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L Pillunat

Publications and source records attributed to L Pillunat.

13 recordsLinked to original sources
PubMed1990

[Total average values of transient visual evoked cortical potentials in tests of the pressure tolerance of the optic nerve].

Transient visually evoked cortical potentials were recorded during an artificial stepwise rise of intraocular pressure. At each pressure step one average was taken. The reversal rate was 1.9 Hz. Two groups of 30 healthy volunteers each were examined: in group one 25 sweeps were averaged and in group two 50 sweeps. Thus the recording time in group two was doubled compared to group one. When all subjects were examined the evoked potentials of the 30 subjects were averaged at each pressure step: the results was a "Grand Average" at the different pressure steps applied. The amplitudes of N2-P2 were plotted versus the intraocular pressure. It is seen that a not monotone or weakly monotone function in the amplitude/pressure curve is more clearly seen in the averages of 25 sweeps. We interpret this result as follows: a not monotone or weakly monotone behaviour is a sign of autoregulation in the optic nerve head. This sign is more clearly shown at a short recording time. The majority of healthy persons show autoregulation, the majority of glaucoma patients do not. According to the results presented here it is advisable to apply short recording times in clinical pressure tolerance testing of the optic nerve head. A short recording time enhances the accuracy of the test.

Adult↗
PubMed1990

[The pressure tolerance test--a new technic in the differential diagnosis of glaucoma].

There can be a damage of optic nerve fibers without a known increase of intraocular pressure. This observation has led to the proposition to measure the pressure tolerance of the optic nerve head. An examination which is performing this task is feasible now with a recently introduced technique. In this paper clinically well defined borderline cases are presented in which the pressure tolerance test yields clinically valuable results. As shown paradigmatically the pressure tolerance test shows to be a valuable tool in the differential diagnosis of glaucoma.

Adult↗
PubMed1989

[Relation of negative pressure difference and artificially elevated intraocular pressure using the suction cup method].

This paper presents regressions and the range of scatter of measured values for current standard ophthalmologic suction cups for the first time. The scatter range is similar to that of blood pressure measurements made by the Riva-Rocci method. Using the regressions presented here it is possible to deduce the increase in pressure from the negative pressure difference in the suction cup; this can be done with sufficient accuracy and the amount of time required is acceptable.

Humans↗
PubMed1989

[Effect of carteolol and timolol eyedrops on the pressure tolerance of the optic nerve head].

In a planned, randomized, double blind study ocular perfusion pressures were measured before and after a 3-day regimen of 2% carteolol hydrochloride or 0.5% timolol maleate. A pressure tolerance test was also carried out. The results of this test revealed the critical pressure: it is the artificially increased intraocular pressure at which the visual function (monitored by visually evoked cortical potentials) is reduced to 20% of its initial value. The ocular perfusion pressures are affected by both drugs. They are more clearly reduced by carteolol than by timolol. The critical pressure is affected by both drugs too. After application of carteolol, the critical pressure is clearly lower than after application of timolol. The difference is statistically significant (p less than 0.05).

Adaptation, Physiological↗
PubMed1988

[Ulrich and Ulrich oculo-oscillodynamography: results in patients with healthy eyes].

Ulrich and Ulrich's method of oculo-oscillodynamography (OODG) is a relatively new method which enables the systolic retinal, systolic ciliary, and systolic ocular perfusion pressure or respectively blood pressure to be measured. The results obtained by the present authors are in good agreement with those of Ulrich and Ulrich (n = 30). The intraocular pressure values obtained with this method correlate somewhat less well with the systemic blood pressure than is the case with suction cup ophthalmodynamometry. However, the correlation coefficients are sufficiently high to permit their application in ophthalmological diagnosis. The results presented here indicate that the diastolic ocular pressure should be determined by applying the formoscillatory criterion. The positive intercept in the regression equations can be explained by the assumption that the regression is curvilinear at systemic blood pressure values which are generally not encountered in humans in whom OODG is of diagnostic importance. It is suggested that the linear regression is a sufficiently exact model at the systemic blood pressures most frequently measured. Normal OODG values can be read off easily from the diagrams published here.

Adult↗
PubMed1988

[Quantitative assessment of the clinical electroretinogram].

The clinical application of electroretinography has been limited until now by the lack of standardisation, especially of stimulus conditions. Normal values for the electroretinographic response parameters can only be used if patients are examined under the conditions which were given for the examination of healthy subjects. It is shown in this paper that the inexpensive apparatus designed by Kooijman and Damhof (1981) can be calibrated by any user simply and at justifiable expense. Normal values for the amplitudes and peak times for the a- and b-wave are presented. The normal range of the values has been defined with regard to the frequency distribution. According to the authors' results, methods of descriptive statistics in skewed distributions are mainly necessary at low stimulus intensities. The descriptive methods for normal distributions were regularly applied at higher stimulus intensities. In general, however, ERG parameters are normally distributed as shown by the distribution of the residuals between the linear regression of the parameter to the logarithm of the corneal illuminance and the measured values. The influence of age on the amplitude was calculated according to the results of Lehnert and Wünsche (1966) and the lower limits of the normal range are given for four age groups. The data presented here may be used as normal values provided that the simple calibration methods are applied. Thus electroretinography is no longer a method merely for the laboratory, but can be used in clinics and offices as well. However, a prerequisite is that the physician has sufficient experience in ophthalmological electrophysiology.

Adult↗
PubMed1988

Effect of different antiglaucomatous drugs on ocular perfusion pressures.

In an attempt to elucidate whether antiglaucomatous drugs, especially beta-blockers, affect systemic and/or ocular blood flow, we measured ocular perfusion pressures (PP), systemic blood pressure (BP) and heart rate in 50 healthy subjects before and after topical instillation of the following eye drops: timolol 0.5% (n = 10), betaxolol 0.5% (n = 10), carteolol 2% (n = 10), pilocarpine 2% (n = 10) and acetazolamide 750 mg per os (n = 10). The ocular perfusion pressures were measured by OODG as described by Ulrich. By means of this method--retinal and ciliary perfusion pressure can be recorded separately and simultaneously. Our results indicated that, in spite of a statistically significant decrease in IOP in all 5 groups, there was no change in retinal or ciliary perfusion pressure, heart rate or blood pressure in any of the groups except the carteolol subjects. The ocular perfusion pressures should be increased with reduction of the IOP when the systemic parameters remain unchanged. This was not the case in our experiments and therefore it can be suggested that a relative reduction in ocular perfusion pressure occurs with all agents and, in this respect, timolol and betaxolol did not affect ocular perfusion pressure more than pilocarpine and acetazolamide. Carteolol, however, produced a slight decrease (alpha less than 0.02) in ocular perfusion pressure, in spite of lowering of the IOP.

Adrenergic beta-Antagonists↗
PubMed1987

[Normal values in the Aulhorn flicker test].

In this paper the results of the Aulhorn flicker test in 105 healthy subjects are described. With decreasing flicker frequencies there was an increasing sensitivity to brightness below the individual flicker fusion frequency. These results contrast with those obtained in patients with acute optic neuritis. In these patients the sensitivity to brightness decreased at low flicker frequencies. The range of frequency intervals between 3 and 50 Hz in which the maximum increase in brightness sensitivity was be observed was also investigated. The results have been compiled in a diagram for clinical use.

Adolescent↗
PubMed1985

Asynchronism of saccadic eye movement in young diabetics as related to HbAIc.

The saccadic eye movements of young diabetic subjects (type I) were analyzed with respect to their synchronism (30 degrees gaze jumps). Regarding the duration (end) of saccadic eye movements, it was found that in diabetics (n = 41) the asymmetry between both eyes (less than or equal to 35 ms) is appreciably more than in normal individuals of equivalent age (n = 25; less than or equal to 10 ms). The asynchronism described is closely correlated with the hemoglobin AIc concentration in the blood.

Brain Diseases↗
PubMed1985

[Ulrich oculo-oscillodynamography: initial results in carotid stenoses].

Oculo-oscillodynamography (OODG) after Ulrich was performed in 11 patients suffering from a monolateral, hemodynamically relevant carotid stenosis identified by Doppler sonography. All of the pressure parameters which can be measured by OODG--systolic retinal, systolic ciliary, and diastolic ocular perfusion pressure--were low on the side concerned. In contrast to the already-established methods of measuring ocular perfusion--ophthalmodynamometry and ophthalmodynamography after Hager--the advantages of OODG are that it not only enables the systolic retinal pressure to be differentiated from the systolic ciliary or diastolic ocular perfusion pressure, but also permits the results of the investigation to be illustrated graphically, so that objective evaluation is possible.

Aged↗
PubMed1985

[Ocular hemodynamics in central and branch artery occlusions].

Ocular oscillodynamograms (OODG) were made in 9 patients with an occlusion of the central artery and 11 patients with an occlusion of one branch artery. While there were no pathologic findings in patients with branch artery occlusions, it was not possible to record any systolic-retinal oscillations of the pulse in patients with an occlusion of the central artery. In three cases the systolic ciliary perfusion pressure was also low owing to carotid stenosis.

Adult↗
PubMed1985

[Computer tomography in partial optic nerve avulsion].

An partial avulsion of the optic nerve was found after a blunt ocular trauma in a 34-year old-patient. For the first time it is possible to demonstrate CT exposures of such a case. The importance of this method in cases of blunt ocular trauma accompanied by hemorrhages of the anterior chamber or the vitreous is discussed.

Adult↗