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K Rohrschneider

Publications and source records attributed to K Rohrschneider.

At least 19 recordsLinked to original sources
PubMed2006

[Static fundus perimetry in normals. Microperimeter 1 versus SLO].

BACKGROUND: The Microperimeter 1 (MP-1) allows for fundus-controlled static perimetry of the central visual field. The purpose of this study was to compare MP-1 fundus perimetry with the already established scanning laser ophthalmoscope (SLO) fundus perimetry concerning detected threshold values of light increment sensitivity in normals. METHOD: In 31 eyes of 31 healthy volunteers a fundus controlled static threshold perimetry was carried out each with the MP-1 (Nidek Technologies) and the SLO (Rodenstock). In the central 21 degrees x 12 degrees visual field light increment sensitivity threshold values for 40 corresponding stimulus locations were compared in a rectangular 3 degree-grid. RESULTS: The average light increment sensitivity was 19.1+/-0.5 dB with the MP-1 and 17.2+/-0.9 dB with the SLO. On average the threshold values of the 40 corresponding test locations were 1.9+/-1.3 dB higher with the MP-1 than with the SLO. CONCLUSION: Both the MP-1 and SLO offer the possibility of a reproducible functional analysis of the central retina under simultaneous fundus control. For comparison of results of the MP-1 and SLO fundus perimetry, a correction factor of approximately 2 dB should be used.

Adult↗
PubMed2006

[Central serous chorioretinopathy--retinal function and morphology: microperimetry and optical coherence tomography].

BACKGROUND: The purpose of this study was to evaluate and compare retinal function and morphology in patients with central serous chorioretinopathy (CSC) using fundus perimetry and optical coherence tomography (OCT). PATIENTS AND METHODS: In 14 eyes of 14 patients with unilateral and first manifestation of CSC, fundus perimetry with the Microperimeter 1 (MP1) as well as OCT were carried out. The average retinal thickness and the average differential light threshold of the corresponding visual field were analyzed. RESULTS: All patients presented a serous detachment of the central neurosensory retina with a maximal retinal thickness of 381+/-82 microm. The microperimetric examination revealed on average a mean defect of 8.3+/-3.8 dB, which showed a good correlation to retinal thickness (r=0.73). Likewise, maximal retinal thickness and mean threshold values in the corresponding visual field displayed a good correlation (r=-0.58). CONCLUSION: The MP1 enables quantification of functional defects in patients with CSC. Although visual acuity was only slightly reduced, all patients showed extensive scotomata in fundus perimetry, which correlated well with retinal thickness.

Adult↗
PubMed2005

[Influence of cutoff filters on reading behavior in age-related macular degeneration].

BACKGROUND: Cutoff filters may improve contrast sensitivity in different retinal dystrophies and therefore lead to improved visual function. We investigated whether cutoff filters result in improved reading ability in age-related macular degeneration (AMD). METHODS: Reading performance was examined in 22 patients with AMD aged 63-91 years (visual acuity 0.1-0.5) using the Radner reading charts. These charts were presented in random order either with or without cutoff filters (Zeiss CF 540 and CF 580) monocularly to the better eye using a defined luminance of the test charts of 105 cd/m(2). RESULTS: Using the CF 540 cutoff filter, there was no significant change in visual acuity while there was a tendency to decrease. Calculating the LogRAD score, which takes reading errors into account, three patients improved by one line, while nine deteriorated, six of them by one line or more. There was no significant improvement using the CF 580 compared to either the CF 540 or to normal reading glasses. CONCLUSIONS: Overall, we found no measurable improvement using the CF 540 cutoff filter. The cutoff filter CF 580, tested for additional comparison, did not show any advantage.

Aged↗
PubMed2004

Adult alpha-mannosidosis: clinical progression in the absence of demyelination.

Alpha-mannosidosis is an inherited lysosomal storage disease. The authors report three siblings (ages 38 to 47 years) with the rare adult variant. All three had late-onset ataxia and retinal degeneration, adding to hearing loss, cognitive impairment, and dysotosis multiplex. One sibling also had psychosis. MRI revealed cerebellar atrophy and predominantly parieto-occipital white matter changes. MR spectroscopy showed no evidence for demyelination. It appears that the disabling course of adult alpha-mannosidosis is caused by lysosomal accumulation rather than demyelination.

Adult↗
PubMed2003

[Diagnosis and follow-up in glaucoma patients using the Heidelberg retina tomograph].

The development of laser scanning tomography in the late 1980s enabled the possibility of an exact three-dimensional biomorphorphometry of the optic nerve head. This technique is designed for 3D measurement of the topography of the optic disc with high accuracy and reproducibility. With the development of the Heidelberg retina tomograph with highly advanced and user-friendly software, a quick examination is possible. Currently the instrument is already used on a routine basis in the ophthalmological practice. It has been shown that glaucomatous changes of the optic disc can be detected using laser scanning tomography before perimetric deterioration occurs. Therefore this technique is crucial in the follow-up of glaucoma patients.

Computer Graphics↗
PubMed2002

CDH23 mutation and phenotype heterogeneity: a profile of 107 diverse families with Usher syndrome and nonsyndromic deafness.

Usher syndrome type I is characterized by congenital hearing loss, retinitis pigmentosa (RP), and variable vestibular areflexia. Usher syndrome type ID, one of seven Usher syndrome type I genetic localizations, have been mapped to a chromosomal interval that overlaps with a nonsyndromic-deafness localization, DFNB12. Mutations in CDH23, a gene that encodes a putative cell-adhesion protein with multiple cadherin-like domains, are responsible for both Usher syndrome and DFNB12 nonsyndromic deafness. Specific CDH23 mutational defects have been identified that differentiate these two phenotypes. Only missense mutations of CDH23 have been observed in families with nonsyndromic deafness, whereas nonsense, frameshift, splice-site, and missense mutations have been identified in families with Usher syndrome. In the present study, a panel of 69 probands with Usher syndrome and 38 probands with recessive nonsyndromic deafness were screened for the presence of mutations in the entire coding region of CDH23, by heteroduplex, single-strand conformation polymorphism, and direct sequence analyses. A total of 36 different CDH23 mutations were detected in 45 families; 33 of these mutations were novel, including 18 missense, 3 nonsense, 5 splicing defects, 5 microdeletions, and 2 insertions. A total of seven mutations were common to more than one family. Numerous exonic and intronic polymorphisms also were detected. Results of ophthalmologic examinations of the patients with nonsyndromic deafness have found asymptomatic RP-like manifestations, indicating that missense mutations may have a subtle effect in the retina. Furthermore, patients with mutations in CDH23 display a wide range of hearing loss and RP phenotypes, differing in severity, age at onset, type, and the presence or absence of vestibular areflexia.

Adolescent↗
PubMed2002

[Follow-up on MEWDS by fundus perimetry and multifocal ERG with the SLO].

BACKGROUND: Most conventional techniques for examination such as perimetry or ERG may not be sensitive enough to detect functional alterations due to MEWDS precisely. We report on a follow-up performed by fundus perimetry and the new technique of multifocal ERG using the scanning laser ophthalmoscope. PATIENT AND METHOD: A 24-year-old female patient (VA 0.2/0.8) was followed up for 7 weeks with these techniques as well as Octopus perimetry, fluorescence angiography, Ganzfeld ERG and biomicroscopy. Multifocal ERG stimulation (mfERG, Retiscan) was performed with the SLO. RESULTS: Visual acuity improved from 0.2 to 0.8 and the central relative scotoma disappeared while a relevant increase of P1-wave amplitudes in mfERG could be observed. CONCLUSION: Combining objective measurements from the fundus controlled SLO-mfERG and results from fundus perimetry enable good correlation of morphology and results, even for minor alterations of the macula only accessible by few established clinical examinations.

Adult↗
PubMed2002

[Diagnosis of retinal diseases. Comparison between multifocal ERG and fundus perimetry - a case study].

BACKGROUND: There are new methods available for function testing of the macula, i.e. multifocal Electroretinography (mfERG) as well as fundus perimetry with the scanning laser ophthalmoscope (SLO). The value and clinical impact of these methods have still to be evaluated. We wanted to compare the results from patients having undergone both examinations. PATIENTS AND METHODS: A total of 33 eyes from 25 patients (visual acuity 0.03-0.8) aged 14-79 years were examined using fundus perimetry with the SLO. In addition, multifocal ERG was performed in all eyes, where 61 local ERGs inside the 30 degrees visual field were recorded. We compared the depth of the scotoma with the reduction of the amplitudes during mfERG taking the fixation status into consideration. RESULTS: Examination time was comparable for both examination techniques. There was good concordance for eyes with retinitis pigmentosa with only central response. In contrast, patients with juvenile macular dystrophy demonstrated different results with comparable size of the defect while sometimes an enlarged pathology during mfERG was observed. Correlation between pathology findings observed in mfERG and fundus changes was difficult due to the change of the point of fixation caused by central scotoma. In age-related macular degeneration correlation of the findings was less obvious. DISCUSSION: The different setting with supra-threshold stimuli during ERG in contrast to near-threshold stimulus presentation during perimetry, might be the reason for differences even in the beginning of retinal diseases. In addition, reduced stability of fixation leads to artifacts during mfERG while it may be compensated for in fundus perimetry. Both methods are of additional value and demonstrate different results depending on the disease.

Adolescent↗
PubMed2002

[Satisfaction with low vision aids].

PURPOSE: To study satisfaction with the prescription of low vision aids (LVA) and to correlate LVA with eye disease and visual function one year after prescription. METHODS: A questionnaire was sent out to 576 patients who had received LVAs in 1998. We evaluated their subjective satisfaction with the LVA as well as with the whole examination in our low vision department and compared the kind of LVA with disease and visual acuity. In addition, we observed whether additional functional deterioration led to problems with the LVA. RESULTS: 301 questionnaires were returned (52 %). They reported on high satisfaction with the management and the LVA (> 90 %). 57 % used their optical LVAs more than 5 times daily mostly for reading and writing (74 % and 78 %, respectively). However, 20 patients were no longer able to read with their LVA due to decrease of function. When comparing the LVAs, most patients with age-related macular degeneration were supplied with magnifiers (30 %). Thirty percent of the patients supplied with CCTVs (43 %; visual acuity 0.02 to 0.3) used the CCTV daily. CONCLUSIONS: The majority of low vision patients is very satisfied with the prescription of LVAs and frequently uses these aids. The adequate LVA is a major factor improving the quality of life. However, due to the possibility of greater deterioration after the disease, follow-up examinations on a regular basis appears to be necessary. The early prescription of CCTVs often helps to preserve the reading ability and should therefore be kept in mind by the physician dealing with low vision patients.

Adolescent↗
PubMed2001

Leber congenital amaurosis and retinitis pigmentosa with Coats-like exudative vasculopathy are associated with mutations in the crumbs homologue 1 (CRB1) gene.

Mutations in the crumbs homologue 1 (CRB1) gene cause a specific form of retinitis pigmentosa (RP) that is designated "RP12" and is characterized by a preserved para-arteriolar retinal pigment epithelium (PPRPE) and by severe loss of vision at age <20 years. Because of the early onset of disease in patients who have RP with PPRPE, we considered CRB1 to be a good candidate gene for Leber congenital amaurosis (LCA). Mutations were detected in 7 (13%) of 52 patients with LCA from the Netherlands, Germany, and the United States. In addition, CRB1 mutations were detected in five of nine patients who had RP with Coats-like exudative vasculopathy, a relatively rare complication of RP that may progress to partial or total retinal detachment. Given that four of five patients had developed the complication in one eye and that not all siblings with RP have the complication, CRB1 mutations should be considered an important risk factor for the Coats-like reaction, although its development may require additional genetic or environmental factors. Although no clear-cut genotype-phenotype correlation could be established, patients with LCA, which is the most severe retinal dystrophy, carry null alleles more frequently than do patients with RP. Our findings suggest that CRB1 mutations are a frequent cause of LCA and are strongly associated with the development of Coats-like exudative vasculopathy in patients with RP.

Adult↗
PubMed2001

[Fundus-controlled functional evaluation in macular diseases with the scanning laser ophthalmoscope].

Exact functional testing in macular diseases still presents a challenge for the ophthalmologist in detecting both small (para)central scotomas and changes in fixation habits. The recent development of scanning laser ophthalmoscopy has enabled functional testing with simultaneous observation of the fundus. In addition to automatic static threshold fundus perimetry, kinetic fundus-controlled perimetry and special fixation tasks can be applied. This method also allows the examination of reading performance combined with the exact observation of fixation and has been increasingly integrated into clinical routine. This allows more exact observations concerning macular function for diagnostic purposes, in evaluating new treatment methods, and as expertises in simulation or aggravation in patients with macular diseases.

Fixation, Ocular↗
PubMed2001

Functional changes measured with SLO in idiopathic macular holes and in macular changes secondary to premacular fibrosis. Function in macular holes.

AIM: To evaluate fundus perimetry and laser scanning tomography in idiopathic macular holes and premacular fibrosis and to describe specific functional findings of the adjacent retina. PATIENTS AND METHODS: Thirty eyes of 30 patients with macular holes and epiretinal membranes (visual acuity 0.05-0.5) aged 64 +/- 13 years were examined using automatic threshold fundus perimetry with simultaneous observation of fixation, as well as a special fixation task with the scanning laser ophthalmoscope (SLO). In addition, area and depth of the holes were measured using scanning laser tomography (Heidelberg retina tomograph). RESULTS: All 21 eyes with full thickness macular holes (0.06-0.75 mm2 area; 0.06-0.53 mm depth) showed an absolute scotoma inside of the hole with location of the fixation area at the left border or top of the hole. In contrast, the patients with impending holes or epiretinal membranes (0.14-0.32 mm2 area, 0.09-0.17 mm depth) could detect bright stimuli during perimetry (10-20 dB and 3-9 dB, respectively). We observed a reduced light increment sensibility (4-13 dB) surrounding the full thickness hole in 15 eyes, either with attached or detached retina. CONCLUSIONS: Fundus perimetry with simultaneous documentation of fixation offers the option to detect functional differences between macular holes and changes secondary to epiretinal membrane formation. There is an area of reduced function even in eyes with clinically and tomographically attached retina surrounding the hole which might influence surgical results.

Adult↗
PubMed2000

Mutations in the ABCA4 (ABCR) gene are the major cause of autosomal recessive cone-rod dystrophy.

The photoreceptor cell-specific ATP-binding cassette transporter gene (ABCA4; previously denoted "ABCR") is mutated, in most patients, with autosomal recessive (AR) Stargardt disease (STGD1) or fundus flavimaculatus (FFM). In addition, a few cases with AR retinitis pigmentosa (RP) and AR cone-rod dystrophy (CRD) have been found to have ABCA4 mutations. To evaluate the importance of the ABCA4 gene as a cause of AR CRD, we selected 5 patients with AR CRD and 15 patients from Germany and The Netherlands with isolated CRD. Single-strand conformation-polymorphism analysis and sequencing revealed 19 ABCA4 mutations in 13 (65%) of 20 patients. In six patients, mutations were identified in both ABCA4 alleles; in seven patients, mutations were detected in one allele. One complex ABCA4 allele (L541P;A1038V) was found exclusively in German patients with CRD; one patient carried this complex allele homozygously, and five others were compound heterozygous. These findings suggest that mutations in the ABCA4 gene are the major cause of AR CRD. A primary role of the ABCA4 gene in STGD1/FFM and AR CRD, together with the gene's involvement in an as-yet-unknown proportion of cases with AR RP, strengthens the idea that mutations in the ABCA4 gene could be the most frequent cause of inherited retinal dystrophy in humans.

ATP-Binding Cassette Transporters↗
PubMed2000

Treatment of corneal neovascularization with dietary isoflavonoids and flavonoids.

The purpose of this study was to investigate the use of dietary isoflavonoids and flavonoids for the treatment of ocular neovascularization. Corneal blood vessels were induced by intrastromal implantation of pellets containing bFGF. Isoflavonoids and flavonoids (Genistein, Fisetin and Luteolin) were dissolved in a microemulsion to increase bioavailability and applied topically in concentrations between 0.5 and 1 ng ml(-1). Corneal neovascularization was quantified under the microscope. In comparison to control eyes, all three substances significantly inhibited corneal neovascularization (P < or = 0.05). Fisetin had the strongest effect followed by Genistein and Luteolin. No significant topical side effects were observed. We concluded that the isoflavonoid Genistein and two structurally related flavonoids are potent inhibitors of corneal angiogenesis in vivo. The wide distribution of the flavonoids in the plant kingdom together with the presented results suggests that flavonoids may contribute to the preventive effect of a plant-based diet on neovascular disease of the eye.

Administration, Topical↗
PubMed2000

[Ab interno trabeculectomy with the Nd:YLF picosecond laser].

BACKGROUND: The outcome of glaucoma surgery is limited by scar formation. As an alternative to current techniques, the opening of the trabecular meshwork ab interno may lead to increased outflow. This study examined the Nd:YLF picosecond laser for ab interno ablation of the trabecular meshwork without opening of the eye. PATIENTS AND METHODS: A Nd:YLF picosecond laser was used which allows tissue to be ablated even through fluids. We performed ablation with different spot sizes and energies in postmortem eyes. Afterwards the effect of the laser treatment was examined by electron microscopy. RESULTS: The ablation threshold for the cornea was found to be 20 J/cm2 for a pulse width of 30 ps. At a lower level of energy (10 J/cm2) ablation of the trabecular meshwork was possible. The size of the focus which was limited by the optics of the slit-lamp was about 50 microns. CONCLUSION: These initial results with a Nd:YLF picosecond laser confirm the possibility of ablating tissue in the trabecular meshwork ab interno without the need to open the eye.

Animals↗
PubMed2000

Cryopreserved human amniotic membrane for ocular surface reconstruction.

BACKGROUND: Amniotic membrane transplantation is used for the reconstruction of the ocular surface in the context of, for example, corneal ulcers or conjunctival scarring. The mechanisms by which preserved amniotic membrane grafts promote reepithelialization are unknown. As a first step the viability and proliferative capacity of amnion cells following cryopreservation of membranes in glycerol is investigated. METHODS: Fresh and cryopreserved (in 50% glycerol) amniotic membranes were investigated histologically and by vital stains. Following enzymatic digestion, amniotic cells were stained for viability and cultured in DMEM+10% FBS. In addition, explant cultures were established from fresh and cryopreserved membranes. RESULTS: Histological examination showed no significant morphological alteration following cryopreservation. While fresh membranes contained predominantly vital cells, no such cells were detected following cryopreservation. Also, cells removed enzymatically from cryopreserved membranes were not viable and did not grow in culture. While both epithelial and fibroblastic cells grew from fresh membranes, no growth was seen from cryopreserved membranes. CONCLUSION: The results suggest that the technique for preservation which is most widely used for ophthalmological amniotic membrane transplantation significantly impairs viability and proliferative capacity. This supports the clinical finding that neither immunological reactions nor signs of ingrowth of amniotic cells are observed in patients. Furthermore amniotic membrane grafts seem to function primarily as matrix and not by virtue of transplanted functional cells.

Amnion↗
PubMed2000

Scanning laser ophthalmoscope fundus perimetry before and after laser photocoagulation for clinically significant diabetic macular edema.

PURPOSE: To prospectively evaluate functional and funduscopic changes after laser treatment in patients with diabetic retinopathy and clinically significant macular edema by scanning laser ophthalmoscope fundus perimetry. METHODS: Thirty eyes of 30 patients with clinically significant macular edema as a result of diabetic retinopathy were prospectively examined before and at least 3 months after focal laser treatment with automatic fundus threshold perimetry using the scanning laser ophthalmoscope. Thresholds of light sensitivity were compared with age-corrected normal values and correlated with corrected visual acuity and subjective appraisal of visual function. RESULTS: In 30 eyes, fundus perimetry lasted for 10.5+/-2.7 (mean+/-SD) minutes with 322+/-67 stimulus presentations for each eye. Whereas eight eyes remained stable (< +/-1 dB change), 15 improved concerning mean deviation (MD) (3.1+/-1.7 dB) after focal laser treatment. Stability of fixation remained the same after focal laser treatment (0.75+/-0.57 degree). Laser scars showed marked loss of function (MD > 13 dB). CONCLUSIONS: Although light sensitivity was reduced in areas of macular edema, there was no correlation between the amount of edema and visual function. Fundus perimetry allows the creation of exact maps of retinal dysfunction before and after laser treatment. It may help in making management decisions in diabetic and nondiabetic patients by offering a sensitive parameter in addition to visual acuity.

Adult↗