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L Neuhauser

Publications and source records attributed to L Neuhauser.

5 recordsLinked to original sources
PubMed1992

Detection of subretinal neovascular membranes with indocyanine green and an infrared scanning laser ophthalmoscope.

We studied 80 patients with subretinal neovascular membranes to demonstrate the features and limitations of indocyanine green angiography. Indocyanine green increased the detection of ill-defined membranes or those in larger exudative maculopathies. Each membrane had a characteristic small dark rim that demarcated it from surrounding choroidal tissue. Nevertheless, the complex vascular structures of the choroid and retina, which are displayed at one time, can sometimes render the separation of new vessels difficult when displayed at the same time. The results of our study indicate that indocyanine green angiography may be suggested as an additional diagnostic tool in cases of ill-defined or exudative subretinal neovascular membranes.

Aged↗
PubMed1992

Fluorescence characteristics of indocyanine green in the normal choroid and in subretinal neovascular membranes.

Indocyanine green angiography with scanning laser ophthalmoscopy is a new supplementary method studying subretinal neovascular membranes. However, it is still controversial as to whether of not exudation of this dye occurs from regular choroidal vessels or such membranes. Fluorescence of the macula area, a parapapillary retinal vein, and of venous blood and plasma was therefore measured with a picture analysis system in five healthy young volunteers. Furthermore, the angiograms of 150 subretinal neovascular membranes were reviewed. Membrane fluorescence was measured in ten exemplary cases and compared with the background fluorescence. The results show that macula fluorescence is detectable much longer than the fluorescence of retinal vessels. However, a comparison with the fluorescence of blood and plasma samples revealed that this late fluorescence must be caused by retinal and choroidal capillaries with a significantly reduced hematocrit. It is not caused by apposition or exudation of indocyanine green. The same was true for the majority of subretinal neovascular membranes. Exudation was rarely detected in membranes that were regularly surrounded by exudates but could be induced by laser coagulation. These observations indicate that exudation occurs only after massive destruction of the endothelial barrier. The results are important for the interpretation of indocyanine green angiograms and for possible photodynamic therapy with this dye.

Adult↗
PubMed1992

Fluorescence characteristics of drusen during indocyanine-green angiography and their possible correlation with choroidal perfusion.

The fluorescence of drusen and their correlation with choroidal perfusion was investigated using indocyanine-green videoangiography in 37 patients (mean age, 66 +/- 16 years) with juvenile and senile drusen. Most senile drusen (89%) blocked choroidal indocyanine-green fluorescence, and only three patients had small, weakly hyperfluorescent drusen at the vascular arcade. In contrast, all juvenile drusen (patients aged 31-52 years) demonstrated strong hyperfluorescence. Impaired choroidal perfusion was not detected. In 33% of the patients, all of them older than 60 years, moderate choroidal hypofluorescence could be explained by the presence of confluent drusen and/or a thickening of the pigment epithelium-Bruch's membrane complex. The results of the present study demonstrate that indocyanine-green angiography enables the differentiation of juvenile drusen from senile drusen, which could be an indication of a differing pathogenesis for the two diseases. Indocyanine-green hyperfluorescence of drusen must be caused by the transmission of choroidal fluoresence. This jeopardizes the hypothesis that the fluorescein fluorescence of drusen is invariably caused by storage of the dye. Our results contradict previous fluorescein studies that have demonstrated impaired choroidal perfusion in patients with age-related macular degeneration.

Adult↗