A preliminary investigation into the effects of ocular lubricants on higher order aberrations in normal and dry eye subjects

Purpose: To study the effects of ocular lubricants on higher order aberrations in normal and self-diagnosed dry eyes. Methods: Unpreserved hypromellose drops, Tears Again™ liposome spray and a combination of both were administered to the right eye of 24 normal and 24 dry eye subjects following classification according to a 5 point questionnaire. Total ocular higher order aberrations, coma, spherical aberration and Strehl ratios for higher order aberrations were measured using the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) at baseline, immediately after application and after 60. min. The aberration data were analyzed over a 5. mm natural pupil using Zernike polynomials. Each intervention was assessed on a separate day and comfort levels were recorded before and after application. Corneal staining was assessed and product preference recorded after the final measurement for each intervention. Results: Hypromellose drops caused an increase in total higher order aberrations (p= <0.01 in normal and dry eyes) and a reduction in Strehl ratio (normal eyes: p= <0.01, dry eyes p= 0.01) immediately after instillation. There were no significant differences between normal and self-diagnosed dry eyes for response to intervention and no improvement in visual quality or reduction in higher order aberrations after 60. min. Differences in comfort levels failed to reach statistical significance. Conclusion: Combining treatments does not offer any benefit over individual treatments in self-diagnosed dry eyes and no individual intervention reached statistical significance. Symptomatic subjects with dry eye and no corneal staining reported an improvement in comfort after using lubricants. © 2013 British Contact Lens Association

A Comparative Predicting Stock Prices using Heston and Geometric Brownian Motion Models

This paper presents a novel approach to predicting stock prices using technical analysis. By utilizing Ito's lemma and Euler-Maruyama methods, the researchers develop Heston and Geometric Brownian Motion models that take into account volatility, interest rate, and historical stock prices to generate predictions. The results of the study demonstrate that these models are effective in accurately predicting stock prices and outperform commonly used statistical indicators. The authors conclude that this technical analysis-based method offers a promising solution for stock market prediction

Neuronavigation assisted endoscopic sinus surgery

In the past two decades, endoscopic sinus surgeries (ESS) have been widely advocated as a safe and effective treatment for disorders of paranasal sinuses that are refractory to medical therapy. ESS caters surgeons with two-dimensional visualization of the anatomical structures; however in scenarios where there is a close anatomical relation between the disease and delicate intracranial or intraorbital structures drastic complications can occur. Hence, endoscopic procedures had to be converted into open surgical procedures if the extent of the disease could not be visualized or cleared thoroughly. Recently however; neuronavigation systems have been combined with ESS to yield better results and facilitate this procedure. The implementation of these systems with ESS has aided surgeons in difficult approaches. We recently decided to use the neuronavigation system of our Neurosurgical department to help aid eradicate various nasal and sinus pathologies in a series of patients

Optimizing measurement of subjective amplitude of accommodation with defocus curves

PURPOSE: To determine whether letter sequences and/or lens-presentation order should be randomized when measuring defocus curves and to assess the most appropriate criterion for calculating the subjective amplitude of accommodation (AoA) from defocus curves. SETTING: Eye Clinic, School of Life &amp; Health Sciences, Aston University, Birmingham, United Kingdom. METHODS: Defocus curves (from +3.00 diopters [D] to -3.00 D in 0.50 D steps) for 6 possible combinations of randomized or nonrandomized letter sequences and/or lens-presentation order were measured in a random order in 20 presbyopic subjects. Subjective AoA was calculated from the defocus curves by curve fitting using various published criteria, and each was correlated to subjective push-up AoA. Objective AoA was measured for comparison of blur tolerance and pupil size. RESULTS: Randomization of lens-presentation order and/or letter sequences, or lack of, did not affect the measured defocus curves (P&gt;.05, analysis of variance). The range of defocus that maintains highest achievable visual acuity (allowing for variability of repeated measurement) was better correlated to (r = 0.84) and agreed best with ( 0.50 D) subjective push-up AoA than any other relative or absolute acuity criterion used in previous studies. CONCLUSIONS: Nonrandomized letters and lens presentation on their own did not affect subjective AoA measured by defocus curves, although their combination should be avoided. Quantification of subjective AoA from defocus curves should be standardized to the range of defocus that maintains the best achievable visual acuity

Ureteral stent placement increases the risk for developing BK viremia after kidney transplantation.

The placement of ureteral stent (UrSt) at kidney transplantation reduces major urological complications but increases the risk for developing nephropathy from the BK virus. It is unclear whether UrSt placement increases nephropathy risk by increasing risk of precursor viral replication or by other mechanisms. We retrospectively investigated whether UrSt placement increased the risk for developing BK Viremia (BKVM) in adult and pediatric kidney transplants performed at the University of Florida between July 1, 2007, and December 31, 2010. In this period all recipients underwent prospective BKV PCR monitoring and were maintained on similar immunosuppression. Stent placement or not was based on surgeon preference. In 621 transplants, UrSt were placed in 295 (47.5%). BKVM was seen in 22% versus 16% without UrSt (P=0.05). In multivariate analyses, adjusting for multiple transplant covariates, only UrSt placement remained significantly associated with BKVM (P=0.04). UrSt placement significantly increased the risk for BKVM. Routine UrSt placement needs to be revaluated, since benefits may be negated by the need for more BK PCR testing and potential for graft survival-affecting nephritis

Comparison of near visual acuity and reading metrics in presbyopia correction

PURPOSE: To provide a consistent standard for the evaluation of different types of presbyopic correction. SETTING: Eye Clinic, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom. METHODS: Presbyopic corrections examined were accommodating intraocular lenses (IOLs), simultaneous multifocal and monovision contact lenses, and varifocal spectacles. Binocular near visual acuity measured with different optotypes (uppercase letters, lowercase letters, and words) and reading metrics assessed with the Minnesota Near Reading chart (reading acuity, critical print size [CPS], CPS reading speed) were intercorrelated (Pearson product moment correlations) and assessed for concordance (intraclass correlation coefficients [ICC]) and agreement (Bland-Altman analysis) for indication of clinical usefulness. RESULTS: Nineteen accommodating IOL cases, 40 simultaneous contact lens cases, and 38 varifocal spectacle cases were evaluated. Other than CPS reading speed, all near visual acuity and reading metrics correlated well with each other (r&gt;0.70, P&lt;.001). Near visual acuity measured with uppercase letters was highly concordant (ICC, 0.78) and in close agreement with lowercase letters (+/- 0.17 logMAR). Near word acuity agreed well with reading acuity (+/- 0.16 logMAR), which in turn agreed well with near visual acuity measured with uppercase letters 0.16 logMAR). Concordance (ICC, 0.18 to 0.46) and agreement (+/- 0.24 to 0.30 logMAR) of CPS with the other near metrics was moderate. CONCLUSION: Measurement of near visual ability in presbyopia should be standardized to include assessment of near visual acuity with logMAR uppercase-letter optotypes, smallest logMAR print size that maintains maximum reading speed (CPS), and reading speed. J Cataract Refract Surg 2009; 35:1401-1409 (C) 2009 ASCRS and ESCR

Comparison of fitting stability of the different soft toric contact lenses

Purpose: To compare lens orientation and rotational recovery of five currently available soft toric lenses. Methods: Twenty subjects were recruited and trialed with each of the study lenses in a random order. Study lenses were PureVision® Toric (B&L), Air Optix® for Astigmatism (Alcon), Biofinity® Toric (CooperVision), Acuvue® Advance for Astigmatism (Vistakon), and Proclear® Toric (CooperVision). Lens orientation in primary position to determine the lens rotation form the vertical position and rotational recovery to primary gaze orientation following a 45° manual misorientation for the different lenses was compared. Results: The Biofinity Toric showed the lowest rotation from the vertical position and the Proclear Toric the highest. Also, the highest and the lowest reorientation speed were related to the Biofinity Toric and the Acuvue Advance for Astigmatism, respectively. The Repeated Measures ANOVA showed a significant difference in the lens rotation (P=. 0.004) and rotational recovery (P<. 0.001) among different contact lenses and the performed multiple comparisons indicated differences in rotation and also in reorientation speed were only seen between the Biofinity Toric when compared to four other lenses (P<. 0.05). Conclusion: Although there was appropriate fitting, based upon lens orientation and reorientation speed, with each of the study lenses it would appear that the optimized ballast technique used in the design of the Biofinity Toric helps reduce lens rotation and improve rotational recovery compared to others

Customer loyalty among daily disposable contact lens wearers

Background: Optometric practices offer contact lenses as cash sale items or as part of monthly payment plans. With the contact lens market becoming increasingly competitive, patients are opting to purchase lenses from supermarkets and Internet suppliers. Monthly payment plans are often implemented to improve loyalty. This study aimed to compare behavioural loyalty between monthly payment plan members and non-members. Methods: BBR Optometry Ltd offers a monthly payment plan (Eyelife™) to their contact lens wearers. A retrospective audit of 38 Eyelife™ members (mean. ±. SD: 42.7. ±. 15.0 years) and 30 non-members (mean. ±. SD: 40.8. ±. 16.7 years) was conducted. Revenue and profits generated, service uptake and product sales between the two groups were compared over a fixed period of 18 months. Results: Eyelife™ members generated significantly higher professional fee revenue ( P<. 0.001), £153.96 compared to £83.50, and profits ( P<. 0.001). Eyelife™ members had a higher uptake of eye examinations ( P<. 0.001). The 2 groups demonstrated no significant difference in spectacle sales by volume ( P= 0.790) or value ( P= 0.369). There were also no significant differences in contact lens revenue ( P= 0.337), although Eyelife™ members did receive a discount. The Eyelife™ group incurred higher contact lens costs ( P= 0.037), due to a greater volume of contact lens purchases, 986 units compared to 582. Conclusions: Monthly payment plans improve loyalty among contact lens wearers, particularly service uptake and volume of lens purchases. Additionally the greater professional fees generated, render monthly payment plans an attractive business model and practice builder

An analysis of penalty kicks in elite football post 1997

The penalty kick in football is a seemingly simplistic play; however, it has increased in complexity since 1997 when the rules changed allowing goalkeepers to move laterally along their goal line before the ball was kicked. Prior to 1997 goalkeepers were required to remain still until the ball was struck. The objective of this study was to determine the importance of the penalty kick in the modern game of football. A retrospective study of the 2002, 2006 and 2010 World Cup and the 2000, 2004 and 2008 European Championship tournaments was carried out, assessing the importance of the penalty kick in match play and shootouts and the effect of the time of the game on the shooter's success rate. This study demonstrated the conversion rate of penalties was 73% in shootouts and 68% in match play. Significantly more penalties were awarded late in the game: twice as many penalties in the second half than the first and close to four times as many in the fourth quarter vs. the first. Teams awarded penalty kicks during match play won 52%, drew 30% and lost 18% of the time; chances of winning increased to 61% if the penalty was scored, but decreased to 29% if missed. Teams participating in either the World Cup or European Championship final match had roughly a 50% chance of being involved in a penalty shootout during the tournament. Penalty shots and their outcome significantly impact match results in post 1997 football