The clinical assessment of systemic hypertension in optometric practice

This thesis sets out to examine in detail the condition of systemic hypertension (high Blood Pressure) in relation to optometric practice in the United Kingdom. Systemic hypertension, which is asymptomatic in the early stages, is diagnosed from the Blood Pressure (BP) measurement recorded by a sphygmomanometer and/or from the complications that have developed in target organs. Optometric practice based surveys revealed that diagnosed systemic hypertension was the most prevalent cardiovascular medical condition (20.5%). Measurement of BP of patients in this sample revealed that if an optometrist included sphygmomanometry into the sight examination then at least one patient each day would be referred for suspect systemic hypertension. Optometric opinion felt that the measurement of BP in optometric practice would advance the profession, being appreciated by both patients and General Practitioners (GPs), but was felt to be an unnecessary routine procedure. The present sight examination for the systemic hypertensive is similar to that of the normotensive patient, but may involve an altered fundus examination and a visual field test. The GPs were in favour of optometric BP measurement and a future role in the share care management of the systemic hypertensive. The application of a new pictorial grading scale for the grading of vascular changes associated with pre-malignant systemic hypertension was found to be both accurate and reliable. Clinical trial of the grading scale in optometric practice found positive correlations between BP and increasing severity of the retinal vascular features. The subtle pre-malignant vascular changes require reliable accurate detection and analysis to assist in the management of the systemic hypertensive patient. Vessel width was shown to decrease with increasing age. Image analysis of the A/V ratio, arteriolar tortuosity and focal calibre changes revealed a positive correlation to the patient's BP (p<0.001). The retinal vasculature is relatively stable longitudinally with only minor changes in response to early disease states. Age and elevated BP increased a patient's risk of developing systemic medical conditions over a two-year period. The application of the pictorial grading scale to optometric practice and training the optometrist in the use of sphygmomanometry would improve the management of the systemic hypertensive patient in optometric practice. Future advances in image analysis hold substantial benefits for the detection and monitoring of subtle vascular changes associated with systemic hypertension.

Marketing responsibility in an era of economic and climatic challenge

Purpose – The purpose of this paper is to illustrate Michael Thomas's concept of civic professionalism and social trusteeship as a future alternative to the current marketing profession's code of conduct and to put this in the context of climate change and ecological sustainability as a model for firms everywhere. Design/methodology/approach – Review of the marketing profession's responsibility towards society, communities and the ecology of the planet in the twenty-first century in the light of climate change. Findings – The hypothesis for the paper emerges as: whether it is possible for Chinese firms to embrace the needs of twenty-first century global ecological sustainability in meeting their own economic requirements for development and financial prosperity. Research limitations/implications – Limited secondary research and primary research that is also limited in terms of scope. Practical implications – As we move into an era of Chinese economic supremacy, we marketers must face up to the responsibility we have towards balancing the progression of global economic development (and selling goods and services in global market systems) with our responsibility towards our cultural systems and the global ecological system (the global ecosystem), the home of all our economic wealth. Social implications – To extrapolate lessons and opportunities for firms from developing economies as they move towards global domination of world economic markets and, suggest strategies for sustainability that they can, and should, adopt. Originality/value – The paper presents a theoretical framework for a global strategy for sustainability, and provides a vision of marketing responsibility that embraces civic professionalism, social trusteeship and a strategy for sustainability.

Is measurement of blood pressure worthwhile in the diabetic eye clinic?

Purpose - The UK Prospective Diabetic Study has confirmed the importance of blood pressure (BP) as a major risk factor for diabetic retinopathy (DR). We wanted to investigate whether measuring the BP in the diabetic eye clinic could identify new hypertensive patients and monitor control in existing ones. Patients and methods - We compared BP in patients attending the diabetic eye clinic with home blood pressure measurement (HBPM) and ambulatory BP measurement (ABPM). In all, 106 patients attending a diabetic eye clinic were selected at random from clinic attendees. BP measurement (on an Omron 705 CP) was performed in the eye clinic and also compared to HBPM three times per day with an Omron 705 CP machine, and was compared to diabetic clinic measurements. In addition, 11 randomly chosen patients had 24 h ABPM to validate the above techniques. Results - In all, 106 patients (70 male and 36 female) were recruited for the study, of which 71 were known to be hypertensive on antihypertensive medication. Of the total, 75 patients (70.8%) had BP>140/85 in the eye clinic, of which 51 (68%) were known to be hypertensive on treatment and this was confirmed in 46 (90%) on HBPM. A total of, 24 patients (22.6%) were newly diagnosed as hypertensive in the eye clinic, which was confirmed by HBPM in 22 patients (92%). The mean BP of the measurements performed in the eye clinic was significantly higher than that carried out in the diabetic clinic (P<0.01). Tropicamide 1% and phenylephrine 2.5% eye drop instillation had no effect on BP. In 11 randomly chosen patients, 24 h ABPM validated both diabetic eye clinic and home BP measurements. Conclusion - Attendance at the diabetic eye clinic is an important chance to detect both new patients with systemic hypertension and those with inadequate BP control. Ophthalmologists should be encouraged to measure BP in their diabetic patients attending diabetic eye clinics, as it is an important risk factor for DR. On the basis of our findings, good BP control is a goal yet to be achieved in diabetic patients with retinopathy.

Regression with input-dependent noise: A Bayesian treatment

In most treatments of the regression problem it is assumed that the distribution of target data can be described by a deterministic function of the inputs, together with additive Gaussian noise having constant variance. The use of maximum likelihood to train such models then corresponds to the minimization of a sum-of-squares error function. In many applications a more realistic model would allow the noise variance itself to depend on the input variables. However, the use of maximum likelihood to train such models would give highly biased results. In this paper we show how a Bayesian treatment can allow for an input-dependent variance while overcoming the bias of maximum likelihood.

Dynamic variability in adaptive systems

One of the reasons for using variability in the software product line (SPL) approach (see Apel et al., 2006; Figueiredo et al., 2008; Kastner et al., 2007; Mezini & Ostermann, 2004) is to delay a design decision (Svahnberg et al., 2005). Instead of deciding on what system to develop in advance, with the SPL approach a set of components and a reference architecture are specified and implemented (during domain engineering, see Czarnecki & Eisenecker, 2000) out of which individual systems are composed at a later stage (during application engineering, see Czarnecki & Eisenecker, 2000). By postponing the design decisions in such a manner, it is possible to better fit the resultant system in its intended environment, for instance, to allow selection of the system interaction mode to be made after the customers have purchased particular hardware, such as a PDA vs. a laptop. Such variability is expressed through variation points which are locations in a software-based system where choices are available for defining a specific instance of a system (Svahnberg et al., 2005). Until recently it had sufficed to postpone committing to a specific system instance till before the system runtime. However, in the recent years the use and expectations of software systems in human society has undergone significant changes.Today's software systems need to be always available, highly interactive, and able to continuously adapt according to the varying environment conditions, user characteristics and characteristics of other systems that interact with them. Such systems, called adaptive systems, are expected to be long-lived and able to undertake adaptations with little or no human intervention (Cheng et al., 2009). Therefore, the variability now needs to be present also at system runtime, which leads to the emergence of a new type of system: adaptive systems with dynamic variability.