Biomedical subjects

Anja M Palmowski-Wolfe

Publications and source records attributed to Anja M Palmowski-Wolfe.

8 recordsLinked to original sources

PubMed2007

Antiphospholipid antibodies in ocular arterial and venous occlusive disease.

PURPOSE: It was the aim of this study to evaluate antiphospholipid antibodies (APA), i.e. lupus anticoagulants (LA) and anticardiolipin (ACA) IgG and IgM, in ophthalmic occlusive disease. METHODS: Over a 3.5-year period, APA were evaluated in 368 patients. RESULTS: Eighty-six patients (23.4%), compared to 5% in the general population, tested positive for APA. APA did not differ significantly between patients with venous (20.6%) or arterial (25.5%) occlusive disease. This included 93 patients with central retinal vein occlusion (18% APA positive), 67 with retinal branch vein occlusion (24% APA positive), 41 with central retinal artery occlusion (22% APA positive), 53 with retinal branch artery occlusion (32% APA positive), 71 with anterior ischemic optic neuropathy (23% APA positive), 12 with posterior ischemic optic neuropathy (33% APA positive) and 31 patients with amaurosis fugax (23% APA positive). Excluding patients with accepted main risk factors, APA were positive in 15.3% of 85 patients. CONCLUSION: The high APA prevalence confirms its relevance in ocular occlusive disorders.

Aged↗

PubMed2006

The 'two global flash' mfERG in high and normal tension primary open-angle glaucoma.

PURPOSE: To analyse the sensitivity of the '2 global flash' multifocal electroretinogram (mfERG) to detect glaucomatous dysfunction in normal tension (NTG) and high tension primary open angle glaucoma (POAG) patients. METHODS: MfERGs were recorded from 20 NTG and 20 POAG patients and compared to those of 20 controls. The mfERG array consisted of 103 hexagons. Each m-sequence step started with a focal flash that could be either dark or light (m-sequence: 2--13, L(max): 200 cd/m(2), L(min): 1 cd/m(2)), followed by two global flashes (L(max): 200 cd/m(2)) at an interval of approximately 26 ms. Focal scalar products (SP) were calculated using focal templates derived from the control recordings (VERIS 4.8). We analyzed 5 response averages (central 7.5 degrees and 4 adjoining quadrants) of the response to the focal flash, the direct component at 10-40 ms (DC) and the following two components induced by the effects of the preceding focal flash on the response to the global flashes at 40-70 ms (IC-1) and at 70-100 ms (IC-2). RESULTS: Both NTG and POAG patients differed from controls in the IC-1 response to the superior quadrants, and POAG patients also differed from controls in the centre. The most sensitive parameter was the IC-1 of the superior temporal quadrant with an area under the ROC curve of 0.82 for POAG and 0.79 for NTG. The DC and the IC-2 did not differ significantly between the groups. When all five response averages of the IC-1 were taken into consideration 90% of the NTG patients and 85% of the POAG patients were correctly classified as abnormal while 80% of the control subjects were correctly classified as normal. CONCLUSIONS: This stimulus sequence holds promise for the diagnosis of early functional changes in POAG. A new finding is that both NTG, as well as POAG can be differentiated from control subjects.

Electroretinography↗

PubMed2006

30 Hz-flicker mfERG in primary open-angle glaucoma patients : 30 Hz-flicker-mfERG in POAG.

PURPOSE: This study was performed in an attempt to gain more information on whether the 30 Hz-flicker mfERG indeed provides a sensitive measure of dysfunction in patients with primary open-angle glaucoma (POAG) as has been suggested previously. METHODS: Eighteen POAG patients with visual field defects (MD > 2.2 dB) and glaucomatous optic neuropathies as well as 10 control subjects underwent mfERG recording as follows: 30 Hz-flicker mfERG, LED stimulus screen, 61 hexagons, Lmax: 180 cd/m2, Lmin: 0 cd/m2, recording time: approximately 5 min, filter setting: 10-200 Hz. The 30 Hz response (also called the fundamental or the first harmonic response (1HW) and the second harmonic wave at 60 Hz (2HW) were analysed as an overall response and in quadrants, as well as in 4 small neighbouring areas per quadrant. The patients' mfERGs were compared to those of the control group and to the mean defect values (MD) of the corresponding quadrants of the Octopus perimetry. RESULTS: Neither in the overall response, nor in the quadrants, nor in the smaller areas examined did amplitudes and phases of the 1HW and the 2HW or the amplitude ratio of the 2HW to the 1HW (DFT-ratio) differ from the controls (P > 0.05-ANOVA). There was no significant correlation between mfERG values and the MD (Spearman-test, Bonferroni). CONCLUSION: Thus, the 30 Hz-flicker mfERG does not seem to be sensitive enough to separate glaucoma patients from normal.

Adult↗

PubMed2006

Influence of dopamine deficiency in early Parkinson's disease on the slow stimulation multifocal-ERG.

PURPOSE: In animal studies intravitreal injection of tetrodotoxin (TTX) results in mfERG waveform changes similar to those observed in glaucoma. As TTX blocks amacrine as well as ganglion cells, there is still a question regarding the underlying cell population responsible for these changes in waveform. In an attempt to assess the contribution of the amacrine cells to these changes, a mfERG was obtained from patients with Parkinson's disease as some amacrine cells are mediated by dopamine, a substance lacking in Parkinson's. METHODS: Eight patients with early Parkinson's disease underwent ophthalmologic examination, testing of contrast sensitivity and electrophysiological examination according to ISCEV standard at least 12 h following their last medication with Dopamine. A slow stimulation mfERG was obtained with a stimulus base interval of 53.3 ms and with a stimulus base interval of 106.6 ms. During MF-ERG recordings 103 hexagons stimulated the central 50 deg of the retina simultaneously and independently (m-sequence 2(13), L(max): 200 cd/m(2), approximately 100% contrast). RESULTS: Contrast sensitivity and ISCEV standard electrophysiological testing was unremarkable. When the mfERG was analyzed, only four patients had an adequate signal-to-noise ratio to allow further data analysis - one of whom was diagnosed with a multi system atrophy in retrospect. The first order response component was analyzed at a filter setting of 10-300 Hz and at 100-300 Hz (OPs) and compared to mfERGs of a control group. On average, in patients, the amplitude of N1P1 was slightly lower in the central and nasal response averages. When the three OPs at a latency of 72-89 ms were analyzed in the 53.3 ms base interval recording, the most marked difference in amplitude was observed in the superior nasal response average of the first OP. Here a mean amplitude of 1.3 nV/deg(2) in patients compared to a mean amplitude of 1.9 nV/deg(2) in the control group (P: 0.08). DISCUSSION: In contrast to our previous findings in NTG, there was a consistent presence of three OPs. Under the stimulus conditions applied, we did not find an influence of dopaminergic amacrine cells on the mfERG in our patients with moderate stages of Parkinsion's. The difficulties in obtaining an adequate signal-to noise ratio due to e.g. muscle artifacts even in Parkinson patients of moderate disease stages render a success of mfERG recording in patients with more advanced stages unlikely. The question of the influence of dopaminergic amacrine cells on the mfERG could possibly be addressed using MPDT in animal research.

Contrast Sensitivity↗

PubMed2006

Slow-stimulated multifocal ERG in high- and normal-tension glaucoma.

PURPOSE: To study the ability and sensitivity of the slow stimulation multifocal ERG (mfERG) to detect glaucomatous damage. METHODS: Right eyes of 20 patients with normal-tension glaucoma (NTG), 15 patients with high-tension glaucoma (HTG) and 15 healthy volunteers underwent testing with the mfERG (VERIS 4.1). The central 50 degrees of the retina were stimulated by 103 hexagons (m-sequence: 2(13)-1, Lmax: 100 cd/m(2), Lmin: 1 cd/m(2), background: 50 cd/m(2)). Each m-sequence step was followed by 3 black frames (Lmax: < 1 cd/m(2)). Five response averages of the first order response component (KI) were analyzed: the central 7.5 degrees and the 4 adjoining quadrants. The amplitudes from the first minimum, N1, to the first maximum, P1, and from P1 to the second minimum, N2, were analyzed as well as the latencies of N1, P1, N2 and the latencies of 3 multifocal oscillatory potentials (mfOPs) with their maxima at about 73, 80 and 85 ms. RESULTS: For each parameter the percentage of deviation from the mean of the control group was calculated. These values were then added for each individual to form a deviation index (DI). Seventeen patients (85.0%) with NTG and 3 patients (20.0%) with HTG showed a DI outside the normal range. The major changes were observed in the mfOPs of the NTG patients. MfOPs were then selectively filtered at 100-300 Hz and their scalar product was analyzed over an epoch of 68-105 ms. This confirmed that mfOPs differed significantly from the control in the central 7.5 degrees and, for NTG, in the nasal field. With a logistic regression analysis the mfOPs had a sensitivity to differentiate 85% of the NTG patients and 73% of the HTG patients from normal. CONCLUSIONS: Under these conditions, the slow-stimulated mfERG can detect glaucomatous dysfunction in NTG (85.0%). The differences observed between NTG and HTG are in support of a different underlying pathomechanism.

Adolescent↗

PubMed2006

A comparison of the fast stimulation multifocal-ERG in patients with an IOL and control groups of different age.

PURPOSE: It has been shown that a cataract significantly reduces mfERG responses in the central 4-14 degrees . Removing the cataract, leads to a significant increase in the response of the central 4 degrees . In this study we compare the mfERG of Woerdehoff et al.'s patients' [Doc Ophthalmol 2004; 108(1): 67-75] following cataract surgery to a healthy control group in order to assess whether, in the elderly, further influences of age need to be considered in addition to optical effects. METHODS: Eighteen patients with an IOL following cataract surgery and 29 healthy volunteers (without clouding of the media or retinal changes) underwent testing of the mfERG (103 hexagons stimulating the central 50 degrees , M-sequence 2(15), Lmax: 200 cd/m2, Lmin<1 cd/m2). For the first order response component we compared the latencies of N1,P1 and N2 as well as the natural logarithm (ln) of the amplitudes N1P1 and P1N2 for four group averages: I. the central 4 degrees, II. 4-7 degrees, III. 7-10 degrees and IV. 10-15 degrees. RESULTS: Mean age was 67 years (SD 10.1) for the IOL patients, 28.5 years (SD 5.6) for a young group of controls (n=15) and 60.2 years (SD 9.2) for the older control group (n=14). Patients with an IOL did not differ in latency from either control group (ANOVA, Tukey). Interestingly, at 10-15 degrees eccentricity, the latency of N2 differed significantly between the younger (41.4 ms, SD 1.4) and the older (43.0 ms, SD 1.9) control group. In the central 4 degrees LnN1P1 amplitudes were significantly lower in the IOL group (mean: 3.7, SD 0.2) than either the younger (mean: 3.9, SD 3.3) or the older (mean: 4.0, SD 0.3) control group. In all other amplitude measures, the older control group had slightly larger mean amplitudes than the younger control group and significantly larger amplitudes than the patients with an IOL, whose amplitudes were lowest. DISCUSSION: Both, primarily optical but also neural phenomena have been described to affect the mfERG changes observed with age. Our results, are in support of this, as the improvement of the mfERG response following cataract surgery does not seem to reach the level of a healthy control group of equal age. Thus, our results suggest, that a control group with an IOL should be used when retinal function is tested in subjects with an IOL.

Adult↗

PubMed2006

LED-generated multifocal ERG on- and off-responses in complete congenital stationary night blindness -- a case report.

We report on the application of a light emitting diode (LED) screen to elicit multifocal ERG on- and off-responses in a patient presenting with the complete type of congenital stationary night blindness (cCSNB): A 63-years old woman was diagnosed with cCSNB by means of standard ERG procedures and dark adaptometry. To confirm this diagnosis and to investigate topographical differences of on- and off-responses a multifocal approach employing long-duration stimuli was added. Results of mfERG-testing were averaged in three groups (a central area of 7.5 degrees , a ring area of 7.5-21.9 degrees and a peripheral ring of 21.9-31.1 degrees ). When compared to normal controls (n = 4) on-responses (P1-amplitudes) were severely reduced symmetrically at all eccentricities, while off-responses showed no reduction resulting in an increased off/on-ratio. Furthermore on-latencies of P1 were delayed symmetrically at all eccentricities, whereas off-latencies were normal. To our knowledge this is the first report of multifocal on- and off-responses in a CSNB-patient. Stimulus-generation with a LED-screen provides the advantage of a stable luminance during the long-duration on-phase.

Dark Adaptation↗

PubMed2005

Retinal perfusion response to a slow multifocal M-sequence flicker stimulation.

PURPOSE: To assess, if a slow multifocal stimulus (mfS) can provoke a perfusion response that can be measured with the Retinal Vessel Analyzer (RVA). METHODS: Seventeen eyes were examined. Pupils were dilated. A 120-second baseline recording was obtained with the RVA. The subject then turned to view an mfS for 56 s. The mfS consisted of 103 hexagons flickering according to an m-sequence with a stimulus base interval of 53.3 ms (L(max) = 100 cd/m(2), L(min) < 1 cd/m(2)). Immediately thereafter, the subject turned to the RVA, where measurements were resumed as soon as the same retinal vessel was targeted and continued for 104 s. Stimulation and recording was repeated twice. The diameter of a retinal vein and artery was measured for a length of at least 1 mm. The maximum vessel response was obtained by linear interpolation of the measured response within the 20 s following mfS. RESULTS: On average, veins dilated by 6.8% and arteries by 7% following mfS (p > 0.005). Such a dilatation could be observed in 9 veins and 7 arteries. Three venous and 2 arterial measurements did not show a dilatation following mfS. However, 13 of 34 measurements could not be analyzed due to signal problems or because the time from the end of mfS and the uptake of measurement exceeded 20 s. CONCLUSION: This slow multifocal ERG stimulus results in a dilatation of arteries and veins that can be measured with the RVA. Coupling an mfS to the RVA has the potential to topographically map changes in retinal perfusion in relation to the respective retinal area stimulated. When implementing the mfS into the RVA setup in order not to lose time due to the refixation in the RVA following mfS, one is required to take the transient nature of this perfusion change into consideration.

Adult↗