Wavefront-guided laser-assisted subepithelial keratectomy in low myopia, myopic astigmatism and high myopia

AIM: To compare the safety, efficacy, predictability, stability and complications of wavefront-guided laser-assisted subepithelial keratectomy (LASEK) in low myopia, myopic astigmatism and high myopia correction. METHODS: A retrospective analysis of 416 eyes were assigned to 3 groups: 159 eyes with low myopia (LM) and mean refractive spherical equivalent (MRSE) of -3.68±1.33 dioptre (D); 161 eyes with myopic astigmatism (MA) and MRSE of -5.99±2.24D and mean cylinder of 2.41±1.07D; and 96 eyes with high myopia (HM) and MRSE of -7.41±0.80D. After an epithelial flap creation, a wavefront-based excimer laser ablation was performed. Safety, efficacy, predictability and stability were evaluated at day 10, 2, 6 and 12mo postoperatively. RESULTS: At 12mo, the MRSE was -0.36±0.31D in LM group, 0.15±0.41D in MA group and 0.58±0.68D in HM group. The uncorrected visual acuity (UCVA) was 20/20 in 90.60 of patients in LM group, 78.90 in MA group and 67 in HM group. Efficacy indices were 0.98, 1.04 and 0.92 in LM, MA and HM groups, respectively. Safety indices were 1.00, 1.07 and 1.05 in LM, MA and HM respectively. Five eyes (3.1) in the LM group gained 1 line. Forty-four eyes (27.3) in MA gained 1-3 lines and eighteen eyes (19.2) of HM group gained 1-2 lines of BSCVA. Only 2 eyes in LM group developed corneal haze. There were not statistically significant differences in efficacy and safety indices amongst three groups. CONCLUSION: Wavefront-guided LASEK is an effective and safe procedure for the treatment of LM, MA, and HM.although in myopic astigmatism the predictability, efficacy and safety indices had been better. ©, 2015, International Journal of Ophthalmology (c/o Editorial Office). All right reserved

Ocular higher-order aberrations changes after implantable collamer lens implantation for high myopic astigmatism

Purpose: To investigate the changes in higher-order aberrations (HOAs) induced by the implantation of implantable collamer lenses (ICLs) and Toric ICL (TICL) in eyes with high myopia and high myopic astigmatism. Methods: We investigated 33 eyes of 18 consecutive patients (in a prospective, interventional case series study), with spherical equivalent errors of �6.00 to �21.09 diopters (D) and cylindrical errors of �0.5 to �4.75 D, who underwent ICL and TICL implantation. Before and after 5 days, 2 and 6 months of surgery, the uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), defocus and adverse events of the surgery were assessed. Ocular HOAs were also evaluated by Hartmann-Shack aberrometry (Technolas PV, Rochester, New York, USA) before and after 6 months of surgery. Results: At 6.0 months after surgery, the UCVA and BCVA in 40 and 66.7 of eyes were 20/20, respectively. Mean defocus refraction and astigmatism was reduced to �0.66 and 0.65 D from �12.79 and 2.18 at baseline, respectively. For a 6 mm pupil, HOAs were not significantly changed, merely from 0.417 ± 0.162 μ before surgery to 0.393 ± 0.119 μ after surgery (P = 0.45). Spherical aberration (Z400) increased significantly (P = 00.0). Surgical induced astigmatism was lower than 0.25 D, and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. Conclusion: This study shows that the ICL and TICL performed well in correcting high myopic astigmatism without significant changes in HOAs during a 6-month observation period, although the spherical aberration (Z400) increased significantly. © 2017 Iranian Society of Ophthalmolog

Ocular higher-order aberrations changes after implantable collamer lens implantation for high myopic astigmatism

Purpose: To investigate the changes in higher-order aberrations (HOAs) induced by the implantation of implantable collamer lenses (ICLs) and Toric ICL (TICL) in eyes with high myopia and high myopic astigmatism. Methods: We investigated 33 eyes of 18 consecutive patients (in a prospective, interventional case series study), with spherical equivalent errors of �6.00 to �21.09 diopters (D) and cylindrical errors of �0.5 to �4.75 D, who underwent ICL and TICL implantation. Before and after 5 days, 2 and 6 months of surgery, the uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), defocus and adverse events of the surgery were assessed. Ocular HOAs were also evaluated by Hartmann-Shack aberrometry (Technolas PV, Rochester, New York, USA) before and after 6 months of surgery. Results: At 6.0 months after surgery, the UCVA and BCVA in 40 and 66.7 of eyes were 20/20, respectively. Mean defocus refraction and astigmatism was reduced to �0.66 and 0.65 D from �12.79 and 2.18 at baseline, respectively. For a 6 mm pupil, HOAs were not significantly changed, merely from 0.417 ± 0.162 μ before surgery to 0.393 ± 0.119 μ after surgery (P = 0.45). Spherical aberration (Z400) increased significantly (P = 00.0). Surgical induced astigmatism was lower than 0.25 D, and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. Conclusion: This study shows that the ICL and TICL performed well in correcting high myopic astigmatism without significant changes in HOAs during a 6-month observation period, although the spherical aberration (Z400) increased significantly. © 2017 Iranian Society of Ophthalmolog

Adjustment formulae to improve the correlation of white-to-white measurement with direct measurement of the ciliary sulcus diameter by ultrasound biomicroscopy

Purpose: This study evaluates the correlation between horizontal white-to-white (WTW) distance using Caliper and Orbscan IIz with the ciliary sulcus diameter measured by high frequency ultrasound biomicroscopy (UBM) and presents an adjustment formula to improve the correlation. Methods: We measured horizontal sulcus-to-sulcus (STS) dimension of 273 right eyes of 273 high myopic patients with 35 MHz UBM and horizontal WTW using Orbscan IIz and Caliper. Mean WTW diameter, differences, and the correlation of measurement methods were evaluated. Results: The mean spherical equivalent was �8.79 ± 4.87 diopters. Mean horizontal STS dimension with UBM was 12.13 ± 0.45 mm (range, 10.81�13.42 mm). Mean WTW diameter in the Caliper method was 11.70 ± 0.40 mm (range, 10.6�12.8 mm) and 11.70 ± 0.40 mm (range, 10.5�13.1 mm) in the Orbscan method. Mean difference of UBM STS and WTW with Caliper was 0.48 ± 0.28 mm (range, �0.19 to 1.37 mm). Mean difference of UBM STS diameter and Orbscan WTW was 0.38 ± 0.31 mm (range, �0.64 to 1.29 mm). The Pearson correlations of WTW diameter measured by Caliper and Orbscan with UBM's STS diameter were 0.778 and 0.773, respectively. This difference diminished after adjustment. The 95 limit of agreement was almost the same in Caliper and Orbscan (�0.07 to 1.03 compared with �0.23 to 0.99). Conclusion: There is a significant difference in measurements between STS diameter using UBM and WTW diameter utilizing Caliper and Orbscan. This difference diminished after our recommended adjustment. © 2017 Iranian Society of Ophthalmolog

Three methods for correction of astigmatism during phacoemulsification

Purpose: To compare the safety and efficacy of three methods for correcting pre-existing astigmatism during phacoemulsification. Methods: This prospective, comparative, non-randomized study was conducted from March 2010 to January 2011, and included patients with keratometric astigmatism �1.25 D undergoing cataract surgery. Astigmatism was corrected using the following approaches: limbal relaxing incisions (LRI) on the steep meridian, extension and suturing of the phaco incision created at the steep meridian (extended-on-axis incision, EOAI), and toric intraocular lens (tIOL) implantation. Keratometric and refractive astigmatism were evaluated 1, 8, and 24 weeks postoperatively. Results: Eighty-three eyes of 72 patients (35 male and 37 female) with mean age of 62.4 ± 14.3 (range, 41-86) years were enrolled. The astigmatism was corrected by using the LRI, EOAI and tIOL implantation methods in 17, 33 and 33 eyes, respectively. Postoperative uncorrected distance visual acuity (UDVA) was significantly improved in all three groups. The difference in postoperative UDVA was not statistically significant among the study groups throughout follow-up except at week 24, when UCVA was significantly better in the tIOL group as compared to the EOAI group (P = 0.024). There is no statistically significant difference of correction index and index of success between three groups at week 24 (P = 0.085 and P = 0.085 respectively). Conclusion: There was no significant difference in astigmatism reduction among the three methods of astigmatism correction during phacoemulsification. Each of these methods can be used at the discretion of the surgeon. © 2016 Journal of Ophthalmic and Vision Research

Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4 (62.3 (55.1�70.8) million) to 6.4 (58.3 (47.6�70.7) million), but is predicted to remain above the World Health Organization�s Global Nutrition Target of <5 in over half of LMICs by 2025. Prevalence of overweight increased from 5.2 (30 (22.8�38.5) million) in 2000 to 6.0 (55.5 (44.8�67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic. © 2020, The Author(s)

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2•72 (95% uncertainty interval [UI] 2•66–2•79) in 2000 to 2•31 (2•17–2•46) in 2019. Global annual livebirths increased from 134•5 million (131•5–137•8) in 2000 to a peak of 139•6 million (133•0–146•9) in 2016. Global livebirths then declined to 135•3 million (127•2–144•1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2•1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27•1% (95% UI 26•4–27•8) of global livebirths. Global life expectancy at birth increased from 67•2 years (95% UI 66•8–67•6) in 2000 to 73•5 years (72•8–74•3) in 2019. The total number of deaths increased from 50•7 million (49•5–51•9) in 2000 to 56•5 million (53•7–59•2) in 2019. Under-5 deaths declined from 9•6 million (9•1–10•3) in 2000 to 5•0 million (4•3–6•0) in 2019. Global population increased by 25•7%, from 6•2 billion (6•0–6•3) in 2000 to 7•7 billion (7•5–8•0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58•6 years (56•1–60•8) in 2000 to 63•5 years (60•8–66•1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019. Interpretation: Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Global burden of 87 risk factors in 204 countries and territories, 1990�2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: Rigorous analysis of levels and trends in exposure to leading risk factors and quantification of their effect on human health are important to identify where public health is making progress and in which cases current efforts are inadequate. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a standardised and comprehensive assessment of the magnitude of risk factor exposure, relative risk, and attributable burden of disease. Methods: GBD 2019 estimated attributable mortality, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 87 risk factors and combinations of risk factors, at the global level, regionally, and for 204 countries and territories. GBD uses a hierarchical list of risk factors so that specific risk factors (eg, sodium intake), and related aggregates (eg, diet quality), are both evaluated. This method has six analytical steps. (1) We included 560 risk�outcome pairs that met criteria for convincing or probable evidence on the basis of research studies. 12 risk�outcome pairs included in GBD 2017 no longer met inclusion criteria and 47 risk�outcome pairs for risks already included in GBD 2017 were added based on new evidence. (2) Relative risks were estimated as a function of exposure based on published systematic reviews, 81 systematic reviews done for GBD 2019, and meta-regression. (3) Levels of exposure in each age-sex-location-year included in the study were estimated based on all available data sources using spatiotemporal Gaussian process regression, DisMod-MR 2.1, a Bayesian meta-regression method, or alternative methods. (4) We determined, from published trials or cohort studies, the level of exposure associated with minimum risk, called the theoretical minimum risk exposure level. (5) Attributable deaths, YLLs, YLDs, and DALYs were computed by multiplying population attributable fractions (PAFs) by the relevant outcome quantity for each age-sex-location-year. (6) PAFs and attributable burden for combinations of risk factors were estimated taking into account mediation of different risk factors through other risk factors. Across all six analytical steps, 30 652 distinct data sources were used in the analysis. Uncertainty in each step of the analysis was propagated into the final estimates of attributable burden. Exposure levels for dichotomous, polytomous, and continuous risk factors were summarised with use of the summary exposure value to facilitate comparisons over time, across location, and across risks. Because the entire time series from 1990 to 2019 has been re-estimated with use of consistent data and methods, these results supersede previously published GBD estimates of attributable burden. Findings: The largest declines in risk exposure from 2010 to 2019 were among a set of risks that are strongly linked to social and economic development, including household air pollution; unsafe water, sanitation, and handwashing; and child growth failure. Global declines also occurred for tobacco smoking and lead exposure. The largest increases in risk exposure were for ambient particulate matter pollution, drug use, high fasting plasma glucose, and high body-mass index. In 2019, the leading Level 2 risk factor globally for attributable deaths was high systolic blood pressure, which accounted for 10·8 million (95 uncertainty interval UI 9·51�12·1) deaths (19·2% 16·9�21·3 of all deaths in 2019), followed by tobacco (smoked, second-hand, and chewing), which accounted for 8·71 million (8·12�9·31) deaths (15·4% 14·6�16·2 of all deaths in 2019). The leading Level 2 risk factor for attributable DALYs globally in 2019 was child and maternal malnutrition, which largely affects health in the youngest age groups and accounted for 295 million (253�350) DALYs (11·6% 10·3�13·1 of all global DALYs that year). The risk factor burden varied considerably in 2019 between age groups and locations. Among children aged 0�9 years, the three leading detailed risk factors for attributable DALYs were all related to malnutrition. Iron deficiency was the leading risk factor for those aged 10�24 years, alcohol use for those aged 25�49 years, and high systolic blood pressure for those aged 50�74 years and 75 years and older. Interpretation: Overall, the record for reducing exposure to harmful risks over the past three decades is poor. Success with reducing smoking and lead exposure through regulatory policy might point the way for a stronger role for public policy on other risks in addition to continued efforts to provide information on risk factor harm to the general public. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens