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.

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.

[Indications for cataract surgery in Denmark in 1980 and 1992. Results from the Danish Cataract Surgery Outcomes Study]. / Indikationer for kataraktkirurgi i Danmark i 1980 og 1992. Resultater fra the Danish Cataract Surgery Outcomes Study.

In Denmark the number of cataract extractions has increased to 350% from 1980 to 1991. During the same period the elderly population at risk has only increased to 117%, 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 = 270). 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 < 0.001). 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.

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.

[Conjunctival nevi in Denmark 1960-1980. A 21-year follow-up]. / Konjunktivale naevi i Danmark 1960-1980. Enogtyve års followup.

The clinicopathological characteristics of 343 naevi of the conjunctiva were studied. A significant increase in the number of naevi excised per year was observed. This may have been caused by an increased exposure to actinic rays. An approximately even distribution was found between the three main locations: caruncle, limbal area and eye ball. Intrastromal naevi were excised at a higher median age than compound naevi, and the lowest median age at excision was for junction naevi, which is in accordance with the known histopathological nature of naevi. Recurrence occurred in nine patients (2.7%), and one had transformed into a malignant melanoma. Eight of the recurring naevi were located in the limbal area. Eight of the nine patients were women, suggesting hormonal factors as a possible cause. Recommendations for the handling of conjunctival naevi are given, based on the present findings and on previous reports.

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.

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.

Patients' acceptance of waiting for cataract surgery: what makes a wait too long?

The patient's perspective about waiting for elective surgery is an important consideration in the management of waiting lists, yet it has received little attention to date. This study was undertaken to assess the acceptability of personal waiting times from the perspective of patients, and to examine waiting time and patient characteristics associated with the perception that a wait for cataract surgery is too long. The international prospective study was conducted in three sites with explicit waiting systems: Manitoba, Canada; Denmark; and Barcelona, Spain. Patients over the age of 50 years were recruited consecutively from ophthalmologists' practices at the time of their enlistment for first-eye cataract surgery. Anticipated waiting time, opinions about personal waiting time, and patients' visual and health characteristics were identified by means of telephone interviews. The 550 patients interviewed at the time of enlistment for surgery anticipated waits varying from < 1 to 24 months. Clinical visual acuity measures were obtained from patients' ophthalmologists/cataract surgeons. Results indicated that anticipated waiting time was the strongest predictor of patients' tolerance of waiting for cataract surgery. Patient dissatisfaction increased with the duration of the anticipated wait. Patients in all three sites were accepting of waits of three months or less, and considered waits exceeding six months to be excessive. Response to waits between three and six months varied across study sites. Patients with low tolerance for waiting had greater self-reported difficulty with vision, as assessed by a Cataract Symptom Score and expressed trouble with vision. Patients' acceptance of waiting was not associated with clinical visual acuity measures or socio-demographic characteristics. The patient perspective on acceptability of waiting times for cataract surgery suggests that restricting waiting times to less than six months and preferably less than three months and utilizing self-reported measures of visual difficulty in prioritizing patients may contribute to improved management of waiting systems. Patients are more tolerant of their personal waiting times than responses to questions about waiting for elective surgery in general would indicate, and appear to accept waiting times that are longer than those identified as reasonable by specialists.

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.

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.

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.

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.

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.

Malignant melanoma of the conjunctiva: occurrence and survival following surgery and radiotherapy in a Danish population.

PURPOSE: To describe patient characteristics, risk of recurrence, and survival in patients with premalignant and malignant melanocytic lesions of the conjunctiva. METHODS: In a retrospective study, 55 cases with a minimum follow-up of 10 years were reviewed. RESULTS: The actuarial 5-and 10-year survival rates were 86% (95% Cl: 76-96%) and 73% (95% Cl: 60-87%) respectively. The 5-year risk of local recurrence was 35% (95% Cl: 21-49%), and the 10-year risk was 43% (95% Cl: 28-58%). Primary acquired melanosis with atypia was the first manifestation in 13 cases, malignant melanoma in 42 cases. No significant difference in survival and recurrence was found between the two groups or by gender, location of primary lesion, histological characteristics, or extent of surgical procedure. A minimum incidence of 0.052 cases a year per 100 000 in Denmark was calculated. CONCLUSION: The results are estimated to represent a nationwide sample of patients. No prognostic factors of significance were identified.

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.

Conjunctival naevi in Denmark 1960-1980. A 21-year follow-up study.

The clinicopathological characteristics of 343 naevi of the conjunctiva were studied. A significant increase in the number of naevi excised per annum was observed. This may have been caused by an increased exposure to actinic rays. Approximately even distribution in the three main locations: caruncle, limbal area and eyeball, was found. Intrastromal naevi were excised at a higher median age than compound naevi, and the lowest observed median age at excision was for junction naevi, which is in accordance with the known histopathological nature of naevi. Recurrence occurred in nine patients (2.7%), and one transformed to a malignant melanoma. Eight of the recurring naevi were located in the limbal area. Eight of the nine patients were women, suggesting hormonal factors as a possible cause. Recommendations for the handling of conjunctival naevi are given, based on the present findings and on previous reports.