Retinal side-effects of sildenafil.
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3',5'-Cyclic-AMP Phosphodiesterases↗
Biomedical subjects
K U Bartz-Schmidt
Publications and source records attributed to K U Bartz-Schmidt.
[Endophthalmitis].
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Diagnosis, Differential↗
Long-term fluctuations of the normalised rim/disc area ratio quotient in normal eyes.
BACKGROUND: The assessment of the cup of the optic disc in follow-up of glaucomatous optic nerve heads depends on the variability of the cup area over time. We examined the variability of topographic measurements depending on scan focus settings and evaluated the long-term fluctuations of the normalised rim/disc area ratio quotient of normal subjects for 1 year. METHODS: Part 1. Evaluation of the influence of scan focus and corneal curvature on the number of pixels per millimetre in one emmetropic volunteer. The scan focus was varied using contact lenses of different refraction. Part 2. HRT examinations of the optic nerve head of five eyes of five volunteers were repeatedly recorded during a 12-month period. The contour line from the first mean topographic image was transferred into the following seven mean topographic images of each subject. RESULTS: Part 1. The size of pixels depends on the adjusted scan focus for mean corneal curvature radius between 6 and 9 mm. However, after image to image scaling the size of pixels is nearly independent to the scan focus. Part 2. We found the highest variation of normalised rim/disc area ratio for the location of the temporal horizontal sectors, followed by the temporal inferior and the temporal superior sectors. Variation was smallest in the nasal sectors. Mean fluctuation of the normalised rim/disc area ratio quotient of the 95th percentile was 0.09 following image to image scaling compared to 0.16 when using individual image scaling. CONCLUSION: Scan focus variation during HRT follow-up examinations can influence optic disc parameters, especially when image to image scaling has not been performed. A confidence area of an individual optic disc could now be calculated. These confidence bands could help to distinguish more easily between progress of glaucomatous optic nerve head damage and physiological intertopographic variation of optic cup measurements. A decrease of more than 43% in the fluctuations of the normalised rim/disc area ratio could be achieved using image to image scaling techniques. For that reason follow-up of glaucomatous optic nerve heads should only be performed using this software application.
Adult↗
Pars plana vitrectomy, endolaser coagulation of the retina and the ciliary body combined with silicone oil endotamponade in the treatment of uncontrolled neovascular glaucoma.
PURPOSE: Neovascular glaucoma develops on a background of ischemic ocular pathologies, such as diabetic eye diseases or central retinal vein occlusion. Development of neovascular membranes in the chamber angle leads to elevated intraocular pressure (IOP). Since cyclodestructive therapy or drainage surgery often fails, we have examined intense antiproliferative surgery as a treatment for advanced neovascular glaucoma. PATIENTS AND METHODS: Thirty-two patients with uncontrolled neovascular glaucoma (mean IOP 45.5 mmHg) subsequent to central retinal vein occlusion or advanced diabetic retinopathy underwent antiproliferative surgery, which comprised pars plana vitrectomy, panretinal laser treatment and direct laser coagulation of the ciliary processes, followed by silicone oil tamponade. Patients were followed up for a minimum of 1 year and as long as 3 years. RESULTS: One week following surgery the IOP was normal, ranging from 8 to 21 mmHg, in 52% of eyes (15/29). After 3 months the IOP was normal in 50% (16/32); after 6 months, in 59% (16/27); and after 1 year, in 72% (18/25). Of the 10 eyes that lost all sight after the surgery, 7 eyes had a history of central retinal vein occlusion. Hypotony was observed in 6% of the eyes (2/32) 3 months after surgery; after 6 months hypotony was present in 15% (4/27), and after 1 year hypotony was present in 12% (3/25). CONCLUSIONS: The theoretical premise of our surgical intervention (antiproliferative surgery) is that laser treatment interrupts the self-enhancing pathway of retinal ischemia, release of proliferative factors and increase in intraocular pressure. The silicone oil endotamponade prevents postoperative complications and supports the rapid regression of rubeosis iridis by separating the anterior from the posterior segment.
Aged↗
Detection of mRNA for proteins involved in retinol metabolism in iris pigment epithelium.
BACKGROUND: To investigate in iris pigment epithelium (IPE) the expression of mRNA for proteins involved in retinol metabolism we used a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) technique. METHODS: RNA was prepared from freshly isolated bovine IPE and retinal pigment epithelium (RPE) cells and reverse transcribed. The expression of mRNA for cellular retinaldehyde binding protein (CRALBP), p63 (RPE63), the presumed retinal pigment epithelial membrane receptor for retinoids, and 11-cis-dehydrogenase (11cisRDH) was determined by RT-PCR using specific primers. Semi-quantitative expression data were obtained by using a series of fivefold dilution of each cDNA with a fixed number of PCR cycles. RESULTS: Bovine IPE and RPE cells express mRNA for CRALBP, 11cisRDH, and RPE63. The mRNA expression for CRALBP and 11cisRDH is high and equal in both cell types. However, RPE63 mRNA expression in IPE cells is relatively low compared with the expression in RPE cells. CONCLUSIONS: The presence of mRNA for CRALBP, RPE63, and 11cisRDH suggests that IPE cells may be able to metabolize retinol.
Aldehyde Oxidoreductases↗
Quantitative morphologic and functional evaluation of the optic nerve head in chronic open-angle glaucoma.
Glaucoma leads to morphologic changes of the optic nerve head and to functional defects. Morphologic changes in the three-dimensional surface structure of the optic nerve head at its entrance site into the globe can be examined by laser scanning tomography. The standard technique for evaluating functional defects in glaucoma is static computerized perimetry. We compared these two techniques to determine which is more sensitive for follow-up of glaucomatous damage of the optic nerve head. If decreased function is presumed to precede imminent cell death, visual field analysis should be the more sensitive method, as cell death results in absolute defects of the visual field. However, the neuronal networks do not necessarily function in this way. In the case of loss of individual elements in the neuronal network, the complex linkages, even at the retinal level, are able to maintain functions and compensate for loss of function, which means that visual field defects would not be prominent. If the damage increases with time and is accompanied by a progressive loss of ganglion cells, however, compensation is eventually no longer possible, and the functional defects then become measurable by visual field analysis. Thus, morphologic absolute changes may be more prominent than visual field defects in the early stages of glaucoma. To evaluate the quantitative relationship between morphometrically measurable defects of the optic nerve head and measurable functional defects, we first examined the visual field with static computerized perimetry and then evaluated the surface structure with a laser scanning tomograph in 90 patients with chronic open-angle glaucoma, 10 patients with ocular hypertension, and 10 patients without any eye disease. Based on the 95th percentile of the standardized rim/disk area ratio, we calculated the relative rim area loss and correlated this with the mean defect in visual field analysis. The scatterplot shows an exponential curve. In the early stages of glaucoma, visual field defects were less prominent than morphologic absolute changes; 40% of the neuroretinal rim area is lost by glaucomatous optic nerve damage before first defects in visual field analysis appear. In late stages of glaucoma, changes in perimetry are more prominent than those observed with biomorphometry. These results show that in the follow-up of patients with early stages of glaucomatous damage, special attention should be given to morphologic absolute changes. In patients with advanced glaucoma, progress of the damage should be observed by repeated functional, rather than morphologic, examinations. It is important to keep in mind, however, that the sensitivity of any method is dependent on technology. One reason why functional tests may not be as sensitive as morphologic examination in observing patients with early stages of glaucoma may simply be that functional tests are not yet sensitive enough to detect early damage.
Adolescent↗
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↗
Retinal damage by light in the golden hamster: an ultrastructural study in the retinal pigment epithelium and Bruch's membrane.
The mechanism of the toxicity of light on the retina remains unclear despite a large number of investigations. The purpose of this study is to identify and localize the ultrastructural changes and the site of the earliest damage after intense light exposure. Nine adult Syrian golden hamsters (Mesocricetus auratus) have been maintained under constant illumination with a high-pressure mercury lamp (HQJ R 80 W Deluxe, Osram, Berlin, light intensity 1000 lx) for 12 h, followed by an additional 3 h in the dark. Light damage is assessed by light and electron microscopy. Morphological evaluation reveals focal damage to the retinal pigment epithelial (RPE) cells in close proximity to less-affected RPE cells and normal photoreceptors. Collagen fibers in Bruch's membrane lose their parallel orientation. Occasionally, fusion of cell membranes of neighboring rod outer segments (ROS) is also observed. Continuous, 12 h exposure of hamsters to intense light results in initial focal damage to some RPE cells, such that severely damaged RPE cells are found adjacent to intact RPE cells. Only slight damage to the photoreceptors is evident, suggesting that the sequence of the pathological changes resulting from light begins with damage to the RPE cells and associated Bruch's membrane.
Animals↗
Primary non familial amyloidosis of the vitreous and subretinal amyloid bodies.
We report a case of primary non familial amyloidosis of the vitreous and subretinal amyloid bodies. Pars plana vitrectomy and subretinal numerable clusters of cystic-like glistering material were extracted. The diagnosis was confirmed only by histological findings.
Amyloidosis↗
[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↗
[Modification of vision by change in rheologic parameters in senile macular degeneration through membrane differential filtration--initial results of a randomized study].
BACKGROUND: Membrane differential filtration (MDF) is known to optimize rheological parameters by eliminating high molecular weight proteins und lipoproteins from the blood and was shown to influence ocular perfusion parameters. Following the hypothesis that these changes may influence the natural course of age-related macular degeneration (AMD) we tested their efficacy in improving visual function in these patients in a randomized trial. PATIENTS AND METHODS: 20 patients (36 eyes) were randomized into two groups. Ten patients (18 eyes) were treated with MDF and ten (18 eyes) served as controls. The first group was treated five times over a period of 21 weeks. In both groups 8/18 of the eyes showed subfoveolar subretinal neovascularisations. Main parameter of the study was visual acuity. Macular visual evoked potentials were also recorded. Plasmaviscosity, whole blood viscosity and erythrocyte aggregation were measured. RESULTS: The ten patients, treated repeatedly over a period of 21 weeks, showed a mean improvement 1.1 (SD 1.9) lines after 21 weeks, while the control group showed a deterioration of visual acuity (0.6 lines, SD 1.7). The macular visual evoked potentials showed an increase of 0.28 microV (SD 1.12) for the therapy group and a deterioration of 0.57 microV (SD 1.31) in the control group. The rheological parameters were lowered in all patients. CONCLUSIONS: We conclude that repetitive treatment with MDF is able to improve visual function in patients with AMD. Further research is necessary to show how to optimize the selection of patients and how to create an individual treatment strategy.
Aged↗
[Vitreoretinal surgery in the treatment of neovascular glaucoma].
PURPOSE: Neovascular glaucoma develops on a background of ischemic ocular pathologies, such as diabetic eye diseases or central retinal vein occlusion. Development of neovascular membranes in the chamber angle leads to elevated intraocular pressure. Since treatment by cyclodestructive therapy or drainage surgery often fails, we have examined intense antiproliferative surgery as a treatment for advanced neovascular glaucoma. PATIENTS AND METHODS: Thirty-two patients with neovascular glaucoma subsequent to central vein occlusion or advanced diabetic retinopathy underwent antiproliferative surgery, which comprised vitrectomy, panretinal laser treatment and direct laser coagulation of the ciliary processes, followed by silicone oil tamponade. Patients were followed for a minimum of 1 year and as long as 3 years. RESULTS: After one week following surgery the intraocular pressure (IOP) was normal, ranging from 8 to 21 mm#Hg, in 52% (15/29 eyes), after 3 months the IOP was normal in 50% (16/32 eyes), after 6 months the IOP was normal in 59% (16/27 eyes) and after 1 year the IOP was normal in 72% (18/25 eyes). Of the 10 eyes that lost all sight after the surgery, 7 eyes had a history of central vein occlusion. Hypotony was observed in 6% (2/32) of the eyes 3 months following surgery; after 6 months hypotony was present in 15% (4/27) of the eyes and after 1 year hypotony was present in 12% (3/25) of the eyes. CONCLUSIONS: The theoretical premise of our surgical intervention (antiproliferative surgery) is based on the assumption that laser treatment interrupts the self enhancing pathway of retinal ischemia, release of proliferative factors and increase in intraocular pressure. The silicone oil endotamponade prevents postoperative complications and supports the rapid regression of rubeosis iridis by separating the anterior from the posterior segment.
Aged↗
Progressive subretinal fibrosis in a child following hemolytic uremic syndrome.
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Child↗
Ultimate fate of rod outer segments in the retinal pigment epithelium.
To investigate the degradation pathway of rod outer segments (ROS) in vivo, we injected gold-labeled ROS into the subretinal space of rabbits using a pars plana approach. Histology and electron microscopy performed on the specimens 72 hr after ROS injection revealed that the retina over the injection site was reattached, the retinal pigment epithelial (RPE) cells were intact, and gold granules were localized inside melanin granules and melanosomes. These results indicate that, in RPE, in vivo degradation of ROS is associated with melanosomes.
Animals↗
Laceration of the eye with a fishing hook.
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Antibiotic Prophylaxis↗
Late onset of Leber's hereditary optic neuropathy in HIV infection.
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Age of Onset↗
Autologous platelet treatment for optic disc pit associated with persistent macular detachment.
PURPOSE: To determine the effectiveness of autologous platelets in repair of optic disc pit associated with persistent macular detachment. PATIENT: We report on a 44-year-old woman with optic disc pit associated with persistent macular detachment. The patient underwent an uneventful pars plana vitrectomy with autologous platelets injected over the optic disc pit. Good anatomical and functional results were obtained. CONCLUSION: This surgical approach may be a valuable adjunct to the surgical management of optic disc pit associated with persistent macular detachment.
Adult↗
Phagocytosis of rod outer segments by human iris pigment epithelial cells in vitro.
BACKGROUND: We set out to evaluate the growth potential of human iris pigment epithelial (hIPE) cells in vitro, to establish whether these cells acquire the ability to phagocytose rod outer segments (ROS) and to compare the phagocytic activity of hIPE to that of human retinal pigment epithelial (hRPE) cells. METHODS: hIPE and hRPE cells were isolated and cultured from human donor eyes and surgical specimens and growth characteristics were analyzed. HIPE and hRPE of an eye of a 46-year-old donor were used for the phagocytosis assay. Phagocytosis was evaluated by adding ROS isolated from porcine retina to cultures of hIPE and hRPE, which had been labeled with the pH-sensitive fluorescent dye, carboxy-SNAFL. After 4 h the number of ingested ROS was counted with a light microscope. For each cell type phagosomes in 500 cells were counted. The epithelial characteristics of the cells used in this study were evidenced by their morphology. RESULTS: Morphologically cultured hIPE are indistinguishable from the hRPE cultured from the same donor eye and show a similar pattern of cytokeratin distribution. Cultured hIPE acquire the ability to phagocytose ROS at a level slightly lower than hRPE; hIPE contained 0.76 phagosomes per cell, hRPE 0.99 phagosomes per cell. CONCLUSION: The morphology of hIPE in culture and the acquisition of the phagocytic phenotype indicate that these cells have the ability to differentiate into cells that have characteristics in common with hRPE. The acquisition of phagocytic activity suggests that it is feasible to culture hIPE from surgical iridectomies and that these cultured cells can be transplanted into the subretinal space in individuals with retinal degenerations.
Cells, Cultured↗