Decreasing rate of capsule complications in cataract surgery: eight-year study of incidence, risk factors, and data validity by the Swedish National Cataract Register

Purpose: To define the incidence of capsule complication and its risk factors in Sweden over an 8-year period.

Setting: Fifty-two ophthalmic surgery units in Sweden.

Design: 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.

Conclusion: The incidence of capsule complications decreased over time. This may be partly the result of fewer risk factors and of better surgical quality.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.