Previous cataract surgery in a defined Swedish population

Increasing incidence of cataract surgery: population-based study

PURPOSE

To estimate the incidence of cataract surgery in a defined population and to determine longitudinal cataract surgery patterns.

SETTING

Mayo Clinic, Rochester, Minnesota, USA.

DESIGN

Cohort study.

METHODS

Rochester Epidemiology Project (REP) databases were used to identify all incident cataract surgeries in Olmsted County, Minnesota, between January 1, 2005, and December 31, 2011. Age-specific and sex-specific incidence rates were calculated and adjusted to the 2010 United States white population. Data were merged with previous REP data (1980 to 2004) to assess temporal trends in cataract surgery. Change in the incidence over time was assessed by fitting generalized linear models assuming a Poisson error structure. The probability of second-eye cataract surgery was calculated using the Kaplan-Meier method.

RESULTS

Included were 8012 cataract surgeries from 2005 through 2011. During this time, incident cataract surgery significantly increased (P<.001), peaking in 2011 with a rate of 1100 per 100 000 (95% confidence interval, 1050-1160). The probability of second-eye surgery 3, 12, and 24 months after first-eye surgery was 60%, 76%, and 86%, respectively, a significant increase compared with the same intervals in the previous 7 years (1998 to 2004) (P<.001). When merged with 1980 to 2004 REP data, incident cataract surgery steadily increased over the past 3 decades (P<.001).

CONCLUSION

Incident cataract surgery steadily increased over the past 32 years and has not leveled off, as reported in Swedish population-based series. Second-eye surgery was performed sooner and more frequently, with 60% of residents having second-eye surgery within 3 months of first-eye surgery.

Risk of late intraocular lens dislocation after cataract surgery, 1980-2009: a population-based study

PURPOSE

To estimate the long-term cumulative risk of late posterior chamber intraocular lens (IOL) dislocation after cataract extraction in a population-based cohort.

DESIGN

Retrospective cohort study and nested case-control study.

METHODS

The records of all residents of Olmsted County, Minnesota, who underwent cataract extraction from January 1, 1980, through May 31, 2009, (14 471 cases in 9577 residents) and who were diagnosed with late posterior chamber IOL dislocation in the same period were reviewed. Cases were identified through the Rochester Epidemiology Project. Three controls chosen from the cataract surgery cohort were matched to each IOL dislocation case by age, gender, and duration of follow-up. Records were reviewed to confirm case status and to ascertain risk factor information. The cumulative risk of IOL dislocation was estimated by using the Kaplan-Meier method. Logistic regression models assessed differences between cases and controls.

RESULTS

We identified 16 cases of late posterior chamber IOL dislocation, 9 with in-the-bag dislocations and 7 with out-of-the-bag dislocations. At 5, 10, 15, 20, and 25 years after cataract extraction, the cumulative risk of IOL dislocation was 0.1%, 0.1%, 0.2%, 0.7%, and 1.7%, respectively. There was no significant difference in the risk of late IOL dislocation after extracapsular cataract extraction when compared with phacoemulsification (P = .21) or between different decades of surgery (P = .92). Pseudoexfoliation and zonular laxity at surgery were associated significantly with late IOL dislocation (P = .01).

CONCLUSIONS

The long-term cumulative risk of late IOL dislocation after cataract extraction was low and did not significantly change over our nearly 30-year study period.

Incidence of cataract surgery from 1980 through 2004: 25-year population-based study

PURPOSE

To estimate sex- and age-specific incidence rates of cataract surgery in a defined United States population and evaluate the change in incidence over time.

SETTING

Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.

METHODS

Rochester Epidemiology Project databases were used to identify all incident cataract surgeries in Olmsted County, Minnesota, residents during the 25-year period from January 1, 1980, through December 31, 2004. Annual incidence rates for each sex and 10-year age group were calculated and adjusted to the 2000 U.S. white population. Change in incidence over time was assessed by fitting generalized linear models assuming a Poisson error structure.

RESULTS

During the study period, 10 245 cataract extractions were performed in 7141 residents of all ages. Overall, the age-adjusted cataract surgery incident rate per 100000 residents was 548 (95% confidence interval [CI], 534-561) for women, 462 (95% CI, 447-478) for men, and 511 (95% CI, 501-521) for all residents. The incidence of cataract surgery increased 500% among women and 467% among men during the study period (P<.001). Overall, the incidence of cataract surgery was highest in residents 70 years and older (3538 surgeries [95% CI, 3322-3764] per 100,000 residents).

CONCLUSIONS

This population-based study found a substantial increase in incident cataract surgery among Olmsted County residents during the 25-year study period. The rate of cataract surgery increased in a nearly linear fashion during a period when phacoemulsification replaced extracapsular cataract extraction in the community.

Duration of self assessed benefit of cataract extraction: a long term study

AIM

To investigate how long patients' improved visual function lasts after a cataract extraction.

METHODS

Patients' self assessed visual function was evaluated using the Catquest questionnaire both before and 6 months after a cataract extraction. The study population consisted of 615 patients undergoing a cataract extraction during 1995-2002. A final follow up with a new questionnaire was performed in 2003, between 1 year and 8 years after surgery.

RESULTS

445 (72.4%) patients were alive at follow up and agreed to participate in the study. The number of subjects still showing improved visual function after surgery decreased with longer follow up. After 7 years, 80% had improved visual function compared with before surgery. 50% of all originally operated subjects were alive 7 years postoperatively and enjoyed better visual function than they had done before surgery. Ocular co-morbidity in the operated eye or self assessed poor visual function before surgery was significantly related to deteriorated visual function at follow up.

CONCLUSION

The number of subjects who experienced improved visual function after a cataract extraction decreased over the course of time postoperatively. Presence of ocular co-morbidity was significantly related to worsened function.

Modeling utility of second-eye cataract surgery

Objectives:To study the impact on public health in terms of utility of various proportions of first-eye and second-eye cataract surgery.

Methods:A model was used to study the impact on a population of a fixed cataract surgical rate (9,250 operations/1,000,000 people) with varying proportions of first-eye and second-eye cataract operations. The study population was the County of Blekinge with a known incidence of previous cataract surgery. The prevalence of cataract, the estimated need for cataract surgery, and the utility values were taken from the literature. The population was grouped by disability stage of cataract and previous cataract surgery in accordance with prevalence studies and data from a large national database on cataract surgery and patients' self-assessed visual function. The mortality rate was taken from real data for the study population.

Results:Given a fixed cataract surgical rate over a period of five years, a high percentage of second-eye cataract surgery (42 percent) resulted in a mean utility of 0.82239 in the population forty years of age and older and the corresponding number for a low percentage of second-eye cataract surgery (25 percent) was 0.82253. A high percentage of second-eye surgeries resulted in 421 more individuals who were well compared with a low percentage of second-eye surgeries. On the other hand, a low percentage of second-eye surgeries resulted in 152 fewer individuals with disability and 118 fewer individuals with dependence compared with a high percentage of second-eye surgeries.

Conclusions:A high frequency of first-eye cataract surgeries instead of second-eye surgeries affects more individuals and means an optimized improvement of utility in a population. This should be recommended if the cataract surgical rate is very insufficient. If the cataract surgical rate is high, more second-eye surgeries should be performed to optimize quality of life to as many as possible.