Biomedical subjects

A S Neubauer

Publications and source records attributed to A S Neubauer.

23 records · Page 2Linked to original sources

PubMed2001

Comparison of foveal thickness measured with the retinal thickness analyzer and optical coherence tomography.

PURPOSE: To assess and compare the reliability and reproducibility of retinal thickness measurements for the retinal thickness analyzer (RTA) and optical coherence tomography (OCT) in normal and edematous retina. METHODS: The authors measured the foveal thickness of 21 normal eyes and 9 eyes with macular edema with both methods in random order. With the RTA, the fovea was measured 10 times; with the OCT, six scans (one horizontal and five vertical cross-sections) of the fovea were obtained. RESULTS: Mean foveal thickness of normal eyes measured 153 microm with OCT and 181 microm with RTA (median for both methods 150 microm). Coefficients of variation (CV) within the same subjects were 10% (OCT) and 9% (RTA) reducing to 9% (OCT) and 7% (RTA) when scans were repeated only five times for both methods. The RTA, however, yielded an interpatient CV of 33% (OCT 17%), which was caused by several falsely high readings in normal individuals. In eyes with retinal thickening the OCT measured a mean of 324 microm with 15% intra- and 58% interpatient CV. The RTA yielded a mean of 403 microm with CV of 18% and 73%, respectively. CONCLUSION: Both methods yield reproducible measurements of foveal thickness in normal individuals and individuals with macular edema. However, falsely high measurements may occur with the RTA, reducing its reliability as compared to the OCT.

Anthropometry↗

PubMed2001

Role of tissue growth factors in aqueous humor homeostasis.

The aqueous humor supplies nutrients to the nonvascularized cornea, lens, and trabecular meshwork. A number of tissue growth factors have been detected in this fluid. The composition of these proteins changes dramatically with different ocular conditions, such as inflammation and glaucoma. In this review, an overview of new findings regarding effects of aqueous humor growth factors is given. Our main emphasis is on the regulation of the avascular anterior eye compartment, the possible role of growth factors in the pathogenesis of glaucoma, and the importance of growth factors for the special immunosuppressive status of the anterior chamber.

Animals↗

PubMed2000

[Bilateral retinal microangiopathy in interferon therapy of malignant melanoma of the skin].

BACKGROUND: Interferon associated retinopathy has been described mainly by Japanese working groups as a complication of systemic interferon therapy for various diseases. In Europe, only few reports exist, especially regarding interferon therapy for dermal malignant melanoma. PATIENT: We report a 58-year-old female patient with symptomatic, bilateral microangiopathy caused by interferon for metastatic dermal malignant melanoma. Multiple bilateral cotton wool spots caused visual field defects and unilateral decreased visual acuity. The retinal changes were reversible when stopping interferon therapy. CONCLUSION: Interferon-associated microangiopathy occurs as a complication of interferon therapy independently of the treated systemic disease. Rarely, retinopathy becomes symptomatic as reported in this case. Symptoms were fully, clinical signs were partially reversible. A regular ophthalmologic monitoring of all patients receiving interferon therapy is recommended. Monitoring aims to detecting vision-threatening retinal changes in a reversible phase.

Female↗

PubMed2000

[Minimally invasive therapy for clinically complete central retinal artery occlusion--results and meta-analysis of literature].

BACKGROUND: Goal of our study was the comparison of the efficacy of various minimal invasive therapeutic regimens for clinically complete central retinal artery occlusion (CRAO) and the comparison with the literature. PATIENTS AND METHODS: In a retrospective study 93 patients treated for CRAO during the period 1994-1998 were identified. 65 of these patients with clinically complete occlusion without a cilioretinal artery were included in the study. Analysis focused on the results of different therapies and the duration of visual impairment till starting treatment. RESULTS: The following therapies were used: acetazolamide (65%), aspirin (60%), bulbus massage (45%), hemodilution (34%), oral pentoxifylline (28%), topical beta blockers (9%), paracentesis (8%), heparin (6%). In 15% of all cases an improvement of at least 3 visual acuity gradations was achieved. No significant positive influence of any treatment method could be identified. Also, a correlation between duration of visual impairment and final visual acuity could not be shown. In the literature very different criteria for inclusion of patients to the studies and for visual acuity improvement are found. When applying comparable criteria to ours most studies show similar results for the therapies listed above as well as for paracentesis and the use of carbogen (95% O2 and 5% CO2). CONCLUSION: The minimal invasive treatments given above do only improve natural course of CRAO in occasional cases. Thus a therapy (-combination) should be chosen, which is adapted to the individual risk factors and is exposing the patient to a low risk by therapy itself.

Acetazolamide↗

PubMed1997

The EWMA control chart: properties and comparison with other quality-control procedures by computer simulation.

A quality-control chart based on exponentially weighted moving averages (EWMA) has, in the past few years, become a popular tool for controlling inaccuracy in industrial quality control. In this paper, I explain the principles of this technique, present some numerical examples, and by computer simulation compare EWMA with other control charts currently used in clinical chemistry. The EWMA chart offers a flexible instrument for visualizing imprecision and inaccuracy and is a good alternative to other charts for detecting inaccuracy, especially where small shifts are of interest. Detection of imprecision with EWMA charts, however, requires special modification.

Algorithms↗