Filtyp
The use of computer-assisted instruction in medical education has increased steadily in the last decade with the availability of personal computers. Many computer-assisted instruction programs train the user to handle various forms of disease or injury. Our intent was to provide medical students with more experience in managing ophthalmological emergencies, and we therefore designed a computerized
Typical glaucomatous visual field defects are often contiguous areas of diminished differential light sensitivity presenting as clusters of abnormally depressed points in the visual field chart. We investigated the value of recognizing arcuate cluster patterns, corresponding to the anatomy of the normal retinal nerve fiber layer. Cluster sizes were quantified using cluster volume and surface area.
We studied the influence of optic disc diameter on the diagnostic power of subjective disc evaluation of glaucoma. One hundred and thirteen colour disc photographs of 91 patients with primary open angle glaucoma and 174 photographs of 89 randomly selected normal subjects were studied. Five ophthalmologists independently classified all eyes as glaucomatous or normal by disc appearance using a maske
Interpretation of numeric automated threshold visual field results is often difficult. A large amount of data is obtained for every single field tested. Various approaches to summarize this data have been suggested, most commonly the mean and standard deviation of departures from age-corrected normal threshold values. These visual field indices differ substantially from subjective field interpreta
This was a double-masked prospective study of the effect on patients with ocular hypertension and other risk factors for glaucomatous damage of intraocular pressure reduction achieved with topical timolol.
In recent years several aids for automated interpretation of visual field data have been suggested. We believed that incorporation of thorough knowledge of normal visual field variability would allow improvements in the performance of such aids since more attention would be paid to field results in areas with low physiological variability. Two visual field models for classification of fields in gl
A new aid to perimetric analysis, the Glaucoma Hemifield Test, primarily evaluates up-down differences in automated static visual field tests. We analyzed the visual fields of 163 eyes of 163 normal subjects and 77 eyes of 77 patients with glaucoma diagnosed on bases other than perimetry using the Glaucoma Hemifield Test and a similar, previously developed, hemifield analysis method. The performan
We have developed an algorithm, the Glaucoma Hemifield Test (GHT), for automated evaluation of single static threshold visual field test results in glaucoma. The GHT uses empirically determined limits of normality for up-down differences in the Statpac probability maps of the Humphrey Field Analyzer to detect localized visual field loss. It is also constructed to detect field loss that is symmetri
We studied the differential light sensitivity in 83 patients who were prospectively followed with computerized threshold preimetry and optic disc pathography because of suspect glaucoma. Eyes with media opacities were excluded from the analysis. Fourteen eyes developed progressive optic disc cupping and/or localized visual field loss. In this glaucoma group light sensitivity in the 10 best points
Automated visual field charts may be difficult to interpret partly because of the magnitude and complex nature of normal threshold variability. We devised two types of empiric probability maps in which this variability is taken into account and the significances of measured threshold values are displayed. These maps are highly sensitive to nonobvious but significant paracentral field loss but will
The present article discusses the role of computerized perimetry in the management of patients with suspect and manifest glaucoma. The value of visual field examination is compared to that of inspection and photography of the optic disc and to some extent to retinal nerve fibre layer photography. Computerized perimetry is related to standard manual visual field examination. Guidelines are offered
Perimetric probability maps depict visual field results in terms of the frequency with which the measured findings are seen in a normal population. We tested clinically the importance of the model of the normal visual field used to calculate such maps. Forty-one eyes of 41 normal subjects and 58 eyes of 46 glaucomatous patients were studied. Probability maps were calculated by means of two differe
The traditional opinion that increased intraocular pressure is the cause of glaucoma is controversial, probably mainly because of the fact that firm evidence for the value of pressure reduction is largely lacking. The present article reviews results from short term studies of visual fields before and after pressure reduction. It also reviews published and unpublished preliminary results from studi
Two groups of normal subjects were submitted to repeated automated static threshold perimetry. Perimetric results were strongly affected by the level of experience in some subjects; in the majority, however, the effect of experience was small. Initial field tests often showed high numbers of depressed points. Sensitivity increased with perimetric training, particularly between the first sessions.
Sixty-three normal subjects and 94 abnormal patients, most of whom had glaucoma, were tested in the central visual field using a threshold-related, eccentricity-compensated, spatially adaptive suprathreshold screening program and a full-threshold program on the Humphrey field analyzer. The initial stimulus locations on the screening test were identical to those of the threshold test; additional sc
Two patients (one with glaucoma with field loss, one with ocular hypertension) with previously known optic disc haemorrhage were followed with frequent disc photography, computerized perimetry and tonometry for a period of one year. Nine haemorrhages were seen in three of the four eyes studied. Three bleedings showed sudden enlargements, interpreted as re-bleedings, during the absorption phase. Ha
With laser iridotomy it may often be difficult to achieve total penetration of the iris, particularly in very light or very dark irides. It may be impossible to determine with the slit-lamp whether a small laser iridotomy is functionally penetrating. We describe a straightforward method to test iridotomies for aqueous flow patency. Transcorneally introduced fluorescein is used to delineate any aqu
During the last few years computerised perimetry has become a clinical reality. This new technique eliminates the operator's error, ensures reproducibility of test procedures and parameters and makes visual field testing of large numbers of patients possible. Great differences exist between computerised perimeters. Differences in hardware for example, the way in which stimuli or field charts are p
