Search Results - "International Ophthalmology"

1573-2630

uveal melanoma ; pre-enucleation irradiation ; tissue culture

Springer Online Journal Archives 1860-2000

Medicine

Abstract In a group of eighteen patients with uveal melanomas, seven underwent low-dose pre-enucleation irradiation of approximately 2000 cGy. All the tumours were propagated in tissue culture and the growth characteristics of tumour cells from irradiated eyes were compared with tumour cells from non-irradiated eyes. Cultures were observed with phase-contrast microscopy, and radioactive thymidine labelling was used to study cell turnover. Although tissue samples from peripheral areas of irradiated tumours produced a mixture of viable and non-viable cells, with reduced ability to attach to substrate, central regions of irradiated tumours contained viable cells which propagated freely in tissue culture.

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1573-2630

absorption spectrum ; calibration ; fluorometry ; infrared spectrum ; sodium fluorescein

Springer Online Journal Archives 1860-2000

Medicine

Abstract The usefulness of sodium fluorescein (SF) and related physical parameters were analysed. Two factors that may affect the molar absorption coefficient (ɛ) of this compound were the presence of impurities and the pH of the solution. As discrepant values can be found in the literature for that coefficient, a purification technique was used and SF quantification was performed according to sodium concentration determined by atomic absorption spectrophotometry. The molar absorption coefficient of the SF solution in phosphate buffer pH 7.4 was determined. To study the influence of pH on ɛ determination, absorption spectra at pH 1, 3, 5, and 10 were also analysed.

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1573-2630

human ; rheology ; shear-thinning ; tears ; viscosity ; dacryology

Springer Online Journal Archives 1860-2000

Medicine

Abstract Blinking involves high rates of shear within the tear film, requiring a low tear viscosity to avoid damage to epithelial surfaces. Conversely, in the open eye, a higher viscosity is desirable to resist drainage and film break-up. Samples of human tears were collected with moderate stimulation from 5 adult males, 3 with normal and 2 with marginally-dry eyes. The apparent viscosity at 22° C was found using a Couette-type rheometer over the range of shear rate 2–160 sec-1. Marked shear-thinning was apparent in all samples, with little apparent difference between normal and dry-eye tears. Although a power-law equation could be fitted over part of the range, analyses according to either the Casson plastic model as used for rabbit tears (with a low yield-point indicative of some very loose initial gel-like structure) or the Steiger-Ory model (a true pseudoplastic model with no initial yield point) were inconclusive over the range of shear rate studied. The descriptive model of Cross gave zero-shear viscosity values of 4.4, 7.1 and 8.3 mPa. sec for normal tears, and 27.1 and 31.1 mPa.sec for dry-eye tears; the corresponding time constants were 0.13, 0.27 and 0.38 sec for normal tears, and 2.7 and 2.9 sec for dry-eye tears. These time-constants can be considered as an approximate relaxation time, indicating the time taken for the tear film to stabilise after a blink.

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1573-2630

clinical tests ; dry eye ; normal clinical profile ; tear proteins

Springer Online Journal Archives 1860-2000

Medicine

Abstract An accurate clinical description of the normal patient must be established before the dry eye patient can be accurately profiled. The current study was designed to (a) determine normal values for, and to seek correlations between, clinical tests used for the evaluation of non dry eye patients' tear film and ocular surface, and (b) compare clinical findings with previously reported levels of non-stimulated and stimulated tear proteins for the same group. Thirty non-contact lens wearing patients (age range 20–64 years) were determined to be free of dry eye based on the results of a series of clinical tests. McMonnie's dry eye questionnaire was used as an initial screening step. Clinical tests included lacrimation kinetics (using sealed, calibrated filter paper strips), non-invasive tear break-up time (NIBUT) measurement by Xeroscope, biomicroscopic evaluation of the anterior segment, assessment of tear prism height and regularity, and fluorescein and Rose Bengal staining. No significant correlations were found between age, questionnaire score, lacrimation kinetics final tear secretion rate or NIBUT. However, NIBUT results did vary by gender. Mean NIBUT for females was 46.3 ± 16.6 (standard deviation) seconds and for males 59.3 ± 2.1 seconds. Some significant correlations were found between clinical test results and levels of non-stimulated and stimulated tear proteins. Overall, the results indicate that this battery of clinical tests will be appropriate for distinguishing between normal and dry eye patients. Combined with tear protein assay, this clinical approach may improve our current understanding of the different types of dry eye.

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1573-2630

Atrophic gastritis ; polyarthritis ; tubular acidosis ; tubolointerstitial nephritis ; Sjögren's syndrome

Springer Online Journal Archives 1860-2000

Medicine

Abstract The characteristics of primary Sjögren's syndrome are described on the basis of the follow-up of 65 patients with extraglandular symptoms at the onset and during the disease. The mean age of the patients at onset was 41.8 years and at the time of definite diagnosis was 45.8 years. Articular (32 cases), lacrimal (30 cases) and salivary (30 cases) manifestations were the most frequent initial symptoms. In only 22 of the 65 patients could Sjögren's syndrome be diagnosed at the onset. In most cases, the articular symptoms observed observed in 56 patients during the course corresponded to true polyarthritis, as verified by joint scintigraphy. Most frequently the wrists and ankles were affected. Chronic atrophic gastritis was found in 35 patients. In the young patients (13 cases), both the antrum and the corpus were affected more frequently than in the controls. In middle-aged patients (21 cases), atrophy of the antrum, and in the elderly (10 cases) atrophy of the corpus was more frequent than in the controls. All three types of chronic atrophic gastritis occurred in the disease. The decreased gastric acid secretion was characteristic of types A and AB gastritis, but the hypergastrinaemia only of type A. It was verified that chronic duodenitis and jejunitis occur in the disease. The pancreatic lesions were mild. Renal involvement was detected in 15 patients, vascular symptoms in 22 and lower-airway changes in 21. The variety of the different symptoms proved that primary Sjögren's syndrome can involve many organs.

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1573-2630

canaliculus ; lacrimal sac ; nasolacrimal duct ; silicone intubation

Springer Online Journal Archives 1860-2000

Medicine

Abstract Mesoscopic structures of the lacrimal drainage pathway were observed under an operating microscope in six cases of 5 adult cadavers. In all these cases the upper and lower canaliculi fused to form the common canaliculus. Two cases with a large common canaliculus showed large projections of mucosa which reduced the inner space of the common canaliculus. The remaining 4 cases with a small common canaliculus did not show any projections. These findings indicate that the human lacrimal system can function physiologically through a small narrow space of the common canaliculus.

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1573-2630

lens light-scattering ; cataract ; Opacity Lens Meter 701 ; normal values

Springer Online Journal Archives 1860-2000

Medicine

Abstract Age-corrected normal values for the Opacity Lens Meter (OLM) 701 were established by measuring 1598 eyes of 799 healthy volunteers. This study revealed a remarkable age-relation for the normal values. The average readings of the OLM of the 30-year-old subjects were around 10 units whereas the average for the 65-year-olds was close to 20 units. The best fit of the opacity vs. age was a quadratic function. The interindividual variation was small in the young and quite large in the older population. The correlation between contralateral eyes was high (R=0.93).

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1573-2630

precorneal retention ; tear fluid composition ; viscous eye drops

Springer Online Journal Archives 1860-2000

Medicine

Abstract The influence of viscolysers on the precorneal residence of a fluorescent tracer was determined, using slit lamp fluorophotometry. The solution acceptability was evaluated by the volunteers by answering a standard questionnaire. The relationship between precorneal retention of viscous eye drops, discomfort and tear fluid composition after instillation of various cellulosic solutions was examined. Irritating hydroxypropylcellulose solution increases the total protein concentration of tears, without change in the ratio of lysozyme to total protein.

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1573-2630

cataract ; retro-illumination photography ; entoptic phenomena

Springer Online Journal Archives 1860-2000

Medicine

Abstract Entoptic visualisation of cataract is a simple technique to use. Retro-illumination photography demonstrates that it can also be accurate. The optics of the methods used are discussed.

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1573-2630

A- and V-patterns ; cyclovertical strabismus ; esotropia ; hypermetropia ; oblique muscles ; stereopsis ; surgery

Springer Online Journal Archives 1860-2000

Medicine

Abstract Among the reasons given for surgery in refractive accommodative esotropia (RAET) are (1) frequent functional deterioration and (2) high prevalence of cyclovertical strabismus and oblique muscle dysfunctions. Of 30 patients with RAET, corrected with glasses and followed for an average of seven years only one deteriorated. We tested a second group of 53 patients with RAET for A- and V-patterns and dysfunction of the oblique muscles. Pseudo-A- and V-patterns occurred without glasses but were absent when glasses were worn during the measurement. Dysfunctions of the oblique muscles were observed without glasses but were clinically insignificant. Our data do not support the reasons cited above for performing surgery in RAET.

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1573-2630

choroidal melanoma ; choroidal metastasis ; magnetic resonance imaging ; metastatic adenocarcinoma

Springer Online Journal Archives 1860-2000

Medicine

Abstract A 51 year old man with biopsy proven pulmonary sarcoidosis and skin test positive for tuberculosis presented with features of an amelanotic flat choroidal mass suggestive of choroiditis. The mass enlarged despite corticosteroids and anti-tuberculous medications. A throrough systemic evaluation for possible primary tumor metastatic to the choroid was negative. Further clinical evaluation and magnetic resonance imaging suggested a diffuse primary choroidal malignant melanoma with optic nerve invasion. The eye was enucleated and the mass proved histopathologically to be a mucin secreting adenocarcinoma of unknown origin despite a repeat systemic work-up. The patient died three months after the onset of symptoms and three weeks after enucleation with diffuse metastases from an unknown primary cancer. Magnetic resonance imaging (MRI) is usually helpful in the differentiation of uveal melanoma from uveal metastasis. In this case, however, it suggested the diagnosis of a diffuse choroidal melanoma. The reason for the atypical MRI findings will be discussed.

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1573-2630

error detection system ; optical sensor ; self-tonometer ; self-tonometry

Springer Online Journal Archives 1860-2000

Medicine

Abstract Self-tonometry could be established as an important diagnostic tool in the early diagnosis and follow-up of glaucoma provided that a self-tonometer is precise, safe and easy to use. Furthermore, it has to comply with the legal standards for tonometer calibration. A new software-controlled detection system for the self tonometer permits the evaluation of external factors during the measurement which influence the precision of the tonometric readings. The updated version of the self-tonometer (ST) was compared to the Draeger hand-held applanation tonometer (HAT) in a clinical study with 82 patients (151 eyes). The results show a regression line characterized by a slope of 0.99, an y interception of 1.41, a correlation coefficient of 0.96 and a standard deviation for the ST readings of ±1.78 mmHg. Self-tonometry improves the IOP monitoring as well as patient compliance and therefore is a potential diagnostic tool in the management of glaucoma.

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1573-2630

surgery ; glaucoma ; trabeculectomy ; goniotrephination ; suture

Springer Online Journal Archives 1860-2000

Medicine

Abstract Major problems in the early postoperative phase in filtering surgery are hypotony, flattening of the anterior chamber and choroidal detachment. We describe a new suture technique for the closure of the conjunctiva in goniotrephination with a fornix-based conjunctival flap which is helpful in reducing these complications. After dissecting the conjunctiva from the limbus, a shallow groove is cut directly behind the former conjunctival insertion. At the end of the operation the conjunctiva is sutured into this groove using a running 10.0 nylon suture in a meander-like fashion. A very tight wound closure results. We used this technique in 104 consecutive goniotrephinations. We found a low incidence of only mild external fistulation, hypotony, flattening of the anterior chamber and choroidal detachment. Astigmatism induced by the operation was-1.2+±1.2D, usually with the rule.

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1573-2630

Springer Online Journal Archives 1860-2000

Medicine

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1573-2630

closed angle glaucoma ; cataract extraction procedure ; gonioscopy

Springer Online Journal Archives 1860-2000

Medicine

Abstract In this paper we present our experience of the last three years in the surgical treatment of eyes with closed angle glaucoma. We have performed an extracapsular lens extraction and posterior chamber intraocular lens implantation on 34 eyes of 34 patients. All of them were affected by closed angle glaucoma with variable control after a Yag laser iridotomy: 6 eyes had high I.O.P. notwithstanding maximal therapy, 11 eyes had I.O.P. under control (less than 21 mmHg) without therapy, 9 with I.O.P. controlled with topical therapy, 8 with I.O.P. controlled with maximal therapy (C.A.I, included). The cases with well controlled glaucoma were operated on because of the presence of a more or less significant lens opacities. After a follow-up of up to 40 months (mean=20.3, range=1–40), all eyes show satisfactory intraocular pressure and no eye needed a filtering procedure. The results of our studies are as follows (values are mean±SD). In the group of 6 eyes with high I.O.P., the mean pre-operative intraocular pressure was 29.7±5.6 mmHg and the mean post-operative I.O.P. was 15.1±1.4mmHg. The mean reduction was 14.5±6.6mmHg (p〈0.005). In the 28 eyes with pre-operative I.O.P. under control (17.5±1.6), the mean post-operative I.O.P. was 14.4±2.3 mmHg, with a mean reduction of 3.1±3.1 mmHg (p〈 0.005). Before the E.C.C.E., 11 eyes had I.O.P. less than 21 mmHg without anti-glaucoma medication, whereas after the E.C.C.E. 28 eyes did not need such a medication. No significant correlation was found between pre-operative and post-operative extension of peripheral anterior synechiae (when assessable) and post-operative intraocular pressure control. The difference between pre- and post-operative anterior chamber depth measured by ultrasonic biometry was remarkable, i.e. M=1.93+0.36mm and 3.42±0.2mm (pre-operative and post-operative, respectively; p〈0.005).

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1573-2630

glaucoma ; pattern-reversal electroretinogram latency ; visual field indices

Springer Online Journal Archives 1860-2000

Medicine

Abstract Pattern reversals with a ramp-like temporal course evoke transient pattern electroretinograms (PERG) that are delayed and attenuated in comparison with responses evoked by a step-like course (abrupt pattern reversals). This delay depends on the reversal time and probably represents a measure for temporal characteristics of the activated retinal structures. A pattern reversal stimulator with adjustable reversa) periods (matrix of 8X14 rectangular red light emitting diodes, element size 2° X 1°, stimulus area 16° X 14°) was used to record transient PERGs from 20 glaucomatous eyes with early or moderate visual field damages (measured with computer perimetry). The q-wave (P1) amplitude difference between the glaucoma group and normal subjects with step-like reversal stimulation was not significantP=0.23). On the other hand, a highly significant separation (P〈 0.0001) between both groups was possible using the P1 latency at ramp-like stimulation or the response latency shift between step and ramp-like stimulation (Pattern reversal time, 30 ms).

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1573-2630

hypertension ocular ; glaucoma ; perimetry

Springer Online Journal Archives 1860-2000

Medicine

Abstract An evaluation was carried out comparing Oculokinetic Perimetry (O. K. P.) with Automatic Perimetry of Thresholds (Hipocampus Perimeter) for ocular hypertension and glaucoma studying 145 eyes. The O.K.P. shows a sensitivity between 35.65 and 38.54%, a specificity of 76.67–79.59%, a + predictive value of 78.72–85.42%, and a — predictive value of 23.71–39.80%.

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1573-2630

color vision defects ; color vision tests ; Stargardt's disease

Springer Online Journal Archives 1860-2000

Medicine

Abstract The color vision of nine patients aged from 13 to 52 years with Stargardt's disease was studied with the following tests: Standard Pseudoisochromatic Plates part 2 (SSP2), Farnsworth-Munsell 100 hue test (FM100), Nagel (red-green) anomaloscope and Besançon (blue) anomalometer. At the beginning of the disease, a very slight defect in red-green color vision could be demonstrated. Later, a distinct acquired red (pseudo-protanomalous) defect in the Nagel anomaloscope and an abnormal error score in the FM100 test were observed. In advanced stages, the red defect became stronger (scotopization) and the FM100 test showed a red-green axis. In the course of the disease, a blue defect with the SPP2 plates and with the Besançon anomalometer could also be found. The visual acuities of the patients had a significant correlation with the matching ranges of the Rayleigh equation and the Moreland equation. The duration of the disease did not show any correlation with the color vision tests.

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1573-2630

measurement ; optic nerve head ; reproducibility

Springer Online Journal Archives 1860-2000

Medicine

Abstract The aim of this study was to determine the intra- and inter-observer variation in the use of a system designed for exact measurements from standard optic nerve head photographs. The commercially available system consisted of a colour CCD Videocamera, a dedicated frame grabber and customised software run on a IBM AT compatible computer. Masked measurements were made 3 times by 2 observers, from stereophotographs of the optic nerve head of 56 eyes from 30 glaucoma suspects. The cup was defined on the basis of contour, not pallor and the disc area was defined as the area inside Elschnig's ring.Intraobserver variances were 0.001±0.001 mm2 for cup area (mean±SD), 0.002+0.002mm2 for disc area and 0.002±0.003 mm2 for rim area. These values for intra-observer variance were comparable with the results obtained using manual planimetric techniques. Intra-observer variance for disc area was significantly larger for the less trained of the two experienced observers.Interobserver variances were 0.004±0.009 mm2 for cup area, 0.008±0.013 mm2 for disc area and 0.009±0.014mm2 for rim area. These inter-observer variances were significantly larger than those previously reported for manual planimetry. The absolute differences between the two observers ranged from −0.35 to + 0.20 mm2 (−0.08±O.llmm2) for cup area, from −0.38 to + 0.15 mm2 (− 0.08±0.11 mm2) for disc area and from − 0.29 to + 0.34 mm2 (− 0.06±0.12 mm2) for rim area. There was a tendency for greater differences between the two observers in the measurement of smaller neuroretinal rim areas, whereas no size dependence of differences existed for the other two measurements. This study emphasises the subjective nature of optic nerve head assessment: despite good intra-observer variance there is significantly more inter-observer variance, precluding its usefulness in routine clinical work.

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1573-2630

malignant melanoma ; internal choroidectomy ; eye wall resection ; retinochoroidectomy ab interno ; macula

Springer Online Journal Archives 1860-2000

Medicine

Abstract Local excision of uveal melanoma is an intriguing therapeutic modality in selected cases. An internal choroidectomy under a retinal flap has been developed as an alternative to retinochoroidectomy in managing posterior pole melanomas. This technique offers more adequate preservation of retinal architecture, thus potentially enhancing central visual function in patients with tumors located close to the fovea.

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