Global health workforce strategies to address the COVID-19 pandemic: Learning lessons for the future

COVID-19 put unprecedented strain on the health and care workforce (HCWF). Yet, it also brought the HCWF to the forefront of the policy agenda and revealed many innovative solutions that can be built upon to overcome persistent workforce challenges. In this perspective, which draws on a Policy Brief prepared for the WHO Fifth Global Forum on Human Resources for Health, we present findings from a scoping review of global emergency workforce strategies implemented during the pandemic and consider what we can learn from them for the long-term sustainability of the HCWF. Our review shows that strategies to strengthen HCWF capacity during COVID-19 fell into three categories: (1) surging supply of health and care workers (HCWs); (2) optimizing the use of the workforce in terms of setting, skills and roles; and (3) providing HCWs with support and protection. While some initiatives were only short-term strategies, others have potential to be continued. COVID-19 demonstrated that changes to scope-of-practice and the introduction of team-based roles are possible and central to an effective, sustainable workforce. Additionally, the use of technology and digital tools increased rapidly during COVID-19 and can be built on to enhance access and efficiency. The pandemic also highlighted the importance of prioritizing the security, safety, and physical and mental health of workers, implementing measures that are gender and equity-focused, and ensuring the centrality of the worker perspective in efforts to improve HCWF retention. Flexibility of regulatory, financial, technical measures and quality assurance was critical in facilitating the implementation of HCWF strategies and needs to be continued. The lessons learned from COVID-19 can help countries strengthen the HCWF, health systems, and the health and well-being of all, now and in the future.

How can countries respond to the health and care workforce crisis? Insights from international evidence

Future global health security requires a health and care workforce (HCWF) that can respond effectively to health crises as well as to changing health needs with ageing populations, a rise in chronic conditions and growing inequality. COVID-19 has drawn attention to an impending HCWF crisis with a large projected shortfall in numbers against need. Addressing this requires countries to move beyond a focus on numbers of doctors, nurses and midwives to consider what kinds of healthcare workers can deliver the services needed; are more likely to stay in country, in rural and remote areas, and in health sector jobs; and what support they need to deliver high-quality services. In this paper, which draws on a Policy Brief prepared for the World Health Organization (WHO) Fifth Global Forum on Human Resources for Health, we review the global evidence on best practices in organising, training, deploying, and managing the HCWF to highlight areas for strategic investments. These include (1). Increasing HCWF diversity to improve the skill-mix and provide culturally competent care; (2). Introducing multidisciplinary teams in primary care; (3). Transforming health professional education with greater interprofessional education; (4). Re-thinking employment and deployment systems to address HCWF shortages; (5). Improving HCWF retention by supporting healthcare workers and addressing migration through destination country policies that limit draining resources from countries with greatest need. These approaches are departures from current norms and hold substantial potential for building a sustainable and responsive HCWF.

A comparison of social prescribing approaches across twelve high-income countries

BACKGROUND

Social prescribing connects patients with community resources to improve their health and well-being. It is gaining momentum globally due to its potential for addressing non-medical causes of illness while building on existing resources and enhancing overall health at a relatively low cost. The COVID-19 pandemic further underscored the need for policy interventions to address health-related social issues such as loneliness and isolation.

AIM

This paper presents evidence of the conceptualisation and implementation of social prescribing schemes in twelve countries: Australia, Austria, Canada, England, Finland, Germany, Portugal, the Slovak Republic, Slovenia, the Netherlands, the United States and Wales.

METHODS

Twelve countries were identified through the Health Systems and Policy Monitor (HSPM) network and the EuroHealthNet Partnership. Information was collected through a twelve open-ended question survey based on a conceptual model inspired by the WHO's Health System Framework.

RESULTS

We found that social prescribing can take different forms, and the scale of implementation also varies significantly. Robust evidence on impact is scarce and highly context-specific, with some indications of cost-effectiveness and positive impact on well-being.

CONCLUSIONS

This paper provides insights into social prescribing in various contexts and may guide countries interested in holistically tackling health-related social factors and strengthening community-based care. Policies can support a more seamless integration of social prescribing into existing care, improve collaboration among sectors and training programs for health and social care professionals.

Skill-Mix Changes Targeting Health Promotion and Prevention Interventions and Effects on Outcomes in all Settings (Except Hospitals): Overview of Reviews

Objectives: Skill-mix changes to step up health promotion and prevention are increasing, but there is limited evidence on their effects. Methods: Overview of reviews, based on a protocol. The search was carried out in six databases, screening was performed ensuring high interrater reliability. All countries, health professions and lay workers in all settings (except hospitals) were included, quality appraisals performed. Results: A total of 31 systematic reviews were included. Expanded roles performing outreach (e.g., home visits) had mostly positive effects on access and health outcomes, primarily for hard-to-reach groups. Task-shifting in colorectal or skin cancer screenings (performed by advanced practice nurses) were suggested effective; supporting roles (by community health workers) increased uptake in screenings, but based on limited evidence. Expanded roles of various professions focusing on lifestyle modification showed promising effects in most reviews, including weight, diet, smoking cessation and physical activity. Reviews on cost-effectiveness were based on limited evidence. Conclusion: Promising skill-mix changes included expanded roles providing lifestyle modifying interventions, task-shifting, and outreach roles for hard-to-reach groups, whereas evidence on costs was limited.

Work like a Doc: A comparison of regulations on residents' working hours in 14 high-income countries

BACKGROUND

Medical residents work long, continuous hours. Working in conditions of extreme fatigue has adverse effects on the quality and safety of care, and on residents' quality of life. Many countries have attempted to regulate residents' work hours.

OBJECTIVES

We aimed to review residents' work hours regulations in different countries with an emphasis on night shifts.

METHODS

Standardized qualitative data on residents' working hours were collected with the assistance of experts from 14 high-income countries through a questionnaire. An international comparative analysis was performed.

RESULTS

All countries reviewed limit the weekly working hours; North-American countries limit to 60-80 h, European countries limit to 48 h. In most countries, residents work 24 or 26 consecutive hours, but the number of long overnight shifts varies, ranging from two to ten. Many European countries face difficulties in complying with the weekly hour limit and allow opt-out contracts to exceed it.

CONCLUSIONS

In the countries analyzed, residents still work long hours. Attempts to limit the shift length or the weekly working hours resulted in modest improvements in residents' quality of life with mixed effects on quality of care and residents' education.

Can healthy ageing moderate the effects of population ageing on economic growth and health spending trends in Mongolia? A modelling study

BACKGROUND

 Population ageing will accelerate rapidly in Mongolia in the coming decades. We explore whether this is likely to have deleterious effects on economic growth and health spending trends and whether any adverse consequences might be moderated by ensuring better health among the older population.

METHODS

 Fixed-effects models are used to estimate the relationship between the size of the older working-age population (55-69 years) and economic growth from 2020 to 2100 and to simulate how growth is modified by better health among the older working-age population, as measured by a 5% improvement in years lived with disability. We next use 2017 data on per capita health spending by age from the National Health Insurance Fund to project how population ageing will influence public health spending from 2020 to 2060 and how this relationship may change if the older population (≥ 60 years) ages in better or worse health than currently.

RESULTS

 The projected increase in the share of the population aged 55-69 years is associated with a 4.1% slowdown in per-person gross domestic product (GDP) growth between 2020 and 2050 and a 5.2% slowdown from 2020 to 2100. However, a 5% reduction in disability rates among the older population offsets these effects and adds around 0.2% to annual per-person GDP growth in 2020, rising to nearly 0.4% per year by 2080. Baseline projections indicate that population ageing will increase public health spending as a share of GDP by 1.35 percentage points from 2020 to 2060; this will occur slowly, adding approximately 0.03 percentage points to the share of GDP annually. Poorer health among the older population (aged ≥ 60 years) would see population ageing add an additional 0.17 percentage points above baseline estimates, but healthy ageing would lower baseline projections by 0.18 percentage points, corresponding to potential savings of just over US$ 46 million per year by 2060.

CONCLUSIONS

 Good health at older ages could moderate the potentially negative effects of population ageing on economic growth and health spending trends in Mongolia. Continued investment in the health of older people will improve quality of life, while also enhancing the sustainability of public budgets.

Practical application of international recommendations and safety standards in the systematic planning and implementation of remediation of sites or areas with residual radioactive material

The IAEA fundamental safety objective is'to protect people and the environment from harmful effects of ionizing radiation'and this must be done 'without unduly limiting the operation of facilities or the conduct of activities that give rise to radiation risks', while ensuring that people and the environment, present and future are protected against radiation risks (IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). In addition,'protective actions to reduce existing or unregulated radiation risks must be justified and optimized'(IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). An international system of radiological protection can be applied such that processes, such as remediation, can be systematically undertaken to address the wide range of'existing exposure situations'present globally. In doing so, decisions made regarding actions undertaken can be demonstrated to be'justified'and'optimized'(i.e. balanced), such that the amount of effort should be commensurate with the risk (applying a'graded approach'). In addition, protection of people and the environment can be demonstrated by comparing the actual exposure to appropriate criteria over the lifetime of remediation. This paper provides an overview of the current IAEA safety standards on remediation of sites or areas contaminated with residual radioactive material within the international system of radiological protection and provides practical examples of their application through case studies considered in IAEA international model validation programs.

Why are "suboptimal" temperatures preferred in a tropical intertidal ectotherm?

In thermally extreme environments it is challenging for organisms to maximize performance due to risks associated with stochastic variation in temperature and, subsequently, over evolutionary time minimizing the exposure to risk can serve as one of the mechanisms that result in organisms preferring suboptimal temperatures. We tested this hypothesis in a slow-moving intertidal snail on tropical rocky shores, where temperature variability increases with time from 30 min to 20 h when recorded at 30 min intervals (due to short-term environmental autocorrelation where temperatures closer in time are more similar as compared to temperatures over a long period of time). Failure to accommodate temporal variation in thermal stress by selecting cool habitats can result in mortality. Thermal performance curves for different traits (heart rate and locomotion) were measured and compared to the snail's thermal preferences in both the field and laboratory. Predicted performances of the snails were simulated based on thermal performance curves for different traits over multiple time scales and simulated carryover effects. A strong mismatch was found between physiological and behavioural thermal maxima of the snails (physiological thermal maximum being higher by ~ 7 °C), but the snails avoided these maxima and sought temperatures 7 - 14 °C cooler. Such a risk-averse strategy can be explained by their predicted performances where the snails should make decisions about preferred temperatures based on time periods ≥ 5 h to avoid underestimating the temporal variation in body temperature. In extreme and stochastic environments, where the temporal variation in environmental conditions can lead to substantial divergence between instantaneous and time-averaged thermal performances, "cooler is better" and "suboptimal" body temperatures are preferred as they provide sufficient buffer to reduce mortality risk from heat stress.

The role of patient navigators in ambulatory care: overview of systematic reviews

BACKGROUND

Patient navigators have been introduced across various countries to enable timely access to healthcare services and to ensure completion of diagnosis and follow-up of care. There is an increasing evidence on the the role of patient navigation for patients and healthcare systems. The aim of this study was to analyse the evidence on patient navigation interventions in ambulatory care and to evaluate their effects on individuals and health system outcomes.

METHODS

An overview of reviews was conducted, following a prespecified protocol. All patients in ambulatory care or transitional care setting were included in this review as long as it was related to the role of patient navigators. The study analysed patient navigators covering a wide range of health professionals such as physicians, nurses, pharmacists, social workers and lay health workers or community-based workers with no or very limited training. Studies including patient-related measures and health system-related outcomes were eligible for inclusion. A rigorous search was performed in multiple data bases. After reaching a high inter-rater agreement of 0.86, title and abstract screening was independently performed. Of an initial 14,248 search results and an additional 62 articles identified through the snowballing approach, a total of 7159 hits were eligible for title/abstract screening. 679  articles were included for full-text screening.

RESULTS

Eleven systematic reviews were included covering various patient navigation intervention in cancer care, disease screening, transitional care and for various chronic conditions and multimorbidity. Nine systematic reviews primarily tailored services to ethnic minorities or other disadvantaged groups. Patient navigators performed tasks such as providing education and counselling, translations, home visits, outreach, scheduling of appointments and follow-up. Eight reviews identified positive outcomes in expanding access to care, in particular for vulnerable patient groups. Two reviews on patient navigation in transitional care reported improved patient outcomes, hospital readmission rates and mixed evidence on quality of life and emergency department visits. Two reviews demonstrated improved patient outcomes for persons with various chronic conditions and multimorbidity.

CONCLUSIONS

Patient navigators were shown to expand access to screenings and health services for vulnerable patients or population groups with chronic conditions who tend to underuse health services.

European countries' responses in ensuring sufficient physical infrastructure and workforce capacity during the first COVID-19 wave

The COVID-19 pandemic has placed unprecedented pressure on health systems’ capacities. These capacities include physical infrastructure, such as bed capacities and medical equipment, and healthcare professionals. Based on information extracted from the COVID-19 Health System Reform Monitor, this paper analyses the strategies that 45 countries in Europe have taken to secure sufficient health care infrastructure and workforce capacities to tackle the crisis, focusing on the hospital sector. While pre-crisis capacities differed across countries, some strategies to boost surge capacity were very similar. All countries designated COVID-19 units and expanded hospital and ICU capacities. Additional staff were mobilised and the existing health workforce was redeployed to respond to the surge in demand for care. While procurement of personal protective equipment at the international and national levels proved difficult at the beginning due to global shortages, countries found innovative solutions to increase internal production and enacted temporary measures to mitigate shortages. The pandemic has shown that coordination mechanisms informed by real-time monitoring of available health care resources are a prerequisite for adaptive surge capacity in public health crises, and that closer cooperation between countries is essential to build resilient responses to COVID-19.

A comparison of 2020 health policy responses to the COVID-19 pandemic in Canada, Ireland, the United Kingdom and the United States of America

This paper compares health policy responses to COVID-19 in Canada, Ireland, the United Kingdom and United States of America (US) from January to November 2020, with the aim of facilitating cross-country learning. Evidence is taken from the COVID-19 Health System Response Monitor, a joint initiative of the European Observatory on Health Systems and Policies, the WHO Regional Office for Europe, and the European Commission, which has documented country responses to COVID-19 using a structured template completed by country experts. We show all countries faced common challenges during the pandemic, including difficulties in scaling-up testing capacity, implementing timely and appropriate containment measures amid much uncertainty and overcoming shortages of health and social care workers, personal protective equipment and other medical technologies. Country responses to address these issues were similar in many ways, but dissimilar in others, reflecting differences in health system organization and financing, political leadership and governance structures. In the US, lack of universal health coverage have created barriers to accessing care, while political pushback against scientific leadership has likely undermined the crisis response. Our findings highlight the importance of consistent messaging and alignment between health experts and political leadership to increase the level of compliance with public health measures, alongside the need to invest in health infrastructure and training and retaining an adequate domestic health workforce. Building on innovations in care delivery seen during the pandemic, including increased use of digital technology, can also help inform development of more resilient health systems longer-term.

Health professional mobility in the WHO European Region and the WHO Global Code of Practice: data from the joint OECD/EUROSTAT/WHO-Europe questionnaire

WHO Member States adopted the Global Code of Practice on the International Recruitment of Health Personnel 10 years ago. This study assesses adherence with the Code’s principles and its continuing relevance in the WHO Europe region with regards to international recruitment of health workers. Data from the joint OECD/EUROSTAT/WHO-Europe questionnaire from 2010 to 2018 are analyzed to determine trends in intra- and inter-regional mobility of foreign-trained doctors and nurses working in case study destination countries in Europe. In 2018, foreign-trained doctors and nurses comprised over a quarter of the physician workforce and 5% of the nursing workforce in five of eight and four of five case study countries, respectively. Since 2010, the proportion of foreign-trained nurses and doctors has risen faster than domestically trained professionals, with increased mobility driven by rising East-West and South-North intra-European migration, especially within the European Union. The number of nurses trained in developing countries but practising in case study countries declined by 26%. Although the number of doctors increased by 27%, this was driven by arrivals from countries experiencing conflict and volatility, suggesting countries generally are increasingly adhering to the Code’s principles on ethical recruitment. To support ethical recruitment practices and sustainable workforce development in the region, data collection and monitoring on health worker mobility should be improved.

Effects of dietary supplementation with vitamin E, selenium yeast or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowl breeders

This study investigated the effects of dietary supplementation with vitamin E (vit. E), selenium yeast (Se yeast), or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowls. Two hundred and forty 24-week old helmeted guinea fowl hens (average weight 1.75 + 0.22 kg) and cocks (average weight 2.15 + 0.20 kg) were assigned into 24 pens; each pen housed 10 hens and 2 cocks. There were four dietary treatments consisting of a basal diet (control), basal diet supplemented with vit. E (30 IU/kg), Se yeast (0.3 mg/kg Se), or both. Six pens were assigned to each treatment. Egg incubation response were estimated using 504 settable eggs sampled from each treatment collected during 15 to 17 weeks in lay. A total of 72 fertile eggs sampled from each treatment were used for the estimation of embryonic development. Quality of day-old keets hatched was scored based on physical conditions, while posthatch growth was measured for 21 days. Guinea fowl breeders fed diet supplemented with both vit. E and Se yeast produced the highest (P < 0.05) number of fertile eggs, percentage fertility, number of hatchlings, hatchability of total eggs, and hatchability of fertile eggs. Supplementation with vit. E + Se yeast resulted in the heaviest (P < 0.05) embryo weight, relative embryo weight, least (P < 0.05) yolk sac weight, and relative yolk sac weight on 25 days of incubation. Hatchlings from breeders fed diet supplemented with Se yeast and vit. E + Se yeast showed normal swallowed yolk. Supplementation of maternal diet with vit. E, Se yeast, and vit. E + Se yeast resulted in improved (P < 0.05) feed conversion ratio of subsequent hatchlings during 1 to 7-day posthatch growth. It can be concluded that dietary supplementation of vit. E + Se yeast in guinea fowl breeders resulted in improved egg fertility, hatchability, heavier embryo weights, hatchlings of good quality, and improved posthatch growth during the first 7 days.

Preferred temperature of intertidal ectotherms: Broad patterns and methodological approaches

Preferred temperature (Tpref) has been measured in over 100 species of aquatic and 300 species of terrestrial ectotherms as a metric for assessing behavioural thermoregulation in variable environments and, as such, has been linked to ecological processes ranging from individual behaviour to population and community dynamics. Due to the asymmetric shape of performance curves, Tpref is typically lower than the optimal temperature (Topt, where physiological performance is at its peak), and the degree of this mismatch increases with variability in Tb. Intertidal ectotherms experience huge variability in Tb on a daily basis and therefore provide a good system to test whether the relationship between Tpref and variation in Tb holds in more extreme environments. A review of the literature, however, only revealed comparisons between Tpref and Topt for five intertidal species and measurements of Tpref for 23 species. An analysis of this limited literature for intertidal ectotherms showed a positive relationship between acclimation temperature and Tpref. There was, however, great variation in the methodologies employed to make these assessments. Factors contributing to behavioural thermoregulation in intertidal ectotherms including small body size; low mobility; interactions among individuals; endogenous clocks; metabolic effects; thermal sensitivity; sampling of the thermal environment and recent acclimation history were considered to varying degrees when measuring Tpref, confounding comparisons between species. The methodologies used to measure Tpref in intertidal ectotherms were reviewed in light of each of these factors, and methodologies proposed to standardize approaches. Given the theoretical predictions about the relationships between Tpref and variability in Tb, the spatial and temporal thermal variability experienced by intertidal ectotherms provides numerous opportunities to test these expectations if assessed in a standardized manner, and can potentially provide insights into the value of behavioural thermoregulation in the more thermally variable environments predicted to occur in the near future.

Equitable access to health insurance for socially excluded children? The case of the National Health Insurance Scheme (NHIS) in Ghana

To help reduce child mortality and reach universal health coverage, Ghana extended free membership of the National Health Insurance Scheme (NHIS) to children (under-18s) in 2008. However, despite the introduction of premium waivers, a substantial proportion of children remain uninsured. Thus far, few studies have explored why enrolment of children in NHIS may remain low, despite the absence of significant financial barriers to membership. In this paper we therefore look beyond economic explanations of access to health insurance to explore additional wider determinants of enrolment in the NHIS. In particular, we investigate whether social exclusion, as measured through a sociocultural, political and economic lens, can explain poor enrolment rates of children. Data were collected from a cross-sectional survey of 4050 representative households conducted in Ghana in 2012. Household indices were created to measure sociocultural, political and economic exclusion, and logistic regressions were conducted to study determinants of enrolment at the individual and household levels. Our results indicate that socioculturally, economically and politically excluded children are less likely to enrol in the NHIS. Furthermore, households excluded in all dimensions were more likely to be non-enrolled or partially-enrolled (i.e. not all children enrolled within the household) than fully-enrolled. These results suggest that equity in access for socially excluded children has not yet been achieved. Efforts should be taken to improve coverage by removing the remaining small, annually renewable registration fee, implementing and publicising the new clause that de-links premium waivers from parental membership, establishing additional scheme administrative offices in remote areas, holding regular registration sessions in schools and conducting outreach sessions and providing registration support to female guardians of children. Ensuring equitable access to NHIS will contribute substantially to improving child health and reducing child mortality in Ghana.

ESTIMATES OF RADIATION DOSES TO THE SKIN FOR PEOPLE CAMPED AT WALLATINNA DURING THE UK TOTEM 1 ATOMIC WEAPONS TEST

A group of Aboriginal people was camped at Wallatinna in South Australia, ~170 km downwind from Emu Field, where an atomic test (the Totem 1 test) was carried out at 07.00 on 15 October 1953 local time (21.30 on 14 October 1953 GMT (Greenwich Mean Time)). They left the camp ~24 hours later. These people stated that a phenomenon that has become known as a 'black mist' rolled through their camp site ~5 hours after detonation and that some of them subsequently became sick, displaying skin reddening and nausea. They feared that the sickness was a result of exposure to high levels of radiation. The purpose of this paper is to determine if these people could have received ionising radiation doses high enough to cause the symptoms displayed. The methodology used for the dose estimates is described in the paper. The exposure modes considered were external exposure due to the passage of a contaminated plume over the camp site, inhalation of material from this plume, external exposure from material deposited on the ground as the plume passed, and consumption of contaminated food and water. The contaminants considered in the airborne cloud and the ground plume were fission products and unburnt plutonium from the nuclear detonation, and neutron activation products caused by vaporisation of the tower used to position the weapon. The source was approximated by a line source. An upper estimate of the effective doses received is ~4 mSv, which is well below the level at which acute radiation effects are observed. This estimate is consistent with earlier assessments, which did not consider inhalation of the contribution from neutron activation products.

Measles among migrants in the European Union and the European Economic Area

Aims: Progress towards meeting the goal of measles elimination in the EU and the European Economic Area (EEA) by 2015 is being obstructed, as some children are either not immunized on time or never immunized. One group thought to be at increased risk of measles is migrants; however, the extent to which this is the case is poorly understood, due to a lack of data. This paper addresses this evidence gap by providing an overview of the burden of measles in migrant populations in the EU/EEA. Methods: Data were collected through a comprehensive literature review, a country survey of EU/EEA member states and information from measles experts gathered at an infectious disease workshop. Results: Our results showed incomplete data on measles in migrant populations, as national surveillance systems do not systematically record migration-specific information; however, evidence from the literature review and country survey suggested that some measles outbreaks in the EU/EEA were due to sub-optimal vaccination coverage in migrant populations. Conclusions: We conclude that it is essential that routine surveillance of measles cases and measles, mumps and rubella (MMR) vaccination coverage become strengthened, to capture migrant-specific data. These data can help to inform the provision of preventive services, which may need to reach out to vulnerable migrant populations that currently face barriers in accessing routine immunization and health services.

Relationship between macular hole size and the potential benefit of internal limiting membrane peeling

Macular hole size is a predictor for anatomical closure. Holes >400 μm in aperture size on an OCT scan are more likely to close when ILM is peeled

Safety profile of the intravitreal streptokinase-plasmin complex as an adjunct to vitrectomy in the rabbit

BACKGROUND

The generation of an atraumatic posterior vitreous detachment (PVD), a common goal in vitreoretinal surgery, is a challenge, particularly in children and young trauma patients. Plasmin has been proposed as an adjunct to vitrectomy to enzymatically generate a PVD. Low doses of streptokinase-activated plasmin were tested in human pilot studies. This dose-escalation study assesses the safety range of intravitreal human streptokinase-plasmin in rabbits.

METHODS

Plasminogen was isolated from human plasma by affinity chromatography, followed by activation with streptokinase (1:1), to generate the streptokinase-plasmin complex. Enzyme doses from 0.1-7 activity units (AU, in 0.1 ml) were injected into the mid-vitreous of 35 eyes; six control eyes were injected with balanced salt solution (BSS, 0.1 ml). Thirty minutes after injection, a two-port vitrectomy was performed. Fundus and slit lamp examinations were performed on days 1 and 7. On days 2 and 7, bright flash electroretinography was performed and compared with preoperative recordings. Some animals receiving higher doses of streptokinase-plasmin (1-7 AU) were followed clinically and with electroretinography for up to 9 months.

RESULTS

A mild-to-moderate inflammatory response was seen in both control and plasmin-treated eyes on day 1, but had disappeared completely by day 7 in most eyes. In the 7 AU group, inflammation was stronger and more protracted. Two of three eyes from this group developed wrinkling of the medullary rays; one of them showed discoloration and traction at the medullary rays in the late follow-up. Electroretinograms (ERGs) of vitrectomized control eyes showed the following changes from preoperative values: 48 h, a-wave -11.10% [no significant (n.s.)], b-wave -14.62% (P=0.046); 7 days, a-wave +9.18% (n.s.), b wave +11.69% (n.s.). For the enzyme-treated eyes: 48 h: a-wave -20.43% (P<0.001), b-wave -9.57% (p<0.001); 7 days: a wave -14.21% (P<0.001), b-wave +2.48% (P<0.001). There was no evidence of dose-dependent ERG changes in enzyme-treated eyes at doses up to 5 AU. Groups of up to 3 AU were investigated by light and transmission electron microscopy, without evidence of toxicity.

CONCLUSION

Streptokinase-plasmin doses up to 3 AU were found to be safe when injected into rabbit eyes followed by vitrectomy.

Indocyanine green mediated photothrombosis for the management of predominantly classic choroidal neovascularisation caused by age related macular degeneration

AIMS

To study the effectiveness of indocyanine green mediated photothrombosis in the management of predominantly classic subfoveal choroidal neovascularisation associated with age related macular degeneration.

METHODS

Prospective, non-comparative, interventional case series of nine patients with predominantly classic subfoveal choroidal neovascularisation secondary to age related macular degeneration who declined photocoagulation or verteporfin photodynamic therapy. Patients were submitted to one or more treatments with an intravenous injection of a small volume of high concentration indocyanine green solution followed by low irradiance, large spot 810 nm continuous laser application via a transpupillary approach. Main outcome measures were change in best corrected visual acuity and macular exudative manifestations.

RESULTS

After 12 months of follow up, the final best corrected visual acuity was the same (plus or minus two ETDRS lines) in five eyes (55%), improved more than two ETDRS lines in three eyes (33%), and worsened by more than two lines in the remaining eye. The improved vision was probably related to partial or complete restoration of the macular architecture as a result of fluid resolution, whereas the worsened vision was primarily the result of treatment failure in achieving substantial choroidal neovascular occlusion. There were no complications related to the procedure.

CONCLUSION

Indocyanine green mediated photothrombosis may be an effective alternative treatment for predominantly classic subfoveal choroidal neovascularisation caused by age related macular degeneration.

Different cardiac response to copper in limpets from metal polluted and clean shores of Hong Kong

The gastropod limpet, Cellana grata, is common on moderately exposed to exposed Hong Kong rocky shores. On the basis of the existing literature on trace metal contamination in Hong Kong, four sites were identified, representative of highly polluted (Aberdeen and Lei Yue Mun) and clean (Cape d'Aguilar and Clear Water Bay) conditions. Limpets from the two polluted sites showed similar, but significantly higher body concentrations of copper than limpets from the two clean sites, which were also similar. Non-invasive measurements of cardiac activity of limpets from the four sites showed between site differences in baseline heart rates under standard seawater, irrespective of pollution level. When acutely exposed to water borne copper (2 h, 0.5+/-0.06 SD ppm), however, limpets from clean sites showed a significantly higher increase in inter-beating time (bradycardia) than those from polluted sites. These results highlight the potential use of cardiac activity to assess the exposure of natural populations of limpets to trace metal pollution.

Visual adaptations in a diurnal rodent, Octodon degus

The degu (Octodon degus) is a diurnal rodent, native to Chile. Basic features of vision and visual organization in this species were examined in a series of anatomical, electrophysiological and behavioral experiments. The lens of the degu eye selectively absorbs short-wavelength light and shows a progressive increase in optical density as a function of age. Electroretinograms recorded using a flicker-photometric procedure reveal three spectral mechanisms: a rod with peak sensitivity of about 500 nm and two types of cone having respective spectral peaks of about 362 nm and 507 nm. Opsin antibody labeling was used to determine the retinal distributions of the three receptor types. A total of about one-third of the approximately 9 million photoreceptors of the degu retina are cones with the two types (507 nm/362 nm) represented in a ratio of about 13:1. The contributions to vision of all three receptor types were examined in a series of behavioral experiments. A consistent feature of both the electrophysiological and behavioral results is that relatively high levels of light adaptation are required to effect the full transition from rod-based to cone-based vision. In behavioral tests degus were shown to be able to make color discriminations between ultraviolet and visible lights.

Constrained global optimization for estimating molecular structure from atomic distances

Finding optimal three-dimensional molecular configurations based on a limited amount of experimental and/or theoretical data requires efficient nonlinear optimization algorithms. Optimization methods must be able to find atomic configurations that are close to the absolute, or global, minimum error and also satisfy known physical constraints such as minimum separation distances between atoms (based on van der Waals interactions). The most difficult obstacles in these types of problems are that 1) using a limited amount of input data leads to many possible local optima and 2) introducing physical constraints, such as minimum separation distances, helps to limit the search space but often makes convergence to a global minimum more difficult. We introduce a constrained global optimization algorithm that is robust and efficient in yielding near-optimal three-dimensional configurations that are guaranteed to satisfy known separation constraints. The algorithm uses an atom-based approach that reduces the dimensionality and allows for tractable enforcement of constraints while maintaining good global convergence properties. We evaluate the new optimization algorithm using synthetic data from the yeast phenylalanine tRNA and several proteins, all with known crystal structure taken from the Protein Data Bank. We compare the results to commonly applied optimization methods, such as distance geometry, simulated annealing, continuation, and smoothing. We show that compared to other optimization approaches, our algorithm is able combine sparse input data with physical constraints in an efficient manner to yield structures with lower root mean squared deviation.

Incidence of retinal detachment and visual outcome in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage

PURPOSE

To determine visual outcomes and the incidence of retinal detachment in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage.

DESIGN

Retrospective consecutive noncomparative interventional case series.

PARTICIPANTS

Thirty-six eyes (15 right eyes and 21 left eyes) of 34 patients (18 female and 16 male) ranging in age from 42 to 94 years. Mean follow-up was 14 months.

METHODS

A comparison of the best-corrected initial visual acuities versus final visual acuities after spontaneous resolution of vitreous hemorrhage or surgical intervention. The number of eyes that were found to have retinal tears or that had a rhegmatogenous retinal detachment develop was documented. Logarithm of the minimum angle of resolution-converted visual acuities was used for comparison. Categorical data were analyzed by Fisher's exact test, and population means were compared by Student's t test.

MAIN OUTCOME MEASURES

Final mean visual acuities, number of eyes with at least one retinal tear, location of retinal tears, number of eyes that had retinal detachment develop, and the number of eyes repaired with scleral buckling surgery and/or pars plana vitrectomy.

RESULTS

Twenty-four of 36 eyes (67%) were found to have at least one retinal break (range, 0-4 breaks), with 88% of breaks located in the superior retina. Eleven eyes (31%) had more than one retinal break. Fourteen of 36 eyes (39%) had a rhegmatogenous retinal detachment develop that was repaired with pars plana vitrectomy and scleral buckling. An additional 14 eyes (39%) underwent vitrectomy for nonclearing vitreous hemorrhage. The incidence of retinal detachment in eyes with a history of retinal detachment in the contralateral eye was 75% (P = 0.04). Seven of 14 eyes (50%) with retinal detachment had coexisting proliferative vitreoretinopathy. Most retinal breaks and detachments occurred in emmetropic or myopic eyes. For all 36 eyes the mean preoperative visual acuity was 20/1233, and the mean final visual acuity was 20/62 (P < 0.0001). Eyes that had a macula-off retinal detachment develop had worse final visual outcomes (20/264; P = 0.01), as did eyes that had proliferative vitreoretinopathy develop (20/129; P = 0.04).

CONCLUSIONS

Acute, spontaneous, nontraumatic posterior vitreous separation with dense fundus-obscuring vitreous hemorrhage is associated with a high incidence of retinal tears and detachment. Close follow-up with clinical examination and ultrasonography is necessary, because many of these eyes may eventually require surgical intervention. Aggressive management with early vitrectomy should be considered when there is a history of retinal detachment in the contralateral eye.

Presumed acquired ocular toxoplasmosis in deer hunters

PURPOSE

To describe acquired ocular toxoplasmosis in deer hunters.

METHODS AND RESULTS

The authors describe five young men presenting with flu-like symptoms followed by visual loss due to a unilateral, focal necrotizing retinitis. All five men gave a history of ingesting undercooked or uncooked venison. All five had elevated toxoplasma serology, and all five improved clinically with an antitoxoplasma regimen.

CONCLUSION

In previously healthy young men, flu-like symptoms associated with visual loss and retinitis should prompt questioning about hunting and raw game meat ingestion, especially when toxoplasmosis is suspected.

Autologous plasmin enzyme in the surgical management of diabetic retinopathy

PURPOSE

This is a pilot study to assess the use of autologous plasmin enzyme (APE) as an adjunct to vitreous surgery in eyes with advanced diabetic retinopathy.

DESIGN

Prospective noncomparative interventional case series.

PARTICIPANTS

Seven patients with advanced diabetic retinopathy selected at random from our practice population.

METHODS

Seven eyes were treated with APE as an adjunct to standard vitreous surgery. Six eyes had macular tractional retinal detachments, and one eye had refractory macular edema. Three fellow eyes had standard vitreous surgery performed for macular tractional retinal detachments without APE. All 10 eyes had macular edema and background diabetic retinopathy.

MAIN OUTCOME MEASURES

The main outcome measures included induction of a posterior vitreous detachment, retinal reattachment, improvement in visual acuity, and resolution of macular edema.

RESULTS

All seven APE-treated eyes achieved spontaneous or easy removal of the posterior hyaloid including one eye that had vitreoschisis over areas of detached retina. All eyes treated with APE had resolution of intraretinal edema. Retinas of all eyes treated with APE were reattached. The three fellow eyes were treated by vitreous surgery without APE. Two of the three fellow eyes had reattached retinas, but none had resolution of intraretinal edema without further focal photocoagulation treatment. Mean visual acuity improvement was 0.7 logarithm of the minimum angle of resolution (LogMAR) units in APE-treated eyes and 0.1 LogMAR units in eyes without APE. The average follow-up period was 14 months.

CONCLUSIONS

This pilot study suggests that APE may be beneficial in the surgical management of diabetic retinopathy.

Adult retinopathy of prematurity: outcomes of rhegmatogenous retinal detachments and retinal tears

PURPOSE

To describe the results of retinal tears and rhegmatogenous retinal detachments (RD) in adults with retinopathy of prematurity (ROP).

DESIGN

Noncomparitive interventional case series.

METHODS

Retrospective cohort of 216 eyes of 108 patients, 15 years or older, followed for up to 23 years (median, 6.2 years).

RESULTS

One eye was initially seen with an RD, and during follow-up 30 eyes had an RD develop. An additional surgical procedure was required in 7 of the 31 eyes (23%) with an RD. Four eyes were initially seen with retinal tears, and during follow-up 19 eyes had a retinal tear develop. Seven of the 23 eyes (30%) with a retinal tear had initial repair fail. Eyes with minimal cicatricial changes from ROP were still at high risk for tears and detachments developing. Eighty percent of eyes with retinal tears and 60% of eyes with an RD that started with vision >20/60 maintained that level of vision at the final examination.

CONCLUSION

In patients with a history of premature birth, features of fundus examinations do not correlate with the occurrence of a retinal tear or RD. Repair of a tear or detachment in such a patient is more likely to require multiple procedures but can still be associated with good visual results. Physicians should consider widespread relief of vitreoretinal traction for a tear or detachment in any patient with a history of premature birth.

Sympathetic ophthalmia associated with pars plana vitrectomy without antecedent penetrating trauma

PURPOSE

To evaluate, describe, and categorize the clinical presentation, clinical course, histopathology, and response to therapy in patients without a history of penetrating ocular trauma who developed sympathetic ophthalmia following pars plana vitrectomy.

METHODS

The records of patients without a history of trauma who underwent pars plana vitrectomy and developed sympathetic ophthalmia were retrospectively reviewed. Cases were analyzed with respect to clinical presentation, fluorescein angiographic findings, anatomic and visual outcomes, histopathology, and response to therapy.

RESULTS

Eight eyes were identified. The median age at presentation was 55 years, with a range of 14 to 62 years. The time from vitrectomy to diagnosis of sympathetic ophthalmia ranged from 2 months to greater than 2 years, with a median of 7 months. Six of eight patients (75%) presented with anterior chamber reaction. All eight patients presented with a vitreous inflammatory response. The optic nerve was inflamed clinically or angiographically in four of eight cases (50%). Small yellow-white sub-retinal pigment epithelial deposits were present in four of eight cases (50%). Two eyes had lesions characterized as multifocal choroiditis. One eye had larger yellow placoid-like lesions. One eye presented with vitritis but no retinal lesions. Subretinal choroidal neovascularization was noted in the inciting eye of one patient. Vision improved in the sympathizing eye with immunosuppressive therapy in five of eight cases (62.5%).

CONCLUSIONS

Sympathetic ophthalmia can be seen following pars plana vitrectomy in patients without penetrating injuries or a history of trauma. Indeed, it may be seen after successful vitrectomy for retinal detachment. Diverse clinical presentations are possible, and persistent or atypical uveitis following vitrectomy should alert the surgeon to the development of sympathetic ophthalmia.

Catalase-like oxygen production by horseradish peroxidase must predominantly be an enzyme-catalyzed reaction

When hydrogen peroxide (H2O2) was provided as the only substrate for horseradish peroxidase C (HRP-C) the catalase-like emission of oxygen gas was observed. The reaction was favored at neutral compared to acidic pH. Addition of the superoxide radical scavengers tetranitromethane (TNM) or superoxide dismutase (SOD) increased activity. TNM's effect was concentration dependent but SOD's was not, indicating that only some of the superoxide generated was released into solution. Manganous ions (Mn2+) react with superoxide radicals to regenerate H2O2 but not oxygen; when added to the reaction medium oxygen production was reduced but not abolished. The effect was essentially concentration independent, suggesting that most oxygen was produced enzymatically and not by chemical disproportionation of superoxide. The catalase-like activities of some site-directed mutants of HRP-C suggest that active site residues histidine 42 and arginine 38 are influential in determining this activity. A clear correlation also existed between catalase activity and the enzymes' resistance to inactivation by H2O2. Computer simulation of a reaction scheme that included catalase-like activity agreed well with experimental data.

Cone-based vision of rats for ultraviolet and visible lights

Rats (Rattus norvegicus) have two classes of cone, one containing an ultraviolet (UV)-sensitive photopigment and the other housing a pigment maximally sensitive in the middle (M) wavelengths of the visible spectrum. The manner in which signals from these two cone types contribute to rat vision was investigated through recordings of a gross electrical potential (the electroretinogram, ERG) and behavioral discrimination tests. Spectral sensitivity functions obtained from both types of measurement indicate clear contributions from each of the cone classes, but there is a marked enhancement of the relative sensitivity to UV light in the behavioral index; for instance, under some photopic test conditions, rats are approximately equally sensitive to middle-wavelength and UV lights. In adaptation tests, thresholds for UV and M lights were found to be differentially elevated in the presence of chromatic adapting backgrounds, thus providing the possibility that signals from the two cones could be used by the rat visual system to support color discriminations. Evidence of dichromatic color vision in the rat was subsequently obtained from tests of wavelength discrimination.

Surgical management of macular holes: a report by the American Academy of Ophthalmology

OBJECTIVE

The document describes macular hole surgery and examines the available evidence to address questions about the efficacy of the procedure for different stages of macular hole, complications during and after surgery, and modifications to the technique.

METHODS

A literature search conducted for the years 1968 to 2000 retrieved over 400 citations that matched the search criteria. This information was reviewed by panel members and a methodologist, and it was evaluated for the quality of the evidence presented.

RESULTS

There are three multicenter, controlled, randomized trials that constitute Level I evidence and compare the value of surgery versus observation for macular hole. There are three multicenter, controlled, randomized trials studying the use of adjuvant therapy in macular hole repair. Postoperative vision of 20/40 or better has been reported in 22% to 49% of patients in randomized trials. The risks of surgical complications include retinal detachment (3%), endophthalmitis (<1%), cataract (>75%), and late reopening the hole (2% to 10%).

CONCLUSIONS

The evidence does not support surgery for patients with stage 1 holes. Level I evidence supports surgery for stage 2 holes to prevent progression to later stages of the disease and further visual loss. Level I evidence shows that surgery improves the vision in a majority of patients with stage 3 and stage 4 holes. There is no strong evidence that adjuvant therapy used at the time of surgery results in improved surgical outcomes. Patient inconvenience, patient preference, and quality of life issues have not been studied.

Using meta computing tools to facilitate large-scale analyses of biological databases

Given the high rate at which biological data are being collected and made public, it is essential that computational tools be developed that are capable of efficiently accessing and analyzing these data. High-performance distributed computing resources can play a key role in enabling large-scale analyses of biological databases. We use a distributed computing environment, Legion, to enable large-scale computations on the Protein Data Bank (PDB). In particular, we employ the Feature program to scan all protein structures in the PDB in search for unrecognized potential cation binding sites. We evaluate the efficiency of Legion's parallel execution capabilities and analyze the initial biological implications that result from having a site annotation scan of the entire PDB. We discuss four interesting proteins with unannotated, high-scoring candidate cation binding sites.

Spectrum of luminescence from laser-created bubbles in water

The spectrum of the luminescence emitted at the collapse of single laser-induced bubbles in water is measured for different maximum bubble radii. Bubbles as large as 2 mm show a molecular OH(*) band at 310 nm in the spectrum, which otherwise can be fitted approximately with a blackbody curve at a temperature of 7800 K. This finding provides a connection between the light emission of single bubbles and multibubble sonoluminescence, since in the latter case the same molecular band is observed. Surface instabilities are observed in the larger bubbles, and may be connected with the OH(*) emission.

Drug approval summaries: arsenic trioxide, tamoxifen citrate, anastrazole, paclitaxel, bexarotene

This report summarizes information on drugs recently approved by the Food and Drug Administration, Office of Drug Evaluation I, Division of Oncology Drug Products. Five applications supporting new claims will be discussed: Trisenox (arsenic trioxide) for induction of remission and consolidation in patients with acute promyelocytic leukemia who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose disease is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression; Nolvadex (tamoxifen citrate) in women with ductal carcinoma in situ, following breast surgery and radiation, to reduce the risk of invasive breast cancer; Arimidex (anastrazole) for first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer; Taxol (paclitaxel), 175 mg/m(2) by 3 h infusion in combination with cisplatin for first-line treatment of advanced ovarian cancer; and Targretin gel (bexarotene) for the topical treatment of cutaneous lesions in patients with stage IA and IB cutaneous T-cell lymphoma who have not tolerated other therapies or who have refractory or persistent disease. Information provided includes rationale for drug development, study design, efficacy and safety results, and pertinent literature references.

Quenched Kosterlitz-Thouless superfluid transitions

Rapidly quenched Kosterlitz-Thouless (KT) superfluid transitions are studied by solving the Fokker-Planck equation for the vortex-pair dynamics in conjunction with the KT recursion relations. Power-law decays of the vortex density at long times are found, and the results are in agreement with a scaling proposal made by Minnhagen and co-workers for the dynamical critical exponent. The superfluid density is strongly depressed after a quench, with the subsequent recovery being logarithmically slow for starting temperatures near T(KT). No evidence is found of vortices being "created" in a rapid quench; there is only decay of the existing thermal vortex pairs.

Soccer ball-related retinal injuries: a report of 13 cases

PURPOSE

To describe the clinical characteristics and management of retinal injuries caused by soccer ball impact as well as the mechanism of injury, prognostic features, risk factors, and possible prevention strategies.

METHODS

Thirteen cases of soccer ball injuries from retina referral practices were retrospectively reviewed, with attention to the mechanism of associated ocular complications and the anatomic and visual outcomes.

RESULTS

Soccer ball injuries occurred in both male and female patients (9 male, 4 female) with ages ranging from 8 to 21 years (median 14 years). These patients were observed from 0 to 64 months (median follow-up, 8 months). Four patients had traumatic macular holes, two eyes had retinal detachment associated with retinal dialysis, two had retinal tears associated with hemorrhage, one had a choroidal rupture, and one had only vitreous hemorrhage and Berlin's edema. Although six eyes had some degree of traumatic retinal pigment epitheliopathy, it was the primary diagnosis in only three. Visual acuity at presentation ranged from 20/20 to count fingers, with 7/13 (54%) having 20/200 or worse vision. Seven eyes underwent surgical procedures; the remainder were observed. Final visions ranged from 20/20 to count fingers, with 3/13 (23%) having 20/200 or worse vision. Six eyes (46%) improved by two or more lines by the last follow-up.

CONCLUSION

Soccer ball-related ocular injuries disproportionately affect young players, are more frequent in females than previously reported, and have more severe visual consequences than previously recognized. Injury prevention strategies to minimize contact between the eye and the soccer ball may reduce the incidence and severity of eye injuries.

External versus internal approach to the removal of metallic intraocular foreign bodies

OBJECTIVE

To review the management of metallic intraocular foreign bodies (IOFB) at a single institution and to compare the use of internal and external approaches for their removal.

SUBJECTS AND METHODS

A retrospective review was conducted on 70 eyes from 70 patients who underwent surgical removal of a metallic IOFB with either an internal (vitrectomy followed by forceps or internal magnet use) or external approach (large electromagnet) by seven vitreoretinal surgeons at a single institution between 1973 and 1996. Visual acuity and complications occurring with the two approaches were the main outcome measures studied.

RESULTS

Overall, patients showed significant improvement in visual acuity following surgical intervention (P < 0.001) despite widely varying surgical techniques. When the authors compared patients treated with an external versus an internal approach they found no statistically significant difference with regard to visual outcome and a trend toward a higher rate of postoperative endophthalmitis in the external approach group.

CONCLUSION

Surgical removal of metallic IOFB results in significant visual improvement. The external approach to the removal of magnetic metallic IOFB remains a viable treatment option in select cases.

Clinical course and surgical treatment of macular epiretinal membranes in young subjects

OBJECTIVE

To examine the surgical and nonsurgical visual outcomes of young subjects with idiopathic macular epiretinal membranes (ERMs).

DESIGN

Retrospective observational and noncomparative interventional case series.

PARTICIPANTS

Nineteen consecutive subjects (20 eyes) aged 40 years or less with an idiopathic macular ERM.

METHODS

Group 1: 10 consecutive eyes were initially seen with visual acuity of 20/50 or better; 7 eyes were observed, and 3 eyes with progressive visual loss to <20/50 underwent vitrectomy and membrane peeling. Group 2: 10 consecutive eyes with presenting visual acuity of 20/60 or worse underwent vitrectomy and membrane peeling.

MAIN OUTCOME MEASURES

Visual acuity, cataract formation, ERM recurrence, operative complications.

RESULTS

Group 1: With no surgery, visual acuity remained stable or improved in 5 of 10 eyes (50%), with a mean follow-up of 3.7 years. Three of 10 eyes (30%) had visual loss < or =20/60 develop and underwent vitrectomy. Postoperative visual acuity improved an average of 6 lines with a mean follow-up of 17.6 months. Group 2: After vitrectomy, visual acuity improved 2 or more lines in 7 of 10 eyes (70%), with a mean improvement of 4.4 lines and mean follow-up of 29.2 months. Groups 1 and 2: Three of 13 eyes (23%) that underwent vitrectomy had recurrent ERM formation.

CONCLUSIONS

Young subjects with idiopathic macular ERMs and a presenting visual acuity of 20/50 or better had a favorable visual outcome with observation. Subjects with an initial vision of 20/60 or worse, or those who had a visual decrease to < or =20/60 had significantly improved visual acuity after vitrectomy. ERM recurrence is relatively high after surgery.

A comparison of visual results and complications in eyes with posterior chamber intraocular lens dislocation treated with pars plana vitrectomy and lens repositioning or lens exchange

PURPOSE

To compare the visual results and the postoperative complications in eyes with posterior chamber intraocular lens (PCIOL) dislocation that underwent pars plana vitrectomy with lens repositioning with eyes that underwent pars plana vitrectomy with lens exchange.

DESIGN

Nonrandomized consecutive comparative case series.

PARTICIPANTS

Fifty-nine eyes (27 right eyes and 32 left eyes) of 56 subjects (28 women and 28 men) ranging in age from 59 to 90 years. Mean follow-up was 34 months.

METHODS

A comparison of the best-corrected preoperative visual acuities, final visual acuities, and postoperative complications in subjects with dislocated PCIOLs that underwent pars plana vitrectomy. Logarithm of the minimum angle of resolution (LogMAR)-converted visual acuities were used for comparison. Categorical data were analyzed by Fisher's exact test, and population means were compared by a pooled Student's t test.

MAIN OUTCOME MEASURES

Final mean visual acuities, change in mean visual acuities, and postoperative complications.

RESULTS

For all 59 eyes the mean preoperative visual acuity was 20/152, and the mean final visual acuity was 20/48. Final visual results were similar between the eyes that underwent lens repositioning (20/55) and the eyes that underwent lens exchange (20/43; P = 0.19). Final visual results were also similar between the eyes that underwent lens exchange with sutured PCIOL placement (20/51) and the eyes that underwent lens exchange with anterior chamber intraocular lens (ACIOL) placement (20/38; P = 0.26). Final mean visual acuity in eyes that received an ACIOL (20/38) was better than in eyes that underwent repositioning of the dislocated lens into the ciliary sulcus (20/65; P = 0.01). The mean increase in visual acuities was greater for eyes with ACIOL placement compared with eyes with sutured PCIOL placement (P = 0.01). For all eyes, final visual results were unaffected by a concurrent diagnosis of age-related macular degeneration (20/52; P: = 0.71), glaucoma (20/48; P = 0.95), or postoperative cystoid macular edema (20/55; P = 0.45). Final visual acuities were significantly worse in eyes with a detectable preoperative afferent pupillary defect (20/200; P<0.0001). Postoperative retinal detachments developed in 4 of 29 eyes (14%) that underwent lens repositioning and in 2 of 30 eyes (7%) that had lens exchange (P = 0.42). Postoperative lens subluxations occurred in 6 of 29 eyes (21%) that underwent lens repositioning and in 1 of 30 eyes (3%) that underwent lens exchange (P = 0.05).

CONCLUSIONS

The final visual results in eyes with dislocated PCIOLs that underwent pars plana vitrectomy with lens repositioning were similar to the visual results obtained in eyes that underwent pars plana vitrectomy with lens exchange. For eyes that underwent lens exchange, final visual results in eyes that received an ACIOL were similar to the visual results obtained in eyes that received a PCIOL; however, eyes with an ACIOL showed a greater increase in mean visual acuity. Eyes with a preoperative afferent pupillary defect had worse final visual results.

Surgical repair of full-thickness idiopathic macular holes associated with significant macular drusen

OBJECTIVE

To evaluate the visual and anatomic results of surgically repaired macular holes in eyes with intermediate or large-sized macular drusen.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Thirty-four eyes of 32 patients undergoing macular hole surgery with preoperative intermediate or large-sized macular drusen as defined by the Age-Related Eye Disease Study (AREDS).

INTERVENTION

Pars plana vitrectomy for standard macular hole repair performed by multiple surgeons.

MAIN OUTCOME MEASURES

Visual acuity, anatomic hole closure.

RESULTS

Initial hole closure failed in 8 eyes (24%) overall, 5 of 28 eyes (18%) with AREDS category 2 drusen and 3 of 6 eyes (50%) with category 3 drusen (P = 0.1263). Final macular hole closure was seen in 93% of category 2 and 67% of category 3 eyes (P = 0.1347). Mean final visual acuity was 20/60 overall, 20/60 for category 2, and 20/50 for category 3 eyes.

CONCLUSIONS

A trend of reduced initial macular hole closure was seen in eyes with significant macular drusen. Reoperation improved closure rates. If closure was accomplished, visual outcomes were excellent.

Evidence for a role of HLA DRB1 alleles in the control of IgE levels, strengthened by interacting TCR A/D marker alleles

BACKGROUND

MHC class II alleles at human chromosome 6p21.1 and alleles in the TCR A/D locus at human chromosome 14q11.2 have been implicated in susceptibility to specific allergies and the modulation of total serum IgE. It has also been hypothesized that HLA and TCR allelic interactions may have a strong influence on predisposition to allergic disease.

OBJECTIVE

This study was performed to investigate the influence of HLA-DRB and DQB1 alleles and D14S50 alleles (adjacent to TCR A/D locus on 14q11.2), individually and in-combination, on total serum IgE levels, and on the development of specific allergies.

METHODS

We performed an association study between HLA-DRB, HLA-DQB1 polymorphisms, D14S50 alleles, total serum IgE expression and specific allergies to house dust mite, grass pollens and cat fur. A sample of 181 individuals was drawn from a larger set of 2415 adults, sampled at random from a district in Nottingham.

RESULTS

Strong association was observed between HLA-DRB1*0701 allele and high total serum IgE expression (P < 0.001). D14S50 alleles alone showed no evidence for independent association. However, there was a significant interaction between DRB1*0701 and D14S50 allele 170 such that, when both were present, there was a further increase in total serum IgE levels.

CONCLUSION

This study suggests that DRB1*0701 allele is involved in the modulation of total serum IgE, and that there is an interaction between DRB1*0701 and a marker adjacent to TCR A/D in the control of IgE expression.

A new approach to stage 3 macular holes

PURPOSE

The purpose of this article is to demonstrate the feasibility of a surgical approach that might be possible in an office setting for idiopathic stage 3 macular holes. The posterior hyaloid of the vitreous and perihole tissue is enzymatically manipulated to create an atraumatic posterior vitreous separation and may stimulate cell proliferation to close macular holes.

DESIGN

Prospective noncomparative interventional case series.

PARTICIPANTS

Nine eyes of eight patients with idiopathic stage 3 macular holes were treated.

METHODS

The patients were treated with an injection of 0.4 IU of autologous plasmin enzyme into the midvitreous cavity and lavage of the vitreous cavity with an infusion light pipe and vitreous cutter followed by filling 70% to 80% of the vitreous cavity with 14% C3F8 and head-down positioning.

MAIN OUTCOME MEASURES

Posterior vitreous detachment, macular hole closure, and vision improvement.

RESULTS

Eight of nine eyes showed a spontaneous posterior vitreous detachment. One eye required minimal suction of less than 50 mmHg to elevate the posterior hyaloid off the retinal surface. Eyes were followed for a minimum of 6 months. All holes closed, and there was an average visual acuity improvement of four lines. The average surgical time for this procedure was 20 minutes.

CONCLUSIONS

Autologous plasmin enzyme-assisted vitreous surgery techniques can reduce operative time, expense, and patient inconvenience while maintaining excellent surgical results, which may allow office-based vitreous surgery for idiopathic stage 3 macular holes.

Vitrectomy for diffuse diabetic macular edema associated with a taut premacular posterior hyaloid

PURPOSE

To evaluate the role of vitrectomy in eyes with diffuse diabetic macular edema associated with a taut posterior hyaloid.

METHODS

Records of 55 eyes of 50 patients with diabetic retinopathy and diffuse clinically significant diabetic macular edema who underwent vitrectomy with stripping of the premacular posterior hyaloid were reviewed. In all 55 eyes, diffuse diabetic macular edema was present on contact lens examination and confirmed with fluorescein angiography. On fundus examination, the premacular posterior hyaloid was attached and appeared taut.

RESULTS

The mean preoperative best-corrected visual acuity was 20/160, and the mean final best-corrected visual acuity was 20/80 (P <.0001, Wilcoxon signed rank test), with 27 (49.1%) of the 55 eyes demonstrating improvement in best-corrected visual acuity of 2 or more lines. Fifty-two (94.5%) of the 55 vitrectomized eyes showed improvement in clinically significant macular edema and in 45 eyes (81.8%) the macular edema resolved completely during a mean period of 4.5 months (range, 1 to 13 months). Eyes with macular ischemia and preoperative best-corrected visual acuity of 20/200 or less tended to respond less favorably to vitrectomy than eyes lacking these characteristics. All eyes had at least 6 months of follow-up after surgery, with a mean follow-up of 23.2 months.

CONCLUSION

In eyes with persistent diffuse diabetic macular edema with a taut premacular posterior hyaloid face unresponsive to laser therapy, vitrectomy with removal of the posterior hyaloid appears to be beneficial in some cases. Careful selection of eyes with favorable preoperative clinical characteristics may improve surgical outcomes.

Nonsurgical management of macular hemorrhage secondary to retinal artery macroaneurysms

OBJECTIVE

To report visual acuity outcomes of nonsurgical management of macular hemorrhage secondary to retinal artery macroaneurysms.

METHODS

Forty-one patients at multiple centers with macular hemorrhage secondary to retinal artery macroaneurysms managed with observation alone were reviewed. Time to clearance of macular hemorrhage, visual acuity at final follow-up, and presence or absence of macular pigmentary changes after absorption of the hemorrhage were recorded for each patient.

RESULTS

On initial examination, visual acuity was 20/200 or worse in all except 4 patients (3 with 20/70, 1 with 20/80). At an average follow-up of 15. 7 months, a final visual acuity of 20/40 or better was achieved in 15 eyes (37%), between 20/50 and 20/100 in 12 (29%), and 20/200 or worse in 14 (34%). Macular pigmentary abnormalities were noted after clearance of the hemorrhage in 23 (56%) of 41 cases, and these eyes generally had worse visual acuity outcomes.

CONCLUSIONS

In eyes with macular hemorrhage secondary to retinal artery macroaneurysms managed with observation alone, good visual acuity outcomes can often be achieved. Poorer visual acuity outcomes are associated with macular pigmentary changes after resorption of blood. Arch Ophthalmol. 2000;118:780-785