Near visual function measured with a novel tablet application in patients with astigmatism

Clinical relevance: While the clinical focus of performance metrics is traditionally based on visual acuity, research from the field of visual impairment has demonstrated that metrics such as reading speed and critical print size correlate much more strongly with subjective patient reported outcomes and assessed ability in real-world tasks. Background: More recently, digital device use has increasingly replaced many paper-based tasks. Therefore, this study aimed to assess the correlation between standard acuity/contrast metrics and functional reading ability compared to real-world performance on an iPad-based reading task with astigmatic patients corrected wearing toric and mean spherical equivalent contact lenses. Methods: Thirty-four adult participants, with −0.75 to −1.50 D of refractive astigmatism, were enrolled in a double-masked cross-over study and fitted with toric and spherical equivalent contact lenses, in random order. A digital application was developed to assess zoom, contrast modifications, the distance at which the tablet was held, blink rate, and time to complete the reading task. High and low contrast near logMAR visual acuity were measured along with reading performance (critical print size and optimal reading speed). Results: The amount participants chose to increase tablet font size (zoom) was correlated with their high-contrast visual acuity with toric correction (r = 0.434, p = 0.010). With best sphere correction, zoom was associated with reading speed (r = −0.450, p = 0.008) and working distance (r = 0.522, p = 0.002). Text zoom was also associated with horizontal (toric: r = 0.898, p < 0.001; sphere: r = 0.880, p < 0.001) and vertical scrolling (toric: r = 0.857, p < 0.001; sphere: r = 0.846, p < 0.001). There was a significant negative association between the selection of text contrast and zoom (toric: r = −0.417, p = 0.0141; sphere: r = −0.385, p = 0.025). Conclusion: Real-world task performance allows more robust assessment of visual function than standard visual metrics alone. Digital technology offers the opportunity to better understand the impact of different vision correction options on real-world task performance

The Role of Corneal Astigmatism When Fitting Orthokeratology Contact Lenses

Purpose: About one-third of children aged 5-17 years old have astigmatism. Children with increasing astigmatism can also have an accompanying increase in myopia via axial elongation. All of the randomized clinical trials to date have excluded patients with more than 1.50 D of astigmatism and there are limited data on the success of orthokeratology in patients with moderate to high astigmatism. The purpose of this thesis was to assess the fit of sphere and toric lenses and quantify the amount of corneal astigmatism corrected, and to determine the effect of peripheral elevation and central corneal astigmatism on toric orthokeratology fitting. Methods: Two different studies were performed. The first was a retrospective analysis on 32 eyes of 16 subjects, half fitted with sphere and half with toric orthokeratology lenses. The post-treatment data after 1-3 months of successful nightly wear were compared to pre-treatment data to analyze the change in corneal astigmatism. The second study was a prospective analysis of the Pentacam tomography of 25 moderate refractive myopic astigmats (1.25 to 3.50 DC), ages 19 to 38 years. A subset of 20 subjects were fitted with Paragon Dual Axis Corneal Refractive Therapy (CRT) lenses that were worn for 10 2 days. Results: Three methods of analysis showed that the decrease in corneal astigmatism for the spherical lens group was 0.10 - 0.22 D, which was approximately 22 - 31% correction, and the toric group was 0.29 - 0.57 D, which was 20 - 36% correction (all p < 0.006). There was a strong correlation between central corneal astigmatism and corneal elevation at the 4, 6, and 8 mm chords (r = 0.979, r = 0.961, r = 0.927, respectively; all p < 0.001). After Dual Axis lens wear, the average decentration of the treatment zone from the pupil center was 0.29 ± 0.23 mm temporal and 0.13 ± 0.26 mm inferior. Conclusion: Toric orthokeratology lenses correct slightly more corneal astigmatism than spherical lenses. Central corneal astigmatism was highly correlated to peripheral elevation and may be a more expedient measure for clinical use when fitting toric orthokeratology lenses. The amount of treatment zone decentration with toric lenses was minimal which may lead to better visual performance.Optometry, College o

Comparison of Toric Orthokeratology and Soft Toric Multifocal Contact Lenses in Managing the Astigmatic Myope

Purpose: Myopia management is an important intervention to reduce the risk of vision threatening ocular disease. Contact lens treatments for patients with astigmatism include toric orthokeratology (TOK) and soft toric multifocal (STM) lenses. The purpose of this study was to quantify visual performance and the potential for myopia management efficacy with TOK and STM in moderate to high astigmatic patients. Methods: Thirty adults, age 18-39 years, with myopia (plano to -5.00 D) and refractive astigmatism (-1.25 to -3.50 D) were recruited to complete this five-visit crossover study. Subjects wore both TOK and STM lenses in random order for 10±2 days each. After lens wear, visual performance and acceptance was measured with logMAR visual acuity and patient-reported outcome surveys. Peripheral refraction and wavefront aberrometry were measured to determine the lens’ potential impact for myopia management. Results: Adults, who are critical users, preferred STM for cost when forced to choose between the two corrections. Compared to baseline, TOK induced a myopic shift in defocus (M) at all retinal locations except 20 degrees nasal (all p<0.03), but STM only induced a myopic shift at 20 degrees temporal (p<0.03). TOK resulted in more myopic defocus than STM at all locations (all p<0.05) except 20 degrees nasal and temporal in the left eye. Higher-order root mean square wavefront error (5 mm pupil diameter) was significantly increased with TOK (0.64±0.22 µm) and STM (0.48±0.11 µm) from baseline (0.24±0.08 µm, both p < 0.001), and TOK was elevated compared to STM (p = 0.026). Conclusion: TOK induced greater peripheral myopic defocus and higher-order aberrations, which may indicate improved efficacy for myopia management. Adult astigmats preferred the vision with TOK over STM

Soft toric contact lens wear improves digital performance and vision—A randomised clinical trial

Purpose To compare objective and subjective digital near visual performance and comfort in low to moderate astigmatic participants fitted with toric versus spherical equivalent silicone hydrogel daily disposable contact lenses. Methods This was a double-masked, randomised, crossover study. Participants aged 18 to 39 years with astigmatism of −0.75 to −1.50 D were recruited and fitted with toric and spherical contact lenses, in random order. Outcomes were measured at baseline and after 1 week of wear with each contact lens type after the follow-up visits. High- and low-contrast near logMAR visual acuity, automated visual acuity, zoom (%), contrast (%), reading distance (cm), critical print size (logMAR) and reading speed were assessed. Participants also completed the validated Near Activity Visual Questionnaire (NAVQ) and Contact Lens Dry Eye Questionnaire 8 (CLDEQ-8) for each correction type. Results Twenty-three participants completed the study (74% female, average age 24.4 ± 4.2 years). When participants wore toric contact lenses, near high- and low-contrast visual acuity and automated visual acuity improved by 3–4 letters (all p < 0.03) and participants were able to read faster on an iPad (p = 0.02). Participants were also able to read with 8% less contrast on the iPad with toric lenses (p = 0.01). Participants reported better subjective vision on the overall NAVQ (p = 0.001) and better comfort on the CLDEQ-8 (p = 0.02) with toric lenses. Fewer participants reported difficulty with maintaining focus at near, reading small print, reading labels/instructions, reading the computer display/keyboard and reading post/mail with toric correction. Conclusions Toric contact lenses improve comfort, subjective and objective visual performance with digital devices and other near tasks compared with the spherical equivalent correction in participants with low to moderate astigmatism

Hypothalamic-pituitary-adrenal axis dysregulation and cortisol activity in obesity: A systematic review.

BackgroundAlthough there is substantial evidence of differential hypothalamic-pituitary-adrenal (HPA) axis activity in both generalized and abdominal obesity, consistent trends in obesity-related HPA axis perturbations have yet to be identified.ObjectivesTo systematically review the existing literature on HPA activity in obesity, identify possible explanations for inconsistencies in the literature, and suggest methodological improvements for future study.Data sourcesIncluded papers used Pubmed, Google Scholar, and the University of California Library search engines with search terms body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, sagittal diameter, abdominal versus peripheral body fat distribution, body fat percentage, DEXA, abdominal obesity, and cortisol with terms awakening response, slope, total daily output, reactivity, feedback sensitivity, long-term output, and 11β-HSD expression.Study eligibility criteriaEmpirical research papers were eligible provided that they included at least one type of obesity (general or abdominal), measured at least one relevant cortisol parameter, and a priori tested for a relationship between obesity and cortisol.ResultsA general pattern of findings emerged where greater abdominal fat is associated with greater responsivity of the HPA axis, reflected in morning awakening and acute stress reactivity, but some studies did show underresponsiveness. When examined in adipocytes, there is a clear upregulation of cortisol output (due to greater expression of 11β-HSD1), but in hepatic tissue this cortisol is downregulated. Overall obesity (BMI) appears to also be related to a hyperresponsive HPA axis in many but not all studies, such as when acute reactivity is examined.LimitationsThe reviewed literature contains numerous inconsistencies and contradictions in research methodologies, sample characteristics, and results, which partially precluded the development of clear and reliable patterns of dysregulation in each investigated cortisol parameter.Conclusions and implicationsThe literature to date is inconclusive, which may well arise from differential effects of generalized obesity vs. abdominal obesity or from modulators such as sex, sex hormones, and chronic stress. While the relationship between obesity and adipocyte cortisol seems to be clear, further research is warranted to understand how adipocyte cortisol metabolism influences circulating cortisol levels and to establish consistent patterns of perturbations in adrenal cortisol activity in both generalized and abdominal obesity

Pulmonary vascular volume, impaired left ventricular filling and dyspnea: The MESA Lung Study.

BackgroundEvaluation of impaired left ventricular (LV) filling has focused on intrinsic causes of LV dysfunction; however, pulmonary vascular changes may contribute to reduced LV filling and dyspnea. We hypothesized that lower total pulmonary vascular volume (TPVV) on computed tomography (CT) would be associated with dyspnea and decrements in LV end-diastolic volume, particularly among ever-smokers.MethodsThe Multi-Ethnic Study of Atherosclerosis recruited adults without clinical cardiovascular disease in 2000-02. In 2010-12, TPVV was ascertained as the volume of arteries and veins in the lungs detectable on non-contrast chest CT (vessels ≥1 mm diameter). Cardiac measures were assessed by magnetic resonance imaging (MRI). Dyspnea was self-reported.ResultsOf 2303 participants, 53% had ever smoked cigarettes. Among ever-smokers, a lower TPVV was associated with a lower LV end-diastolic volume (6.9 mL per SD TPVV), stroke volume, and cardiac output and with dyspnea (all P-values ConclusionReductions in pulmonary vascular volume were associated with lower LV filling and dyspnea among ever-smokers, including those without lung disease, suggesting that smoking-related pulmonary vascular changes may contribute to symptoms and impair cardiac filling and function without evidence of impaired LV relaxation