Twenty-four patients of comparable age, blood pressure, and degree of dementia were classified by an "Ischemic Score" based on clinical features into "multi-infarct" and "primary degenerative" dementia. Regional cerebral blood flow (CBF) was measured by the intracarotid xenon 133 method. Both groups showed a decreased proportion of rapidly clearing brain tissue (largely gray matter). Cerebral blood flow per 100 gm brain per minute was normal in the primary degenerative group but low in the multi-infarct group. This suggests the blood flow is adequate for metabolic needs of the brain in patients with primary degenerative dementia but inadequate for those with multi-infarct dementia. There was no correlation between degree of dementia and CBF in the primary degenerative group but an inverse relationship existed in the multi-infarct group. Reactivity of blood vessels to reduction of arterial carbon dioxide pressure was normal in both groups.

Pfizer, UK National Institute for Health Research Biomedical Research Centre.

No abstract

This modeling exercise indicates that most patients in glaucoma clinics are not at high risk of progressing to statutory blindness. The likelihood of patients suffering impairment in their lifetimes is linked to VF loss at presentation, which illuminates the importance of reliably detecting significant VF defects in primary care.

PURPOSE. Evaluation of progressive visual field (VF) damage is often based on pointwise sensitivity data from standard automated perimetry; however, frequency-of seeing and test-retest studies demonstrate that these measurements can be highly variable, especially in areas of damage. The aim of this study was to characterize VF variability by the level of sensitivity using a statistical method to quantify heteroscedasticity. METHODS.A total of 14,887 Humphrey 24-2 SITA Standard VFs from 2736 patients (2736 eyes) attending Moorfields Eye Hospital from 1997 to 2009 were studied retrospectively. The VF series of each eye was analyzed using pointwise linear regression of sensitivity over time, with residuals (difference from fitted-value) from each regression pooled according to both observed and fitted sensitivities. RESULTS.The median (interquartile range) patient age, follow-up, and series length was 64 (54-71) years, 5.5 (3.9-7.0) years, and 6 (5-7) VFs, respectively. The inferred variability as a function of fitted-sensitivity was in good agreement with previous estimates. Variability was also described as a function of measured sensitivity, which confirmed that variability increased rapidly as the observed sensitivity decreased.CONCLUSIONS. This study highlights a new approach for characterizing VF variability by the level of sensitivity. A considerable strength of the method is that inference is based on thousands of clinic patients rather than the tens of subjects in test-retest studies. The results can help distinguish real VF progression from measurement variability and will be used in models for glaucoma progression detection. (Invest Ophthalmol Vis Sci. 2012;53:5985-5990)

Monocular measures, such as better eye MD, can give the impression that a patient's VF loss is more degraded than it might be under binocular viewing. This effect is more pronounced in patients with advanced VF defects. The IVF offers a rapid assessment of a patient's binocular VF severity without extra testing.

No abstract

BLR provides a significantly more accurate estimate of the rate of change in MS than the standard OLSLR approach, especially in short time series, suggesting that structural measurements can be used successfully in statistical models to assist clinicians monitoring VF progression in patients with OHT. Further studies are necessary to validate the method in glaucoma patients.