PubMed Health⌕ Search

Biomedical subjects

G Grabner

Publications and source records attributed to G Grabner.

At least 19 recordsLinked to original sources

[The Salzburg-Moorfields Collaborative Glaucoma Study: first results of the prevalence and 5-year incidences in this prospective, population-based longitudinal study].

BACKGROUND: This prospective, population-based longitudinal study describes prevalences and 5-year incidences of individuals with normal findings, ocular hypertension (OHT) and primary open-angle glaucoma (POAG) admitted to the Salzburg-Moorfields Collaborative Glaucoma Study (SMCGS). PATIENTS AND METHODS: The SMCGS is embedded in a government-supported glaucoma blindness prevention programme in Salzburg (Austria) which is designed for a minimum of 10-years follow-up. Each subject receives a complete ophthalmological examination. In total, the findings of 853 subjects with complete data sets were analysed and evaluated. RESULTS: The prevalence of participants with normal findings was 75 % (95 % CI: 72 - 78 %) at the initial examination, decreasing to 64 % (95 % CI: 60 - 67 %) at the 5-year follow-up. The prevalence of OHT at the initial exam of 2.3 % (95 % CI: 1.4 - 3.6 %) increased to 3.5 % (95 % CI: 2.4 - 5.0 %) at the 5-year follow-up exam with an incidence of 1.2 % (95 % CI: 0.6 - 2.2 %). Finally, the prevalence of POAG of 0.6 % (95 % CI: 0.2 - 1.4 %) increased to 1.6 % (0.9 - 2.7 %) at the 5-year exam which corresponds to a 5-year incidence of POAG of 1.0 % (0.5 - 2.0 %). CONCLUSION: The prevalence of POAG increases statistically significantly when compared at the initial and 5-year follow up exam (p = 0,002). Our results confirm the positive relation between age and the prevalence of POAG (odds ratio = 0.89, 95 % CI: 0.81 - 0.98). The prevalence and 5-year incidence rates in this glaucoma prevention study are similar to those of other population-based studies.

Adult↗

[Clinical management of severe ocular surface disease].

Severe ocular surface diseases, such as Stevens-Johnson syndrome, ocular cicatricial pemphigoid or severe ocular burns may result in a significant loss of corneal stem cells, eventually leading to vision impairment or even corneal blindness. In case of unilateral involvement, limbal autografting, by means of transplanting limbal stem cells from the healthy fellow eye, has proved to be an effective procedure for restoring the integrity of the ocular surface. Limbal allografts may be performed in patients with bilateral disease, however, systemic immunosuppression is mandatory in these cases, with a long-term outcome that is frequently reduced compared to limbal autografts due to acute or chronic graft rejection. In recent years, amniotic membrane transplantation has been successfully employed as an additional tool in ocular surface reconstruction. The AlphaCor synthetic cornea, which is made of flexible acrylic may be considered as an alternative in patients with repeated corneal graft failures. Both limbal transplantation and the AlphaCor have been shown to be effective in eyes with an adequate tear film, but are most likely to fail in severe dry eyes or in patients with cicatrising diseases. Such conditions are the domain of keratoprostheses (KPros) with rigid optics, which certainly can be considered as the 'last resort' to restore vision in patients with profound corneal blindness not amenable to conventional corneal and limbal grafting. The osteo-odonto-keratoprosthesis according to Strampelli and modified by Falcinelli makes use of a "biological" support consisting of a longitudinal section of one of the patient's teeth that is also supported by the surrounding alveolar bone tissue. Compared to other devices favourable long-term results have been reported. In patients lacking any usable teeth, implantation of a keratoprosthesis with haptics made of Dacron (Pintucci-KPro) or tibial bone (Temprano-KPro) might be considered.

Burns, Chemical↗

[Driving habits of patients with glaucoma].

BACKGROUND: Central visual field defects due to glaucoma are common, increasing with old age. Impaired visual processing, for instance caused by glaucoma, may play a role in the aetiology of car accidents involving older drivers which can result in personal injury. Mandatory eye exams with assessment of the visual field in elderly people holding a driving licence will become more and more important, especially in a continuously ageing and increasingly mobile population. MATERIALS AND METHODS: In this prospective study, 80 patients with overt glaucoma and 52 patients without glaucoma, all holders of a valid driving licence, were enrolled. For each patient, the best corrected visual acuity was recorded and an examination of the central visual field was performed with automatic perimetry. In addition, a detailed questionnaire about the current driving habits of the patient was requested. RESULTS: In summary, 29 patients (36 %; 95 % CI: 26 - 48 %) of 80 glaucoma patients were driving a motor vehicle with binocular congruent scotomata within the central 30 degrees visual field, which is not sufficient to meet current legal requirements in Austria. In addition, 3 out of 29 impaired patients had a visual acuity that was below the mandatory legal requirements. A total of 39 patients (49 %; 95 % CI: 37 - 60 %) of the glaucoma patients fulfilled legal requirements. Examination of these patients showed only monocular or binocular central visual field defects that were not congruent. However, 12 (15 %; 95 % CI: 8 - 25 %) patients were holders of a valid driving licence, but had stopped driving some time ago. Based on the prevalence of glaucoma and the number of driving licence holders, the projected number of actively driving glaucoma patients who do not meet the legal requirements regarding the visual field is probably around 15,400 (7,400 - 29,500) in Austria and around 163,500 (79,000 - 313,500) in Germany. CONCLUSIONS: Time limits for the validity of the driving licence within the European Community have been set. In addition, the legal requirements for driving a motor vehicle should also be clearly defined, especially the requirements regarding the visual field and the acceptable dimensions of central scotomata. In addition, a mandatory eye exam for older drivers to be performed by ophthalmologists should be considered in order to detect persons posing a safety risk in traffic.

Adolescent↗

Measurement of stray light and glare: comparison of Nyktotest, Mesotest, stray light meter, and computer implemented stray light meter.

AIM: To evaluate the properties of devices for measuring stray light and glare: the Nyktotest, Mesotest, "conventional" stray light meter and a new, computer implemented version of the stray light meter. METHODS: 112 subjects, divided in three groups: (1) young subjects without any eye disease; (2) elderly subjects without any eye disease, and (3) subjects with (early) cataract in at least one eye. All subjects underwent a battery of glare and stray light tests, measurement of visual acuity, contrast sensitivity, refraction, and LOCS III cataract classification. Subjects answered a questionnaire on perceived disability during driving. RESULTS: Repeatability values were similar for all glare/stray light tests. Validity (correlation with LOCS III and questionnaire scores), discriminative ability (ability to discriminate between the three groups), and added value (to measurement of visual acuity and contrast sensitivity) were all superior for both stray light meters. Results of successive measurements are interrelated for the conventional but not the new stray light meter. This indicates a better resistance to fraud for the latter device. CONCLUSIONS: The new computer implemented stray light meter is the most promising device for future stray light measurements.

Adaptation, Ocular↗

[Amniotic membrane transplantation with limbal stem cell transplantation as a combined procedure for corneal surface reconstruction after severe thermal or chemical burns].

BACKGROUND: Severe thermal and chemical burns may result in limbal deficiency leading to persistent epithelial defects, complete conjunctival epithelial ingrowth and vascularisation of the cornea. If sufficiently severe, these burns may lead to very significant visual impairment. Amniotic membrane transplantation with limbal transplantation has recently been proposed as a new method for corneal surface reconstruction. PATIENTS AND METHODS: A total of 14 patients (age 18-62 years, mean age 42 years) with limbal deficiency resulting from thermal ( n=1) or chemical burns ( n=13) underwent surgery. The corneal pannus was completely removed and the amniotic membrane was grafted onto the cornea. Limbal transplantation using autografts obtained from contralateral eyes was performed simultaneously in seven cases. Allografts from a donor were transplanted in seven cases with bilateral involvement. These patients received oral cyclosporin A postoperatively. The mean follow-up time was 18 months. RESULTS: In all cases of limbal autografts the corneal surface showed a complete and stable epithelialisation within a few weeks. Out of seven patients with limbal allografts three displayed recurrent epithelial defects in the long term. The initially semitransparent amniotic membrane became more translucent and biomicroscopically invisible within several months after surgery. There was an increase in visual acuity in most cases, limited mostly by irregular astigmatism due to the initial stromal loss. CONCLUSIONS: Amniotic membrane transplantation with limbal transplantation allows reconstruction ocular surfaces severely damaged by chemical or thermal burns. In most cases, however, additional surgical procedures such as lamellar or penetrating keratoplasty are required for adequate visual rehabilitation.

Administration, Oral↗

Relation between perceived driving disability and scores of vision screening tests.

AIM: To determine the relation between perceived driving disability and vision screening tests. METHODS: 93 subjects, aged 50 years and over, with binocular visual acuity of at least 20/80. Perceived driving disability (PDD) was assessed by a questionnaire. Subtracting daytime from night-time driving question scores revealed PDD at night (PDDN), subtracting scores of questions for driving in familiar places from those in unfamiliar places revealed PDD at unfamiliar places (PDDU). RESULTS: PDD was strongly related to visual acuity, contrast sensitivity and useful field of view (UFOV). Specific relations existed between PDDN and Nyktotests and Mesotests and between PDDU and UFOV. These associations were enhanced in a subset of subjects with better visual acuities. CONCLUSIONS: Vision screening tests correlate well with perceived driving disabilities, especially when a subtraction method is used in the questionnaire to reveal condition dependent disabilities. Additional tests for visual acuity are useful, especially in subjects with better visual acuity.

Automobile Driving↗

One year results of European Multicenter Study of intrastromal corneal ring segments. Part 2: complications, visual symptoms, and patient satisfaction.

PURPOSE: To assess intraoperative and postoperative complications, visual symptoms, and patient satisfaction after implantation of intrastromal corneal ring segments (ICRS, KeraVision, Inc.) for the correction of myopia and to demonstrate the reversibility and adjustability of refractive corrections with this method. SETTING: Twelve European investigational sites. METHODS: Patients with myopia of -1.0 to -6.0 diopters (D) were assigned to receive 1 of 5 ICRS thicknesses (0.25, 0.30, 0.35, 0.40, or 0.45 mm). Complications and visual symptoms were noted, and patient satisfaction was assessed at each postoperative visit (1 and 7 days and 1, 2, 3, 6, and 12 months). Refractive data were assessed after removal or exchange of the ICRS. RESULTS: Of 163 eyes of 110 patients enrolled, 159 eyes of 107 patients were implanted with an ICRS (52 patients had bilateral implantation). Intraoperative complications occurred in 2% of eyes (4/163 eyes in 3 patients) that were withdrawn from the study: 3 eyes had anterior surface perforations and 1 had a posterior microperforation into the anterior chamber. Most patients had no visual symptoms at 12 months; symptoms usually occurred rarely or sometimes and were mild in severity. At 12 months, good or excellent patient satisfaction was reported for 94% of eyes. Twelve ICRSs (8%) were removed, mainly because of undercorrection and induced astigmatism, and 2 were exchanged. All eyes were within +/-1.00 D of the preoperative manifest refraction spherical equivalent. CONCLUSIONS: The ICRS was safe for correction of low to moderate myopia. Severe postoperative visual symptoms were rare, and patient satisfaction was high. The refractive correction was largely reversible.

Adult↗

One year results of European Multicenter Study of intrastromal corneal ring segments. Part 1: refractive outcomes.

PURPOSE: To assess the efficacy, predictability, stability, and safety of correcting myopia with intrastromal corneal ring segments (ICRS, KeraVision, Inc.). SETTING: Twelve European investigational sites. METHODS: Patients with myopia of -1.0 to -6.0 diopters (D) and best spectacle-corrected visual acuity (BSCVA) of 20/20 or better (except in 3 eyes) were assigned to receive 1 of 5 ICRS thicknesses (0.25, 0.30, 0.35, 0.40, or 0.45 mm). Efficacy was assessed by postoperative uncorrected visual acuity (UCVA), predictability of refractive outcome (deviation from predicted cycloplegic refraction spherical equivalent), and stability of refractive effect (manifest refraction spherical equivalent [MRSE]). Safety was assessed by maintenance or loss of preoperative BSCVA and induced manifest refraction cylinder. Measurements were made preoperatively and 1 and 7 days and 1, 2, 3, 6, and 12 months postoperatively. RESULTS: One hundred fifty-nine ICRSs were implanted in the eyes of 107 patients (52 patients had bilateral implantation). Preoperatively, UCVA was worse than 20/40 in 98% of eyes (155/159); 12 months postoperatively, it was 20/20 or better in 63% of eyes (83/132) and 20/40 or better in 96% (127/132). Predicted refractive corrections for each ICRS thickness generally correlated with achieved corrections. At 12 months postoperatively, 90% of eyes (124/138) were within +/-1.00 D of plano (MRSE). Two or more lines of BSCVA were lost in 6% of eyes (8/135); all 8 eyes had BSCVAs of 20/25 or better. CONCLUSION: The ICRS safely, effectively, and predictably reduced or eliminated low to moderate myopia. Refractive correction was stable through the 12 month follow-up.

Adult↗

Scanning laser polarimetry (SLP) for optic nerve head drusen.

Optic nerve head drusen (ONHD) are either clinically invisible or clearly protruding from the disc, in the later case leading to the condition of an irregular, indistinct disc margin or a swollen disc on biomicroscopy. They also may cause visual field defects, even with slow progression. Scanning laser polarimetry (SLP) has been proposed as a rapid, objective and reproducible technology for retinal nerve fiber layer (RNFL) assessment and clinical studies have demonstrated that SLP can help to distinguish between normal and glaucomatous eyes, identify glaucoma suspects and correlates well with visual field defects. The purpose of this study was to evaluate the potential applicability of SLP in 20 consecutive patients with optic nerve head drusen (18 bilateral) that were clinically visible (22 eyes) and invisible (16 eyes). RNFL thickness was studied in patients with and without visual field defects. Patients with visual field defects and ONHD were significantly older and had a small, but significant reduction of visual acuity. Some global SLP parameters (average thickness, ellipse average) were significantly different between subjects with normal and abnormal visual fields. The comparison of the groups with visible and invisible drusen showed that there was no difference in demographic or perimetric data. RNFL thickness measurements were also very similar in both groups. Clinical visibility of drusen was not correlated with RNFL thinning as measured with the GDxTM. SLP assessment, however, was well correlated with functional loss. This objective, non-invasive technology may be an additional option for RNFL evaluation in this condition and an especially useful tool for long-term follow-up.

Adolescent↗

Pulsatile ocular blood flow in patients with pseudoexfoliation.

PURPOSE: Pseudoexfoliation syndrome is one of the most frequent causes of open-angle glaucoma and is statistically significant associated with a high risk of hypertension, angina, myocardial infarction or stroke and retinal vein thrombosis. The aim of this study was to evaluate the pulsatile ocular blood flow (POBF) in pseudoexfoliation syndrome without (PEX) and with glaucoma (PEG). METHODS: Seventeen eyes with PEX, 17 with PEG and 11 normal eyes of age-matched patients were enrolled. A complete ophthalmological examination included measuring the POBF with the Langham Pneumotonometer as well as the nerve fiber layer thickness by scanning laser polarimetry (GDx). RESULTS: The blood flow parameters, pulse volume and POBF, were statistically significant different between normals and patients with PEG (p < 0.003, t-test). A negative correlation between the intraocular pressure and the POBF was found for all eyes tested. Analysis of GDx? parameters showed a negative correlation for the "number" with the POBF and a positive one for ellipse modulation. CONCLUSION: Although pseudoexfoliation is reported to be a systemic disease measurement of the POBF could not detect any difference between normals and PEX, but was statistically significant different in PEG. Assessments of nerve fiber layer thickness as determined by scanning laser polarimetry also showed a correlation with POBF in some parameters tested.

Aged↗

[Automobile drivers with retinal diseases - a prospective analysis].

BACKGROUND: The study was designed to prospectively evaluate the driving habits of patients with retinal diseases, who were referred to the specialised retinal ambulatory care center of the Landesaugenklinik Salzburg. The main purpose of this study was to compare the legal requirements for visual acuity, as currently valid in Austria and Germany for driving motor vehicles, with the results found in this patients cohort and to analyse driving patterns of the patients with valid licenses. With these data, it seems possible to suggest a suitable time for a legally mandatory eye examination as to identify subjects with a potentially rising higher accident risk when driving. MATERIALS AND METHODS: In this study, 100 patients - all holders of a valid driving licence - with diabetic retinopathy or age related macular degeneration were enrolled. From each patient, the visual acuity (corrected or uncorrected depending on the driving habit) was recorded and a detailed questionnaire regarding the actual driving habits was requested. The resulting data were analysed in view of the legal requirements of both countries, Austria and Germany. RESULTS: Of 100 patients holding a valid driving licence a total of 31 were driving their motor vehicles with a legally insufficient visual acuity, 26 of 50 still driving. Of 50 patients suffering from diabetic retinopathy, 26 drove their cars illegally. Only 4 out of the above mentioned 31 patients had received sufficient information from their referring ophthalmologists. The average age of "illegal" drivers was 66.2 years. CONCLUSIONS: Within the European Community common legal requirements for driving a motor vehicle (regarding mainly the visual acuity) be clearly defined and a mandatory eye exam performed by qualified ophthalmologists for older subjects should be postulated. An individual and age related time limit to be placed on the driving licences of persons suffering from systemic diseases associated with relevant visual loss should to be discussed. Furthermore, ophthalmologists should be obliged to give detailed information to the patient with adequate documentation.

Aged↗

Eurosol versus fetal bovine serum-containing corneal storage medium.

PURPOSE: To evaluate the usability of Eurosol, a new medium-term corneal storage medium without components of bovine origin. METHODS: Ten pairs of human donor corneas were placed in tissue culture at 31 degrees C for 7, 14, 21, 28, or 35 days. One cornea of each pair was cultivated in conventional storage medium on Earls' minimum essential medium base containing 2% fetal bovine serum; the other one was stored in Eurosol. Corneas were examined with inverse light microscopy; corneal thickness was measured; and scanning electron microscopy was performed. RESULTS: No significant difference in corneal thickness and endothelial cell count was found at any time. Scanning electron microscopy showed a complete endothelial cell layer on all corneas. CONCLUSION. The findings indicate a potential clinical applicability of the tested serum-free medium-term storage medium, offering a safer alternative to conventional media containing fetal bovine serum.

Cell Count↗

Evaluation of donor tissue with a new videokeratoscope: the Keratron Scout.

PURPOSE: To evaluate the percentage of corneas with an epithelial surface quality sufficient for a reliable screening of donor eyes with keratoconus and after photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) treatment for refractive errors. The usefulness of the computer-assisted, video-keratography system Keratron Scout in making this determination was evaluated. METHODS: Forty eyes from 20 donors were screened within 30 minutes after enucleation and within 24 hours postmortem. At first a meticulous slit-lamp evaluation of the corneal surface and stroma was performed; thereafter eight pictures per eye were taken with the Keratron Scout, and an ultrasound pachymetry reading of the corneal center was taken. "True curvature," algorithm-based color maps were used for analysis. Epithelium was not removed, because all corneas were suitable for transplantation. Balanced salt solution was used to keep the corneas moist. The low intraocular pressure regularly found in postmortem eyes was raised to within normal ranges by intravitreal injection. Corneas were classified according to the integrity of their epithelial surface, which influences the regularity of the topography maps. RESULTS: The quality of the images acquired varied, depending mostly on the quality of the epithelium. Regular topography patterns were found in 15 eyes (37.5%); in 14 eyes (35%), minimal epithelial roughness or sloughing in just one quadrant of the cornea was detected. Moderate to severe epithelial irregularities or defects were found in nine eyes (22.5%). Screening for abnormal shape was possible in 90% of the tested eyes, where no changes caused by prior refractive surgery or keratoconus were apparent. CONCLUSION: The postmortem quality of the epithelial surface allows screening for keratoconus or refractive procedures in the majority of donor eyes. Video-keratography with the Keratron Scout seems to offer a sensitive and quick method for this purpose, thereby adding an additional safety feature to eye banking in view of the rapid development of corneal refractive surgery.

Adolescent↗

Diode laser transscleral cyclophotocoagulation for refractory glaucoma.

PURPOSE: To evaluate the efficacy of contact diode laser transscleral cyclophotocoagulation using different treatment parameters. METHODS: All eyes undergoing contact diode laser transscleral cyclophotocoagulation between April 1991 and September 1997 at our two institutions were enrolled. Success was defined as an intraocular pressure less than or equal to 22 mm Hg or absence of pain for poorly sighted and blind eyes. RESULTS: Two hundred six eyes of 204 patients (Salzburg, 117 eyes; New York, 89 eyes) were enrolled. Mean patient age was 65.8 +/- 18.7 years (range, 4-96 years). Mean follow-up was 9.2 +/- 11.2 months (range, 3-56 months). Mean preoperative and postoperative IOPs were 42.1 +/- 11.0 mm Hg (range, 24-76 mm Hg) and 17.3 +/- 10.9 mm Hg (P < 0.001) and 20.3 +/- 13.2 mm Hg (P < 0.001) at 12 and 24 months, respectively. The number of laser applications (mean, 18.6 +/- 4.2; range, 10-40) and maximal laser power (mean, 2,352 +/- 408.5 mW; range, 1,500-3,000) were not associated with a lower postoperative IOP. An IOP less than or equal to 22 mm Hg was achieved in 72.7% of eyes at the mean follow-up of 9 months. Thirty-three (16.0%) eyes required at least one retreatment. Phthisis occurred in four (1.9%) eyes. CONCLUSION: Contact diode laser transscleral cyclophotocoagulation is useful in eyes with refractory glaucoma in which the risks of outflow surgery are deemed unacceptable.

Adolescent↗

Interaction of 4-hydroxybiphenyl with cyclodextrins: effect of complex structure on spectroscopic and photophysical properties.

The structures, spectroscopic and photophysical properties of the inclusion complexes between 4-OH-biphenyl and cyclodextrins (CD) in water were studied theoretically and experimentally. The complex structures were predicted using a dynamic Monte Carlo procedure including solvation effects and analyzed via computed and experimentally determined circular dichroism. The interpretation of the induced circular dichroism spectra indicated the formation of stable 2:2 complexes between the probe and alpha-CD, while 1:1 structures account for the circular dichroism induced by beta- and gamma-CD. Fluorescence emission quantum yields and lifetimes, measured as a function of the CD concentration, confirmed the formation of this higher order complex with alpha-CD. Prototropic equilibration in the singlet excited state was found to be depressed in 2:2 complexes due to the hydrophobic environment of the OH groups, while it remained unperturbed in 1:1 complexes, where the substituent is exposed to the aqueous environment. Triplet-triplet absorption and triplet quenching data supported this interpretation. The photophysical properties of both the 1:1 and the 2:2 complexes are characterized by a significant reduction of the nonradiative decay rates.

Biphenyl Compounds↗

Confocal microscopy after implantation of intrastromal corneal ring segments.

OBJECTIVE: Confocal in vivo real-time microscopy was used to study the corneal morphologic features in eyes after Intrastromal Corneal Ring Segments (ICRS; now called KeraVision INTACS, KeraVision, Inc., Fremont, CA) implantation. DESIGN: Noncomparative, interventional case series. PARTICIPANTS: The authors performed confocal real-time microscopy on a total of 21 eyes from 11 patients. Seventeen eyes from 10 patients (five female, five male; mean age 32.3 years; range 22-42 years) underwent uncomplicated ICRS surgery to correct myopia and were examined after surgery (average 8.6 months; range 2-15 months). Three patients had the ICRS implanted into only one eye, and those eyes were compared with the untreated fellow eyes. One eye of another patient was examined 1 and 6 months after ICRS removal. INTERVENTION: Flying slit-confocal microscopy was performed with water immersion objectives in the corneal center and near the nasal or temporal ICRS. Corneal optical sections were recorded in real time without further digital processing and were reviewed frame by frame. MAIN OUTCOME MEASURES: Video frames selected from all corneal layers were evaluated qualitatively and quantitatively. RESULTS: In the central cornea, we found normal morphologic features at all layers. In peripheral sections, epithelial cells with highly reflective nuclei in the basal cell layer were observed in six of 17 eyes (35%) implanted with ICRS. We found an intact corneal nerve plexus and undisturbed corneal endothelium immediately underneath the ICRS. Around the ICRS, moderate fibrosis was seen. In one eye, linear structures in bamboo-like orientation were detected after ICRS removal in the last keratocyte layer underneath the collapsed tunnel. CONCLUSIONS: Whereas the central corneal zone appears unchanged, the corneal stroma adjacent to the ICRS displays a slight, but distinct, activation of wound healing. Epithelial cells with highly reflective nuclei in this region may be an indicator for an increased biologic stress caused by the device.

Adult↗