[Progressive loss of vision in suspected tumor].
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Adult↗
Biomedical subjects
T Böker
Publications and source records attributed to T Böker.
Ultrasound biomicroscopy for examination of the sclerotomy site after pars plana vitrectomy.
PURPOSE/METHODS: The pars plana sclerotomy has been considered to be a potential site for complications. Ultrasound biomicroscopy was used for in vivo examination of the entry sites in 20 eyes of 19 patients after vitrectomy. RESULTS/CONCLUSIONS: In all patients the entry sites were identified by ultrasound biomicroscopy. Extensive membranes at the sclerotomy were found in eyes treated for complications after vitrectomy. Ultrasound biomicroscopy allows in vivo examination of the pars plana sclerotomy and gives further insight into postoperative complications.
Ciliary Body↗
Increased lipid peroxide level and myeloperoxidase activity in the vitreous of patients suffering from proliferative vitreoretinopathy.
BACKGROUND: Retinal pigment epithelium cells and activated phagocytes are believed to be involved in the pathogenesis of proliferative vitreoretinopathy (PVR). Both cell types are capable of producing oxygen free radicals and other molecules with a high oxidative potential which can lead to a propagation of oxidative damage. It was the aim of this study to investigate whether products of oxidative reactions are detectable in the vitreous body of patients suffering from PVR. METHODS: In vitreous aspirates of patients vitrectomized because of PVR (n = 27), macular pucker (n = 9), or other reasons (controls, n = 31), the following parameters were determined: lipid peroxides (LPO), determined as malondialdehyde-like substances (MDA) and as thiobarbituric acid-reactive substances (TBARS), and myeloperoxidase activity (MPO). RESULTS: Compared with the controls, both LPO levels and MPO activities were significantly elevated in the vitreous of patients suffering from PVR. Vitreous of patients with macular pucker did not reveal any significant differences from controls in the parameters analyzed. CONCLUSION: Our results suggest that both oxygen free radicals and inflammation-related reactions participate in the process of PVR. Oxidative tissue damage is obviously not involved in the pathogenesis of macular pucker.
Free Radicals↗
No cataract two years after pneumatic retinopexy.
PURPOSE: This study was conducted to examine possible adverse effects on lens transparency caused by pneumatic retinopexy using sulfur hexafluoride gas. METHODS: In a prospective study, both lenses of 33 patients undergoing pneumatic retinopexy in one eye were monitored up to 24 months postoperatively by slit-lamp examination and Scheimpflug photography. RESULTS: Pneumatic retinopexy does not cause significant lens opacifications up to 2 years after surgery. CONCLUSION: Temporary gas tamponade for pneumatic retinopexy is not associated with permanent changes in lens transparency.
Adult↗
Hyperopia and choroidal neovascularization.
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Choroid↗
Increased lipid peroxides and inflammatory parameters in the retina adjacent to choroidal melanoma.
Oxidative tissue damage and inflammatory reaction were investigated in the neurosensory retina of five eyes with malignant choroidal melanoma and correlated to the distance from the tumour. The results showed elevated levels of both lipid peroxides (expressed as thiobarbituric acid reactive substances) and myeloperoxidase in the retina adjacent to the tumour. The values declined with distance from the tumour. The results indicate that production of oxygen free radicals contributes to tumour associated retinopathy.
Choroid Neoplasms↗
Free radical scavenging and antioxidant activity of allopurinol and oxypurinol in experimental lens-induced uveitis.
PURPOSE: In addition to the inhibition of xanthine oxidase, allopurinol is known to act, dependent on the dose, as a free radical scavenger, an antioxidant, and a "scavenger" of hypochlorous acid. This activity was investigated using a model of lens-induced uveitis. METHODS: Lipid peroxides (LPO) were determined in aqueous humor and in retinal tissue. Reduced and oxidized glutathione (GSH and GSSG) of the aqueous humor and myeloperoxidase (MPO) activity in the iris-ciliary body complex were analyzed. Allopurinol and oxypurinol concentrations were determined by high-performance liquid chromatography in aqueous humor and retinal tissue of both control eyes and eyes with uveitis. These measurements were performed 6 hours after intravenous application of allopurinol. RESULTS: In lens-induced uveitis, LPO are significantly elevated, GSH is reduced, and GSSG and MPO are increased. A xanthine oxidase inhibition dose (< 10 mg/kg body weight) of allopurinol showed no effects on oxidative tissue damage in the model used in this study. Higher doses, however, were able to reduce the oxidative damage. Allopurinol (20 mg/kg body weight) had slight effects on GSH and GSSG. All parameters improved using a dose of 50 mg/kg body weight; a dose of 100 mg/kg body weight only showed additional improvement in GSH and GSSG. There was no further change in the other parameters. Allopurinol and oxypurinol concentrations in aqueous humor and retinal tissue showed a dose dependency reaching scavenger concentrations after application of 50 mg/kg body weight of allopurinol. CONCLUSIONS: These results suggest that the xanthine oxidase mechanism plays a minor role in the oxidative tissue damage due to lens-induced uveitis. Free radicals and oxidants are generated by activated leukocytes; therefore, the effect of higher doses of allopurinol is due to its free radical scavenging and antioxidative activity.
Allopurinol↗
Solitary retinal granuloma as a presenting sign of sarcoidosis.
A 31-year-old white patient was referred with a recent history of decreased visual acuity in his left eye. A raised, greyish-white lesion close to the optic nerve was the only ophthalmological finding. Upon systemic work-up a chest X-ray revealed enlarged pulmonary lymph nodes. A biopsy obtained during bronchoscopy led to the diagnosis of sarcoidosis. No other manifestation was noted. Following systemic steroid treatment the lesion regressed and visual acuity improved. Granulomatous inflammatory diseases have to be ruled out in cases of prominent greyish-white fundus lesions.
Adult↗
Results and prognostic factors in pneumatic retinopexy.
We analyzed 133 consecutive cases of primary retinal detachment treated by pneumatic retinopexy (PR). The postoperative follow-up period was at least 6 months (mean, 16.7 months; maximum, 36 months). In all, 97 cases (72.9%) were successfully treated by a single PR. In 19 cases (14.3%) primary reattachment was not achieved. In another 17 cases (12.8%) redetachment occurred. Redetachment was never observed later than 6 months following PR. It was caused by missed or new retinal tears in 8 eyes (6.0%) and by proliferative vitreoretinopathy in 7 eyes (5.3%). A final reattachment rate of 98.5% was achieved. Preoperative factors suggesting primary failure or redetachment were (1) extensive retinal detachment (P < 0.01), (2) pseudo- or aphakia (P = 0.01), (3) the retinal status of the fellow eye (P < 0.05), and (4) poor visual acuity in cases of attached macula (P < 0.01). In cases with preoperatively detached macula, visual acuity (VA) recovered considerably better following PR than following conventional buckling procedures. As compared with cases of successful PR, recovery of VA in all eyes requiring reoperation was significantly reduced. It was, however, still equivalent to the VA of eyes treated by scleral buckling. Surgical success is influenced by preoperative factors such as pseudo- or aphakia, extensive retinal detachment, poor initial VA in cases of attached macula, or the state of the fellow eye. These factors have to be taken into consideration in decisions for or against PR. The anatomical and functional outcome proves the value of this technique in the treatment of primary rhegmatogenous retinal detachment.
Adult↗
Increased lipid peroxide levels and myeloperoxidase activity in the vitreous of patients suffering from proliferative diabetic retinopathy.
Lipid peroxide (LPO) levels, as determined by high-performance liquid chromatography (HPLC) and by the thiobarbituric acid (TBA) method, and myeloperoxidase (MPO) activity in vitreous of patients vitrectomized because of proliferative diabetic retinopathy were compared with LPO levels and MPO activity in vitreous of patients with no vitreoretinal proliferation. Both LPO levels and MPO activity were significantly elevated in the vitreous of patients with fibrovascular vitreoretinal proliferations secondary to diabetes. The TBA method produced higher values for LPO levels than did the HPLC method. The correlation between the two methods was 0.94. Our results suggest that both oxygen-free radicals and inflammation-related reactions can participate in the pathogenesis of diabetic retinopathy.
Chromatography, High Pressure Liquid↗
Refractive error and choroidal perfusion characteristics in patients with choroidal neovascularization and age-related macular degeneration.
The refractive error of 186 eyes with choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD) was determined. It was found that the risk for the development of this form of ARMD increased with increasing degrees of hyperopia. The 96 patients afflicted with bilateral CNV were significantly older than the unilaterally affected patients (P = 0.027). Abnormal choroidal perfusion was identified in 66.4% of the fluorescein angiograms. These findings support the concept that hyperopic shortening in eyes afflicted with ARMD might cause secondary changes in the choroidal vasculature, predisposing them to choroidal neovascularization.
Aged↗
Predictive diagnosis in familial adenomatous polyposis: evaluation of molecular genetic and ophthalmologic methods.
Familial adenomatous polyposis (FAP) is an autosomal-dominant precancerous condition characterized by the appearance of hundreds to thousands of colorectal polyps. The responsible gene (APC) has been mapped and identified. The cancer prevention policy for persons at risk (children and sibs of FAP patients) implies an early diagnosis of the disease. A presymptomatic diagnosis allows to limit the regular rectosigmoidoscopic examination to those persons having inherited the disease gene. Presymptomatic diagnosis can be achieved by molecular genetic methods (direct and indirect genotype analysis) and by funduscopic examination of retinal pigment anomalies that are characteristic for FAP. The aim of this study was to examine the power of the molecular genetic and ophthalmologic methods for presymptomatic diagnosis in FAP. For this purpose 60 FAP families with 171 persons at risk were examined. By direct mutation analysis a presymptomatic diagnosis was achieved in 32% of the persons at risk; indirect genotype analysis was possible in 88% of the families in which more than one FAP patient was available. The ophthalmologic examination allowed a presymptomatic conclusion in 79% of the persons at risk. In no case there was a discrepancy in the results between the methods applied. The ophthalmologic presymptomatic test is useful especially in families where the index patients has a new mutation in the APC gene that has not been identified.
Adenomatous Polyposis Coli↗
Evidence for the prevention of oxidative tissue damage in the inner eye by vitamins E and C.
The injection of oxidative metabolites such as lipid peroxides (LPO) into the vitreous cavity led to tissue damage demonstrable by a dose-dependent increase in intravitreal and intralental LPO levels, which are expressed as thiobarbituric-acid-reactive substances (TBARS). This process was accompanied by an inflammatory response as indicated by the occurrence of leukocyte-derived myeloperoxidase (MPO) in the vitreous body. Intramuscular injections of vitamin E were very effective in reducing both TBARS and MPO activity, whereas vitamin C had a moderate effect on TBARS only. The injection of a combination of the two vitamins was no more effective than treatment with vitamin E alone.
Animals↗
Idiopathic posterior subretinal neovascularization (IPSN) is related to myopia.
In 153 eyes with idiopathic posterior subretinal neovascularization (IPSN) and myopia of no greater than -6 dpt, the relative risk of this disorder was determined with regard to refraction. It was shown that the probability of developing this condition is directly proportional to the degree of myopia. By using data obtained from the literature for calculating the relative risk regarding refraction, it was demonstrated that the same is true for subretinal neovascularization in degenerative myopia greater than -7.5 dpt (Fuchs' spot). The relative risk for developing one of both disorders increases exponentially with increasing myopia.
Adolescent↗
[Lens changes following pneumatic retinopexy: preliminary results of linear densitometry image analysis of Scheimpflug photographs two months after operation].
The small degree of morbidity and a better postoperative visual acuity are the advantages of pneumatic retinopexy in comparison to encircling procedures in the treatment of retinal detachment. The injection of air or gas into the vitreous cavity can theoretically induce a cataract postoperatively. Two months after pneumatic retinopexy (SF6-gas) Scheimpflug photography and microdensitometric evaluation of the negative were performed on 22 pairs of phacic eyes showing changes in the transparency of the lens. The deterioration of transparency in the operated eye was small but higher than that of the non-operated eye. Due to the short follow up period no prognosis is possible as to the future lens transparency changes.
Cataract↗
Brain SPECT imaging with Tc-99m HMPAO in ophthalmoplegia plus.
In 14 patients with ophthalmoplegia plus Tc-99m hexamethylpropylene amineoxime (HMPAO) brain SPECT imaging was performed. Three patients showed bilateral parieto-occipital hypoperfusions, and two patients had left parietal defects (one with an additional right temporal lesion). Two patients presented with occipital hypoperfusions and one with a distinct hypoperfusion in the medial part of both frontal lobes. Hypoperfusion of the visual cortex might result from permanently decreased input from the degenerated retina. The hypoperfusion in the visual cortex and in other regions alternatively might reflect direct central nervous system (CNS) involvement due to neuronal degeneration or to impaired vascular function caused by morphologically changed mitochondria in smooth muscle and endothelial cells. The data suggest CNS involvement in ophthalmoplegia plus with abnormalities of cerebral blood flow similar to those found in other mitochondrial encephalomyopathies.
Adult↗
[Delayed resorption of subretinal fluid after pneumatic retinopexy].
Delayed resorption of pooled subretinal fluid has been reported to cause impaired visual acuity due to involvement of the macula in up to 10% of all case. In our series of 60 eyes treated consecutively with pneumatic retinopexy for retinal detachment, 9 eyes experienced delayed absorption of subretinal fluid. Only 6 eyes showed the phenomenon of pooled, localized subretinal fluid without peripheral extension to the ora serrata. The time for complete absorption of these circumscribed subretinal bullae ranged from 8 to 52 weeks (mean 22.7 weeks). Impaired visual acuity could not be detected in any of these cases. This may be due to the location of these bullae, which never involved the macula. Therefore, we do not consider the occurrence of this phenomenon to be a reason not to carry out pneumatic retinopexy.
Adult↗
[Development of lens opacities in a period of 6 months after pneumatic retinopexy].
When performing a pneumatic retinopexy, air or gas is injected into the vitreous cavity to reattach a primary, rhegmatogenous retinal detachment. SF6 gas, for examples, remains in the vitreous cavity for up to 2 weeks before it is completely absorbed. It is conceivable that the injection of SF6 gas into the vitreous cavity interferes with lens metabolism, thus causing opacities of the lens. Even minor early changes in lens transparency can be monitored by Scheimpflug photography. Two months after performing a pneumatic retinopexy, 31 out of 100 consecutive eyes showed a loss of lens transparency, which was not pronounced or statistically significant. Six months after surgery the loss of transparency was more pronounced in all lens layers, increasing from the front to the back. The increment was statistically significant for the anterior lens cortex. Further investigations are needed to determine whether lens changes are the result of the intraocular tamponade with SF6 gas or are related to other factors, such as the surgical maneuver itself.
Cataract↗