Biomedical subjects

P Bernth-Petersen

Publications and source records attributed to P Bernth-Petersen.

At least 19 recordsLinked to original sources

PubMed2001

Combined cataract and glaucoma surgery.

The management of cataract in glaucoma patients has been continuously changing over the past decade. Extracapsular cataract extraction has been replaced by small-incision phacoemulsification with foldable lenses, and in glaucoma surgery, adjunctive antifibrotic therapy based on risk factors for failure has become standard. Furthermore, new techniques in filtering and nonfiltering surgery have been suggested. The techniques, however, change so fast that well-controlled studies with a follow-up of more than 12 months are increasingly seldom. The purpose of this paper is to review the current literature and to point out some new ideas for the future investigation.

Antimetabolites↗

PubMed1999

Intraoperative clinical practice and risk of early complications after cataract extraction in the United States, Canada, Denmark, and Spain.

OBJECTIVE: To examine variation in intraoperative clinical practice and rates of adverse events after cataract surgery across four different healthcare systems. DESIGN: Multicenter cohort study. PARTICIPANTS: Patients were recruited from ophthalmic clinics in the United States (n = 75); in the Province of Manitoba, Canada (n = 12); in Denmark (n = 17); and the City of Barcelona, Spain (n = 10). In all, 1420 patients undergoing first eye cataract surgery were enrolled, with preoperative, perioperative, and postoperative clinical data collected on 1344 patients (95%). MAIN OUTCOME MEASURES: Occurrence of 23 specified intraoperative and early postoperative adverse events was measured. Four-month postoperative visual acuity outcome also was measured. RESULTS: Phacoemulsification was performed in two thirds of the extractions in the United States and Manitoba, in one third in Denmark, and in 3% in Barcelona (P < 0.001). More than 96% of extractions in North America and Denmark were performed with the patient under local anesthesia, whereas general anesthesia was used for 38% of extractions in Barcelona (P < 0.001). Rates of intraoperative adverse events were 11% to 12.8% in Manitoba, Denmark, and Barcelona and significantly lower in the United States (6%), mainly because of a lower rate of capsular rupture (P < 0.01). Significantly higher rates of early postoperative events were seen in the United States (18.8%) and Manitoba (20.4%) compared to Denmark (7.9%) and Barcelona (5%) (P < 0.001). The differences among sites in rates of events could not be explained by differences in recorded patient characteristics or surgical techniques. The occurrence of perioperative events was significantly associated with a worse 4-month visual outcome. CONCLUSION: The observed variation in clinical practice might represent a general trend of a slower diffusion of new medical technology in Europe compared with that of North America. Rates of intraoperative and early postoperative events varied significantly across sites.

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PubMed1998

Visual outcomes of cataract surgery in the United States, Canada, Denmark, and Spain. Report From the International Cataract Surgery Outcomes Study.

OBJECTIVE: To compare visual outcomes obtained following cataract surgery in 4 sites in North America and Europe where considerable differences in the organization of care and patterns of clinical practice have been previously described. METHODS: Patients scheduled for first eye-cataract surgery and aged 50 years or older were enrolled consecutively in a prospective multicenter study that collected clinical and patient interview data preoperatively and postoperatively. From the United States, 772 patients were enrolled; from the Province of Manitoba (Canada), 159; from Denmark, 291; and from the City of Barcelona (Spain), 200. Preoperative and 4-month postoperative visual acuity was obtained for 92% of the patients (n = 1291). RESULTS: The mean 4-month postoperative visual acuity of eyes operated on varied significantly across the 4 sites (P < .001) and had the following Snellen decimal fraction measurements: 0.49 in Barcelona, 0.65 in Denmark, 0.66 in Manitoba, and 0.74 in the United States. However, while crude visual acuity outcome figures varied significantly, no significant difference was observed across the 4 sites regarding the risk of poorer visual outcome after controlling for differences in age, preoperative visual acuity, and general health status for patients with no ocular comorbidity. Older age, poorer preoperative visual acuity, poorer preoperative general health status, and coexisting ocular comorbidity were predictors of a poorer visual outcome. CONCLUSION: A previously identified variation in treatment modalities across the 4 sites did not seem to affect patients' visual acuity outcomes.

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PubMed1998

Cross-cultural differences in the reporting of global functional capacity: an example in cataract patients.

OBJECTIVES: Patient-based health status measures have an important role to play in the assessment of health care outcomes. Among these measures, global assessments increasingly have been used, although the understanding of the performance of these indicators and the determinants of patients responses is underdeveloped. In this study, the performance of a single-item global indicator of visual function in cataract patients of four international settings was compared. METHODS: Visual acuity and ocular comorbidity was assessed by patients' ophthalmologist using Snellen-type charts in patients referred for a first cataract surgery in the United States, Manitoba (Canada), Denmark, and Barcelona (Spain). Patients also were interviewed by telephone and asked to report overall trouble with vision on a single-item indicator ("great deal," "moderate," "a little," "none") and to complete the Visual Functioning Index (VF-14), a scale of visual function ranging from 0 (worst function) to 100 (best level of function), along with other questions including the degree the patient was bothered by symptoms as measured by the Cataract Symptom Score (CSS). A total of 1,407 patients completed the clinical examination and the preoperative interview. RESULTS: Distribution of overall trouble with vision varied across the sites, with the proportion of patients reporting a great deal of trouble ranging from 21.7% to 37.9%. In all sites, patients reporting more trouble with vision tended to show a poorer age-adjusted and sex-adjusted visual acuity. The proportion of patients reporting great deal of trouble with vision was higher in the groups with worse visual acuity (P < 0.001). In multivariate analysis, after controlling for clinical and sociodemographic factors, the patients from Manitoba (OR = 0.32, 95% CI = 0.20, 0.51) and those from Barcelona (OR = 0.33, 95% CI = 0.20, 0.56) were less likely to report a great deal of trouble with their vision (P < 0.01) than the Danish and US patients. No such differences were found among the US patients from three sites. CONCLUSIONS: There is international variation in the self-reporting of global vision-related functional capacity that is not explained by clinical or sociodemographic factors, which may be because of cultural differences. International comparisons of patient-based health outcomes should not rely only on single-item indicators until there is convincing evidence of their cross-cultural equivalence.

Activities of Daily Living↗

PubMed1998

Variation in indications for cataract surgery in the United States, Denmark, Canada, and Spain: results from the International Cataract Surgery Outcomes Study.

BACKGROUND/AIMS: International comparisons of clinical practice may help in assessing the magnitude and possible causes of variation in cross national healthcare utilisation. With this aim, the indications for cataract surgery in the United States, Denmark, the province of Manitoba (Canada), and the city of Barcelona (Spain) were compared. METHODS: In a prospective multicentre study, patients scheduled for first eye cataract surgery and aged 50 years or older were enrolled consecutively. From the United States 766 patients were enrolled; from Denmark 291; from Manitoba 152; and from Barcelona 200. Indication for surgery was measured as preoperative visual status of patients enlisted for cataract surgery. Main variables were preoperative visual acuity in operative eye, the VF-14 score (an index of functional impairment in patients with cataract) and ocular comorbidity. RESULTS: Mean visual acuity were 0.23 (USA), 0.17 (Denmark), 0.15 (Manitoba), and 0.07 (Barcelona) (p < 0.001). When restricting the sample to eyes with normal retina and macula, no significant difference between United States and Denmark was observed (p > 0.05). Mean VF-14 scores were 76 (USA), 76 (Denmark), 71 (Manitoba), and 64 (Barcelona) (p < 0.001). CONCLUSION: Similar indications for cataract surgery were found in the United States and Denmark. Significantly more restricted indications were observed in Manitoba and Barcelona. Possible explanations for the results are discussed, including differences in sociodemographic characteristics, access to care, surgeons' willingness to operate, and patient demand.

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PubMed1997

International variation in ophthalmologic management of patients with cataracts. Results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in the management of patients with cataacts in 4 health care systems and to discuss the potential implications for cost and utilization of services. DESIGN: To characterize current clinical practice on patients with no coexisting medical or ocular conditions, a standardized questionnaire was sent to random samples of ophthalmologists in the United States (response rate, 82.5%), Canada (66.9%), and Barcelona, Spain (70.4%), and to all ophthalmologists in Denmark (80.1%). From the United States, 526 ophthalmologists who performed cataract surgery participated in the study; there were 276 from Canada, 89 from Barcelona, and 82 from Denmark. RESULTS: Although in all 4 sites most surgeons reported that they performed A-scanning, fundus examination, and refraction routinely before surgery, significant crossnational variation was observed in preoperative ophthalmic and medical testing. While preoperative medical tests were virtually unused in Denmark, they were widely used in the other sites. A significantly higher proportion of the surgeons in the United States and Barcelona reported that they performed less than 100 extractions per year compared with surgeons in Canada and Denmark (P < .001). A significantly higher proportion of the surgeons in the United States and Canada were performing predominantly phacoextraction compared with surgeons in Denmark and Barcelona (P < .001). Both within and across sites, considerable variation in number of follow-up visits and postoperative tests was observed. CONCLUSIONS: Significant international variation in the management of healthy patients with cataracts has been observed. If less intensive care is not associated with poorer outcomes, there is the potential for less costly care of patients with cataracts. Further research identifying the most cost-effective practices is needed.

Adult↗

PubMed1997

International variation in anesthesia care during cataract surgery: results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in anesthesia care and monitoring during cataract surgery and to discuss its implications for cost and safety. METHODS: A standardized questionnaire was sent to random samples of ophthalmologists in the United States, Canada, and Barcelona, Spain, and to all ophthalmologists in Denmark. The survey was conducted in 1993 and 1994. Certified ophthalmologists who had performed 1 or more cataract extractions in the previous year were eligible for enrollment. RESULTS: The response rates were 62% in the United States (n=148), 67% in Canada (n=276), 70% in Barcelona (n=89), and 80% in Denmark (n=82). The anesthetic technique for cataract surgery varied significantly between sites (P<.001). Surgeons reported that retrobulbar blocks were used for 46% of the cataract extractions in the United States, 70% in Canada, 66% in Denmark, and 31% in Barcelona. In Barcelona, general anesthesia was used for 23% of the cataract extractions; it was used for less than 3% of the extractions at the other 3 sites. Peribulbar blocks or topical anesthesia was used for the remaining extractions. In the United States, Canada, and Barcelona, surgeons reported that vital functions were monitored during more than 97% of the extractions and anesthesia surveillance was used during more than 78% of the extractions. In Denmark, ophthalmologists reported that vital functions were monitored and anesthesia surveillance was used for 1% of the cataract extractions (P<.001). CONCLUSIONS: Substantial international variation in anesthesia care and monitoring during cataract surgery was observed. The findings suggest a need for further research to determine whether less intensive monitoring is cost-effective.

Anesthesia↗

PubMed1997

International applicability of the VF-14. An index of visual function in patients with cataracts.

PURPOSE: There is increased recognition that a rigorous approach to functional assessment should complement the assessment of clinical status. The authors compare the reliability, validity, and responsiveness to clinical change of a visual function index (VF-14) in non-U.S. and in U.S. patients with cataracts. DESIGN: An observational longitudinal study was performed. PARTICIPANTS: One thousand four hundred seven first eye cataract surgery patients were recruited in four international sites: Manitoba (Canada), Denmark, Barcelona (Spain), and the United States. INTERVENTION: Patients were evaluated before cataract surgery and at a 4-month postoperative follow-up visit. Patients completed the preoperative interview and the clinical examination (766 in the United States, 152 in Manitoba, 291 in Denmark, and 198 in Barcelona), and 91.3% of those (1284) also completed the 4-month postoperative follow-up interview and were evaluated postoperatively by an ophthalmologist. MAIN OUTCOME MEASURES: The authors used the following measures: the visual function index (VF-14), the Sickness Impact Profile (SIP), global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity (VA) in each eye. RESULTS: The VF-14 showed a high internal consistency reliability level in all sites (Cronbach's alpha coefficients > or = 0.84). Correlation of preoperative visual function index scores with the Vision-Related SIP was strong (r = -0.68 in non-U.S. and r = -0.57 in U.S. patients) and with VA in the eye with better vision was moderate (r = 0.40 and r = 0.27, respectively), the pattern of relationships being very similar among U.S. and non-U.S. patients. In patients with only first-eye surgery who reported that their initial trouble with vision had improved, the amount of change in visual function as assessed by the VF-14 (effect size) was large (1.01 for the non-U.S. patients and 1.17 for the U.S. patients). CONCLUSIONS: The non-U.S. versions of the visual function index (VF-14) analyzed are as reliable, valid, and responsive to clinical change as the original U.S. version. These versions are appropriate for international studies of cataract patients outcomes and possibly in routine clinical practice.

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PubMed1997

Risk of endophthalmitis after cataract extraction: results from the International Cataract Surgery Outcomes study.

AIM: To estimate risk of infectious endophthalmitis after cataract extraction in Denmark and to compare results with the risk of this complication in the USA. METHODS: In the national Danish administrative hospital register, 19,426 patients were identified who underwent first eye cataract surgery from 1985 to 1987 and who were 50 years of age or older. Of these, 61 patients had postoperative endophthalmitis. RESULTS: A 12 month cumulative risk of rehospitalisation for endophthalmitis was estimated at 0.18% (95% CI 0.09-0.26) after extracapsular cataract extraction with lens implant. Advanced age, male sex, intracapsular cataract extraction, and anterior vitrectomy were all associated independently with an increased risk of postoperative endophthalmitis. When restricting the sample to patients aged 65 years or older, in order to allow comparisons to be made with the US National Study of Cataract Outcomes, a 12 month risk of 0.17% (95% CI 0.08-0.25) was estimated. The previously reported US risk of 0.12% is included in the confidence interval of the risk estimated in the Danish sample. CONCLUSION: Despite considerable differences in the healthcare systems, no statistically significant difference in outcome of surgery as measured by risk of endophthalmitis was shown between Denmark and the USA.

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PubMed1996

Visual impairment and general health among Danish cataract patients. Results from the Danish Cataract Surgery Outcomes Study. I.

This Danish multicenter study was undertaken to evaluate current indications for cataract extraction and to compare the heath status among patients enlisted for cataract surgery with that reported for the background population. A consecutive sample of 290 patients from all ophthalmic hospital departments in Denmark was examined and interviewed prior to cataract extraction. The mean visual acuity in the eye enlisted for surgery was 0.17. A visual acuity of < 0.05 occurred in 11.1% and 46.7% had a visual acuity of > or = 0.05 to 0.3. Comparing these figures to other recent European studies it seems reasonable to conclude that in Denmark surgery is performed at an earlier stage of the disease. Only a few patients with no functional impairment were seen; other appropriate indications for surgery were seen for these patients. Occurrence of angina, bronchitis and prior myocardial infarction was higher in the cataract sample as compared to the random sample of Danes. The likelihood of preferring an outpatient procedure was significantly increased among younger patients, patients of better general health and among patients with better pre-operative visual acuity in eye enlisted for surgery.

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PubMed1996

Changing threshold for cataract surgery in Denmark between 1980 and 1992. Results from the Danish Cataract Surgery Outcomes Study. II.

In Denmark the number of cataract extractions has increased 350% from 1980 to 1991. During the same period the elderly population at risk has only increased 17%, and thus cannot account for the large increase in the number of extractions. In order to investigate whether more comprehensive clinical indications could be a possible explanation, we compared pre-operative visual acuity and visual impairment in two consecutive samples of Danish cataract surgery patients obtained in 1980 (n = 73) and in 1992 (n = 290). Criteria for inclusion were similar and both samples were representative for the whole country. During the period mean pre-operative visual acuity increased from 0.04 to 0.16 in the eye enlisted for surgery (p < 0.00001). Visual functional impairment could be compared by using the same questionnaire for patient interview in 1992 as was used in 1980. In 1992 the degree of impairment was significantly less for reading, outdoor orientation and self care activities. A change in surgical threshold or clinical indications for surgery appears to be a major contributing factor to the large increase in surgical rates, even though a trend to perform second eye cataract surgery more often might also be of some importance.

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PubMed1996

Risk of retinal detachment following cataract extraction: results from the International Cataract Surgery Outcomes Study.

AIMS: To estimate the risk of retinal detachment (RD) following cataract extraction in Denmark, and to compare the risk with that following cataract extraction in the USA, and with that in a sample of Danish patients who did not have ocular surgery. METHODS: A sample was created from the administrative Danish Hospital Register and included 19,252 patients who underwent first eye cataract surgery between 1985 and 1987, and who were 50 years of age or older. The patients were then followed for 4-6 years using the register data. The design and definition of events were identical to the US National Study of Cataract Outcomes. RESULTS: In Denmark a 4 year cumulative risk of hospitalisation for RD of 0.93% (95% confidence interval (CI) 0.71-1.16) was observed following an extracapsular cataract extraction with a lens implant. A similar cumulative risk of RD was reported from the US study. Thus, no difference in outcomes concerning risk of RD was shown between Denmark and the USA. In a multivariate analysis younger age, male sex, and intracapsular cataract extraction were all associated with higher risk of postoperative RD. A reference group of 7636 people not undergoing any ocular surgery was created and the incidence of RD in this group was calculated. During the sixth year following cataract surgery, the incidence of RD in the cataract group was still 7.5 (95% CI 1.6-22.0) times higher than that observed in the reference group.

Age Factors↗

PubMed1985

Regional variation in indications for cataract surgery? An analysis of the pre-IOL period.

A comparison of indications for cataract surgery in 3 major clinics was done. These clinics serve the population of 3 Danish counties for which the standard operation ratio previously has been shown to be below average, average and above average. Evaluated on basis of pre-operative visual acuity in both eyes, no differences in the indications were found between the 3 clinics. Other possible determinants of rate variation might be differences in doctors' and patients' attitude towards cataract treatment, variation in cataract prevalence and in ophthalmic service supply.

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PubMed1985

Cataract surgery. Outcome assessments and epidemiologic aspects.

Part one defines the topics and study purposes. The 12 studies reviewed in this survey focuses on following 3 topics of which the current knowledge is very limited: Assessment of outcome of cataract surgery (effectiveness studies). Pre-operative prediction of outcome of cataract surgery. Epidemiologic aspects of cataract surgery. These three topics were chosen as study objectives because more accurate knowledge of these points is necessary to assure a better cataract treatment in future, and as a basis for securing sufficient resource allocation to cataract surgery in the public health care. Each topic will be treated separately in the following 3 parts. Part two concerns the effectiveness studies on cataract surgery (publ. I-VI). Primary, a visual functioning index is presented and evaluated. The index is meant as a new supplementary tool for evaluation of the rehabilitation effect. This index, together with visual acuity and other outcome evaluators, was then used for assessment of the effectiveness of cataract extraction generally and in different sub-groups, supplemented with quantitative assessment of rehabilitation problems and analysis of outcome predictors. In a consecutive series of patients, in which intraocular lenses were not used, it was found, that 82% of the patients obtained a final visual acuity of 0.5 or better and 74% of the patients had normal or near normal basic visual functioning at one year follow-up. In spite of these good results, the rehabilitation of these aphakics were difficult. The difference between the two figures above represents some of the 'aphakic vision cripples' with severe difficulties of adaptation to aphakic spectacles. 26% of cataract extracted patients in a normal consecutive group were found to be dissatisfied with the outcome. Two main reasons for dissatisfaction were found: macular disease and low quality of vision with aphakic spectacles, especially in monaphakics, of which 75% had complaints about vision. Although monaphakics nearly reach the same level in basic functioning as the biaphakics, the latter are much more satisfied. It seems likely that basic visual functioning is gained by first eye surgery and more delicate visual functioning and a subjective 'visual comfort' is obtained by second eye surgery. Adaptation to aphakic spectacles seem to be far less difficult for the biaphakics. In series of patients rehabilitated with intraocular lenses or extended-wear contact lenses, the monaphakics appear to have a generally better visual functioning and they are much more satisfied with outcome than spectacles corrected monaphakics.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1983

Epidemiologic aspects of cataract surgery. I. Trends in frequencies.

A 51% increase in number of cataract extractions during the period 1970-79 is found. Neither population growth nor changes in age structure could alone account for this increase. Other factors such as economic resource allocation, changes in indications for cataract surgery and increased demand appear to be involved in this increase. Two large danish data sources were examined to determine the age and sex specific cataract extraction rates 1977-79. These rates are found to be in part equivalent to rates reported from England but substantially lower than rates found in USA. The age and sex specific rates are used as basis for estimation of number of extractions year 2000. A 60 to 80% increase is likely because of population growth in the older age groups, extention of indications for cataract surgery and more demand for good vision in old age.

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PubMed1983

Intraocular lenses versus extended-wear contact lenses in aphakic rehabilitation. A controlled clinical study.

A controlled clinical study with random allocation of method of rehabilitation (lens implant or contact lenses) was designed for comparative outcome assessments. Sixty-one patients were included in the study: 31 patients randomized to lens implantation and 30 patients to extended-wear contact lens rehabilitation with early post-operative fitting. Complication rates were low in both groups with slight accumulation of intraocular complications in the implant group and of external complications in the contact lens group. We found no significant differences between the groups in final visual acuity, in vision dependent practical functioning, or in patients' contentment. Two main points summarize our results and impressions from this study: At the expense of a slightly higher risk the lens implant patients get the most convenient and comfortable rehabilitation and at the expense of frequent visits for follow-up and lens cleaning the contact lens patients get the safest rehabilitation. The patient offered contact lens rehabilitation should be capable of alert cooperation, fairly mobile and living within easy access to ophthalmic service, while the patient offered lens implant does not need to fulfill these criteria.

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PubMed1983

Cataract extraction in the 'nineties'.

A total of 55 cataract extractions were performed on 53 patients aged 90 years or more in the period 1972 to 1982. Assessment of the outcome was based on data from hospital records and on questionnaires to the patient's ophthalmologist and general practitioner. Cataract surgery had improved visual acuity in 42 patients. Only 25 patients (47%) could, however, utilize the improved visual acuity, and obtain some practical benefit from the cataract extraction. Thus, the benefits of cataract surgery seem to be reduced in this age group. The reasons appear to be a high frequency of severe macula degeneration, some degree of senility hindering the adaptation to aphakic spectacles, and a somewhat higher frequency of per- and post-operative complications. This suggests that indications for cataract surgery in very old patients should be limited, at least if rehabilitation with aphakic spectacles is planned. An earlier surgical intervention would probably have been advantageous in the majority of these patients.

Age Factors↗

PubMed1983

Epidemiologic aspects of cataract surgery. II: Regional variation in frequencies.

A large data source was examined to determine age and sex specific cataract extraction rates in different counties and urbanization areas in Denmark. Significant regional variation in surgical rates could be demonstrated in spite of a comprehensive Public Health Service System. When comparing rates in different urbanization areas and in towns with and without ophthalmologists, we found the lowest surgical rates in areas or towns short of ophthalmic service. However, a direct correlation could not be found between standard operation ratio and ophthalmic surgeon/ophthalmic bed supply on county level. The reason might be that cataract extraction rates are influenced by a number of other factors, as cataract extraction has become an elective surgical procedure.

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