Towards universal ambient ionization: direct elemental analysis of solid substrates using microwave plasma ionization.

A microwave plasma was used for direct ambient ionization mass spectrometry of solid substrates, rapidly yielding atomic spectra without sample digestion or pre-treatment. Further, molecular spectra for the organic components of the substrate were obtained simultaneously, in an ambient ionization format. Initial characterization of the microwave plasma coupling to an ion trap mass spectrometer was carried out using solution standards and a microwave plasma torch (MPT) configuration. The configuration of the microwave plasma was then optimized for ambient ionization. The atomic and organic composition for samples applicable to nuclear and conventional forensic screening, including explosive/radionuclide mixtures and inorganic/organic gunshot residue component mixtures were successfully determined. The technologies employed are readily fieldable; the feasibility of a multimode ion source that could be coupled with a portable ion trap mass spectrometer for rapid, on-site, elemental, isotopic, and molecular screening of samples is demonstrated.

[Astigmatism after trans-scleral posterior chamber lens implantation in young children]. / Astigmatismus nach transskleraler Hinterkammerlinsenimplantation bei Kleinkindern.

BACKGROUND: The purpose of this study was to evaluate the postoperative astigmatism after trans-scleral fixation of intraocular lenses in children and to develop a strategy for amblyopia prophylaxis. PATIENTS AND METHODS: In eight eyes with lentectomy, posterior chamber intraocular lenses were fixed in the ciliary sulcus by trans-scleral sutures. The postoperative astigmatism was measured by retinoscopy every 1 to 2 weeks in the first 2 months, followed by monthly intervals thereafter. Keratometry was performed with an automated hand keratometer. RESULTS: Postoperative astigmatism was 2.5 to 8.0 D. The astigmatism regressed to 0.75 D in half the eyes within 4 weeks and in five of the eyes within 16 weeks. In one of the eight eyes, the astigmatism decreased to 2.0 D and in two it remained unchanged. The astigmatism did not change any more after 16 weeks postoperatively. Visual acuity was 0.016 to 1.0. CONCLUSIONS: Our study shows that the postoperative astigmatism regresses soon and does not seriously interfere with amblyopia therapy. If greater than 2 D, half of the astigmatism should be corrected with glasses, even in the early postoperative period. After 16 weeks, full correction is recommended.

[Amiodarone-associated optic neuropathy: an independent syndrome? Three patients with bilateral optic neuropathy]. / Amiodaron-Optikusneuropathie: ein eigenständiges Krankheitsbild? Drei Patienten mit beidseitiger Optikusneuropathie.

BACKGROUND: Optic neuropathy has been reported to occur during antiarrhythmic therapy with amiodarone. Whether or not there is a causal relationship has been discussed controversely. PATIENTS: Three patients presented with a visual impairment three to seven months after starting amiodarone therapy. In all three patients both optic discs were swollen and showed hemorrhages on the margin. After discontinuing amiodarone, the vision improved and the swelling of the optic discs resolved. CONCLUSION: The bilateral occurrence at the same time, the close time correlation with the amiodarone application and the improvement after discontinuing amiodarone suggest that our three patients suffered from a toxic effect of amiodarone rather than an incidental other disease, as for instance ischemic optic neuropathy.

Heterophoria and fixation disparity: a review.

Heterophoria does not provide a reliable clue for ordering prisms in an asthenopic patient. The same reservation applies to associated phoria, as determined by prism correction of fixation disparity. Subjective tests for fixation disparity, even those with a fusionable fixation target, do not correctly indicate the vergence position of the eyes under natural viewing conditions. Attempts to measure fixation disparity on the basis of stereo disparity, using the "Measuring and Correction Methods of H.-J. Haase", have failed.

[Can fixation disparity be detected reliably by measurement and correctional techniques according H.J. Haase (MKH)?]. / Ist die Feststellung einer Fixationsdisparation mit der Mess- und Korrektionsmethodik nach H.-J. Haase (MKH) verlässlich?

BACKGROUND: The theory of the "Measuring and Correction Methods of H.-J. Haase" (MCH) states that a small misalignment of one eye, called fixation disparity, indicates a difficulty in overcoming a "vergence position of rest" that is different from ortho position. This difficulty, so the theory, can cause asthenopic complaints, such as headaches, and these complaints can be relieved by prisms. The theory further claims that fixation disparity can be ascertained by a series of tests which depend on the subject's perception. The tests most decisive for the diagnosis of a so-called fixation disparity type 2 consist of stereo displays. The magnitude of the prism that allows the subject to see the test configurations in symmetry is thought to be the one that corrects the "vergence position of rest". METHODS: Nine subjects with healthy eyes in whom a "fixation disparity type 2" had been diagnosed were selected for the study. Misalignment of the eyes was determined according to the principle of the unilateral cover test. Targets identical for both eyes were presented on the screen of the Polatest E. Then, the target was deleted for one eye and the ensuing position change of the other eye was measured, using the search coil technique. This test was performed both with and without the MCH prism. RESULTS: In all 9 subjects the misalignment was less than 10 minutes of arc, i.e. in the range of normal fixation instability. Averaging across the 9 subjects, the deviation of the eye (misaligned according to MCH) was 0.79 +/- 3.45 minutes of arc in the direction opposed to that predicted by the MCH, a value not significantly different from zero. The MCH prism elicited a fusional vergence movement the magnitude of which corresponded to the magnitude of the MCH prism. CONCLUSION: Ascertaining fixation disparity with the MCH is unreliable. Accordingly, it appears dubious to correct a "vergence position of rest" on the basis of the MCH.

Bilateral optic neuropathy after bone marrow transplantation and cyclosporin A therapy.

BACKGROUND: Cyclosporin A (CsA) is widely used as a prophylactic and therapeutic agent against graft-versus-host disease after bone marrow transplantation. Under this condition optic neuropathy has been found and considered as a possible side effect of cyclosporin A. CASE REPORT: A 52-year-old man presented with bilateral optic disc swelling and visual loss 6 months after bone marrow transplantation. Cyclosporin A was the only medication with a known neurotoxic side effect. After cessation of cyclosporin A and treatment with oral prednisone, vision improved within 2 months. Optic disc swelling ameliorated within 6 months but partial optic atrophy developed. DISCUSSION: Cyclosporin A given after bone marrow transplantation may have caused bilateral optic neuropathy in our patient. Microangiopathy of the optic nerve may be the pathogenetic mechanism.

Transscleral suture fixation of posterior chamber intraocular lenses in children under 3 years.

BACKGROUND: Children who have undergone lentectomy for congenital or traumatic cataract do not have adequate capsular support for secondary posterior chamber intraocular lens (PC-IOL) implantation and thus will become severely amblyopic if contact lens intolerance occurs. In order to prevent amblyopia we fixed PC-IOLs by transscleral sutures in three children younger than 3 years. Clinical outcome, visual acuity and course of refraction were studied. METHODS: Four eyes of three children with contact lens intolerance were operated. Posterior chamber lenses (PC-IOL) were sutured in the ciliary sulcus by transscleral sutures. Two children had monocular traumatic cataract and one child underwent surgery on both eyes for congenital cataract. To allow adjustment of refraction in situ without removing the primarily implanted and transsclerally fixed PC-IOL we used the piggyback intraocular lens system for implantation. RESULTS: Visual acuity improved in all four eyes. The two children with traumatic cataract achieved visual acuity of 0.7 and 1.0, respectively, and stereopsis. No complications related to the technique of transscleral suture fixation of the PC-IOL were observed. Postoperative changes in refractive power were caused by a myopic shift between -1.0 D and -9.0 D. Follow-up was 25-70 months. CONCLUSION: Transscleral suture fixation of PC-IOLs did not cause specific complications during follow-up of up to 70 months. This technique offers an important option for the correction of an aphakic refractive error which cannot be corrected otherwise. In future the piggyback intraocular lens system may help to rather atraumatically correct postoperative changes in refractive power.

[Strabismus surgery under subconjunctival anesthesia: technique and evaluation by patient and his surgeon]. / Augenmuskeloperationen in subkonjunktivaler Anästhesie: Technik sowie Wahrnehmung durch den Patienten und seinen Operateur.

BACKGROUND: In adults, eye muscle surgery can be performed under local anesthesia without retrobulbar injection. We wanted to know how patients and surgeons perceive this procedure. PATIENTS AND METHODS: 50 patients and 3 surgeons were interviewed with a questionnaire after operation on one or two straight eye muscles, including revisions in 11 cases. The patients were sedated with benzodiazepines. The conjunctiva was anesthetized with tetracaine eye drops. During the operation, mepivacaine was irrigated under the muscle insertion using a blunt needle. RESULTS: The patients perceived little or no pain during the operation. This corresponded to the surgeon's judgement. 96% of the patients would prefer local over general anesthesia in case of a second operation. CONCLUSION: The technique can be recommended for surgery of rectus muscles in adults, even in the case of revision.

[Fixation disparity with the Pola pointing test: not representative for eye position under natural viewing conditions]. / Fixationsdisparation am Pola-Zeigertest: nicht repräsentativ für die Augenstellung unter natürlichen Sehbedingungen.

BACKGROUND: According to certain findings obtained with the Zeiss Polatest, H.J. Haase defined a "Fixation Disparity Type One". In this diagnosis, the "Zeigertest" is particularly important. The Zeigertest consists of a central ring presented to both eyes for fixation, a vertical clock hand presented to the right eye and two markings at the six and twelve o'clock positions presented to the left eye. All parts are surrounded by a binocularly visible frame. Subjects with a "Fixation Disparity Type One" see a misalignment between the clock hand and the peripheral markings. We investigated (1) whether the perceived misalignment correlated with an objective deviation of the eyes from orthovergence and (2) whether subjects with a "Fixation Disparity Type One" had a deviation of the eyes from orthovergence when looking at a natural, i.e., fully fusionable object. SUBJECTS AND METHODS: Out of 303 medical students, 10 subjects with a "Fixation Disparity Type One" were selected and asked to indicate the perceived alignment or misalignment in the Zeigertest with a laser pointer. Two subjects without fixation disparity served as controls. The position of both eyes was recorded using the search coil technique. One of the 10 subjects with "Fixation Disparity Type One" had to be excluded due to excessive blinking. Experiment 1: In the beginning all parts of the Zeigertest were presented to both eyes (natural viewing condition). Then, the object for one of the eyes was switched off leaving the frame as the only fusional stimulus. The outcome variable was a refixation movement of the other eye. This experiment is similar to the unilateral cover test. Experiment 2: In the beginning all parts of the Zeigertest were presented to both eyes (natural viewing condition). Then, the original Zeigertest was switched on (clock hand presented only to the right eye, peripheral markings only to the left eye). The outcome variable was a change of vergence. RESULTS: Experiment 1: A significant refixation movement did not occur in any of the subjects. Experiment 2. In all 9 subjects with "Fixation Disparity Type One" the vergence changed significantly between 2.4 and 14.9 arcmin. The change of vergence correlated significantly with the angle of the perceived misalignment between clock hand and peripheral markings. CONCLUSION: A fixation disparity ascertained at the Zeigertest does not indicate a fixation disparity under natural viewing conditions.

[Etiology of contact lens failure in pediatric aphakia. Indications for intraocular lenses?]. / Ursachen des Kontaktlinsen-Abbruchs bei kindlichen Aphakien. Indikation für Intraokularlinsen?

UNLABELLED: Due to the low rate of complications, lentectomy and contact lens fitting is the standard treatment for congenital cataract. However, contact lens fitting is not possible in all children. The authors report the main reasons for discontinuation of contact lenses in their patients. METHOD: In 134 consecutive lentectomies of 90 children, the underlying eye diseases and general diseases, the age at operation, compliance of parents and children, and social background were analyzed. RESULTS: Twenty of the 90 children had to discontinue contact lens wearing. Twelve of these children were operated on one eye and 8 on both eyes. Only 2 children showed signs of contact lens complications. In 2 children treatment was stopped because of the poor visual prognosis and in 10 children the parents discontinued contact lens treatment because of a severe handicap of the child (n = 2) or due to misunderstanding and parental noncompliance (n = 8). Six children refused contact lenses without obvious reasons. Among the latter, children 2-4 years of age were at the greatest risk. Children with additional systemic abnormalities frequently developed contact lens intolerance. CONCLUSION: In children with systemic abnormalities and in the case of parental communication and compliance problems, discontinuation of contact lenses has to be expected in up to 30% of cases. In these children and in children who object to contact lenses at the age of 2-4 years, intraocular lens implantation should be considered, especially in unilateral cataract, if successful contact lens treatment is not achievable within 8-12 weeks.

[Orbital sarcoidosis--a case with an unusual course]. / Orbitale Sarkoidose--ein Fall mit ungewöhnlichem Verlauf.

BACKGROUND: Most cases of orbital sarcoidosis are associated with a systemic sarcoidosis. PATIENTS AND METHODS: A 67-year-old woman suffered from an orbital mass on the right side, which led to disturbance of the ocular motility. Slight improvement was achieved by the administration of systemic steroids. RESULTS: Histologically a chronic granulomatous inflammation was revealed in the biopsy of the orbital mass. The suspected diagnosis was sarcoidosis, but three conventional chest X-rays within 10 months and the serum angiotensin-converting-enzyme were normal. Suprisingly a computertomography of the chest showed mediastinal lymphomas. CONCLUSION: Granulomatous orbital inflammation without any local cause or other systemic granulomatous disease strongly suggests a systemic sarcoidosis. In case of missing lymph node enlargement in conventional chest X-ray computertomography should be performed.

Visual field defects in optic neuritis and anterior ischemic optic neuropathy: distinctive features.

BACKGROUND: We analyzed the value of visual-field defects in the differential diagnosis of optic neuritis (ON) and non-arteritic anterior ischemic optic neuropathy (AION). METHODS: Ninety-nine consecutive patients with acute-onset optic neuropathy formed the basis for this study. Compressive and vasculitic neuropathies were excluded. Eighty-six patients fulfilled the criteria for either ON (50 patients): < or = 35 years, normal disk, recovery of visual function, or AION (36 patients): > or = 60 years, swelling of the disk, no recovery of visual function. Without knowledge of other clinical data, visual fields obtained by Gold-mann perimetry were classified into five types of defects (forced choice). With the correct diagnosis at hand, fields were reviewed for characteristic features. RESULTS: Forced-choice classification into defect types [%]: Central scotoma ON 68, AION 18; superior altitudinal defect ON 13 AION 7; inferior altitudinal defect ON 8, AION 52; peripheral defect ON 1, AION 5; diffuse defect ON 10, AION 18. Search for pathognomonic defects: a scotoma centered on the fixation point with a sloping border occurred exclusively in ON (25 of 50 patients). An inferior altitudinal defect with a sharp border along the horizontal meridian, particularly in the nasal periphery, occurred only in AION (10 of 36 patients). A steep centrocecal scotoma occurred in 3 of the 36 AION cases and not at all in the ON cases. Scotomas in the center breaking through to the periphery, superior altitudinal defects (with a sloping border along the horizontal meridian) and diffuse depressions verging on blindness occurred in both ON and AION. CONCLUSION: A sctoma centered on the fixation point with a sloping border is highly characteristic of ON, while an inferior altitudinal defect with a sharp border along the horizontal meridian, particularly in the nasal periphery, is highly characteristic of AION. To identify these diagnostic criteria, it can be necessary to examine full fields. With restriction of perimetry to 30 degrees a large central scotoma can be mistaken for a diffuse defect and the border in the nasal periphery can be missed.

MRI of lymphomas of the orbits and the paranasal sinuses.

PURPOSE: The purpose of this study was to point out MR characteristics of non-Hodgkin lymphomas of the orbits and the paranasal sinuses and the benefit of fat-suppressed contrast-enhanced sequences. METHOD: The MR images of 16 patients with lymphoma of the orbits and the paranasal sinuses were retrospectively analyzed for signal intensity, contrast enhancement, bone destruction, and mass effect. The findings were confirmed by means of biopsy (Stage IE disease) or follow-up imaging after chemotherapy (Stage IV disease). RESULTS: MRI clearly delineated the extension of the lymphomas. On the T1-weighted images, the signal intensity of the lymphoma was hypointense compared with the gray matter of the brain in 12 cases and intermediate in 4 cases. The T2-weighted fast SE images showed a hyperintense signal in 12 cases, intermediate in 3 cases, and even hypointensity in 1 case. All lesions enhanced after intravenous Gd-DTPA administration, reliably visible in the T1-weighted fat-suppressed sequences but not visible in three cases in the T1-weighted SE sequences. Bony wall destruction was evident in cases with paranasal but never in isolated orbital lymphoma. CONCLUSION: While extension of lymphoma can be accurately described by MRI, a specific diagnosis is not achievable on the basis of signal intensities and enhancement patterns alone. Therefore, at least in cases of suspected Stages IE and IIE, biopsy proof is needed. Fat-suppressed contrast-enhanced sequences possess the highest detection rate and should therefore always be applied.

Shift of equiluminance in congenital color vision deficiencies: pattern-ERG, VEP and psychophysical findings.

We compared electrophysiological responses [pattern-ERG (PERG) and VEP] and psychophysical measures to color stimuli to separate different forms of anomalous color vision. PERG and VEP were recorded from seven normals and 14 subjects with congenital color vision deficiencies. Stimuli were color checkerboards with 0.5 deg check size, phase reversing at 34 rev/sec. The luminances of the red and green parts were varied in opposite direction from 0 to 30 cd/m2, while the hue of individual squares and space-averaged luminance were held constant. This allowed for one equiluminance condition where flicker appeared fused. In the seven normals, the subjective equiluminance was reached at a luminance ratio red/(red + green) = 0.50-0.53. At that point, the PERG amplitude was moderately, and the VEP amplitude sharply reduced. In 14 color anomalous subjects both the PERG and VEP were sharply reduced at equiluminance. These dips were shifted compared to normals and the dip position corresponded to the predicted luminance ratios obtained by calculations from L- and M-cone activation using the Smith-Pokorny transformation. As we found a close correlation of the VEP-dip position and the anomalous quotient, these electrophysiological measures may allow objective assessment of color vision deficiencies.

Little correlation of the pattern electroretinogram (PERG) and visual field measures in early glaucoma.

Pattern-electroretinograms (PERG) to checkerboard reversal at 16/s. 0.8 degrees and 15 degrees check size and visual fields (Octopus G1) were retrospectively analyzed in 40 eyes of 30 patients with early glaucoma. The mean visual field defect was calculated separately for the central 26 degrees x 34 degrees covered by the PERG stimulus (MDc) and the more peripheral area (MDp) surrounding the stimulus. Deeper field loss was correlated with a reduced pattern electroretinogram amplitude (p < 0.01 for both MDp and MDc), indicating that the pattern electroretinogram deteriorates as glaucoma advances. If the analysis was confined to those 18 eyes (16 patients) that had no field defect within the area covered by the PERG stimulus (normal MDc but abnormal MDp), 13 of these had an abnormal PERG amplitude (p < 0.001). The results suggest that the PERG can reveal impairment of ganglion cell function that is not detected by conventional perimetry.

Duction ranges in normal probands and patients with Graves' ophthalmopathy, determined using the Goldmann perimeter.

BACKGROUND: We examined whether the Goldmann perimeter is suitable for measuring the range of monocular ductions, especially in the follow-up of patients with Graves' ophthalmopathy. METHODS: Using the Goldmann perimeter, the range of monocular ductions was determined in one eye of 100 normal probands (aged between 21 and 70 years) and of 36 patients (aged between 29 and 66 years) with a motility disturbance due to Graves' ophthalmopathy. Subjects were asked to follow target I/4e which was slowly moved by the examiner in the vertical and the horizontal meridian. The end-point of the pursuit movement observed by the examiner was taken as the duction limit. Subjects were measured twice, in half of the cases by the same, in the other half by two different examiners. RESULTS: In the 100 normal probands, the mean ranges of ductions were: elevation 37.6 degrees, depression 58.0 degrees, adduction 51.6 degrees, abduction 48.7 degrees. There was a slight age-related decline. The intraobserver and interobserver mean coefficients of variation ranged between 1.5% and 3.8%. In the 36 patients with Graves' ophthalmopathy the coefficients were between 0.7% and 2.3%. In both the normal probands and the Graves' ophthalmopathy patients, the coefficients were smaller for the total vertical and horizontal duction ranges than for adduction, abduction, elevation and depression alone. CONCLUSIONS: Measurements of the range of monocular ductions with the Goldmann perimeter are highly reproducible and appear to be suitable for follow-up studies in patients with Graves' ophthalmopathy.

Diameter of the optic nerve in idiopathic optic neuritis and in anterior ischemic optic neuropathy.

PURPOSE: There is considerable overlap in the clinical profile of patients with idiopathic optic neuritis (ON) and anterior ischemic optic neuropathy (AION). We tested the hypothesis that the retrobulbar diameter of the optic nerve may be a criterion for the differential diagnosis between ON and AION. METHODS: The diameter of the optic nerve was measured by B-scan ultrasonography with the eye in an abducted position. Only patients with a unilateral optic neuropathy were included, 16 ON patients (mean age 24 years, 5 with and 11 without disc swelling) and 9 patients with AION (mean age 72 years). As controls for the ON patients 10 young normal subjects (mean age 25 years) and as controls for the AION patients 10 elderly subjects with eye problems not related to the optic nerve (mean age 76 years) were examined. RESULTS: In the ON patients with disc swelling the diameter of the optic nerve was 5.4 +/- 0.5 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.043). In the ON patients without disc swelling the diameter of the optic nerve was 4.4 +/- 0.4 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.003). In the AION patients the diameter of the optic nerve was 3.0 +/- 0.3 mm on the affected and 2.8 +/- 0.4 mm on the unaffected side. This difference was not significant (Wilcoxon-test, p = 0.093). Comparing the optic nerves with ON and AION to those of the controls, the diameter was significantly enlarged in the nerves with ON and normal in the nerves with AION (one factor repeated ANOVA). CONCLUSION: The diameter of the optic nerve is increased in ON without disc swelling and even more so in ON with disc swelling. The enlargement is probably due to edema of the nerve itself, not the surrounding subarachnoidal space. In AION, the diameter of the optic nerve is normal. Measuring the diameter of the optic nerve by B-scan ultrasonography is particularly useful in the differential diagnosis between ON with disc swelling and AION.

A case of localized retinal damage in thallium poisoning.

PURPOSE: To determine the cause of visual impairment and to document the late eye disturbances in a case of thallium poisoning. PATIENT: A 44-year-old woman presented with a history of repeated attacks of complete alopecia over a period of several months, diffuse pain in both legs, transient gastrointestinal disturbances, abasia with a progressive paraparesis, paresthesia in the fingertips, and polyneuropathy. She complained of slowly progressive visual deterioration in both eyes which began about six months after the first attack of alopecia. The optic discs showed distinct signs of temporal atrophy together with a deep temporal excavation. The Goldmann perimetry revealed an absolute central scotoma. Traces of thallium were found in the urine and in the serum. The district attorney later discovered that her husband had been trying to poison her with thallium. METHODS: The clinical and electrophysiological examinations included visual evoked potentials (VEP) and electroretinography (flash ERG, multifocal ERG and pattern ERG). RESULTS: The VEP showed a reduction in amplitude and a prolonged latency indicating a conduction block. The pattern ERG was initially normal. At a follow-up examination 6 years later, a slight amplitude reduction in the pattern ERG was found. The multifocal ERG showed a diminished amplitude in the center of the retina (up to +/- 10 degrees visual angle). CONCLUSIONS: The electrophysiological investigations in our patient--who had an optic atrophy--indicated a conduction block of the retinal nerve fibers (VEP) and an additional lesion at or before the retinal bipolar cells (multifocal ERG), localized in the central +/- 10 degrees. These findings suggest that thallium poisoning can lead to a combined lesion of the retinal nerve fibers and the neural retina.

Midline granuloma presenting as orbital cellulitis.

BACKGROUND: Lethal midline granuloma usually presents with rhinorrhoea and redness of the skin above the nose. Early ocular symptoms are very rare. We here describe a patient who presented with acute orbital cellulitis. PATIENT: A 73-year-old woman had a 24-h history of severe pain around her left eye. We saw the typical clinical picture of orbital cellulitis. A CT scan revealed a diffuse infiltration of the left upper and lower lid, the anterior orbit and the ethmoidal sinuses. RESULT: On surgical exploration we found a granular, partly necrotic tumour. Histological examination revealed an angiocentric nasal T-cell lymphoma (midline granuloma). CONCLUSION: Midline granuloma should be included in the differential diagnosis of acute orbital cellulitis.