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Biomedical subjects

A S Neubauer

Publications and source records attributed to A S Neubauer.

At least 19 recordsLinked to original sources
PubMed2006

Cost utility for penetrating keratoplasty in patients with poor binocular vision.

PURPOSE: Cost-utility and cost-effectiveness analyses are of increasing importance to clinicians and health policy experts. This study determines the costs in Germany and other countries in relation to gain of utility for patients with bilateral poor vision owing to corneal disease undergoing penetrating keratoplasty (PK) in 1 eye. DESIGN: A cost-utility analysis was performed using retrospective clinical data and high-level evidence-based data. PARTICIPANTS: Sixty patients (mean age, 46.3 years) with bilateral poor vision who underwent PK for corneal disease. METHODS: Visual acuity and utility values were obtained before and 1 year after PK and after suture removal. A 10-year graft survival rate of 80% was assumed. Expenses included costs for the corneal transplant and surgery, medication, and optical rehabilitation. A discount rate of 5% was applied for costs and quality-adjusted life years (QALYs). Cost-utility analysis encompassed a 10-year period after surgery. MAIN OUTCOME MEASURES: The number of QALYs was calculated for the study group undergoing PK. This was divided into the cost of the procedure to get the number of euros spent per QALY gained. RESULTS: Median binocular preoperative visual acuity was -log mean angle of resolution (-logMAR) 0.91+/-0.53 (Snellen equivalent 20/160) yielding a utility value of 0.67. After suture removal and optical rehabilitation, binocular visual acuity increased to median -logMAR 0.36+/-0.36 (20/46) with a utility value of 0.79. Over the 10 years after surgery and considering graft survival and discounting, a cost utility of 9551 euros per QALY was gained (equivalent to US11,557 dollars). One-way sensitivity analysis yielded a range from 7706 euros to 12874 euros per QALY, highlighting the robustness of the model. CONCLUSIONS: Although an expensive procedure, PK is cost effective in patients with bilateral poor vision.

Adolescent↗
PubMed2006

[Visual quality of life after vitreoretinal surgery for epiretinal membranes].

PURPOSE: To date, the increase of visual acuity and morphological parameters have been used to assess the benefit of a surgical intervention. The aim of this prospective study was to evaluate changes in patients' visual quality of life due to vitreoretinal surgery for epiretinal membranes. PATIENTS AND METHODS: Twenty patients with unilateral epiretinal membrane and good visual acuity of the fellow eye were included. Best corrected visual acuity and visual quality of life assessed by the visual function index (VF-14) were obtained preoperatively and 3 months after pars plana vitrectomy and peeling. RESULTS: Median visual acuity increased from 0.28 to 0.4 postoperatively. Visual quality of life (VF-14 values) rose from 72.8+/-4.7 (SEM) to 83.3+/-2.9 (p<0.05). Analysis revealed that patients with preoperatively low VF-14 values and preoperatively low visual acuity notably profited from surgery. The increase of visual quality of life can be predicted better than increase of visual acuity. Combined cataract surgery had no significant influence. CONCLUSION: In addition to best corrected visual acuity, quality of life measurements are important predictive and outcome parameters to estimate the value of vitreoretinal surgery.

Aged↗
PubMed2006

[Value-based medicine in ophthalmology].

PURPOSE: Value-based medicine (VBM) unifies costs and patient-perceived value (improvement in quality of life, length of life, or both) of an intervention. Value-based ophthalmology is of increasing importance for decisions in eye care. METHODS: The methods of VBM are explained and definitions for a specific terminology in this field are given. The cost-utility analysis as part of health care economic analyses is explained. RESULTS: VBM exceeds evidence-based medicine by incorporating parameters of cost and benefits from an ophthalmological intervention. The benefit of the intervention is defined as an increase or maintenance of visual quality of life and can be determined by utility analysis. The time trade-off method is valid and reliable for utility analysis. The resources expended for the value gained in VBM are measured with cost-utility analysis in terms of cost per quality-adjusted life years gained (euros/QALY). Numerous cost-utility analyses of different ophthalmological interventions have been published. CONCLUSION: The fundamental instrument of VBM is cost-utility analysis. The results in cost per QALY allow estimation of cost effectiveness of an ophthalmological intervention. Using the time trade-off method for utility analysis allows the comparison of ophthalmological cost-utility analyses with those of other medical interventions. VBM is important for individual medical decision making and for general health care.

Consumer Behavior↗
PubMed2005

[Evaluation of portable TGDc-01 tonometers and comparison with the Goldmann applanation tonometer].

PURPOSE: The aim of this study was to evaluate patients' acceptance and intraocular pressure (IOP) readings of a new digital mobile tonometer (TGDc-01) and compare it to Goldmann applanation tonometry. METHOD: Measurements repeated five times with the TGDc-01 and three times with Goldmann tonometry were performed in 100 eyes of 100 patients by two independent investigators. Patients' acceptance of both techniques was evaluated by a visual analogue scale (VAS). RESULTS: The mean IOP with the TGDc-01 yielded 15.4 mmHg for investigator 1 and 12.7 mmHg for investigator 2 (range: 4-43 mmHg). Results of the measurements with Goldmann tonometry showed 17.6 mmHg for investigator 1 and 17.3 mmHg for investigator 2 (9-42 mmHg). The IOP difference of the two tonometry methods was highly significant (p<0.001). The intraobserver variability was 29% for investigator 1 and 8% for investigator 2. Mean IOP values of the two investigators taken with the TGDc-01 differed significantly (p<0.01) from each other by a mean of 2.6 mmHg. CONCLUSIONS: The new mobile tonometer TGDc-01 is better accepted by patients but IOP values are significantly lower compared to Goldmann tonometry and variability is high. Regarding glaucoma diagnostics it seems to be less suitable than Goldmann tonometry.

Adult↗
PubMed2005

[Screening for diabetic retinopathy and optic disc topography with the "retinal thickness analyzer" (RTA)].

BACKGROUND: The RTA features a fundus photography mode and optic disc topography. Those two new modes were investigated regarding their clinical use. METHODS: First, the combination of wide-field photography with a retinal thickness map was assessed for tele-screening for diabetic retinopathy in 31 eyes. Second, normal values of the optic disc were collected on 30 non-glaucomatous probands in the non-mydriatic mode and compared to the results of the mydriatic mode, for which reproducibility was also investigated. RESULTS: For diabetic retinopathy, the RTA yielded mean 93% sensitivity for proliferative diabetic retinopathy and 100% sensitivity for detecting diabetic macular edema compared to clinical examination at specificities ranging from 58 to 96%. Regarding the measurements of the optic disc, the normal values in mydriasis coincided with those in miosis in all but 4 of 12 parameters. CONCLUSIONS: The RTA is suitable for application in tele-screening for diabetic retinopathy. The topography of the optic disc is highly reproducible and may be used for glaucoma diagnostics.

Diabetic Retinopathy↗
PubMed2005

[Cost-effectiveness of screening for amblyopia].

BACKGROUND: The effectiveness of a screening program for amblyopia has been discussed controversely for several years. While the medical profit is obvious, little is known on the cost-effectiveness of such a screening program. METHODS: By literature research all important variables were determined: incidence of amblyopia, sensitivity of different screening modalities, effectiveness of therapy, costs as well as the loss of utility and life quality by an existing amblyopia. Based on those data in a simple model the costs of a screening program for amblyopia were determined per quality adjusted life year (QALY). The result was analyzed for its stability by sensitivity analysis and compared to the costs of other therapies. RESULTS: Amblyopia occurs with an incidence of approximately 2 % (1.3 - 12 %). Most Screening programs reach a sensitivity of 60 - 90 % and cause costs of 900 - 1400 Euro per detected case. By appropriate therapy with mean costs of 2300 Euro approx. 60 % of the cases obtain useful vision of > 20/40. However, therapy results vary considerably. After discounting the incremental cost-effectiveness ratio (ICER) reaches 7684 Euro/QALY for a screening and treatment program for amblyopia. This is well comparable with other therapies and accepted to be cost-efficient. Sensitivity analysis yielded 24 700 Euro/QALY and 57,633 Euro/QAL with higher discounting for worst case scenarios. CONCLUSION: Screening for amblyopia meets the basic requirements of cost-effectiveness.

Amblyopia↗
PubMed2005

[Changes in the G-DRG System from 2003 to 2005 in Ophthalmology--Ophthalmologic G-DRG 2003 to 2005].

BACKGROUND: The objective of the study was to illustrate the effect of the extensive changes of the German DRG System on reimbursement of clinical ophthalmology during the years 2003, 2004 and 2005. METHODS: All ophthalmologic patients treated as in-patients at the Department of Ophthalmology at the University Munich during the year 2003 served as a reference data basis. By means of appropriate software those cases were then re-grouped according to the G-DRG classification of the years 2003, 2004 and 2005. This resulted in different reimbursements caused only by system changes for an exemplary hospital of maximum medical care. In addition, the same calculations were performed for four virtual, typical clinics based on the calculation data of the "Institut für Entgeltsysteme (InEK)". For those four clinics it was assumed that 80 % of the cases came from one of the subspecialties retina, glaucoma, cataract or strabismus surgery. RESULTS: Changes in the G-DRG system caused the sample hospital of maximum care to loose 8.5 % case mix index (CMI) during the period of 2003 to 2005. For three of the four virtual, typical ophthalmological clinics the theoretic reimbursement conditions also deteriorated: retina surgery -- 10.6 %, glaucoma surgery - 15.8 % and cataract surgery -- 17.9 % CMI. Only strabismus surgery showed an increase of + 5.6 % in CMI during the period examined. CONCLUSION: Over the years 2003 to 2005 the CMI clearly deteriorated for many ophthalmological subspecialties given otherwise identical conditions. To calculate the changes specifically for an individual hospital, the individual base rates have to be considered.

Computer Simulation↗
PubMed2004

[Homogeneity of G-DRGs in ophthalmology].

BACKGROUND: Since the year 2004 hospitals in Germany are obliged to participate in a payment system based on diagnosis-related groups (DRG), which bases hospital reimbursement on the diagnosis and treatment of patients. The aim of this study was to analyze the data of the first German national hospital cost data calculation for their homogeneity. METHODS: The cases at the LMU hospital in Munich were calculated analogous to the national hospital cost data calculation for a period of 7 months. These exemplary data were then analyzed in detail for homogeneity. RESULTS: For many DRGs, the numbers of cases in the analysis were within a range similar to those in the official nationwide calculation. The costs and lengths of stay were similar to those of the official national calculation. CONCLUSIONS: Many ophthalmologic DRGs are quite inhomogeneous necessitating regrouping to avoid false incentives. For cases with high complexity the current system may lead to cost deficits especially for hospitals providing maximum care.

Analysis of Variance↗
PubMed2003

[Measuring patient's quality of life in ophthalmology].

BACKGROUND: The assessment of patient's quality of life is not only of vital importance for clinical trials of new therapies but also becomes more and more implemented into daily clinical therapeutical decisions. METHODS: Different methods for evaluating quality of life are available. A well-known questionnaire for measuring global quality of life is the Short Form 36 (SF 36). However, in ophthalmology more specific instruments for measuring visual quality of life are needed. We review the usefulness of specific questionnaires such as the Visual Function 14 (VF-14) or the National Eye Institute Visual Function Questionnaire (NEI-VFQ) in their application to common ophthalmologic diseases such as cataract, age-related macular degeneration and glaucoma. Studies applying these methods were identified by a search in the Medline database. RESULTS: Several instruments to measure visual life quality in ophthalmologic patients are available. Internal consistency and validity are shown. CONCLUSIONS: Evaluating visual quality of life is an important parameter for assessing ophthalmologic diseases and the value of different therapies. It is an important outcome variable in clinical studies. Furthermore, individual visual quality of life should be considered in individual therapeutic decisions and helps to assess the economic effect of current and new therapies.

Aged↗
PubMed2003

Detecting chloroquine retinopathy: electro-oculogram versus colour vision.

AIM: To investigate the relative sensitivity and specificity of two tests of retinal function (the electro-oculogram (EOG) and a computerised colour vision test) in screening for ocular toxicity caused by chloroquine and hydroxychloroquine. METHODS: 93 patients with rheumatic diseases receiving long term chloroquine and hydroxychloroquine therapy were followed for an average of 2.6 years. Clinical examination, an EOG, and a quantitative test of colour vision were carried out every 6 months. RESULTS: Mild fundus changes were observed in 38 patients. Four patients developed typical bull's eye maculopathy, three of whom had received 250, 365, and 550 g total dose of chloroquine, and one 1500 g of hydroxychloroquine. Statistical analysis of all patients showed that for those with no fundus changes or stippled pigmentation a number showed elevation of tritan threshold, so that if macular stippling is a sign of mild retinopathy the test on tritan changes has a 64% sensitivity and 63% specificity for an upper threshold value of 7%. All four patients with bull's eye lesions showed a marked disturbance of tritan colour vision, with a threshold of 14.8%, a sensitivity of 75%, and a specificity of 94%. For protan colour vision a threshold of 10% gives 75% sensitivity and 91% specificity. By contrast, neither an absolute nor a relative EOG reduction was a valid criterion for early or late chloroquine retinopathy. In advanced retinopathy an Arden coefficient (AQ) <180% yields 50% sensitivity and 54% specificity. When AQ <160% is the threshold, sensitivity does not increase but specificity rises to 82%. Occurrence of marked corneal deposits on clinical examination yields 50% sensitivity and 90% specificity in this situation. CONCLUSION: Screening for chloroquine retinopathy can be improved by using a sensitive colour test. Disturbance of the tritan axis appears to occur first. A normal test result on computerised colour testing virtually excludes any retinopathy by antimalarials. The EOG is of little diagnostic value.

Aging↗
PubMed2002

Melanoma inhibitory activity: a novel serum marker for uveal melanoma.

The aim of this study was to evaluate the tumour-associated antigen melanoma inhibitory activity (MIA) as a potential novel serological tumour marker in primary and metastatic uveal melanoma in both the laboratory and the clinical setting. In the laboratory setting, immunohistochemical staining with MIA antibody was performed in paraffin-embedded tissues from six amelanotic uveal melanomas and eight metastatic lesions of uveal melanomas. In the clinical setting, serum samples of 139 patients with uveal melanoma were examined; eight of these patients had overt metastatic disease. Sixty-one initially metastatic disease-free patients were followed over time (median follow-up 240 days, 95% confidence interval 60-883 days) and MIA levels were assessed repeatedly. A one-step enzyme-linked immunosorbent assay was used to quantify the MIA serum levels. In the laboratory setting, five of the six primary uveal melanomas and seven of the eight metastatic lesions stained immunohistologically positive for MIA. In the clinical setting, the 131 patients without overt metastatic disease demonstrated a median serum concentration of MIA of 6.6 ng/ml. In the eight patients with overt metastatic disease, the median serum concentration of MIA was 26.28 ng/ml. This difference was highly statistically significant (P < 0.001, analysis of variance). During follow-up, three initially metastatic disease-free patients developed overt metastatic disease, and the MIA level increased from a median of 6.6 ng/ml before to 29.2 ng/ml after clinical detection of metastatic disease. In the 58 other patients, the serum level remained stable during the entire follow-up period. In conclusion, MIA is expressed in primary and metastatic lesions of uveal melanomas, and a statistically significant elevation in MIA serum levels in patients who develop metastatic disease due to uveal melanoma indicates its promising role as a serum marker for monitoring uveal melanoma patients for metastasis.

Adult↗
PubMed2002

Interobserver and intraobserver variability of measurements of uveal melanomas using standardised echography.

AIMS: To report on the intraindividual and interindividual variability of tumour size (height and base diameter) measurements using standardised echography in a masked prospective study. METHODS: 20 consecutive eyes of 20 patients were examined on four different visits by three experienced examiners using standardised echography. As common in standardised echography, tumour height was evaluated with A-scan technique, while transverse and longitudinal base diameter were calculated with B-scan. RESULTS: Tumour height measurements using A-scan were more accurate than base diameter measurements using B-scan. The standard deviation for tumour height over all visits/measurements was 0.18 mm (A-scan), 0.79 mm for transverse, and 0.69 mm for longitudinal base diameters (B-scan). The interclass correlation coefficient (ICC) was much higher for tumour height measurements with A-scan (0.7735 for three examiners on one visit) than for transverse (0.6563) or longitudinal (0.4522) base diameter measurements with B-scan techniques. CONCLUSIONS: A-scan techniques for tumour height measurements provide very reproducible results with little intraindividual and interobserver variability. As B-scan techniques for tumour base evaluation are less accurate they should be used for topographic and morphological examinations.

Adult↗
PubMed2001

[Electronic versus paper-based patient records: a cost-benefit analysis].

BACKGROUND: The aim of this study is to compare the costs and benefits of electronic, paperless patient records with the conventional paper-based charts. METHODS: Costs and benefits of planned electronic patient records are calculated for a University eye hospital with 140 beds. Benefit is determined by direct costs saved by electronic records. RESULTS: In the example shown, the additional benefits of electronic patient records, as far as they can be quantified total 192,000 DM per year. The costs of the necessary investments are 234,000 DM per year when using a linear depreciation over 4 years. In total, there are additional annual costs for electronic patient records of 42,000 DM. Different scenarios were analyzed. By increasing the time of depreciation to 6 years, the cost deficit reduces to only approximately 9,000 DM. Increased wages reduce the deficit further while the deficit increases with a loss of functions of the electronic patient record. However, several benefits of electronic records regarding research, teaching, quality control and better data access cannot be easily quantified and would greatly increase the benefit to cost ratio. CONCLUSION: Only part of the advantages of electronic patient records can easily be quantified in terms of directly saved costs. The small cost deficit calculated in this example is overcompensated by several benefits, which can only be enumerated qualitatively due to problems in quantification.

Cost-Benefit Analysis↗
PubMed2001

[Application of diagnosis related groups (DRGs) in ophthalmology in Germany].

Starting on 01.01.2003 the hospital reimbursement system in Germany will be transferred completely to a diagnosis-related groups (DRG) system based on the data of 2001. As the reimbursement system is of vital importance for the development of a speciality, current information is given about the impact of the new payment system on ophthalmology. The Australian AR-DRG system to be adopted in Germany distinguishes 20 DRGs for ophthalmology. The patients are grouped into the DRGs according to their principal diagnoses and comorbidities and the procedures coded by electronic data processing. Errors in coding and missing data may cause reductions in the hospital budget as do economically inhomogeneous DRGs. The tight timetable given by the legislation requires completion of determining DRG groups and weightings by 31.12.2001. However, important prerequisites such as the mapping tables of the Australian DRGs are still missing, which means that hospitals have to prepare for the new system like a pilot flying blind with no instruments.

Cost Control↗
PubMed2001

[Cornea donation. Factors influencing consent].

BACKGROUND: The purpose of the study was to determine factors that influence the decision of the next living relative of a deceased for consent on cornea donation. METHODS: The interviews with the relatives of 94 potential cornea donors of the Eye Bank of the Ludwig-Maximilians-Universität, Munich were analysed. The influence of sociological factors on the frequency of obtained consent was investigated. RESULTS: During a 3-month-period, 77 relatives of 94 possible donors were asked for consent to cornea donation and 56 consents (73%) and 21 refusals (27%) were obtained. In 17 (18%) of the cases the relatives could not be reached. Analysis showed a higher consent rate for donors with a university degree (82%) versus those without (71%). Consent was more often obtained for donors who were divorced (88%) than from those who were single (62%). Children of full age (83%) consented more frequently to cornea donation than husbands and wives (78%) or the parents of the deceased (60%). Examination of the postal codes of the residential area indicated more frequent refusals for donors from the rural (54% consent rate) than the urban Munich population (77% consent rate). The situation was the opposite for the residential area of the consenting relative where there was a higher willingness to donate in cases of suicide (93%) in contrast to other causes such as natural deaths (78%) and traffic accidents (71%). CONCLUSION: Socio-economic factors such as education, marital status, residential area and situational factors such as the cause of death, play an important role on the willingness to consent to donate. This study can improve the understanding of the donor family's decision making and as such help the physician asking for consent and improve information to the public which may increase the number of cornea donors in Germany.

Adolescent↗
PubMed2001

Central corneal thickness measurement with a retinal optical coherence tomography device versus standard ultrasonic pachymetry.

PURPOSE: To demonstrate the capability of a standard, commercially available optical coherence tomography device (originally designed to measure retinal thickness) to image the human cornea in vivo and to measure central corneal thickness (CCT) in normal and edematous corneas. The intrapatient precision and interpatient variability of this novel application was compared to standard ultrasonic pachymetry. Also, the correlation of both methods was investigated. METHODS: CCT measurements using optical coherence tomography (OCT) and ultrasonic pachymetry (PACH) were obtained in 36 normal eyes and 16 eyes with corneal edema. RESULTS: Direct in vivo imaging of the cornea and measurements of CCT by OCT could be performed in all eyes. In normal subjects, CCT(OCT) was 530+/-32 microm and CCT(PACH) was 581+/-34 microm. The two methods showed a highly significant correlation with a standardized regression coefficient of 0.988. The difference between both methods was constant over the range of CCT (mean difference, 49.4+/-5.9 microm). The mean intrapatient SD of CCT measurements was 4.90 microm and 4.96 microm for OCT and PACH, respectively. In patients with corneal edema, mean CCT(OCT) was 601+/-59 microm, and mean CCT(PACH) was 667+/-68 microm. The difference between the two techniques increased slightly with increasing corneal edema (mean difference, 66.9+/-10.9 microm). CONCLUSION: Imaging of the human cornea can be performed by a standard retinal OCT device, and OCT measurement of CCT shows excellent correlation to values obtained by PACH, giving similar readings separated by a constant difference. In corneal edema, the difference between the two methods is additionally increased, but continues to demonstrate excellent consistency.

Adult↗