The sports science of curling: a practical review.

Curling is a sport played on ice in which two teams each deliver 8 granite stones towards a target, or 'house'. It is the only sport in which the trajectory of the projectile can be influenced after it has been released by the athlete. This is achieved by sweeping the ice in front of the stone to change the stone-ice friction and thereby enable to stone to travel further, curl more or stay straight. Hard sweeping is physically demanding. Different techniques of sweeping can also have different effects on the stone. This paper will review the current research behind sweeping a curling stone, outline the physiological demands of sweeping, the associated performance effects and suggest potential strategies of sweeping that can be used by both coaches and curling teams. Key pointsSweeping a curling stone can be highly physically demanding.Effective sweeping requires a combination of downward force and brush head speed, determined by the stone velocity.Sweeping on the left or right of a stone can help the stone to remain straight or curl more depending on the rotation of the stone.This can lead to the development of sweeping and playing tactics and contribute to team selection.

Comorbidities and Prescribed Medications in Patients With or Without Dry Eye Disease: A Population-Based Study.

PURPOSE: To assess the proportion of comorbidities in patients with dry eye disease (DED) compared with matched patients without DED in a comprehensive US population. DESIGN: Retrospective case-control study. METHODS: Healthcare records for insurance claims data, detailing medical services incurred by military personnel and their families and dependents in military and civilian facilities across the United States from January 1, 2003, to March 31, 2015, were obtained from the Department of Defense (DOD) Military Health System (MHS). Diagnostic and procedural codes related to DED from selected International Classification of Diseases, Ninth Revision (ICD-9) Current Procedural Terminology codes and prescriptions for cyclosporine A ophthalmic emulsion were used to identify patients with newly diagnosed and prevalent DED in the MHS database. Age, sex, and geographically matched patients without DED were also identified from healthcare claims records. Medication use and comorbidities in these patient populations were assessed and compared. RESULTS: In both the newly diagnosed and prevalent DED samples, the most common comorbidities were hypertension, cataracts, thyroid disease, type 2 diabetes, and glaucoma. All comorbidities were significantly higher in the DED vs non-DED groups (P < .001). Medication use (including, but not limited to, ophthalmic agents and drugs to treat comorbidities) was also significantly higher in the DED than in the non-DED groups (P < .001). CONCLUSIONS: The high proportions of patients with DED with a range of comorbidities and prescribed medications highlight the need for a multidisciplinary approach to the management of these patients.

Dry eye disease ranking among common reasons for seeking eye care in a large US claims database.

OBJECTIVES: Dry eye disease (DED) is a complex multifactorial condition of the ocular surface characterized by symptoms of ocular discomfort, irritation, and visual disturbance. Data previously reported from this study showed an increase in prevalence and incidence of DED with age and over time. The objective of this study was to compare the ranking of DED prevalence among other ocular conditions that led patients to seek eye care. METHODS: In this population-based study using the US Department of Defense Military Health System claims database of >9.7 million beneficiaries, indicators of DED and other ocular conditions were analyzed over time. The overall prevalence (2003-2015) and annual incidence (2008-2012) of DED and other ocular conditions were estimated using an algorithm based on two independent indicators derived from selected diagnostic and procedure codes and prescriptions for cyclosporine ophthalmic emulsion for DED and diagnostic codes for the indicators of other common ocular conditions. RESULTS: In 2003-2015, the most common ocular conditions were disorders of refraction and accommodation (25.84%), cataracts (17.14%), glaucoma (7.27%), disorders of the conjunctiva (6.76%), other retinal disorders (5.94%), and DED (5.28%). DED was the fifth most prevalent ocular condition in women (7.78%) and ninth most prevalent in men (2.96%). In 2012, DED had the third highest annual incidence (0.87%), behind disorders of refraction/accommodation (1.87%) and cataracts (1.50%). CONCLUSION: This study provided further epidemiologic evidence for DED as a commonly occurring condition that drives patients to seek treatment.

Estimated Prevalence and Incidence of Dry Eye Disease Based on Coding Analysis of a Large, All-age United States Health Care System.

PURPOSE: To assess overall prevalence, annual prevalence, and incidence of dry eye disease (DED) in a large, representative population in the United States. DESIGN: Prevalence and incidence study. METHODS: Retrospective analysis using the Department of Defense (DOD) Military Health System (MHS) data on beneficiary medical claims from United States DOD military and civilian facilities, January 1, 2003 through March 31, 2015. PATIENT POPULATION: Using an algorithm, medical diagnostic codes indicative of DED and prescriptions for cyclosporine ophthalmic emulsion identified a DED population from 9.7 million MHS beneficiaries (DOD service members, retirees, and dependents, aged 2-80+ years). MAIN OUTCOME MEASURES: DED overall prevalence (2003-2015), annual prevalence (2005-2012), and annual incidence (2008-2012) stratified by sex, age group, and International Statistical Classification of Diseases and Related Health Problems, Ninth Revision diagnosis code grouping. RESULTS: DED prevalence was 5.28% overall, 7.78% among female beneficiaries, 2.96% among male beneficiaries and increased with age from 0.20% for ages 2-17 years, to 11.66% for individuals aged 50+ years. Annual prevalence increased from 0.8% to 3.0% overall, from 1.4% to 4.5% in female beneficiaries, and from 0.3% to 1.6% in male beneficiaries. Annual prevalence increased across age groups starting at age 18-39, 0.1%-0.6%, to age 50+, 1.8%-6.0%. Annual incidence increased from 0.6% to 0.9% overall, from 0.8% to 1.2% in female beneficiaries, and from 0.3% to 0.6% in male beneficiaries. Across age groups, annual incidence increased starting at age 18-39 (0.2%-0.3%), to age 50+ (1.0%-1.6%). CONCLUSIONS: DED overall prevalence, annual prevalence, and incidence were found to increase over time for all demographics. These findings highlight the continued importance of research and therapeutic development for this common condition.

Evaluation of Aircrew Low-Intensity Threat Laser Eye Protection.

Prototype low-intensity threat laser eye protection (LIT-LEP) spectacles were evaluated for US Coast Guard (USCG) cockpits and night vision goggle compatibility. The impetus for interest in aviation LIT-LEP is driven in part by the fact that easily accessible 0.5-2.0 W high-power laser pointers exceed safety standards for direct on-axis viewing. A repeated-measures experimental design was used to assess LIT-LEP performance relative to a no-LEP control for the following tasks: Near- and far contrast acuity, night vision goggle far-contrast acuity, emissive and non-emissive light source color-vision screening, and USCG multifunctional display color symbol discrimination reaction time and accuracy. Near- and far-contrast acuity results demonstrated good LIT-LEP performance for typical in- and out-of-cockpit lighting conditions. Night vision goggle performance suffered marginally at only one contrast level (85%; 20/30 acuity line). Color vision test results showed good color balance in that S-, M-, and L-cone performance did not demonstrate a clinical diagnostic color defect for emissive or non-emissive light sources when wearing LIT-LEP. Color symbol discrimination reaction-time-task results based on inverse efficiency scores revealed that some non-primary flight display colors exhibited a combination of slower speed and decreased accuracy. The findings will contribute to an acquisition decision as well as guide future LEP designs.

Adaptation of impression cytology to enable conjunctival surface cell transcriptome analysis.

PURPOSE: This study investigates the extent of the human transcriptome that can be quantified from conjunctival impression cytology extracts. The aim is to determine if sufficient RNA can be isolated from a patient's conjunctival surface to identify differences in gene expression between dry eye and normal patients of (a) an array of 96 inflammatory biomarkers and associated receptors, and (b) if this comparison can be expanded to the entire transcriptome. MATERIALS AND METHODS: CIC was used to collect conjunctival surface cells from 53 qualifying normal and dry eye patients. Based on prior optimization of all assay steps, RNA was isolated from the samples using a Qiagen RNeasy Plus Mini Kit and qRT-PCR was used to determine gene expression of 96 genes using TaqMan Low Density Array cards. Samples from six normal and six dry eye patients were then assayed on an Illumina Human HT-12 BeadChip. RESULTS: Optimization steps yielded an RNA processing procedure that improved yield from an initial 12 genes through 96, then to the entire human transcriptome. For the HT-12 BeadChip, more than 30 genes differed by a factor of >1.5 between the dry eye and normal groups and seven genes were down-regulated by a factor of >2.0 in the dry eye group: HLA-DRB5, PSCA, FOS, lysozyme, TSC22D1, CAPN13 and CXCL6. CONCLUSIONS: Conjunctival impression cytology can be used to collect sufficient RNA from conjunctival surface cells that, when processed optimally, allows successful transcriptome-wide expression analysis. While the current transcriptome analysis used a limited patient group, larger studies of patients with various types and severities of dry eye should reveal significant gene expression trends that can then be targeted to improve dry eye treatment options.