Biomedical subjects

K O Arend

Publications and source records attributed to K O Arend.

4 recordsLinked to original sources

PubMed2006

Retrobulbar haemodynamics and morphometric optic disc analysis in primary open-angle glaucoma.

BACKGROUND: Previous studies confirmed reduced retrobulbar haemodynamics in primary open-angle glaucoma (POAG). AIM: To investigate a correlation between retrobulbar haemodynamics and morphometric neuroretinal rim analysis in patients with POAG. METHODS: 51 patients with POAG (mean (standard deviation (SD)) age 65 (11) years) were included in this clinical study. Blood flow velocities (peak systolic velocity (PSV) and end-diastolic velocity (EDV)) of the ophthalmic artery, central retinal artery (CRA), posterior ciliary arteries (PCA) and central retinal vein were measured using colour Doppler imaging (Siemens Sonoline Sienna, Erlangen, Germany). Optic disc morphometry was carried out using scanning laser tomography (Heidelberg Retinal Tomograph II Heidelberg Egineering Heidelberg, Germany). The stereometric parameters of the neuroretinal rim (rim area, rim volume, cup shape measure and retinal nerve fibre layer (RNFL) cross-sectional area) were used for analysis. RESULTS: The PSV of the CRA was significantly (p<0.001) correlated with rim area (r = 0.50) and rim volume (r = 0.51). The minimum velocities of the central retinal vein were significantly (p<0.001) correlated with rim volume (r = 0.56) and RNFL cross-sectional area (r = 0.49). No correlations were found for the flow velocities of the ophthalmic artery and PCAs. CONCLUSION: Retrobulbar haemodynamics of the central retinal artery and vein are correlated with the neuroretinal rim damage in POAG.

Aged↗

PubMed2006

Retrobulbar haemodynamics in non-arteritic anterior ischaemic optic neuropathy.

AIM: To compare retrobulbar haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) and age-matched controls by colour Doppler imaging (CDI). METHODS: 25 patients with acute NAION and 35 age-matched controls participated in this study. By means of CDI, the blood flow velocities of the ophthalmic artery, central retinal artery (CRA), and nasal and temporal short posterior ciliary arteries (PCAs) were measured. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) and Pourcelot's resistive index were determined. RESULTS: In the ophthalmic artery, no marked differences between patients with NAION and controls were detected. PSV and EDV of the CRA (p<0.001, p = 0.002) and PSV of the nasal PCA (p<0.05) were significantly decreased in patients with NAION compared with healthy controls. No marked differences between patients and controls were detectable for temporal PCAs. CONCLUSION: Blood flow velocities of the nasal PCA and the CRA are considerably reduced in patients with acute NAION compared with controls. Patients with NAION in part showed markedly different retrobulbar haemodynamics.

Acute Disease↗

PubMed2006

[Diagnostic approaches for early detection of glaucoma progression].

BACKGROUND: To monitor the efficiency of glaucoma therapy it is necessary to detect progression of the disease as soon as possible. This survey presents the results on functional and morphological approaches to detect glaucoma progression. MATERIAL AND METHODS: Risk factors identified in the therapeutic intervention studies should be used to evaluate the possible risk for progression. The functional test approaches of standard achromatic perimetry (SAP), short wavelength automated perimetry (SWAP) and frequency doubling technology (FDT) are described. Furthermore, morphologic changes are described by means of optic nerve head and nerve fiber photography, optic nerve head tomography, optic coherence tomography and nerve fiber polarimetry. RESULTS: The risk factors identified in the interventional studies were as follows: 1. higher intraocular pressure, 2. worse mean deviation (MD), 3. older age, and 4. frequent disc hemorrhages. Additionally, in patients with normal pressure glaucoma, migraine headaches were identified. Patients with ocular hypertension showed a higher risk of conversion into open angle glaucoma in case of higher pattern standard deviation (PSD), thinner central corneal thickness and larger vertical cup-to-disc ratio. The optic nerve head photography was the standard procedure of morphological monitoring in the interventional studies. A direct comparison of the available techniques on nerve fiber thickness and optic nerve head morphology is not yet available. SAP represents the functional methodology with the most validated results. SWAP and FDT showed that progression in early glaucoma can be detected before SAP damage occurs. CONCLUSION: Glaucoma patients should be regularly tested with SAP and optic nerve head photography. Automated nerve fiber or optic nerve head morphology measuring techniques might be favourable to complete the diagnostic monitoring. In patients without glaucomatous damage SWAP and FDT may be able to detect changes earlier than SAP. The results of a review of the literature are presented and discussed for each technology.

Clinical Trials as Topic↗

PubMed2005

[Update on prospective glaucoma intervention studies].

BACKGROUND: Previously published prospective therapeutic intervention studies in ocular hypertension and glaucoma are summarized. MATERIAL AND METHODS: The concept of intraocular pressure reduction was evaluated in normal tension glaucoma ["Early manifest glaucoma trial (EMGT)"], the "Collaborative normal-tension glaucoma study (CNTGS)" and ocular hypertension ["Ocular hypertensive study (OHTS)" as well as the "European glaucoma prevention study (EGPS)"]. Early open angle glaucoma patients were included in the EMGT trial as well as the "Collaborative initial glaucoma treatment study (CIGTS)", whereas advanced glaucoma patients were examined in the "Advanced glaucoma intervention study (AGIS)". RESULTS: The study design, the results and the conclusions will be highlighted in the text. CONCLUSIONS: The therapeutic concept of intraocular pressure reduction decreases the risk of progression by 50 % in normal tension glaucoma, ocular hypertension and early open angle glaucoma. The mean pressure reduction to 12 mmHg in advanced glaucoma abolished visual field progression. The natural course of the disease documented by the control groups is now known. Sensitive glaucoma progression detection is clinically available by glaucoma change probability maps (Humphrey-full threshold perimetry) used in the EMGT.

Clinical Trials as Topic↗