title: Decreasing rate of capsule complications in cataract surgery: eight-year study of incidence, risk factors, and data validity by the Swedish National Cataract Register.
abstract: OBJECTIVE
  To define the incidence of capsule complication and its risk factors in Sweden over an 8-year period.
  
  
  METHODS
  Fifty-two ophthalmic surgery units in Sweden.
  
  
  METHODS
  Database study.
  
  
  METHODS
  Data were collected prospectively in the Swedish National Cataract Register (NCR) from 2002 through 2009. The NCR contains 97.3% of the total number of cataract extractions in Sweden over the 8-year study period. One mandatory variable in the register is capsule complications during surgery. As a means to validate the accuracy of register data on capsule complications, a randomly selected sample of 2400 registrations was compared with corresponding medical records.
  
  
  RESULTS
  The analyses were based on 602,553 cataract extractions reported to the NCR. A capsule complication was reported in 12,574 cataract extractions, corresponding to a frequency of 2.09%. The incidence of this complication consistently decreased each year from 2002 to 2006, after which it stabilized. Poor corrected distance visual acuity in the surgical eye (≤ 0.1), the occurrence of glaucoma, diabetic retinopathy, and age were among the parameters significantly related to a capsule complication. Some of these parameters also decreased over time. However, even after adjusting for this, there was an obvious decrease in capsule complications over time. The validity test showed a certain underreporting of capsule complications to the registry, but it was not significant and did not change over time.
  
  
  CONCLUSIONS
  The incidence of capsule complications decreased over time. This may be partly the result of fewer risk factors and of better surgical quality.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: EyeNet Sweden, Blekinge Hospital, Karlskrona, Sweden. mats.lundstrom@ltblekinge.se
authors.forename: Mats
authors.initials: M
authors.lastname: Lundström
authors.forename: Anders
authors.initials: A
authors.lastname: Behndig
authors.forename: Maria
authors.initials: M
authors.lastname: Kugelberg
authors.forename: Per
authors.initials: P
authors.lastname: Montan
authors.forename: Ulf
authors.initials: U
authors.lastname: Stenevi
authors.forename: William
authors.initials: W
authors.lastname: Thorburn
mesh_terms: D000368:Aged; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications; D007905:Lens Diseases / Q000453:epidemiology* / Q000209:etiology; D019654:Lens Implantation, Intraocular; D008297:Male; D018918:Phacoemulsification; D057852:Posterior Capsule of the Lens / Q000473:pathology*; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014792:Visual Acuity