Jens Christian Norregaard

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.

Endothelial cell damage after cataract surgery: divide-and-conquer versus phaco-chop technique.

PURPOSE: To compare endothelial cell damage during cataract surgery performed using the divide‐and‐conquer or phaco‐chop nuclear fracturing technique. SETTINGS: Department of Ophthalmology, Frederiksberg University Hospital, Frederiksberg, Denmark. METHODS: In a prospective study, 60 eyes of 60 patients were randomly assigned to 1 of 2 groups (30 eyes each group) based on the phacoemulsification technique used: phaco chop or divide and conquer. During surgery, phaco time, phaco power, irrigation volume, and grade of nuclear firmness were recorded. The endothelial cell density, variation in endothelial cell size, percentage of hexagonal cells, and central corneal thickness (CCT) were recorded at baseline and 3 and 12 months postoperatively. Sample size was based on a power calculation (power 0.90, P = .05, clinically important difference = 300 cells/mm2). RESULTS: Significantly less phaco power was used during phaco‐chop surgery than during divide‐and‐conquer surgery. Postoperatively, both groups had a significant but equal decrease in cell density. There were no statistically significant changes in variation in endothelial cell size, percentage of hexagonal cells, or CCT. Visual acuity increased significantly and equally in the 2 groups. Higher endothelial cell loss was significantly correlated with shorter axial length. CONCLUSIONS: It has been suggested that the phaco‐chop technique is less harmful to the corneal endothelium than the divide‐and‐conquer technique because it uses less phaco power. The findings did not support this hypothesis as similar and low cell loss was observed in the 2 groups.

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.

Corneal endothelial cell changes associated with cataract surgery in patients with type 2 diabetes mellitus.

Purpose: To investigate the corneal endothelial cell density and morphology in patients with and without diabetes after phacoemulsification with intraocular lens implantation. Methods: A clinical prospective study including 30 patients with type 2 diabetes and 30 control patients without diabetes scheduled to undergo cataract surgery. No difference in preoperative age was observed between the 2 groups (P = 0.90). Sample size was based on a power calculation (power 0.90; P = 0.05). The patients without diabetes had a casual blood glucose test performed to disclose undetected diabetes. The patients with diabetes had a serum glycosylated hemoglobin (HbA1c) test performed to reveal the glycemic control. The endothelial cell density, variation in endothelial cell size (CV), percentage of hexagonal cells, and central corneal thickness (CCT) were recorded at baseline and at 3 months postoperatively. Results: The mean decrease in endothelial cell density at 3 months in the diabetic group was 154 cells per square millimeter (6.2%) and 42 cells per square millimeter (1.4%) in the control group. The difference in cell loss between the 2 groups was significant (P = 0.04). A significant decrease in the percentage of hexagonal cells was also seen in the diabetic group (P = 0.01). There was no statistically significant change in CV or CCT. Visual acuity increased significantly and equally in the 2 groups. Conclusions: The present study reveals a significantly greater loss of corneal endothelial cells in a diabetic group under good glycemic control, compared with nondiabetic group 3 months after phacoemulsification. The morphological changes in the endothelial cells in patients with well-controlled diabetes were not reflected in impaired function as judged by CCT.

Corneal Endothelial Cell Loss After Mitomycin C-augmented Trabeculectomy

PurposeTo determine the effect on the corneal endothelium of mitomycin C (MMC)-augmented trabeculectomy 3 and 12 months after surgery. Patients and MethodsIn a prospective, observational clinical study, 14 eyes of 14 patients with well-established open angle glaucoma were followed for 12 months after MMC-augmented trabeculectomy. We measured the endothelial cell density, the variation in mean cell size, the percentage of hexagonal cells, and the central corneal thickness at baseline and 3 and 12 months postoperatively. ResultsThe mean endothelial cell density was 2525 [standard deviation (SD) 457] cells/mm2 before surgery and 2332 (SD 643) cells/mm2 and 2283 (SD 597) cells/mm2 at 3 and 12 months after surgery, respectively, representing a cell loss of 9.5% (P=0.052) and 10.0% (P=0.027). The cell loss from 3 to 12 months was nonsignificant (P=0.40). After 12 months of follow-up, the variation in mean cell size and the percentage of hexagonal cells had not yet stabilized around the preoperative values. ConclusionsOur results show that significant cell loss occurs during or immediately after MMC-augmented trabeculectomy. However, no progressive cell loss was observed from 3 to 12 months, demonstrating that MMC has no prolonged toxic effect on the corneal endothelium. From 3 to12 months after MMC-augmented trabeculectomy, active endothelial adaptations were taking place.

Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus

Purpose:  To investigate corneal endothelial cell density and morphology in type II diabetic and non‐diabetic patients and to relate potential differences to the glycaemic status.

Corneal endothelial cell changes after cataract surgery in patients on systemic sympathetic α-1a antagonist medication (tamsulosin).

Purpose:  The purpose of this study was to assess the incidence of intraoperative floppy iris syndrome (IFIS) and the morphology of the corneal endothelium after cataract extraction in Caucasian male patients exposed to the α‐1a adrenergic receptor antagonist tamsulosin.

Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions.

Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign prostatic hyperplasia with α‐1a adrenergic receptor inhibitors, especially tamsulosin. The present paper describes the syndrome and discusses its pharmacological background. Several techniques to prevent and to deal with the syndrome are presented.

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.