Unstable Vancouver B1 periprosthetic femoral fracture fixation: A biomechanical comparison between a novel C-shaped memory alloy implant and cerclage wiring.

BACKGROUND: To compare the biomechanical stability of a novel, C-shaped nickel-titanium shape memory alloy (SMA) implant (C-clip) with traditional cerclage wiring in the fixation of a Vancouver B1 (VB1) periprosthetic femoral fracture (PFF). METHODS: In total, 18 synthetic femoral fracture models were constructed to obtain unstable VB1 fracture with an oblique fracture line 8 cm below the lesser trochanter. For each model, the distal portion was repaired using a 10-hole locking plate and four distal bi-cortical screws. The proximal portion was repaired using either three, threaded cerclage wirings or three, novel C-shaped implants. Specimens underwent biomechanical testing using axial compression, torsional and four-point bending tests. Each test was performed on three specimens. RESULTS: The C-clip was statistically significantly stronger (i.e., stiffer) than cerclage wiring in the three biomechanical tests. For axial compression, medians (ranges) were 39 (39-41) and 35 (35-35) N/mm, for the C-clip and cerclage wiring, respectively. For torsion, medians (ranges) were, 0.44 (0.44-0.45) and 0.30 (0.30-0.33) N/mm for the C-clip and cerclage wiring, respectively. For the four-point bending test, medians (ranges) were 39 (39-41) and 28 (28-31) N/mm; for the C-clip and cerclage wiring, respectively. CONCLUSION: Results from this small study show that the novel, C-shaped SMA appears to be biomechanically superior to traditional cerclage wiring in terms of stiffness, axial compression, torsion and four-point bending, and may be a valuable alternative in the repair of VB1 PFF. Further research is necessary to support these results.

Psychosocial strain and coping of Finnish working mothers during the COVID-19 lockdown: a job demand-control approach.

Introduction: In March 2020 many countries around the world, including Finland, implemented lockdown measures to mitigate the unprecedented impacts of the coronavirus infectious disease (COVID-19) on public health. As a result, school and daycare settings closed indefinitely and working from home became the new normal for a big part of the workforce, which came with increased homeschooling and childcare responsibility for mothers. Methods: In this article we present the findings from maternal responses to open ended questions on psychosocial well-being, and experiences of combining work, family life and homeschooling during the COVID-19 national lockdown in Finland in March-May 2020. Working mothers' responses (n = 72) were analyzed through the lens of Karasek's job demand-control model, focusing on how the mothers experienced the demands of their life during the lockdown, and how they saw their possibilities to control the situation. Results: The findings indicated important variation in the level of experienced demand and control and associated compensatory factors during the COVID-19 lockdown across different subgroups of working mothers. Discussion: The findings have implications for understanding strain and plausible supports among working mothers during the COVID-19 lockdown as well as in the face of acute adversity including the next possible public health crisis.

The long and short of it: a comprehensive assessment of axial length estimation in myopic eyes from ocular and demographic variables.

BACKGROUND/OBJECTIVES: Axial length, a key measurement in myopia management, is not accessible in many settings. We aimed to develop and assess machine learning models to estimate the axial length of young myopic eyes. SUBJECTS/METHODS: Linear regression, symbolic regression, gradient boosting and multilayer perceptron models were developed using age, sex, cycloplegic spherical equivalent refraction (SER) and corneal curvature. Training data were from 8135 (28% myopic) children and adolescents from Ireland, Northern Ireland and China. Model performance was tested on an additional 300 myopic individuals using traditional metrics alongside the estimated axial length vs age relationship. Linear regression and receiver operator characteristics (ROC) curves were used for statistical analysis. The contribution of the effective crystalline lens power to error in axial length estimation was calculated to define the latter's physiological limits. RESULTS: Axial length estimation models were applicable across all testing regions (p ≥ 0.96 for training by testing region interaction). The linear regression model performed best based on agreement metrics (mean absolute error [MAE] = 0.31 mm, coefficient of repeatability = 0.79 mm) and a smooth, monotonic estimated axial length vs age relationship. This model was better at identifying high-risk eyes (axial length >98th centile) than SER alone (area under the curve 0.89 vs 0.79, respectively). Without knowing lens power, the calculated limits of axial length estimation were 0.30 mm for MAE and 0.75 mm for coefficient of repeatability. CONCLUSIONS: In myopic eyes, we demonstrated superior axial length estimation with a linear regression model utilising age, sex and refractive metrics and showed its clinical utility as a risk stratification tool.

Platelet-rich plasma for treating dry eye disease - A systematic review and meta-analysis.

PURPOSE: Dry eye disease has public health and economic significance. Platelet-rich plasma is rich in anti-inflammatory agents and growth factors, both beneficial for ocular surface repair. This study aimed to conduct a systematic review and meta-analysis to summarize the benefits of platelet-rich plasma for treating dry eye disease and its adverse effects. METHODS: Prospective comparative studies using platelet-rich plasma as monotherapy for dry eye disease were included for efficacy assessment. Before-after studies were included for adverse events assessment. Data sources included PubMed, Google Scholar, Web of Science, and Scopus. A systematic review and meta-analysis protocol was pre-registered on PROSPERO (CRD42022347982). PRISMA guidelines were followed. The National Health Institute (NIH) quality assessment tool for before-after studies, the Cochrane risk of bias tool (RoB2), and the methodological index for non-randomized studies were used to assess the risk of bias. Heterogeneity was assessed using the I2 statistic. RESULTS: 19 studies (10 comparative and 9 before-after) were included in the systematic review and meta-analysis. The occurrence rate of adverse effects was 2.6 % (95 % CI: 0.5 - 4.7). The pooled standardized mean difference (SMD) for dry eye symptoms was 0.81 (95 % CI: 0.25 - 1.37; I2 = 82 %; p < 0.00001; Z = 2.84, p = 0.004); tear quality was 0.44 (95 % CI: 0.06 - 0.81; I2 = 67 %; p = 0.003; Z = 2.26, p = 0.02); tear quantity was 0.45 (95 % CI: 0.03 - 0.88; I2 = 74 %; p = 0.0003; Z = 2.10, p = 0.04); and corneal staining 0.72 (95 % CI: 0.14 - 1.30; I2 = 85 %; p < 0.00001; Z = 2.43, p = 0.02). CONCLUSION: The current study shows that platelet-rich plasma is efficacious in managing dry eye disease, significantly reducing dry eye signs and symptoms. Such significant improvements could translate to improved quality of life.

Short-term effects of cyclopentolate and tropicamide eye drops on macular choroidal thickness in myopic children.

BACKGROUND: To investigate the short-term effects of cyclopentolate and tropicamide eyedrops on choroidal thickness (ChT) in myopic children using placebo or low-dose atropine eyedrops. METHODS: The analysis included 242 myopic individuals (7-19 years) enrolled in two randomised placebo-controlled clinical trials of low-dose atropine eyedrops. Cycloplegia was induced using either one drop of 1% cyclopentolate (n = 161), two drops of 1% cyclopentolate (n = 32) or two drops of 1% tropicamide (n = 49). ChT measurements were taken using swept-source optical coherence tomography before and 30 min after administering the cycloplegic eye drops. A subset of 51 participants underwent test-retest measurements prior to cycloplegia. RESULTS: Mean changes in subfoveal ChT after two drops of tropicamide and one and two drops of cyclopentolate were -2.5 µm (p = 0.10), -4.3 µm (p < 0.001) and -9.6 µm (p < 0.001), respectively. Subfoveal ChT changes after one and two drops of cyclopentolate were significantly greater than the test-retest changes (test-retest mean change: -3.1 µm; p < 0.05), while the tropicamide group was not significantly different (p = 0.64). Choroidal thinning post-cyclopentolate was not significantly different between atropine and placebo treatment groups (p > 0.05 for all macular locations). The coefficient of repeatability (CoR) in the tropicamide group (range: 8.2-14.4 µm) was similar to test-retest (range: 7.5-12.2 µm), whereas greater CoR values were observed in the cyclopentolate groups (one drop: range: 10.8-15.3 µm; two drops: range: 12.2-24.6 µm). CONCLUSIONS: Cyclopentolate eye drops caused dose-dependent choroidal thinning and increased variation in pre- to post-cycloplegia measurements compared with test-retest variability, whereas tropicamide did not. These findings have practical implications for ChT measurements when cyclopentolate is used, particularly for successive measurements.

Myopia outcome study of atropine in children: Two-year result of daily 0.01% atropine in a European population.

PURPOSE: The Myopia Outcome Study of Atropine in Children (MOSAIC) is an investigator-led, double-masked, randomized controlled trial investigating the efficacy and safety of 0.01% atropine eye drops for managing myopia progression in a predominantly White, European population. METHODS: Children aged 6-16 years with myopia were randomly allocated 2:1 to nightly 0.01% atropine or placebo eye drops in both eyes for 2 years. The primary outcome was cycloplegic spherical equivalent (SE) progression at 24 months. Secondary outcomes included axial length (AL) change, safety and acceptability. Linear mixed models with random intercepts were used for statistical analyses. RESULTS: Of 250 participants enrolled, 204 (81.6%) completed the 24-month visit (136 (81.4%) treatment, 68 (81.9%) placebo). Baseline characteristics, drop-out and adverse event rates were similar between treatment and control groups. At 24 months, SE change was not significantly different between 0.01% atropine and placebo groups (effect = 0.10 D, p = 0.07), but AL growth was lower in the 0.01% atropine group, compared to the placebo group (-0.07 mm, p = 0.007). Significant treatment effects on SE (0.14 D, p = 0.049) and AL (-0.11 mm, p = 0.002) were observed in children of White, but not non-White (SE = 0.05 D, p = 0.89; AL = 0.008 mm, p = 0.93), ethnicity at 24 months. A larger treatment effect was observed in subjects least affected by COVID-19 restrictions (SE difference = 0.37 D, p = 0.005; AL difference = -0.17 mm, p = 0.001). CONCLUSIONS: Atropine 0.01% was safe, well-tolerated and effective in slowing axial elongation in this European population. Treatment efficacy varied by ethnicity and eye colour, and potentially by degree of COVID-19 public health restriction exposure during trial participation.

TFOS Lifestyle: Impact of the digital environment on the ocular surface.

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).

Choroidal Thickness Profiles and Associated Factors in Myopic Children.

SIGNIFICANCE: This study addresses the lack of choroidal thickness (ChT) profile information available in European children and provides a baseline for further evaluation of longitudinal changes in ChT profiles in myopic children as a potential biomarker for myopia treatment and identifying children at risk of myopic progression. PURPOSE: This study aimed to investigate ChT profiles and associated factors in myopic children. METHODS: Baseline data of 250 myopic children aged 6 to 16 years in the Myopia Outcome Study of Atropine in Children clinical trial were analyzed. Choroidal thickness images were obtained using swept-source optical coherence tomography (DRI-OCT Triton Plus; Topcon Corporation, Tokyo, Japan). The macula was divided into nine Early Treatment of Diabetic Retinopathy Study locations with diameters of 1, 3, and 6 mm corresponding to the central fovea, parafoveal, and perifoveal regions. Multiple linear regression models were used to investigate determinants of ChT. RESULTS: Choroidal thickness varied across the macular Early Treatment of Diabetic Retinopathy Study locations ( P < .001): thickest in the perifoveal superior region (mean ± standard deviation, 249.0 ± 60.8 µm) and thinnest in the perifoveal nasal region (155.1 ± 50.3 µm). On average, ChT was greater in all parafoveal (231.8 ± 57.8 µm) compared with perifoveal (218.1 ± 49.1 µm) regions except superiorly where the ChT was greater in the perifoveal region. Longer axial length and higher myopic spherical equivalent refraction were consistently associated with thinner ChT at all locations in the multiple linear regression models. Asian race was significantly associated with thinner ChT only at parafoveal and perifoveal superior regions after Bonferroni correction ( P = .004 and P = .001, respectively). CONCLUSIONS: Choroidal thickness was thinnest in the nasal macular region and varied systematically across all macular locations, with axial length and spherical equivalent refraction being the strongest determinants of ChT. Longitudinal evidence will need to evaluate whether any differences in ChT profiles are predictive of myopic progression and to determine the role of ChT measurements in identifying myopic children most in need of myopia control treatment.

Strabismus and amblyopia in Africa - a systematic review and meta-analysis.

The objective of this review was to estimate the prevalence of strabismus and amblyopia in Africa. A systematic online literature search was conducted for articles on strabismus and amblyopia in Africa. Meta-analysis was performed, using the Freeman-Tukey double arcsine transformation, to estimate the prevalence of strabismus and amblyopia in Africa. Subgroup analyses were conducted according to age, gender, study year, and type of amblyopia. Meta-regression was used to evaluate the influence of predetermined factors on the prevalence of amblyopia. 8 (1 population-based & 7 school-based) and 21 (3 population-based & 18 school-based) studies on strabismus and amblyopia with sample sizes of 22,355 and 46,841, respectively, were included in the review. Overall prevalence of strabismus in Africa was estimated to be 0.8% (95% CI: 0.4% - 1.4%); exotropia was 0.2% (95% CI: 0.1% - 0.5%) and esotropia was 0.5% (95% CI: 0.1% - 1.2%). Overall prevalence of amblyopia was estimated to be 0.6% (95% CI: 0.3% - 0.9%); refractive and strabismic amblyopia were 1.1% (95% CI: 0.2% - 2.5%) and 0.4% (95% CI: 0.2% - 0.6%), respectively. Prevalence estimate of amblyopia in males was 1.8% (95% CI: 0.7% - 3.3%) and in females was 1.3% (95% CI: 0.4% - 2.6%). There was a significant association between the prevalence of amblyopia and the type of amblyopia (p = .007) and the study year (p = .006). Although there appears to be a relatively low prevalence of strabismus and amblyopia in Africa, there is a dearth of well-designed population-based studies on strabismus and amblyopia in Africa, resulting in the lack of epidemiological information on strabismus and amblyopia within the general African population. Information about the prevalence of strabismus and amblyopia across Africa can inform policy making and design and implementation of public health intervention program.

Regional variations and temporal trends of childhood myopia prevalence in Africa: A systematic review and meta-analysis.

PURPOSE: To provide contemporary and future estimates of childhood myopia prevalence in Africa. METHODS: A systematic online literature search was conducted for articles on childhood (≤18 years) myopia (spherical equivalent [SE] ≤ -0.50D; high myopia: SE ≤ -6.00D) in Africa. Population- or school-based cross-sectional studies published from 1 Jan 2000 to 30 May 2021 were included. Meta-analysis using Freeman-Tukey double arcsine transformation was performed to estimate the prevalence of childhood myopia and high myopia. Myopia prevalence from subgroup analyses for age groups and settings were used as baseline for generating a prediction model using linear regression. RESULTS: Forty-two studies from 19 (of 54) African countries were included in the meta-analysis (N = 737,859). Overall prevalence of childhood myopia and high myopia were 4.7% (95% CI: 3.3%-6.5%) and 0.6% (95% CI: 0.2%-1.1%), respectively. Estimated prevalence across the African regions was highest in the North (6.8% [95% CI: 4.0%-10.2%]), followed by Southern (6.3% [95% CI: 3.9%-9.1%]), East (4.7% [95% CI: 3.1%-6.7%]) and West (3.5% [95% CI: 1.9%-6.3%]) Africa. Prevalence from 2011 to 2021 was approximately double that from 2000 to 2010 for all studies combined, and between 1.5 and 2.5 times higher for ages 5-11 and 12-18 years, for boys and girls and for urban and rural settings, separately. Childhood myopia prevalence is projected to increase in urban settings and older children to 11.1% and 10.8% by 2030, 14.4% and 14.1% by 2040 and 17.7% and 17.4% by 2050, respectively; marginally higher than projected in the overall population (16.4% by 2050). CONCLUSIONS: Childhood myopia prevalence has approximately doubled since 2010, with a further threefold increase predicted by 2050. Given this trajectory and the specific public health challenges in Africa, it is imperative to implement basic myopia prevention programmes, enhance spectacle coverage and ophthalmic services and generate more data to understand the changing myopia epidemiology to mitigate the expanding risk of the African population.

Prevalence of keratoconus in Ghana: A hospital-based study of tertiary eye care facilities.

PURPOSE: To estimate the prevalence of keratoconus in tertiary eye care facilities in Ghana. METHODS AND ANALYSIS: In this hospital-based retrospective cohort study, medical records of patients from tertiary/referral eye care facilities in Ghana were reviewed. Included in the study were records of individuals who visited the eye care facilities and were diagnosed of keratoconus within the period of January 2016 to December 2019 inclusive. Data on patients' demographics, severity of keratoconus, mode of diagnosis, treatment, and visual acuity outcomes were analysed. RESULTS: Out of the total of 142,209 records reviewed, 75 patients were diagnosed of keratoconus in at least one eye (127 eyes; 86.8% bilateral cases), representing a prevalence estimate of 53 per 100000 (95% confidence interval (CI): 41 to 65 per 100000). The mean ± SD age of patients at the time of diagnosis was 21.1 ± 9.5 years (66.2% males). The mean ± SD keratometry in keratoconus patients was 52.1 ± 7.0: majority (76.5%) of the cases were moderate to severe keratoconus. The main primary treatment regimen was corneal transplant (58.8%) followed by spectacles (25.0%), crosslinking (8.8%) and rigid contact lens (7.3%). There was a significant association between post-treatment visual acuity outcomes and treatment type (p < 0.001). CONCLUSION: Our study represents the first prevalence estimate of keratoconus in Ghana. The prevalence of keratoconus estimated in our study is lower than that reported in countries with tropical climates. This could be due to lower uptake of referrals, underdiagnosis and/or misdiagnosis of the condition in lower-level health facilities.

Biomechanical Efficacy and Effectiveness of Orthodontic Treatment with Transparent Aligners in Mild Crowding Dentition-A Finite Element Analysis.

Orthodontic treatment increasingly involves transparent aligners; however, biomechanical analysis of their treatment effects under clinical conditions is lacking. We compared the biomechanical efficacy and effectiveness of orthodontic treatment with transparent aligners and of fixed appliances in simulated clinical orthodontic treatment conditions using orthodontic finite element (FE) models. In the FE analysis, we used Model Activation/De-Activation analysis to validate our method. Fixed appliances and 0.75-mm and 0.5-mm thick transparent aligners were applied to a tooth-alveolar bone FE model with lingually-inclined and axially-rotated central incisors. Compared to the fixed appliance, the 0.75-mm and 0.5-mm transparent aligners induced 5%, 38%, and 28% and 21%, 62%, and 34% less movement of the central incisors and principal stress of the periodontal ligament and of the alveolar bone, respectively, for lingual inclination correction. For axial-rotation correction, these aligners induced 22%, 37%, and 40% and 28%, 67%, and 48% less tooth movement and principal stress of the periodontal ligament and of the alveolar bone, respectively. In conclusion, transparent aligners induced less tooth movement, it is sufficient for orthodontic treatment, but 0.5-mm aligners should be used for only mild corrections. Additionally, the Model Activation/De-Activation analysis method is suitable for FE analysis of orthodontic treatment reflecting clinical treatment conditions.

Relationship between peripheral refraction, axial lengths and parental myopia of young adult myopes

Purpose: To determine the relationship between peripheral refraction at the horizontal retina, axial length and parental history of myopia between myopic adults who have positive parental myopia and those with negative parental myopia.Methods: 69 males and 44 females in the age range of 18–25 years were assigned either a negative parental myopia (NPM) or positive parental myopia (PPM) group. In the corrected and uncorrected states, peripheral refractive error was measured up to 30° horizontally in 10° steps using an open field autorefractor. Axial length was measured using an Opto US1000 Fine A-Scan Ultrasonography (model US1000).Results: Relative peripheral refractive error showed more hyperopic defocus that was statistically significantly more increased in the positive parental myopia group than in the negative parental myopia group (P ≥ 0.02). The overall mean ± SD axial length of all subjects was 23.38 ± 0.32 mm (range 23.01–25.01 mm). The study showed a statistically significant difference (P = 0.005) in axial lengths of young adult myopes (23.45 ± 0.36 mm) with parental myopia compared to those with similar spherical equivalent refraction who have non-myopic parents (23.28 ± 0.19 mm).Conclusion: There was significantly more hyperopic defocus at 30° N and 30° T retina in the corrected states of young adult myopes who had myopic parents compared to their counterparts with non-myopic parents. (AU)

Relationship between peripheral refraction, axial lengths and parental myopia of young adult myopes.

PURPOSE: To determine the relationship between peripheral refraction at the horizontal retina, axial length and parental history of myopia between myopic adults who have positive parental myopia and those with negative parental myopia. METHODS: 69 males and 44 females in the age range of 18-25 years were assigned either a negative parental myopia (NPM) or positive parental myopia (PPM) group. In the corrected and uncorrected states, peripheral refractive error was measured up to 30° horizontally in 10° steps using an open field autorefractor. Axial length was measured using an Opto US1000 Fine A-Scan Ultrasonography (model US1000). RESULTS: Relative peripheral refractive error showed more hyperopic defocus that was statistically significantly more increased in the positive parental myopia group than in the negative parental myopia group (P ≥ 0.02). The overall mean ± SD axial length of all subjects was 23.38 ± 0.32 mm (range 23.01-25.01 mm). The study showed a statistically significant difference (P = 0.005) in axial lengths of young adult myopes (23.45 ± 0.36 mm) with parental myopia compared to those with similar spherical equivalent refraction who have non-myopic parents (23.28 ± 0.19 mm). CONCLUSION: There was significantly more hyperopic defocus at 30° N and 30° T retina in the corrected states of young adult myopes who had myopic parents compared to their counterparts with non-myopic parents.

PREVALENCE OF MEIBOMIAN GLAND DYSFUNCTION IN AFRICA: A SYSTEMATIC REVIEW AND META-ANALYSIS OF OBSERVATIONAL STUDIES.

PURPOSE: To review and summarize information on meibomian gland dysfunction (MGD) epidemiology in Africa. METHODS: A systematic search of online databases was conducted for literature/studies on MGD in Africa. Meta-analysis was conducted to estimate the prevalence of MGD in Africa. Meta-regression was used to explore sources of heterogeneity. RESULTS: Twelve studies conducted in five countries were included in the review. All studies were hospital-based studies. Nine studies were included in the meta-analysis; the total sample size was 4963 and participants' age range was 17-96 years. The overall prevalence estimate of MGD in Africa was 45.9% (95% CI: 27.6-64.1%). Prevalence of MGD among males and females were each pooled from three studies and in urban and rural setting from 6 and 3 studies, respectively. Prevalence of MGD among males and females were 56.0% (95% CI: 22.4-89.5%) and 58.9% (95% CI: 28.5-89.4%) respectively; in urban and rural settings were 42.8% (95% CI: 21.1-64.5%) and 65.7% (95% CI: 25.7-95.7%), respectively. There was no association of MGD with sex (p = .872) and with study setting (p = .231). CONCLUSION: There is a paucity of evidence on MGD prevalence in Africa, emphasizing the need for epidemiological studies to enhance our understanding of region-specific differences in MGD in Africa. The pooled estimate from hospital-based studies, however, suggests a substantial MGD burden in Africa. Epidemiological studies are needed to assess if this translates to a high disease burden within the general African population.

Efficient Design of a Clear Aligner Attachment to Induce Bodily Tooth Movement in Orthodontic Treatment Using Finite Element Analysis.

Clear aligner technology has become the preferred choice of orthodontic treatment for malocclusions for most adult patients due to their esthetic appeal and comfortability. However, limitations exist for aligner technology, such as corrections involving complex force systems. Composite attachments on the tooth surface are intended to enable active control of tooth movements. However, unintended tooth movements still occur. In this study, we present an effective attachment design of an attachment that can efficiently induce tooth movement by comparing and analyzing the movement and rotation of teeth between a general attachment and an overhanging attachment. The 3D finite element modes were constructed from CBCT data and used to analyze the distal displacement of the central incisor using 0.5- and 0.75-mm-thick aligners without an attachment, and with general and overhanging attachments. The results show that the aligner with the overhanging attachment can effectively reduce crown tipping and prevent axial rotation for an intended distal displacement of the central incisor. In all models, an aligner with or without attachments was not capable of preventing the lingual inclination of the tooth.

Evaluation of postoperative refractive error correction after cataract surgery.

Suboptimal cataract surgery outcomes remain a challenge in most developing countries. In Ghana, about 2 million people have been reported to be blind due to cataract with about 20% new cases being recorded yearly. The aim of this study was to evaluate postoperative correction of refractive errors after cataract surgery in a selected eye hospital in Ashanti Region, Ghana. This was a retrospective study where medical records of patients (aged 40-100) who reported to an eye hospital in Ghana from 2013-2018 were reviewed. Included in the study were patients aged ≥40 years and patients with complete records. Data on patient demographics, type of surgery, intra-ocular lens (PCIOL) power, availability of biometry, postoperative refraction outcomes, pre- and postoperative visual acuity were analyzed. Data of two hundred and thirteen eyes of 190 patients who met the inclusion criteria were analyzed. Descriptive analysis and Chi-square test were carried out to determine the mean, median, standard deviation and relevant associations. The mean ± SD age was 67.21±12.2 years (51.2% were females). Small Incision Cataract Surgery (99.5%) with 100% IOL implants was the main cataract surgery procedure in this study. Pre-operative biometry was performed for 38.9% of all patients on their first eye surgery and 41.5% for second eye surgeries. About 71% eyes in this study were blind (presenting VA<3/60) before surgery; 40.4% had post-operative VA <3/60. Pre-existing ocular comorbidities discovered post- surgery, attributed to suboptimal visual outcomes. More than half (55.3%) of patients did not undergo postoperative refraction due to loss to follow-up. Year of surgery (p = .017), follow up visits< 2months (p < .0001) and discovered comorbidity post-surgery (p = .035) were the factors significantly associated with postoperative refraction. Myopia and compound myopic astigmatism were the dominant refractive error outcomes. The timing of post-operative refraction had a significant effect on postoperative refraction done. These findings indicate a clinically meaningful significance between completion of postoperative care and postoperative refraction done. Consequently, with settings in most developing countries, where less biometry is done, it is appropriate that post-operative refractive services are encouraged and done earlier to enhance the patients' expectations while increasing cataract surgery patronage.

Job satisfaction and its associated factors among opticians in Ghana: a cross-sectional study.

BACKGROUND: Job satisfaction refers to the feeling of contentment one experiences with their job. Job satisfaction among opticians is a crucial variable in determining their motivation and has consequential influence on the quality of eye health care, systems and services. Nevertheless, little has been done to assess job satisfaction levels among human resources for eye-health, such as opticians, in Ghana. This study assessed (for the first time) the job satisfaction level among opticians in Ghana, and the factors associated with their job satisfaction. METHODS: This was a cross-sectional survey involving all registered and licensed opticians working in Ghana. A validated, well-structured job satisfaction questionnaire was distributed to 195 opticians across all regions of the country. The questionnaire was composed of 15-item job satisfaction variables which were measured on a five-point Likert scale ('1-strongly disagree' to '5-strongly agree'). Logistic regression analyses were used to investigate the association between sociodemographic characteristics and factors of job satisfaction, and the overall job satisfaction level. RESULTS: A total of 101 opticians responded to the study. The mean presenting age of all participants was 25.3 ± 5.0 years (21 to 47 years), with majority being males (57.4%). The mean score of the overall job satisfaction level reported by participants was 2.65, with 12.9% (95% confidence interval [CI]: 7.0-21.0%) of them being satisfied with their jobs. There was no statistically significant association between overall job satisfaction and sociodemographic characteristics (p > 0.05; for all). Only salary was significantly associated with overall level of job satisfaction (odds ratio [OR]: 16.5; 95% CI: 2.06-132.86; p = 0.008). CONCLUSION: Majority of opticians working in Ghana were not satisfied with their jobs. Enhancing salary/remuneration would improve the job satisfaction level among opticians in the country. There is the need for effective management of human resources for eye-health (particularly opticians) and policy revision on ophthalmic healthcare administration in Ghana.

Keratoconus in Africa: A systematic review and meta-analysis.

PURPOSE: The aim of this review is to evaluate the prevalence of and factors associated with keratoconus in Africa. METHOD: A systematic online literature search was conducted for articles on keratoconus in Africa. Meta-analysis was performed to estimate the prevalence of keratoconus in Africa. The Freeman-Tukey double arcsine transformation was used to minimize the effects of studies with extremely high or low prevalence estimates on the overall pooled estimates. Leave-one-out sensitivity analysis was used to assess the robustness of the pooled effects and potential outliers. Meta-regression was performed to explore associations between keratoconus, gender and age. RESULTS: Twelve studies were included in the review; 5 from Egypt, 2 from South Africa, 2 from Kenya, 1 from Sudan, 1 from Ghana and 1 from Nigeria. Two studies were conducted in allergic conjunctivitis patients, 4 in keratoconus patients, 1 in contact lens service seekers, 1 in pre-LASIK patients, 1 in refractive patients and 1 in a student population. Eight studies were included in the meta-analysis. The overall prevalence estimate of keratoconus in Africa was 7.9% (95% CI: 2.5%-16.0%). The prevalence of keratoconus among males and females in Africa was estimated to be 9.3% (95% CI: 2.5%-19.5%) and 5.8% (95% CI: 1.5%-12.7%) respectively. The estimated prevalence of unilateral and bilateral keratoconus was 2.6% (95% CI: 0.4%-6.5%) and 5.8% (95% CI: 1.6%-12.3%), respectively. The estimated prevalence of mild keratoconus was 2.2% (95% CI: 0.7%-4.7%), moderate keratoconus was 3.5% (95% CI: 0.0%-11.8%) and severe keratoconus was 4.0% (95% CI: 0.0%-19.6%). There was no significant association between gender and the prevalence of keratoconus in Africa (p = 0.63), and age and the prevalence of keratoconus in Africa (p = 0.78). CONCLUSION: The estimated prevalence of keratoconus reported here is higher than prevalence values reported in other meta-analyses or different geographical locations. This is mainly because studies included in this meta-analysis were either conducted on a cohort at high risk of keratoconus or a population with high possibility of finding keratoconus patients. There is a dearth of well-designed population-based studies on keratoconus in Africa, resulting in a lack of epidemiological information. This highlights the urgent need for research on keratoconus in Africa.