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C Lüke

Publications and source records attributed to C Lüke.

24 records · Page 2Linked to original sources
PubMed1999

Electrophysiological abnormalities in age-related macular degeneration.

BACKGROUND: Results from psychophysical tests indicate that in age related macular degeneration (ARMD) retinal function is globally impaired. Observations in single ARMD cases showing abnormalities of the electrooculogram (EOG) and electroretinogram (ERG) encouraged us to systematically examine ARMD patients by means of electrophysiological tests to confirm a global retinal dysfunction in ARMD. METHODS: Sixty-six patients with ARMD were examined clinically and by means of EOG, ERG, triple scotopic ERG, and fluorescein angiography (FA). RESULTS: EOG data were considerably reduced in ARMD. Scotopic a- and b-waves of the ERG were mildly affected. The bright flash response showed reduced b-waves with normal implicit times. The amplitude of the oscillatory potential OP2 was significantly reduced and photopic responses were also pathologic compared with an age-matched control group. Geographic atrophy and pigment epithelium detachment showed specific abnormalities in the ERG, whereas in soft drusen EOG changes were more conspicuous. CONCLUSIONS: In addition to data from psychophysical tests the results from electrophysiological examinations indicated a global reduction of retinal function in ARMD which seemed to be present not only in the macula but also elsewhere in the retina.

Aged↗
PubMed1999

Improvement of visual acuity in patients suffering from diabetic retinopathy after membrane differential filtration: a pilot study.

BACKGROUND: Membrane differential filtration is an extracorporeal treatment procedure which eliminates high molecular weight proteins and lipids from the blood. This pilot study was initiated to investigate the short-term effects on blood rheology and visual function in patients suffering from diabetic retinopathy. METHODS: Six patients with non-proliferative diabetic retinopathy, clinically significant macular edema (five patients, nine eyes) and inactive proliferative diabetic retinopathy (one patient, one eye) underwent a single treatment with a hollow fiber secondary plasma filter. The main parameter measured was visual acuity prior to and after treatment. Biochemical and rheological parameters (whole blood and plasma viscosity, and erythrocyte aggregation) were also measured. The mean follow-up was 25 (range 4-90) days after treatment. RESULTS: The mean improvement of visual acuity was 1.4 lines (SD 0.8 lines, p = 0.002) 24 h after therapy. This remained stable during the follow-up period. The rheological measures were significantly lowered. A significant reduction of total protein, fibrinogen, IgG, IgM, IgA, alpha-2-macroglobulin, total cholesterol, LDL and HDL was found. CONCLUSION: This study demonstrates the rheological impact of membrane differential filtration. It was shown that rheological changes correlated with clinical improvement in patients suffering from diabetic retinopathy with clinically significant macular edema.

Aged↗
PubMed1999

Antibiotics and light responses in superfused bovine retina.

1. Our objective was to study effects of clindamycin and ciprofloxacin on the electroretinogram (ERG) of isolated bovine retinas. 2. Electroretinograms of isolated superfused bovine retinas were recorded under normal conditions and during application of clindamycin and ciprofloxacin. The b-wave reduction was plotted against the drug concentration. In several cases retinal oxygen uptake was also measured. Clindamycin was available only in a preparation containing benzyl alcohol. To differentiate between effects caused by the antibiotic and the alcohol, ERGs were also recorded under superfusion with benzyl alcohol. To record drug effects on photoreceptors synaptic transmission was blocked using 1 mM aspartate. 3. At concentrations between 0.3 and 10 mM clindamycin significantly reduced the amplitude of the b-wave of the ERG. A comparable reduction of retinal oxygen uptake was found at concentrations 10-fold higher. Clindamycin, 3 mM, did not affect the a-wave after preincubation with aspartate. Benzyl alcohol at concentrations of 0.3 and 1 mM did not affect the b-wave, whereas at higher concentrations the b-wave was found to be reduced. Considerable b-wave reductions were found with ciprofloxacin at concentrations of between 0.03 and 0.6 mM. All effects proved to be fully reversible and dose-dependent. 4. Ciprofloxacin and clindamycin did both alter neural function in the isolated superfused bovine retina. The nontoxic dosages found here differ considerably from results in rabbits after intravitreal injections. This is probably due to species differences.

Animals↗
PubMed1999

[Current strategies for treatment of CMV retinitis in patients with AIDS].

BACKGROUND: CMV retinitis is the most common manifestation of active CMV infection in patients with AIDS. Before ganciclovir became available, the prognosis of CMV retinitis was very poor. Meanwhile a number of strategies for the management of CMV retinitis have evolved. To date no antiviral agent has proved effective in preventing reactivation of retinitis. Therefore the available antiviral agents delay rather than prevent relapse of CMV retinitis. Each relapse produces a more serious disease and retinitis becomes progressively less manageable. METHOD: A review of current therapeutic strategies for the treatment of CMV retinitis with regard to the challenge of clinical resistance is given. CONCLUSION: Effective treatment of clinically resistant CMV retinitis must consider the individual conditions. Thus, it is probable, that integration of both local and systemic therapies may be required to reduce the frequency of reactivation and thereby to decelerate the progression of the disease. Literature search in medline.

AIDS-Related Opportunistic Infections↗
PubMed1996

The triple flash electroretinogram and its significance in macular diseases. B-wave recovery as a diagnostic tool.

PURPOSE: The purpose of this study was to evaluate recovery data for the b-wave of the electroretinogram (ERG) elicited using multiple flash stimulation with increasing stimulus intervals in normal controls and in patients with macular diseases. The results will describe effects of age and macular disease and define indexes characterizing the recovery process. METHODS: Scotopic Ganzfeld flash ERGs were elicited using interstimulus intervals of 140, 280, and 560 ms. Relative b-waves were calculated as the ratio b140 ms/b560 ms and b280 ms/b560 ms, respectively. Responses obtained in 134 eyes of 134 normal controls served as reference data. Fifty-four patients with different macular diseases were also examined and their data compared to the reference data. RESULTS: Relative b-wave amplitudes correlated with interstimulus interval and with flash luminance, but not with age. All patients had a normal ERG when recorded following the standard of clinical electroretinography. A sigmoidal model was suggested, providing three indexes characterizing the b-wave recovery process. Relative b-waves and recovery indexes varied in age-related macular degeneration, central serous retinopathy, vitelliform macular degeneration, Stargardt's disease, and pattern dystrophy. CONCLUSION: The triple flash ERG reflects energy-yielding and -utilizing mechanisms. It proved to be more sensitive in detecting functional lesions in macular diseases than the standardized explorating procedure. The b-wave recovery model allows differentiation between two independent mechanisms contributing to the b-wave recovery process. One or more of the three characterizing indexes are affected in different macular diseases.

Adolescent↗