ABSTRACT
INTRODUCTION: This prospective observational case series aimed to determine whether the lateral decubitus position, which is commonly adopted during sleep, has an effect on intraocular pressure (IOP) in normal controls. METHODS: Patients without glaucoma were recruited from those visiting outpatient clinics for non-glaucomatous conditions. The left eye of each patient was included. IOP was first measured using Tono-Pen® XL applanation tonometer in the supine position, following which a second measurement was immediately obtained for the left lateral head position. Measurements were obtained with the patient lying on one soft and one hard pillow for each position, and patients remained awake during these measurements. One tonometry reading was obtained for each position. Readings were recorded only when the average of four independent readings produced a statistical confidence index of 5%. Results were analysed using the paired Student's t-test for comparison of the means. RESULTS: IOP in the left lateral decubitus position (17.48 ± 3.18 mmHg) was significantly higher than in the supine position (14.48 ± 3.09 mmHg) when using soft pillows (p < 0.001). When hard pillows were used, IOP in the left lateral decubitus position also exceeded that measured in the supine position (16.65 ± 3.54 mmHg vs. 13.65 ± 3.58 mmHg; p < 0.001). There was no statistically significant difference in the IOPs measured for the same position when different kinds of pillows were used. CONCLUSION: The lateral decubitus position adopted during sleep is associated with changes in IOP in healthy volunteers.
Subject(s)
Intraocular Pressure , Posture , Sleep , Adult , Aged , Female , Glaucoma , Humans , Male , Middle Aged , Prospective Studies , Tonometry, Ocular , WakefulnessABSTRACT
BACKGROUND: In 2003 the National Institute of Clinical Excellence published guidelines recommending the use of brain natriuretic peptide (BNP) and the electrocardiogram (ECG) as part of the diagnostic work up of individuals with heart failure. However, the guideline did not address whether one test was superior to the other or whether performing both tests was superior to performing single tests. AIM: To investigate the relative test accuracy of the ECG, BNP, N terminal-pro brain natriuretic peptide (NT-proBNP) and combinations of two or more tests in the diagnosis of left ventricular systolic dysfunction (LVSD) in the primary care setting. DESIGN OF STUDY: Cohort studies making within-subject comparisons of intervention diagnostic test(s) with reference standard results. METHOD: Standard systematic review methodology was followed. RESULTS: Thirty-two primary studies met the review inclusion criteria. Studies were of variable quality and highly clinically heterogeneous, therefore restricting the use of meta-analysis. Within these limitations BNP, NT-proBNP and the ECG all had similar test sensitivity (>80% in the majority of studies). Specificity of the three tests was not as good. Three studies directly comparing BNP and the ECG found no difference in sensitivity and limited support for improved specificity of BNP. Two studies found no difference in sensitivity and limited evidence for an improvement in specificity for the combination of the ECG and BNP compared to single tests. CONCLUSION: On the basis of existing evidence, the ECG, BNP and NT-proBNP are useful in excluding a diagnosis of LVSD (good sensitivity). However, use of abnormal test results to select individuals for echocardiography may overwhelm services. There is currently no evidence to justify the use of one test over another or the use of tests in combination. The additional cost of BNP is not self-evidently justified by improved test accuracy. Further research is needed to directly compare the diagnostic performance of these tests in homogeneous, representative primary care populations.