Selective suppression of sphincter activation during sacral anterior nerve root stimulation

The purpose of this work was to electrically activate small-diameter motor fibers in the sacral anterior roots innervating the urinary bladder, without activating the large-diameter fibers to the sphincter. Quasitrapezoidal current pulses were applied through tripolar spiral nerve electrodes on selected anterior sacral roots during acute experiments on eight dogs, maintained under pentobarbital anesthesia. Pressures were recorded from the bladder and sphincter with catheter-mounted gauges. Stimulation with biphasic quasitrapezoidal pulses showed decrease in sphincter recruitment with increasing pulse amplitudes. The minimum current amplitude that resulted in maximum sphincter suppression was used to stimulate the roots with trains of 20 Hz pulses, with 60 mL of saline filling the bladder. Pressures were also recorded when 100 micros rectangular pulse trains at 20 Hz, both continuous and intermittent, were applied. Trains of stimuli were applied before and after dorsal root rhizotomy. Suppression of sphincter activation was defined to be a percentage, [(Maximum pressure -Minimum pressure)/Maximum pressure x100. The results from 22 roots in eight animals show that with single pulses, the average percentage suppression of sphincter activation was 76.3% (+/-14.0). The minimum current for maximum sphincter suppression was 1.29 mA (+/-0.62). The average bladder pressure evoked was 50 cm of water during pulse train stimulation, with no significant difference due to pulse type. With pulse trains, the sphincter pressures were significantly higher when the bladder was filled. Evacuation of fluid occurred in three animals with average flow rates of 1.0 mL/s.     

Results of proximal metaphyseal fractures in children

BACKGROUND: The aims of the present study were: determining the extent of the two typical outcomes (valgus deformity and leg overgrowth); examining the extent, limits and duration of possible spontaneous corrections; and analysing the consequences of different types of therapy. METHODS: Metaphyseal tibial fractures in children are rare (incidence 5.6:100,000). Seven children were retrospectively re-examined by their medical records and roentgenograms. The patients' ages at the time of the accident ranged from 1 year 10 months to 10 years 2 months, and the average observation period was 34 months. RESULTS: All the patients experienced a subjective recovery, with the exception of one child who had minor functional problems. All of them were able to move their knee joint freely. Six patients developed a genu valgum (proximal tibia angle between 6 degrees and 16 degrees ); each of them was treated conservatively. Only two patients--both under the age of 5--experienced a partial spontaneous correction. Overgrowth on the side of the fracture was observed in four cases, varying from 0.5 cm to 1.5 cm, most pronounced after complete reduction and stable osteosynthesis. CONCLUSIONS: We recommend surgical correction and osteosynthesis as the preferred method of treatment, even with the increased likelihood of overgrowth. This is based on our observation of valgus deformity occurring in all cases after conservative treatment, with partial remodelling seen only in children up to the age of 5.     

Retrospective analysis of ruthenium-106 brachytherapy for small and medium-sized malignant melanoma of the posterior choroid

BACKGROUND: Transpupillary thermotherapy is a new and most promising treatment modality for up to medium-sized choroidal melanoma at the posterior pole. We analysed the results of conventional ruthenium-106 brachytherapy in these special tumour subgroup. PATIENTS AND METHODS: Results of ruthenium-106 brachytherapy (radioactive dose to the tumour apex 150 Gy) in a series of 52 eyes with primary malignant choroidal melanoma (posterior to the equator, thickness 相似文献   

Determination of the solubility of perfluorocarbon liquids in silicone oil in vitro and in vivo

PURPOSE: To investigate the solubility of perfluorocarbon liquids (PFCL) in silicone oil. METHODS: Forty-eight samples of silicone oil (1,300 mPas, n = 22; 5,000 mPas, n = 26) were analyzed for dissolved fluorocarbon molecules after surgical removal from patients who had initially undergone vitreoretinal surgery with (n = 41) and as control without (n = 7) the use of perfluorodecalin in headspace gas chromatography. In vitro, the solubility of three different PFCL-perfluorooctane (PFO), perfluorodecalin (PFD), and fluoromethylcyclohexane (FMCH)-in silicone oil of various viscosities was determined. The diffusion phenomena during a direct exchange were studied. RESULTS: In 39 of 41 silicone oil samples removed from patients who had undergone vitreoretinal surgery with the use of PFD, small amounts of dissolved perfluorocarbons could be detected. The mean value in 5,000-mPas silicone oil was 939.0 x 10-4 m/% and in 1,300-mPas silicone oil was 322.75 x10(-4) m/%. No perfluorocarbon molecules were found in seven control patients. In vitro, the following maximum solubilities in 1,000-mPas silicone oil were measured at room temperature: PFO, 3.2 m/%; PFD, 5.1 m/%; and FMCH, 10.3 m/%. The maximum values measured in 5,000-mPas silicone oil were PFO, 3.3 m/%; PFD, 5.7 m/%; and FMCH, 8.5 m/%; and in 100-mPas silicone oil were PFO, 2.4 m/%, and PFD, 5.1 m/%. CONCLUSION: Perfluorocarbon liquids dissolve in silicone oil. This may lead to transient formation of "heavy silicone oil," but no stable heavy silicone oil can be created adding PFCL. Intraocularly, retained PFCL vanish in silicone oil and are removed during silicone oil removal.     

Kestenbaum and artificial divergence surgery for abnormal head turn secondary to nystagmus. Specific and nonspecific effects of artificial divergence

Recommendations concerning the kind and dosage of eye muscle surgery for nystagmus vary in the literature. The present paper is an evaluation of the effects of Kestenbaum and artificial divergence surgery on abnormal head posture in a retrospective study. Exclusively patients with surgery for nystagmus-related horizontal head-turn (HT), with binocular vision and without previous eye muscle surgery were considered. Of the 78 patients, aged 3 to 68 years, 52 had a HT to the left side; 47 patients were male. In the Kestenbaum group (n = 31), the preoperative HT of 30 degrees (20-40) (median, 0.1-0.9 quantile) was reduced to 10 degrees (0-30) by surgery of 14 mm (10-20) on each eye. Four patients received further surgery. In the artificial divergence group (n = 27), the HT of 30 degrees (25-40) was reduced to 5 degrees (0-20) by recess-resect surgery of 10 mm (7-12) on the adducted eye. Seven patients needed further surgery. In the combined Kestenbaum plus artificial divergence group (n = 20), the HT of 30 degrees (25-40) was reduced to 7 degrees (-5-15) by surgery of 29 mm (21-37) on both eyes together. No further surgery was necessary. Kestenbaum surgery had a similar effect/dose ratio as recess-resect surgery for strabismus. If a test with base-out prisms suggests that artificial divergence is promising, this concept is preferable. It can be integrated into Kestenbaum surgery.     

Laser in situ keratomileusis for hyperopia and hyperopic astigmatism using the Meditec MEL 70 spot scanner

PURPOSE: To evaluate safety, predictability, efficacy, and stability of laser in situ keratomileusis (LASIK) for spherical hyperopia and hyperopia with astigmatism. METHODS: In this retrospective study we analyzed the results of 23 eyes of 23 patients who had LASIK for spherical hyperopia (preoperative cylinder < or = 0.75 D) and 44 eyes of 44 patients who had LASIK for hyperopia with astigmatism; (Bausch & Lomb Hansatome microkeratome with a 180-microm plate and a suction ring for a 9.5-mm flap diameter; Asclepion-Meditec MEL 70 G-scan flying spot laser with a 1.8-mm Gaussian beam). RESULTS: In Group 1 (spherical hyperopia), mean preoperative spherical equivalent refraction was +4.88 +/- 2.13 D (range +2.13 to +9.63 D); in Group 2 (hyperopic astigmatism), +4.33 +/- 2.15 D (range +0.50 to +9.50 D). One year after LASIK, mean spherical equivalent refraction was +0.30 +/- 0.90 D (range -0.75 to +2.50 D) in Group 1 and +0.29 +/- 1.27 D (range -3.25 to +3.25 D) in Group 2. In Group 1, 78%, and in Group 2, 42% were within +/- 0.50 D. In Group 1, no eyes lost two or more lines, and one eye (6%) lost one line of best spectacle-corrected visual acuity at 1 year. In Group 2, one eye (4%) lost one line and one eye (4%) lost more than two lines at 1 year. Uncorrected visual acuity of 20/40 or better was achieved in 83% (Group 1) vs. 62% (Group 2) at 1 year; these values improved to 100% vs. 71% for corrections up to +6.00 D. CONCLUSIONS: LASIK with the Meditec MEL 70 G-Scan flying spot laser seemed to be safe and effective for hyperopia and hyperopia with astigmatism for corrections up to +6.00 D. Large flap diameters are necessary to avoid epithelial ingrowth.     

Optic disc hemorrhages and generalized vascular disease

PURPOSE: To study the relationship between optic disc hemorrhages and four different groups of medications used in general vascular disease and diabetes. METHODS: The authors screened citizens of the city of Malm?, Sweden who were between 57 and 79 years old (32,918 subjects), in order to find individuals with undetected glaucoma. One set of optic disc photographs was taken of each participant and examined for optic disc hemorrhages. Logistic regression was used, with platelet aggregation inhibitors, antihypertensive agents, cholesterol-lowering medication, and antidiabetic agents as independent variables that were tested in isolation as well as in various combinations and adjusted for age and gender. RESULTS: Optic disc hemorrhages were significantly more common in individuals taking platelet aggregation inhibitors (OR 3.16, P < 0.0001). There was no significant association between ODH and the other three groups of medications. CONCLUSIONS: The significant relationship between platelet aggregation inhibitors and optic disc hemorrhages is a new and interesting finding that could indicate an association between optic disc hemorrhages and generalized vascular disease. Alternatively, it could mean that platelet aggregation inhibitors prolong resorption of or predispose to optic disc hemorrhages.     

Retinal dysfunction and anterior segment deposits in a patient treated with rifabutin

PURPOSE: To describe the clinical and electrophysiological findings in a young boy with decreased vision possibly due to retinal damage by rifabutin. METHODS: An 8-year-old boy with osteomyelitis was referred due to visual disturbance. During a period of 4 years, the boy was examined six times with electroretinography. Ophthalmological examination included testing of visual acuity, slit-lamp inspection, fundus inspection, fundus photography and kinetic perimetry. Two electrophysiological methods were performed for objective evaluation of retinal function, namely full-field electroretinography and multifocal electroretinography. RESULTS: We found a slightly reduced visual acuity, a slowly increasing amount of yellow-white deposits on the posterior surface of the cornea and on the anterior part of the lens, a normal fundus appearance, and normal visual fields. However, the electroretinogram was abnormal on several occasions during therapy with rifabutin, but returned to normal 3 months after withdrawal of the medication. The multifocal electroretinogram returned to normal after the full-field electroretinogram had done so. The anterior chamber deposits still remain. CONCLUSION: Long-term treatment with rifabutin may have a reversible and previously undescribed side-effect on retinal function. The drug may also accumulate irreversibly on the posterior surface of the cornea and on the anterior surface of the lens. We suggest that objective evaluation of retinal function with electrophysiological methods should be performed in patients with visual disturbance during treatment with rifabutin.     

Trabecular aspiration in pseudoexfoliative glaucoma--surgery to primarily reduce intraocular pressure

BACKGROUND: Trabecular aspiration has been discussed during the past few years as a new surgical method in the treatment of pseudoexfoliative glaucoma. In this procedure PEX-material, pigment and detritus are aspirated from the trabecular meshwork. Trabecular aspiration has been evaluated mainly in combination with cataract extraction. This study reports on our first experiences concerning the IOP-reducing effect of trabecular aspiration as a primary surgical method in the management of pseudoexfoliative glaucoma. MATERIALS: 17 eyes of 14 patients (7 m, 7 f; 12 OD, 5 OS; age 71 +/- 6 years) with pseudoexfoliative glaucoma were included in this study and operated on by standardised trabecular aspiration (vacuum max. 200 mm Hg, 180 - 270 degrees, 5 min). Therapy success was defined as an IOP reduction by more than 20 % and less than 21 mm Hg. RESULTS: Therapy success was 82 % (14 out of 17) on the first postoperative day, 50 % after 30 days (8 out of 16) and 23 % after 180 days (3 out of 13). IOP was 26.8 +/- 8.5 mm Hg before surgical intervention, 18.1 +/- 11.4 mm Hg after 1 day, 19.1 +/- 7.9 mm Hg after 30 days and 19.2 +/- 5.2 mm Hg after 180 days. Mean quantity of antiglaucomatous eye drops application was 3.1 +/- 0.9 preoperatively, 0.9 +/- 1.6 after 1 day, 0.8 +/- 1.2 after 30 days and 1.0 +/- 1.3 after 180 days. CONCLUSIONS: Trabecular aspiration achieves a good short-term effect in the reduction of IOP in patients with pseudoexfoliative glaucoma. However, this effect was limited to a few weeks in most patients. Trabecular aspiration as a primary surgical method in the management of pseudoexfoliative glaucoma does not appear to be suitable for long-term IOP reduction.