Kees Wijsman

Reproducibility of topographic parameters obtained with the heidelberg retina tomograph.

The Heidelberg retina tomograph is a confocal scanning laser ophthalmoscope that permits recording of topographic information related to the optic nerve and retina. We studied the reproducibility of the topographic parameters obtained by recording five times sequentially the images obtained from one eye of five healthy people and five glaucoma patients. The reproducibility coefficients ranged from 60.5 to 99.4%. The results indicate that, for the parameters examined, the instrument has a high level of reproducibility.

Reliability of Optic Disk Topographic Measurements Recorded with a Video-Ophthalmograph

The video-ophthalmograph records the topography of the optic disk via simultaneous stereoscopic images which are stored and analyzed with the help of a microcomputer. This information is used to generate the vertical cup-disk ratio, the vertical optic disk diameter, the cup volume, and the neuroretinal rim area. To determine the reliability of the data, we recorded information for one eye of each of five patients ten times to determine the interphotographic error variance. We also analyzed one photograph for each of five patients ten times to determine the intraphotographic variance attributable to repeated analysis of the same photograph. The interphotographic and intraphotographic coefficients of variation were 2% to 18% and 2% to 7% respectively for these measurements.

Comparison of Visual Field Defects in Normal-Tension Glaucoma and High-Tension Glaucoma

In a prospective comparison of visual defects in 23 patients with normal-tension glaucoma and 23 with high-tension glaucoma, the groups were matched for equal involvement of the optic disk. F profiles on the Octopus 201 Perimeter were used to quantify thresholds at 1-degree intervals from fixation to define eccentricity, depth, and slope of the scotoma. The mean eccentricity of scotomas in the normal-tension group was 4.86 degrees from fixation; in the high-tension group it was 2.96 degrees. These differences were statistically significant (P less than .01). No statistically significant differences were found between the slopes of the scotomas or depths of the scotomas in the two groups.

The Correlation Between Cup-Disk Ratio, Neuroretinal Rim Area, and Optic Disk Area Measured by the Video-Ophthalmograph (Rodenstock Analyzer) and Clinical Measurement

The video-ophthalmograph (Rodenstock analyzer) records the topography of the optic disk via simultaneous stereoscopic video images which are stored and analyzed with the help of a microcomputer. We performed a prospective study of 49 eyes of 49 patients to compare the vertical cup-disk ratio, the horizontal cup-disk ratio, the neuroretinal rim area, and the optic disk area obtained with the video-ophthalmograph with those obtained with manual analysis of black-and-white stereoscopic photographs. The correlation coefficients were 0.67, for vertical cup-disk ratio (P = .0000), 0.63 for horizontal cup-disk ratio (P = .0000), 0.72 for neuroretinal rim area (P = .0000), and 0.89 for optic disk area (P = .0000).

Correlation of retinal nerve-fiber-layer loss, changes at the optic nerve head and various psychophysical criteria in glaucoma

In 61 eyes of 61 patients with glaucoma, semiquantitative assessment of retinal nerve-fiber-layer (RNFL) loss and neuroretinal rim measurement of the optic nerve head by means of the Optic Nerve Head Analyzer were correlated to the outcomes of automated light-sense, flicker and resolution perimetry and the Farnsworth-Munsell (FM) 100-Hue test. A significant influence of age on total RNFL and total diffuse RNFL scores was found, but there was no measurable effect of age on neuroretinal rim area. Total RNFL and total diffuse RNFL scores showed a good correlation to the various visual field indices: total RNFL score vs mean flicker frequency as determined by flicker perimetry, r = − 0.606, P < 0.0001; total RNFL score vs mean sensitivity as determined by light-sense perimetry, r = −0.385, P=0.002; and total RNFL score vs mean ring score as determined by resolution perimetry, r = 0.341, P = 0.007. There was no significant correlation between RNFL scores and the FM 100-Hue score. Correlation between the neuroretinal rim area and the various psychophysical indices was poor and mostly not statistically significant. The high correlation of flicker scores with RNFL loss provides interest for future applications of this perimetric technique.

The Correlation Between Optic Disk Topography Measured by the Video-Ophthalmograph (Rodenstock Analyzer) and Clinical Measurement

The video-ophthalmograph (Rodenstock analyzer) records the topography of the optic disk via simultaneous stereoscopic images, which are stored and analyzed with the help of a microcomputer. We performed a prospective study on 68 eyes of 68 patients to compare the vertical cup-disk ratio obtained with the video-ophthalmograph to that obtained with manual analysis of black-and-white stereoscopic photographs. The correlation coefficient was 0.61, highly significant at P = .0000.

The effect of refractive blur on the visual field using the ring perimeter

Abstract. To determine the effect of optically induced blur on the visual field measured with high pass spatially filtered targets, 10 normal subjects had field examinations with 0 diopter + 1.00 diopter or + 2.00 diopter of overcorrection in the cyclopleged state. All subjects showed a significant loss of sensitivity when defocussed, but not with pupil dilation. Mean thresholds for the central field rose from 4.79 ± 0.68 dB (Mean ± SD) with the image focussed and pupil dilated, to 7.16 ± 0.72 dB with two diopters of image blur (P < 0.001). The effects of defocussing did not differ significantly between the central and peripheral parts of the field. The great influence of defocussing the image on sensitivity should be considered during clinical perimetry as the 2.37 dB decline shown would place the groups mean sensitivity below die fifth percentile for age corrected normals.

Reproducibility of computerized pallor measurements obtained with the Rodenstock Disk Analyzer

Computerized pallor measurements of the optic nervehead were performed by global analysis with the Rodenstock Disk Analyzer. Total intervideographic and intravideographic variability was calculated. The coefficients of variation ranged from 8.3% to 20.08% for intervideographic variability of different pallor histogram values. The intravideographic variability for pallor histogram values ranged from 0.82% to 2.94%.

Adrenergic and adrenolytic effects on intraocular pressure

We compared the pressure-lowering effects of timolol, pindolol, epinephrine and the mixture of timolol and epinephrine with that of placebo over a 12-h period. All agents reduced the pressure significantly but with varying time courses. The mixture of timolol and epinephrine reduced the pressure significantly more than did timolol or epinephrine alone, especially at 12 h after the last administration of the drops.