Peter Bernth-Petersen

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.

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.

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.

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.