeking intentional solar UV radiation exposure.

Conclusions

The spread of misinformation is particularly alarming when spread by medical professionals, and existing data suggesting vitamin D has immune-boosting abilities can add to viewer confusion or mistrust in health information. Further, the suggestions made in the videos may increase the risks of other poor health outcomes, such as skin cancer from solar UV radiation.

The influence of sleep health on dietary intake: a systematic review and meta-analysis of intervention studies

BACKGROUND

Poor dietary intake increases disease risk, and poor sleep influences diet. This systematic review and meta-analysis of intervention studies aimed to evaluate the effect of sleep health on dietary intake in adults.

METHODS

Five online databases were used to identify studies published between 1970 and 2019. Included studies were interventions that modified sleep and reported dietary outcomes.

RESULTS

Fifty four full texts were assessed and 24 publications were included. Following risk of bias appraisal, data were narratively summarised and a sub-group of studies (n = 15) was meta-analysed to determine the effect of sleep on dietary intake. One intervention modified sleep timing and 23 modified duration. Sleep duration was partially restricted (≤5.5 h night^-1 ) (n = 16), totally restricted (n = 4), partially and totally restricted (n = 1), and extended (n = 2). Dietary outcomes were energy intake (n = 24), carbohydrate, fat, protein intake (n = 20), single nutrient intake (n = 5), diet quality (n = 1) and food types (n = 1). Meta-analysis indicated partial sleep restriction results in higher energy intake in intervention compared with control [standardised mean difference (SMD) = 0.37; 95% confidence interval (CI) = 0.21-0.52; P < 0.001], with a mean difference of 204 kcal (95% CI = 112-295; P < 0.001) in daily energy intake, and a higher percentage of energy from fat, protein, carbohydrate (fat: SMD = 0.33; 95% CI = 0.16-0.51; P < 0.001; protein: SMD = 0.30, 95% CI = 0.12-0.47, P = 0.001; carbohydrate: SMD = 0.22, 95% CI = 0.04-0.39, P = 0.014).

CONCLUSIONS

Partial sleep restriction with duration of ≤5.5 h day^-1 increases daily energy intake, as well as fat, protein and carbohydrate intake. Further research is needed to determine the relationship between other dimensions of sleep health and dietary intake.

Diet and sleep health: a scoping review of intervention studies in adults

BACKGROUND

Recent research has demonstrated an association between dietary intake and sleep health that can influence chronic disease risk factors. A scoping review of research studies investigating dietary intake and sleep was undertaken to determine the extent and scope of research in laboratory-based, free-living and mixed settings. Additionally, this review determines how well subpopulations and geographical locations are represented and the methodologies used to assess outcome measures.

METHODS

Five online databases were used to identify papers published between 1970 and 2017. Included studies were those conducted in adults and reported both outcomes of interest: (i) sleep health, including sleep restriction and sleep hygiene and (ii) dietary outcomes, including altered nutrients, dietary patterns and supplements.

RESULTS

In total, 129 publications were included with the majority being dietary interventions investigating sleep outcomes (n = 109) with fewer being sleep interventions investigating and reporting dietary outcomes (n = 20). Dietary interventions were most often carried out in free-living environments, in contrast to sleep interventions that were most often carried out in laboratory-based environments. The majority of dietary interventions investigated use of a supplement (n = 66 studies), which was predominantly caffeine (n = 49). Sleep interventions investigated sleep duration only, with the majority (n = 17) investigating the effect of partial sleep restriction under 5.5 h per night on dietary intake, while three studies investigating total sleep deprivation.

CONCLUSIONS

Investigating broader aspects of dietary such as overall diet quality and dietary patterns and other components of sleep health such as quality,  timing and sleep hygiene are important aspects for future research.

Making health informatics competencies useful: an applied health informatics competency self-assessment system

Years ago we undertook to define Health Informatics (HI) competencies. This effort resulted in the creation of a document that articulated HI roles, the challenges faced by HI professionals, the high-level tasks that they needed to undertake to address these challenges and the competencies (skills, knowledge, and experience) they needed to complete these tasks. Unfortunately, in so doing we created what is arguably the most boring book in history, shoes contents are very difficult to extract, use, maintain and improve. We report here the completion of a pilot of a system that we believe corrects this situation. It is a webbased tool that incorporates all of the material, from roles to detailed competencies, enabling them to be accessed and used for a variety of purposes, the most notable of which is professional self-assessment.

Reverse epidemiology in peritoneal dialysis patients: the Canadian experience and review of the literature

High Body Mass Index (BMI) has been associated with improved survival of End-Stage Renal Disease (ESRD) patients on chronic hemodialysis (HD); however, studies on the relationship of BMI with survival in Peritoneal Dialysis (PD) patients have yielded conflicting results. The purpose of this study was to evaluate the impact of BMI on survival of Canadian ESRD patients on PD, correcting for their age, sex, race, diabetes mellitus, and arterial hypertension. In an intent to treat study, we reviewed data of the Canadian Organ Replacement Register (CORR), of incident patients, starting PD between 1994 and 1998 and followed up from their initial PD treatment to the end of 2003. Patients were censored at loss to follow up, transplantation, and the end of the observation period. Cox regression (multivariate) analysis was performed and adjustments were made for age, gender, race, primary renal disease and BMI. During these years, 4054 patients commenced PD, 1742 (43%) of them were females and 1471 (36.3%) were diabetics. The majority were Caucasians (n=3058, 75.4%); 120 (3%) belonged to the First Nations, 137 (3.4%) were black, and the rest (739 pts-18.2%) belonged to various other ethnicities. Based on quartiles of the BMI distribution, 1130 patients (28%) had a BMI < 18.5 kg/m(2); 1163 (28.7%), 18.5-24.9 kg/m(2); 1214 (30%), 25-29.9 kg/m(2); 547 (13.5%) > 30 kg/m(2). Intent to treat Cox regression analysis showed that being underweight was a strong risk factor for death. Specifically, a BMI less than 18.5 was associated with a death hazard ratio (HR) 1.3, (CI: 1.1-1.6). On the contrary, BMI > 30 was not associated with worse survival than those with normal BMI (HR = 1.009, CI = 0.89-1.14). High-BMI patients should not be discouraged from PD just because of their size.

WebSAT: a web-based competency self-assessment system linking to educational resources

We describe a web-based system that enables an individual to assess him/her self against the set of competencies required for a variety of roles in the area of Applied Health Informatics (AHI). The competencies themselves were developed by a multi-disciplinary team under the auspices of the Canadian Institute for Health Research (CIHR), and include the knowledge, skills, and experience necessary to fulfill specific roles as an applied health informatician. Both textual and graphical information is presented to the user and potential mechanisms for correcting competency gaps are presented in this online interactive system.

Reliability of exophthalmos measurement and the exophthalmometry value distribution in a healthy Dutch population and in Graves' patients. An exploratory study

AIM

The purpose of this study was to test the reliability of an exophthalmometer commonly used in the Netherlands; to determine the exophthalmometry value distribution with this instrument and to assess the upper exophthalmometry limits of normal in a healthy, adult, Caucasian, Dutch population. Furthermore, to assess the effects of gender and age on exophthalmometry readings in this group and in a group of Graves' patients by comparing healthy, adult, Caucasian, Dutch individuals with adult, Caucasian, Dutch Graves' patients.

METHODS

To test the reliability of our Hertel exophthalmometer, we determined the interobserver variation between two observers by measuring 160 eyes in healthy, adult, Caucasian, Dutch females and males (10 females and 10 males in each decade between 20 and 60 years of age). These data were also used for the assessment of the Hertel value distribution and for defining the upper limits of normal in these individuals by logistic regression analysis. The effects of disease, age and gender were established using these data plus data of a retrospective study of 393 adult, Caucasian, Dutch females (n=294) and males (n=99) with Graves' orbitopathy in whom Hertel values were measured with the same exophthalmometer.

RESULTS

Exophthalmometry using an Hertel exophthalmometer appeared reliable (Pearson correlation coefficient for interobserver variation 0.89; 96% of the Hertel values measured by two observers were within the limits (of 2 mm) of agreement). Hertel values usually show a normal distribution in healthy individuals and in Graves' patients and are sex- and age-dependent, but there was no dependence on age in this small series in adults. Logistic regression analysis revealed an upper limit of normal of 16 mm in females and 20 mm in males in our group, using the exophthalmometer described.

CONCLUSIONS

Exophthalmometry is reliable and absolute measurement of proptosis is feasible. International standardization of Hertel exophthalmometry is required in order to compare exophthalmometry data in the literature reliably.

Screening for ophthalmic involvement in asymptomatic patients with metastatic breast carcinoma

BACKGROUND

Breast carcinoma metastasises to the eye more frequently than is clinically recognised. The incidence is perhaps not appreciated, either because of the more common involvement and consequences of spread to major organs (such as lung, liver, or bone) or because a number of eye lesions are small and asymptomatic. Over a 6-month period, all patients with locally advanced or metastatic breast cancer were screened for ocular involvement and as a result management recommendations made.

MATERIALS AND METHODS

Between January 2001 and June 2001, 68 patients with known locally advanced or metastatic breast carcinoma were referred for a screening ophthalmic examination. The aim of the study was to assess the frequency of asymptomatic ocular metastases by breast carcinoma in visually asymptomatic patients. The recognition and early treatment of both ocular metastases and ocular manifestations of metastatic breast carcinoma are important in maximising the quality of life in this group of palliative patients. These patients were all referred and recruited from the Beatson Oncology Centre and Breast Unit at the Western Infirmary, Glasgow by the oncologist (ANH). Examination included visual acuity assessment, slit-lamp examination, tonometry, and indirect ophthalmoscopy.

RESULTS

The median time from diagnosis of breast carcinoma to ophthalmic screening was 5 years (range 6 months-23 years). No patient had any evidence of choroidal metastases on ophthalmic examination. Four patients (5.8%) had ophthalmic manifestations of metastatic breast carcinoma and a further two had ocular complications of treatment. One patient had a restrictive motility problem from a metastatic deposit to her lateral rectus muscle and another had corneal punctate epitheliopathy secondary to a seventh nerve palsy. A further patient had coarse nystagmus from cerebellar metastases and the final patient of the four had a Horner's syndrome from metastases in the neck. In addition, two patients had symptomatic dry eyes whose onset coincided with commencement of chemotherapy.

CONCLUSION

Ophthalmic manifestations of metastatic breast carcinoma occurred in 5.8% of asymptomatic patients. Orbital metastases were documented in one patient. No case of choroidal metastases was observed in this group with advanced or metastatic disease. Therefore, patients do not need to be routinely screened particularly for choroidal metastases.

A review of the outcome of upper lid lowering for eyelid retraction and complications of spacers at a single unit over five years

AIM

To review the outcome of upper lid lowering for eyelid retraction at a single unit over five years and to report the high complication rate with mersilene mesh as a spacer material.

METHODS

We retrospectively reviewed the case records of 48 patients who underwent upper lid lowering for lid retraction between January 1995 and January 2000.

RESULTS

The indication for surgery was eyelid retraction secondary to dysthyroid disease in 41 patients, seventh nerve palsy in 3 cases, overcorrection of ptosis elsewhere in 3 cases and previously treated orbital lymphoma in one patient. A good result was achieved in 80% with a single procedure. Undercorrection occurred in 10% and overcorrection occurred in 8%. Spacer material, either mersilene mesh or more recently vicryl, was used in 42% of lids. Late extrusion of mersilene mesh occurred in 20% of lids that had a spacer inserted an average of 18 months postoperatively.

CONCLUSIONS

The high extrusion rate with mersilene was unacceptable and the alternative spacer material vicryl is now used. The possibility of revisional surgery because of under- or overcorrection should be explained to patients.

Cystinosis, cataract surgery, and corneal erosions

A 21-year-old man presented with severe corneal cystinosis and steroid-related cataract bilaterally. Rather than combined cataract surgery and penetrating keratoplasty, the patient had uneventful phacoemulsification and intraocular lens implantation after which visual acuity improved to 66 in both eyes. The outcome indicates that conventional phacoemulsification is sufficient in these cases. A guarded prognosis is advised in patients with cystinosis having cataract surgery as the fundal view is often impaired and there may be associated maculopathy.

Visual outcomes and complications of posterior chamber intraocular lens implantation in the first year of life

PURPOSE

To document the visual outcome and postoperative complications in infants who had congenital cataract surgery with posterior chamber intraocular lens (PC IOL) implantation in the first year of life.

SETTING

The Children's Hospital, Dublin, Ireland.

METHODS

Twenty-seven eyes of 20 infants were reviewed. Seven infants (14 eyes) had bilateral congenital cataract and 13 (13 eyes), uniocular cataract. The mean age at surgery was 4 months (range 3 weeks to 11 months). A standard surgical technique involved anterior capsulorhexis, phacoemulsification with or without posterior capsulorhexis with in-the-bag PC IOL implantation, and no anterior vitrectomy. Surgery was performed by 1 surgeon. The mean follow-up was 41 months (range 6 to 88 months).

RESULTS

The main complication was lens reproliferation into the visual axis. Of the 11 eyes that did not have a primary posterior capsulorhexis, 10 had 1 or more capsulotomies. Seven required a neodymium:YAG (Nd:YAG) laser capsulotomy a mean of 6 months postoperatively, and 2 had 2 Nd:YAG capsulotomies. Six eyes also had a surgical capsulotomy when the membrane was deemed too thick for further laser treatment. Fourteen of 25 eyes had a primary posterior capsulorhexis; 8 had no further intervention. Four eyes had persistent hyperplastic primary vitreous (PHPV), 3 required a surgical capsulotomy, 2 had an Nd:YAG laser capsulotomy, 2 had an anterior vitrectomy, and 1 developed open-angle glaucoma. There was a mean refractive shift of 6.0 diopters after a mean follow-up of 41 months, with most of the myopic shift occurring in the first 24 months.

CONCLUSIONS

Visual axis reopacification was the main complication of IOL implantation in infants, with PHPV leading to more complications and repeat procedures. Anterior vitrectomy appeared to reduce the reoperation rate. Results indicate that primary posterior capsulorhexis is important and Nd:YAG capsulotomy is not satisfactory in infants. In addition, the reduction in glaucoma with IOL implantation, if borne out over the long term, is a significant advantage in cases of congenital cataract.

An audit of the ophthalmic division of the accident and emergency department of the Royal Victoria Eye and Ear Hospital, Dublin

The objective was to study the patterns of emergency department visits and to make recommendations on ways of improving the service. Patients' demographic data, diagnoses, source of referral and follow-up were entered onto a database. Three thousand seven hundred consecutive patients' visits over a six-week period were entered. The average daily attendance ranged between 80-100 people. 54% of patients were self-referrals. 20% had a previous visit to the hospital. 17% were referred from a GP, 5% from another hospital and 3% from opticians. Superficial injury to the eye and ocular adnexae was the most common diagnostic category. 56% of patients were discharged at the first visit. 23% returned for review to casualty. 14% were referred to OPD, 3% directly to a consultant for review and 1% were admitted to hospital. Waiting times for consultation for patients was highly variable ranging from thirty minutes to five hours, mean two hours. The department provides a service far in excess of its defined function. Non urgent problems accounted for as much as 60-70% of all emergency department visits. Improvement of ophthalmic training of GPs, introduction of an ophthalmic triage system and expansion of outpatient services is recommended so that casualty remains a genuine emergency service and not a primary care service with uncontrollable numbers and unacceptable waiting times for patients.

Delayed superficialization of brachiobasilic fistula: technique and initial experience

HYPOTHESIS

Angioaccess procedures for dialysis have varied patency rates with frequent need for intervention. A superficialized arteriovenous brachiobasilic fistula created as a 2-step procedure will have good long-term patency with minimal complication.

DESIGN

Retrospective medical record review and patient interview.

SETTING

Tertiary referral university hospital.

PATIENTS

Twelve patients who underwent delayed superficialization of brachiobasilic fistula from September 1994 to April 2000.

MAIN OUTCOME MEASURES

Patency of fistula for dialysis, and major and minor complications, including revisions.

RESULTS

Delayed superficialization of brachiobasilic fistula was performed in 12 patients. Fistulas have been used for a mean duration of 22.4 months (range, 10-59 months). Two patients required alternate access owing to thrombosis of brachiobasilic fistula.

CONCLUSIONS

The delayed superficialized brachiobasilic arteriovenous fistula has a good initial patency rate with minimal complications. It should be considered early in patients if radiocephalic fistula is unavailable.

Balloon dacryocystoplasty study in the management of adult epiphora

PURPOSE

To determine the efficacy of dacryocystoplasty with balloon dilation in the treatment of acquired obstruction of the nasolacrimal system in adults.

METHODS

Balloon dacryocystoplasty was performed in 52 eyes of 42 patients under general anaesthetic. A Teflon-coated guidewire was introduced through the canaliculus and manipulated through the nasolacrimal system and out of the nasal aperture. A 4 mm wide 3 cm coronary angioplasty balloon catheter was threaded over the guidewire in a retrograde fashion and dilated at the site of obstruction.

RESULTS

There was complete obstruction in 30% of cases and partial obstruction in 70%. The most common site of obstruction was the nasolacrimal duct. The procedure was technically successful in 94% of cases. The overall re-obstruction rate was 29% within 1 year of the procedure. There was an anatomical failure rate of 17% for partial obstruction and 69% for complete obstruction within 1 year.

CONCLUSIONS

Balloon dacryocystoplasty has a high recurrence rate. There may be a limited role for this procedure in partial obstructions. Further refinements of the procedure are necessary before it can be offered as a comparable alternative to a standard surgical dacryocystorhinostomy.

Ischaemic optic neuropathy following bilateral neck dissection

Two cases of ischaemic optic neuropathy, which occurred as a complication of oncological neck surgery, are reported. These cases are submitted because of the apparent scarcity in the literature of this complication after head and neck surgery. They are also unusual because they presented with different clinical manifestations of ischaemic optic neuropathy after separate forms of bilateral neck dissection. A literature review identifies a small number of similar cases and risk factors and preventative measures are discussed.

Differential binding of the insecticidal lectin GNA to human blood cells

Evidence of snowdrop lectin binding to human white cells supports the need for greater understanding of the possible health consequences of incorporating plant lectins into the food chain.

Factors influencing long-term primary cadaveric kidney transplantation--importance of functional renal mass versus avoidance of acute rejections--the Toronto Hospital experience 1985-1997

1. The 5-year actuarial graft, patient and functional graft survival rates were analyzed in 743 consecutive primary cadaveric kidney transplants from The Toronto Hospital between January 1985-December 1997. 2. Recipient age > or = 55 years, male recipient sex, recipient diabetes mellitus, CIT > 36 hours and delayed graft function were found to significantly decrease patient survival. 3. Recipient age > or = 55 years, sensitization to HLA antigens (peak PRA > 50%), donor/recipient HLA antigen mismatches, CIT > 36 hours, delayed graft, function and 6-month SCr > 200 mumol/L were found to significantly decrease graft survival. 4. Acute rejection episodes had no significant impact on overall 5-year patient or graft survival. 5. The observation that serum creatinine > 200 mumol/L had a major adverse influence on long-term outcome reflects the importance of functional renal mass on graft survival.

Primary posterior capsulorhexis without anterior vitrectomy in pediatric cataract surgery: longer-term outcome

PURPOSE

To assess the effectiveness of primary posterior capsulorhexis without anterior vitrectomy in preventing posterior capsule opacification (PCO) in pediatric cataract surgery.

SETTING

Children's Hospital, Dublin, Republic of Ireland.

METHODS

The study comprised 32 eyes of 22 pediatric patients who had cataract extraction between 1994 and 1998. Extracapsular cataract extraction was performed using radiofrequency diathermy capsulorhexis to the anterior and posterior capsules without an anterior vitrectomy. Posterior chamber intraocular lens implantation was performed in 20 eyes. There were 23 congenital, 6 developmental, and 3 traumatic cataracts.

RESULTS

Patient age ranged from 1 month to 12 years. Mean follow-up was 19 months (range 6 to 50 months). Twenty-seven of 32 eyes (84.4%) had a clear visual axis at last follow-up. Five eyes required a neodymium: YAG capsulotomy, which was performed a mean of 5 months postoperatively (range 1 to 9 months). The incidence of PCO requiring capsulotomy was 15.6%.

CONCLUSION

Primary posterior capsulorhexis without anterior vitrectomy was safe and effective, with a low reopacification rate. Long-term follow-up of this patient cohort is necessary.

Outcome of kidney transplantation from high-risk donors is determined by both structure and function

METHOD

Despite the need to expand the donor pool, it is unclear what parameters should be used. The value of donor renal pathology and calculated creatinine clearance (CrCl) in determining recipient outcome was assessed in 57 kidney transplants from 34 donors in whom pretransplant renal biopsies were performed because of age > or =60, hypertension, and/or vascular disease. We retrospectively compared clinical outcomes in these recipients and 57 control recipients selected to have the same baseline demographics but receiving transplants from low risk donors who were significantly younger (32+/-13.9 vs. 61+/-7.3 years) and lighter weight (71+/-18.1 vs. 84+/-20.2 kg) than the high-risk donors (P<.001 for both).

RESULTS

Recipients of high-risk kidneys had a higher incidence of delayed graft function, defined by a <10% fall in serum creatinine (Cr) in the first 24 hr, (56% vs. 30%, P<.01), a higher incidence of rejection (60% vs. 37%, P = .02) and a higher Cr level (197+/-64 vs. 144+/-54 micromol/L at 18 months, P<.005). Graft and patient survival were similar; 12% and 5% vs. 91% and 9% in high-risk vs. control groups, respectively (P = NS). Donor renal pathology was scored 0-3 (none to severe disease) in four areas: glomerulosclerosis, interstitial fibrosis, tubular atrophy, and vascular disease. A donor vessel score of 3/3 was associated with a 100% incidence of delayed graft function and a mean 1-year Cr level of 275+106 micromol/L (compared with 43% and 192+54 micromol/L in those with lower vessel scores, P<.05). Calculated donor CrCl <100 ml/min was associated with higher recipient Cr levels at 1 year, 240+/-95 micromol/L vs. 180+/-54 micromol/L in recipients of kidneys from donors with CrCl levels >100 ml/min (P<.05). The mean 1-year Cr level was 320+/-102 micromol/L in recipients with both a vascular score of 3/3 and a donor CrCl <100 ml/min and 184+/-63 micromol/L in those with neither factor (P = .001).

CONCLUSION

Calculated donor CrCl and donor vascular pathology predict recipient graft function and may be helpful in selecting high-risk donors for single kidney transplantation.

Thrombotic microangiopathy in renal transplant recipients treated with cyclosporin A

Thrombotic microangiopathy is an uncommon but well described complication of renal transplantation. This study is a review of the case records of 18 patients with biopsy proven post transplant thrombotic microangiopathy, without cellular rejection. There was no single characteristic underlying cause of renal failure in native kidneys. Although only two (11%) patients had undergone previous transplantation, 16 (89%) had panel reactive antibodies (PRA). All patients received prophylactic antilymphocyte globulin, a single patient had cyclosporin A (CSA) at the time of transplant and in 16 patients CSA was introduced when graft function was established. On this protocol 16 (89%) patients had early graft function. All patients developed acute renal failure and 16 (89%) required dialysis. Nine (50%) patients developed hematological abnormalities. All patients were treated aggressively with anti-rejection therapy, CSA was temporarily withdrawn, and 2 (11%) patients received plasmapheresis. Seven (39%) patients lost their grafts. Renal function in the remaining patients recovered to serum creatinine levels ranging from 104 mumol/l to 430 mumol/l (1.2 mg% to 4.8 mg%). All patients with surviving grafts had CSA successfully reintroduced. This study indicates that there is an association between patients who develop posttransplant thrombotic microangiopathy after CSA administration and high PRA levels. The condition appears to respond to anti-rejection therapy and stopping CSA in the majority of cases. The safe reintroduction of CSA suggests that endothelial cell damage in the posttransplant period may be multifactorial and not solely due to CSA therapy.