Intraocular lens power calculation in keratoconus; a review of literature

Purpose: To review the published literature regarding cataract surgery in keratoconus (KCN) patients with emphasis on challenges encountered during intraocular lens (IOL) power calculation and their solutions. Methods: A literature review was performed to investigate all the relevant articles on the advancements of IOL calculations in KCN patients. Results: Cataract surgery in keratoconic eyes can improve patients' refraction, and proper patient selection and IOL calculation methods are necessary to get the best results. The main problem in KCN patients is unreliable biometric measurements. It is more difficult to make conclusions in more advanced keratoconic corneas, as the steep keratometric values in these eyes will result in the selection of a low-power IOL. Presence of a low-power IOL will yield in extreme postoperative hyperopia, and IOL exchange might be mandatory. In cases in which keratoplasty may be needed in the future, contact lens fitting can help surgeons make a better decision preoperatively. Axial length (AL) measurements may have better repeatability and reproducibility than keratometry (K) readings in keratoconic eyes. SRK II formula may provide the most accurate IOL power in mild KCN. There is still not a comprehensive consensus of which formula is the best one in moderate and severe KCN, as the literature is limited in this subject. Conclusions: Various methods of IOL power calculation optimization and recommendations may hold the key to improve surgical outcomes in keratoconic eyes. There are multiple sources of biometric error in KCN patients, hence IOL calculation methods may not be as efficient as expected in these eyes. © 2019 Iranian Society of Ophthalmolog

Temporal Artery Biopsy for Diagnosing Giant Cell Arteritis: A Ten-year Review

Purpose: To assess the use of temporal artery biopsy (TAB) in diagnosing giant cell arteritis (GCA) and to evaluate patients� clinical and laboratory characteristics. Methods: We conducted a retrospective chart review of patients with suspected GCA who underwent TAB and had complete workup in a tertiary center in Iran between 2008 and 2017. The 2016 American College of Rheumatology (ACR) revised criteria for early diagnosis of GCA were used for each patient for inclusion in this study. Results: The mean age of the 114 patients in this study was 65.54 ± 10.17 years. The mean overall score according to the 2016 ACR revised criteria was 4.17 ± 1.39, with 5.82 ± 1.28 for positive biopsies and 3.88 ± 1.19 for negative biopsies (p <0.001). Seventeen patients (14.9) had a positive biopsy. Although the mean post-fixation specimen length in the biopsy-positive group (18.35 ± 6.9 mm) was longer than that in the biopsy-negative group (15.62 ± 8.4 mm), the difference was not statistically significant (P = 0.21). There was no statistically significant difference between the groups in terms of sex, serum hemoglobin, platelet count, and erythrocyte sedimentation rate. There were statistically significant differences between the biopsy-negative and biopsy-positive groups with respect to patients� age and C-reactive protein level (P < 001 and P = 0.012, respectively). Conclusion: The majority of TABs were negative. Reducing the number of redundant biopsies is necessary to decrease workload and use of medical services. We suggest that the diagnosis of GCA should be dependent on clinical suspicion. © 2020 JOURNAL OF OPHTHALMIC AND VISION RESEARC

Dehydration of potato slices following brief dipping in osmotic solutions: effect of conditions and understanding the mechanism of water loss

A novel variant of osmotic dehydration, named here as post-dipping dehydration – where a material is dipped in a salt or sugar solution for a very short time followed by simple exposure to ambient conditions was explored with the aim of lowering water content of potato slices but at the same time not gain a high level of sugar/salt. The rate of water loss, which was rapid initially, was found to approach equilibrium. This paper also explored whether the water loss process could subsequently be kick started once again, by employing a multi-stage process, where each stage consisted of osmotic solution dipping followed by ambient holding of the potato slices that had reached equilibrium in the earlier stage. Water loss values comparable to conventional osmotic dehydration could be achieved thus, but with significantly lower overall solid gain (less than 50%) – which can potentially yield a significantly healthy product option

Canadian Burden of Skin Disease From 1990 to 2017: Results From the Global Burden of Disease 2017 Study

Background: Skin diseases can have high morbidity that can be costly to society and individuals. To date, there has been no comprehensive assessment of the burden of skin disease in Canada. Objectives: To evaluate the burden of 18 skin and subcutaneous diseases from 1990 to 2017 in Canada using the Global Burden of Disease (GBD) data. Methods: The 2017 GBD study measures health loss from 359 diseases and injuries in 195 countries; we evaluated trends in population health in Canada from 1990 to 2017 using incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs). Data are presented as rates (per 100 000), counts, or percent change with the uncertainty interval in brackets. Results: From 1990 to 2017 for all skin diseases, DALY rates increased by 8 to 971 per 100 000 (674-1319), YLD rates increased by 8 to 897 per 100 000 (616-1235), YLL rates increased by 4 to 74 per 100 000 (53-89), and death rates increased by 18 to 5 per 100 000 (3-6). DALY rates for melanoma increased by 2 to 54 per 100 000 (39-68), for keratinocyte carcinoma by 14 to 17 per 100 000 (16-19), and for skin and subcutaneous disease by 8 to 900 per 100 000 (619-1233). The observed over expected ratios were higher for skin and subcutaneous disease (1.37) and keratinocyte carcinoma (1.17) and were lower for melanoma (0.73). Conclusions: The burden of skin disease has increased in Canada since 1990. These results can be used to guide health policy regarding skin disease in Canada. © The Author(s) 2020

Organoids and organ chips in ophthalmology

Recent advances have driven the development of stem cell-derived, self-organizing, three-dimensional miniature organs, termed organoids, which mimic different eye tissues including the retina, cornea, and lens. Organoids and engineered microfluidic organ-on-chips (organ chips) are transformative technologies that show promise in simulating the architectural and functional complexity of native organs. Accordingly, they enable exploration of facets of human disease and development not accurately recapitulated by animal models. Together, these technologies will increase our understanding of the basic physiology of different eye structures, enable

Safety and effectiveness of high-dose vitamin C in patients with COVID-19: a randomized open-label clinical trial

Background: Vitamin C is an essential water-soluble nutrient that functions as a key antioxidant and has been proven to be effective for boosting immunity. In this study, we aimed to assess the efficacy of adding high-dose intravenous vitamin C (HDIVC) to the regimens for patients with severe COVID-19 disease. Methods: An open-label, randomized, and controlled trial was conducted on patients with severe COVID-19 infection. The case and control treatment groups each consisted of 30 patients. The control group received lopinavir/ritonavir and hydroxychloroquine and the case group received HDIVC (6 g daily) added to the same regimen. Results: There were no statistically significant differences between two groups with respect to age and gender, laboratory results, and underlying diseases. The mean body temperature was significantly lower in the case group on the 3rd day of hospitalization (p = 0.001). Peripheral capillary oxygen saturations (SpO2) measured at the 3rd day of hospitalization was also higher in the case group receiving HDIVC (p = 0.014). The median length of hospitalization in the case group was significantly longer than the control group (8.5 days vs. 6.5 days) (p = 0.028). There was no significant difference in SpO2 levels at discharge time, the length of intensive care unit (ICU) stay, and mortality between the two groups. Conclusions: We did not find significantly better outcomes in the group who were treated with HDIVC in addition to the main treatment regimen at discharge. Trial registration irct.ir (IRCT20200411047025N1), April 14, 2020 © 2021, The Author(s)

The global burden of childhood and adolescent cancer in 2017: an analysis of the Global Burden of Disease Study 2017

© 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Accurate childhood cancer burden data are crucial for resource planning and health policy prioritisation. Model-based estimates are necessary because cancer surveillance data are scarce or non-existent in many countries. Although global incidence and mortality estimates are available, there are no previous analyses of the global burden of childhood cancer represented in disability-adjusted life-years (DALYs). Methods: Using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 methodology, childhood (ages 0–19 years) cancer mortality was estimated by use of vital registration system data, verbal autopsy data, and population-based cancer registry incidence data, which were transformed to mortality estimates through modelled mortality-to-incidence ratios (MIRs). Childhood cancer incidence was estimated using the mortality estimates and corresponding MIRs. Prevalence estimates were calculated by using MIR to model survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated by multiplying age-specific cancer deaths by the difference between the age of death and a reference life expectancy. DALYs were calculated as the sum of YLLs and YLDs. Final point estimates are reported with 95% uncertainty intervals. Findings: Globally, in 2017, there were 11·5 million (95% uncertainty interval 10·6–12·3) DALYs due to childhood cancer, 97·3% (97·3–97·3) of which were attributable to YLLs and 2·7% (2·7–2·7) of which were attributable to YLDs. Childhood cancer was the sixth leading cause of total cancer burden globally and the ninth leading cause of childhood disease burden globally. 82·2% (82·1–82·2) of global childhood cancer DALYs occurred in low, low-middle, or middle Socio-demographic Index locations, whereas 50·3% (50·3–50·3) of adult cancer DALYs occurred in these same locations. Cancers that are uncategorised in the current GBD framework comprised 26·5% (26·5–26·5) of global childhood cancer DALYs. Interpretation: The GBD 2017 results call attention to the substantial burden of childhood cancer globally, which disproportionately affects populations in resource-limited settings. The use of DALY-based estimates is crucial in demonstrating that childhood cancer burden represents an important global cancer and child health concern. Funding: Bill & Melinda Gates Foundation, American Lebanese Syrian Associated Charities (ALSAC), and St. Baldrick's Foundation

The global, regional, and national burden of pancreatic cancer and its attributable risk factors in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

Background: Worldwide, both the incidence and death rates of pancreatic cancer are increasing. Evaluation of pancreatic cancer burden and its global, regional, and national patterns is crucial to policy making and better resource allocation for controlling pancreatic cancer risk factors, developing early detection methods, and providing faster and more effective treatments. Methods: Vital registration, vital registration sample, and cancer registry data were used to generate mortality, incidence, and disability-adjusted life-years (DALYs) estimates. We used the comparative risk assessment framework to estimate the proportion of deaths attributable to risk factors for pancreatic cancer: smoking, high fasting plasma glucose, and high body-mass index. All of the estimates were reported as counts and age-standardised rates per 100 000 person-years. 95% uncertainty intervals (UIs) were reported for all estimates. Findings: In 2017, there were 448 000 (95% UI 439 000\u2013456 000) incident cases of pancreatic cancer globally, of which 232 000 (210 000\u2013221 000; 51\ub79%) were in males. The age-standardised incidence rate was 5\ub70 (4\ub79\u20135\ub71) per 100 000 person-years in 1990 and increased to 5\ub77 (5\ub76\u20135\ub78) per 100 000 person-years in 2017. There was a 2\ub73 times increase in number of deaths for both sexes from 196 000 (193 000\u2013200 000) in 1990 to 441 000 (433 000\u2013449 000) in 2017. There was a 2\ub71 times increase in DALYs due to pancreatic cancer, increasing from 4\ub74 million (4\ub73\u20134\ub75) in 1990 to 9\ub71 million (8\ub79\u20139\ub73) in 2017. The age-standardised death rate of pancreatic cancer was highest in the high-income super-region across all years from 1990 to 2017. In 2017, the highest age-standardised death rates were observed in Greenland (17\ub74 [15\ub78\u201319\ub70] per 100 000 person-years) and Uruguay (12\ub71 [10\ub79\u201313\ub75] per 100 000 person-years). These countries also had the highest age-standardised death rates in 1990. Bangladesh (1\ub79 [1\ub75\u20132\ub73] per 100 000 person-years) had the lowest rate in 2017, and S\ue3o Tom\ue9 and Pr\uedncipe (1\ub73 [1\ub71\u20131\ub75] per 100 000 person-years) had the lowest rate in 1990. The numbers of incident cases and deaths peaked at the ages of 65\u201369 years for males and at 75\u201379 years for females. Age-standardised pancreatic cancer deaths worldwide were primarily attributable to smoking (21\ub71% [18\ub78\u201323\ub77]), high fasting plasma glucose (8\ub79% [2\ub71\u201319\ub74]), and high body-mass index (6\ub72% [2\ub75\u201311\ub74]) in 2017. Interpretation: Globally, the number of deaths, incident cases, and DALYs caused by pancreatic cancer has more than doubled from 1990 to 2017. The increase in incidence of pancreatic cancer is likely to continue as the population ages. Prevention strategies should focus on modifiable risk factors. Development of screening programmes for early detection and more effective treatment strategies for pancreatic cancer are needed. Funding: Bill &amp; Melinda Gates Foundation