Biomedical subjects

J B Rogers

Publications and source records attributed to J B Rogers.

12 recordsLinked to original sources

PubMed1994

Test-retest variability of topographic measurements with confocal scanning laser tomography in patients with glaucoma and control subjects.

Using confocal scanning laser tomography, we studied the test-retest variability of topographic measurements of the optic nerve head and parapapillary retina in 30 patients with glaucoma and 30 normal control subjects. We obtained three independent images, separated by between one and six hours, centered on the optic nerve head. We condensed each original 256 x 256-pixel image to a 64 x 64-pixel image, thereby allowing a realistic estimate of the empiric 90% confidence interval of testretest variability at each condensed pixel. Confidence interval maps generated for each subject showed highest measurement variability along the cup border and blood vessels. The mean standard deviation equivalents of test-retest variability in the patients and controls were 31.20 and 25.94 microns, respectively. These differences were statistically significant (P = .010). Variability increased with age (P < .001). When the analysis was repeated for discrete parapapillary areas, the group differences were not statistically significant (P = .100).

Adult↗

PubMed1993

Comparison of high-pass resolution perimetry and pattern discrimination perimetry to conventional perimetry in glaucoma.

We compared two new perimetric techniques, high-pass resolution perimetry and pattern discrimination perimetry, to conventional automated static perimetry in an ongoing prospective study. Forty-eight patients with open-angle glaucoma whose median age was 63.4 (range 15.6 to 89.7) years were included in the study. There was a significant correlation between the results obtained with high-pass resolution perimetry and conventional perimetry for both the whole field and the four quadrants (p < 0.001). However, the correlation between pattern discrimination perimetry and conventional perimetry was poor. The differences between the correlations of the newer techniques with conventional perimetry were statistically significant for the whole field and the superior quadrants (p < 0.01) and were borderline significant for the inferior quadrants. Although the three techniques showed very good concordance in both the extent and location of damage of the visual field in some patients, in others it was poor. Our results show that high-pass resolution perimetry and pattern discrimination perimetry may be measuring different components of the visual response.

Adolescent↗

PubMed1981

Time dependent changes in anterograde scopolamine-induced amnesia in rats.

These experiments studied the effect of scopolamine on memory formation and subsequent memory recall. Different groups of rats were trained on a Y-maze brightness discrimination task 20 min after IP injection of 2 mg/kg scopolamine HBr, an anticholinergic. Retention tests were then conducted 1 day or 2, 4, or 6 weeks after training. Deficits in retention performance were observed at 1 day and 2 weeks after training but not at the longer intervals. In addition, other rats were trained in the same manner and after the same dose of scopolamine but were then retention tested 20 min after 0.5 mg/kg physostigmine salicylate, a cholinesterase inhibitor. These subjects also showed deficits at 1 day and 2 weeks but were not different from controls at the longer intervals. Amnesia was not, however, produced after treatment with scopolamine methyl nitrate or by injections of scopolamine HBr administered immediately after training. These results suggest that scopolamine, present in the central nervous system during training or within the first few moments thereafter, modifies the formation of the memory trace in such a way that memory is not available for recall for a period of weeks.

Animals↗

PubMed1973