Frequency of Intraocular Lens Dislocation and Pseudophacodonesis, 20 Years After Cataract Surgery - A Prospective Study

Purpose: To examine the incidence and trends of late intraocular lens (IOL) dislocation/decentration and the frequency of pseudophakodonesis.

Design: Prospective, population-based cohort study.

Methods: A total of 800 patients were examined before cataract surgery in 1997-1998. Twenty years later, 100 of 133 survivors (75%) participated in the follow-up. An eye examination was performed including assessment for pseudophakodonesis and dislocation of the IOL. The medical records of all included patients at baseline were studied. Main outcome measures were previous IOL exchange or repositioning surgery, significant IOL dislocation, degree of pseudophakodonesis, and visual acuity.

Results: Twenty years after the original cataract surgery, 10 of the 800 patients at risk (1.2%) had needed dislocation surgery. Before cataract surgery, 39% of all patients had pseudoexfoliations (PXF). Mean time from cataract surgery to dislocation surgery was 12 years 6 months (range 3 years 9 months to 19 years 3 months). The cumulative incidence over 20 years was 6% in patients with PXF and 2% without PXF at surgery (P = .035). Mean age at cataract surgery in the 10 dislocated cases was 68.3 years (range 58-80). Twenty years after surgery, 5 of 98 (5%) patients had moderate/pronounced pseudophakodonesis.

Conclusions: In this population-based cohort, the 20-year cumulative incidence of IOL dislocation needing surgical attention was significantly higher in patients with PXF than without PXF before surgery. The individual patient seems to have a low risk of being affected by this complication, but dislocated IOLs may cause a relatively large public health care burden, because of the large number of people in society with previous cataract surgery.