PubMed Health⌕ Search

Biomedical subjects

B Feigl

Publications and source records attributed to B Feigl.

17 recordsLinked to original sources
PubMed2006

Functional loss in early age-related maculopathy: the ischaemia postreceptoral hypothesis.

We review proposed models and psychophysical and electrophysiological tests performed in many studies for early age-related maculopathy (ARM). We suggest that ischaemia is the trigger for impaired retinal pigment epithelium function causing imbalance of secretion of vascular growth factors, reduced disc degradation capability and reduced metabolic activity and possible inflammatory response. This results in increased deposition of cell debris, such as drusen and thickens Bruch's membrane causing even more ischaemia of the overlying neurosensory retina. The photoreceptors are more resistant to ischaemia given their proximity to the choroid. Furthermore, being 'upstream' from the inner retinal layers, they act as an oxygen sink depriving retinal layers further from the choroid. Postreceptoral cell layers and especially parts of the inner nuclear layer that are located in the watershed zone between two sources of blood supply are preferentially vulnerable to ischaemia. Based on psychophysical and electrophysiological findings we propose that most of the function impairment in early ARM starts postreceptorally.

Electroretinography↗
PubMed2005

Cone- and rod-mediated multifocal electroretinogram in early age-related maculopathy.

PURPOSE: To investigate the cone- and rod-mediated multifocal electroretinograms (mfERG) in early age-related maculopathy (early ARM). METHODS AND SUBJECTS: We investigated the cone- and rod-mediated mfERG in 17 eyes of 17 subjects with early ARM and 16 eyes of 16 age-matched control subjects with normal fundi. All subjects had a visual acuity of 6/12 or better. We divided the ARM subjects into two groups based on drusen size and retinal pigment epithelium abnormalities-a less advanced (ARM1) and a more advanced (ARM2) group. The mfERG data were compared to templates derived from the control group. We analysed the mfERG results for the central and peripheral fields (CP method) and the superior and inferior fields (SI method). RESULTS: While the mean cone results showed no statistically significant difference between the groups, the rods showed significantly delayed responses in the ARM1 group for the CP and the SI methods, but not in the ARM2 group, although there was a trend of longer latencies compared to the control group. CONCLUSION: Our results show a functional impairment of the rods in early ARM subjects. As there is histopathological evidence showing earlier rod than cone impairment in early ARM, following the rod function with the mfERG might be helpful in diagnosis or for monitoring the progression of early ARM.

Aged↗
PubMed2005

Monitoring retinal function in early age-related maculopathy: visual performance after 1 year.

PURPOSE: To monitor visual performance in early age-related maculopathy (ARM). METHODS: We measured monocular visual function-high-contrast visual acuity (HC-VA), central visual fields (mean sensitivity, MS), colour vision (desaturated Panel D-15), Pelli-Robson (P-R), and cone- and rod-mediated multifocal electroretinograms (mfERG) in 13 ARM subjects and 13 age-matched control subjects with normal fundi at baseline and after 1 year. All had visual acuity of 6/12 or better. The mfERG data were compared to templates derived from the control group at baseline. We analysed the mfERG results by averaging the central and peripheral fields and the superior and inferior fields (CP and SI methods) and by calculating the local responses. RESULTS: The mean rod-mediated responses were significantly delayed in the ARM group for the CP (P=0.04) and the SI methods (P=0.03) at baseline compared to the control group. This did not change significantly after 1 year, whereas the mean cone-mediated responses were within the normal range at both times. Although the local analysis revealed lower amplitudes for the cone- and rod-mediated responses at baseline this was not found after 1 year and only the local rod-mediated latencies were delayed at both times (P<0.01). HC-VA, desaturated Panel D-15 and P-R were significantly worse in the ARM group (P< or =0.01) at baseline but did not show further significant deterioration. Progressive fundus changes were found in only two subjects (18%). CONCLUSION: Although there was significant impairment of retinal function in early ARM at baseline no further deterioration was evident after 1 year.

Aged↗
PubMed2003

[Transpupillary thermotherapy in exudative, age-related macular degeneration].

OBJECTIVE: To assess the effectiveness of a single transpupillary thermotherapy (TTT) in patients with exudative, age-related macular degeneration (AMD). METHODS: In a prospective pilot study, 14 patients with a mean age of 78 years (range: 70-92 years) with subfoveal choroidal neovascularisation (CNV) due to exudative, age-related macular degeneration were treated with a single TTT using a diode laser (810 nm). Seven patients had a classic and seven an occult CNV. Laser beam size was 4.5 mm,the power setting was 800 mW and the exposure lasted 60 s. RESULTS: Twelve out of 14 patients could be followed for a period of 18 months. Stabilisation of the visual acuity was achieved in two patients, ten patients lost three or more Snellen lines. In none of the patients a regression of the CNV could be observed immediately after TTT. Inactive fibrotic scars developed in six patients at the end of the study. CONCLUSION: Our results suggest that TTT, according to our protocol, has no beneficial effect on the spontaneous course of the CNV in patients with AMD.

Aged↗
PubMed2001

[Multifocal ERG in central areolar choroidal dystrophy].

BACKGROUND: In comparison to full-field ERG a multifocal ERG (mf-ERG) provides functional mapping of the central retina and detection of more localised defects. Central areolar choroidal dystrophy is an autosomal dominant inherited disorder with central atrophy of the choriocapillaries, the retinal pigment epithelium (RPE) and the photoreceptors. Full-field ERG often shows only slight to moderate reductions. The purpose of our study was to investigate the electroretinographic activity of the posterior pole with the mf-ERG in comparison to the photopic full-field ERG in these patients. PATIENTS AND METHODS: We performed a mf-ERG and a photopic full-field ERG in 4 patients with central areolar choroidal dystrophy and in 20 age-matched volunteers who constituted the normal control group. RESULTS: In all patients reductions in b-wave amplitudes of the first order kernel of the mf-ERG in both eyes were evident. Full-field ERG showed decreased b-wave amplitudes in only three eyes. Subnormal amplitudes were found in two eyes and normal amplitudes in three eyes. Additionally ophthalmoscopic lesions were found to a lesser extent than by the mf-ERG. DISCUSSION: The mf-ERG is a valuable tool in detecting central areolar choroidal dystrophy and might be useful in early detection and follow-up, when ophthalmoscopy and full-field ERG are still normal. Moreover it could contribute to differential diagnosis of other retinal diseases of the posterior pole.

Aged↗
PubMed2000

Morphologic characteristics of disciform scarring after radiation treatment for age-related macular degeneration.

OBJECTIVE: To investigate the influence of radiation therapy on the development of disciform lesions in patients with age-related macular degeneration (AMD). DESIGN: A prospective, nonrandomized, comparative trial (patient self-controlled). PARTICIPANTS: Forty eyes with exudative AMD involving the central fovea in 40 consecutive patients were enrolled in this study. INTERVENTION: Radiation was administered to the posterior pole with an 8-mV photon beam from a linear accelerator. A dose of 14.4 Gy, 1.8 Gy per day, five fractions per week was delivered through a single port. MAIN OUTCOME MEASURES: The visual acuity and the morphologic characteristics, demonstrated by fundus photography, fluorescein, and indocyanine green angiography, were investigated before treatment and every 3 months after treatment over a period of 24 months. In 10 patients with bilateral disease the disciform lesions were compared. RESULTS: Twenty five patients could be followed regularly over the period of 24 months. The disciform lesions occurring after radiation were classified in three types. Type I (10 patients) was characterized by being smaller than 2 DD in size, with little fibrotic tissue underneath the retina, but pronounced retinal pigment epithelial changes. Type II (seven patients) showed extensive growth of the choroidal neovascularization (CNV) extending to and beyond the arcades with angiographically active loops in the peripheral parts. Eight patients had type III lesions develop characterized by a size greater than 2 DD but fewer than 6 DD and by a different amount of fibrotic tissue, hemorrhage, and lipid. Type I scarring was significantly associated with occult CNV without pigment epithelial detachments, whereas type II scarring was associated with classic CNV at the initial presentation (P<0.05). CONCLUSIONS: Although no severe side effects have been reported after radiation therapy for AMD, a subgroup of patients may experience extensive growth of CNV after radiation, causing greater functional damage than occurs spontaneously.

Aged↗
PubMed2000

Optical coherence tomography (OCT) in acute macular neuroretinopathy.

PURPOSE: To evaluate the value of ocular coherence tomography (OCT) concerning diagnosis and pathogenesis of acute macular neuroretinopathy. METHODS: A 33-year old woman complained of sudden onset of central scotomas in her right eye because of acute macular neuroretinopathy. We performed a direct ophthalmoscopy, a visual field testing, a fluorescein angiography (FA) a multifocal ERG (mf-ERG) and an OCT. RESULTS: We found typical paracentral scotoma in visual field testing, a normal FA and mf-ERG in her right eye. In OCT there was a band of higher reflectivity (115 microm) overlying an intact band corresponding to the retinal pigment epithelium (RPE)/ choriocapillaris complex. Retinal thickness was within the normal range. CONCLUSION: OCT can be an additional valuable tool in acute macular neuroretinopathy as it is a disease with discrete pathology and often normal results in other diagnostic tests.

Acute Disease↗
PubMed2000

Melanoma-associated retinopathy versus abnormal retinal function due to interferon-alpha/Isotretinoin therapy in cutaneous malignant melanoma.

PURPOSE: To analyze whether an abnormal retinal function in patients with a cutaneous malignant melanoma was due to paraneoplastic retinopathy or due to isotretinoin or interferon-alpha. METHODS: We studied 15 patients with malignant melanoma in stage IIa and IIb who are all participants in a randomized, multicentered, double-blind placebo-controlled clinical trial comparing interferon-alpha/isotretinoin versus interferon-alpha/placebo performed by the Department of Dermatology, University of Graz. Our assessment included a full ophthalmic history and examination, electrophysiological testing (ERG, EOG), dark adaption, color vision and visual field testing. RESULTS: The most prevalent ocular symptom patients complained about was ocular dryness (8 patients). Electrophysiological as well as psychophysical testings showed no abnormalities in 12 patients. In 1 patient the therapy was stopped because of electrophysiological and psychophysiological pathology. This patient suffered from severe reduction of night vision and visual disturbances. Another patient had had night blindness since childhood which remained stable. CONCLUSIONS: We postulate that in 1 of 15 patients, visual complaints are caused with a high probability by melanoma-associated retinopathy although, in the literature, isotretinoin is described to show similar effects on retinal function.

Aged↗
PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗
PubMed1999

[Serous detection of the neuroretina in Waldenström disease. A case report].

BACKGROUND: Waldenstrom's Macroglobulinemia is a monoclonal gammopathy producing pathologic IgM antibodies with increased blood viscosity, platelet dysfunction and retinal hemorrhages. As a complication a serous detachment of the macula is described. The pathogenesis of the serous detachment is still not fully understood. CASE REPORT: A 73-year-old male patient was presented with Waldenstrom's Macroglobulinemia, a typical hyperviscosity retinopathy and serous detachment of the macula. We performed fluorescein (FA)- and indocyaningreenangiography (ICG) before and three months after chemotherapy. Especially ICG-angiographic findings revealed a serous detachment that was restricted to the posterior pole but showed a fingershaped enlargement to the optic disc. CONCLUSION: FA- and especially ICG-angiographic findings can help to get more information about the pathogenetic mechanism of serous detachment in Waldenstrom's Macroglobulinemia. Besides toxic alteration of the retinal pigmentepithelium, oncotic and hydrostatic pressure, a pathologic communication between the optic disc, the subarachnoid space and the subretinal space is discussed.

Aged↗
PubMed1997

Application of HELP in nonarteritic anterior ischemic optic neuropathy: a prospective, randomized, controlled study.

BACKGROUND: Heparin-induced extracorporeal LDL/fibrinogen precipitation (HELP) eliminates selectively fibrinogen, LDL, cholesterol, triglycerides and LP(a) from blood plasma using extracorporeal circulation. The reduction of fibrinogen and LDL by about 50% after only one procedure immediately improves the hemorheological situation. METHOD: In a prospective, randomized, controlled study over a period of 3 months, 40 patients with nonarteritic ischemic optic neuropathy (NAION) were randomly assigned to either HELP or hemodilution therapy to determine the efficacy of these two treatments on visual acuity and fields. RESULTS: After transformation of the Snellen acuity into logMAR units the statistical analysis did not show a significant difference between the two groups (P = 0.48). An increase of the visual acuity by two or more lines was obtained in 9 patients (47.4%) of the HELP group, 10 (52.6%) remained stable and none got worse. In the hemodilution group, visual acuity increased in patients (33.4%), 9 (42.8%) remained stable and 5 (23.8%) experienced a decrease. The calculated mean sensitivity of visual fields at baseline improved statistically significantly (P < 0.01) in the HELP group from 6.83 +/- 4.52 dB to 8.27 +/- 4.89 dB, but did not change significantly in the hemodilution group (6.25 +/- 4.12 dB to 6.12 +/- 3.92 dB). CONCLUSION: The HELP system seems to be safe and more effective than hemodilution in improving the hemorheological and the functional situation in NAION and could be a promising regimen in the treatment of NAION.

Aged↗
PubMed1996

Influence of a single HELP application on hemorheology and retinal hemodynamics.

The heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) eliminates selectively fibrinogen, total cholesterol, low-density lipoproteins (LDL) and triglycerides and improves hemorheology. We investigated the hemodynamic changes in 10 patients without ocular diseases performing a video fluorescein angiography after a single HELP procedure measuring the arm-retina time (ART) and the arteriovenous passage time (AVP). Laboratory parameters such as fibrinogen, cholesterol, LDL, triglycerides, red cell transit time, plasma and whole-blood viscosity were determined and retinal circulation was measured immediately before and after the HELP application. All of the laboratory parameters were lowered significantly. The ART was unaffected by the HELP procedure; however, there was a significant AVP reduction from 2.41 +/- 0.49 to 1.97 +/- 0.47 (p < 0.005). These results support the hemorheological and hemodynamic efficiency of the HELP system in microcirculatory diseases.

Adult↗
PubMed1995

Roxithromycin in the treatment of Lyme disease--update and perspectives.

Spirochaetal infections have been successfully treated with penicillin; more recently, erythromycin has been used in cases with known penicillin allergy. The discovery of the spirochaete Borrelia burgdorferi and the elaboration of a new generation of macrolides with properties that differ from older macrolides have led to new ways of treating spirochaetal disease with these compounds. This paper presents data on the in vitro and in vivo efficacy of a combination of roxithromycin and co-trimoxazole against B. burgdorferi. In vitro (checkerboard technique; B. burgdorferi strain B31; modified BSK II medium) it was found that while roxithromycin showed excellent efficacy against B. burgdorferi (MIC 0.031 mg/l), co-trimoxazole had no effect. However, the combination of both chemotherapeutics led to a minor synergistic effect, decreasing the MIC for roxithromycin by one dilution step at concentrations of co-trimoxazole from 256 to 8 mg/l. In addition, a clearly reduced growth of microorganisms was seen at concentrations of roxithromycin as low as 0.015 mg/l in combination with 256 to 4 mg/l co-trimoxazole, when compared to the positive controls. Most interestingly, however, the motility of B. burgdorferi was markedly reduced even when the two drugs were combined at very low concentrations. In an in vivo, non-randomised, open, prospective pilot study it was found that of 17 patients with confirmed late Lyme borreliosis (stage II/III), treated with combined roxithromycin (300 mg b.i.d.) and co-trimoxazole for 5 weeks, 13 (76%) recovered completely by the end of treatment, and four continued to have symptoms on follow-up at 6 and 12 months. This success rate is similar to that seen with i.v. penicillin and ceftriaxone. It appears that the reduced motility of B. burgdorferi makes the pathogen more accessible to the immune system.

Administration, Oral↗
PubMed1994

Ophthalmic manifestations in Lyme borreliosis. A review.

Lyme borreliosis is an emerging tick-borne spirochetal infection characterized by a broad variety of symptoms, ranging from neurologic disorders and different skin manifestations to cardiac symptoms. Many ocular and neuro-ophthalmic symptoms have recently been attributed to Lyme disease. Especially in endemic areas ophthalmologists need to be aware of Borrelia burgdorferi as a possible causal agent. The aim of this paper is to present a short review of the literature of ophthalmic disorders resulting from Borrelia burgdorferi infections.

Eye Infections, Bacterial↗