Cataract Surgery Volumes and Complications per Surgeon and Clinical Unit: Data from the Swedish National Cataract Register 2007 to 2016

Abstract

To investigate the change in proportion of high-volume cataract surgeons during the period 2007 to 2016 and determine the impact of operation volume per surgeon and clinical unit on the rate of capsule complications. Retrospective, register-based study. Patients undergoing and surgeons performing cataract surgery at Swedish ophthalmologic departments 2007-2016. All cataract procedures performed during a 10-year period were analyzed, and the change in operation volume of individual surgeons over time was determined. The yearly incidence of capsule complications was correlated to the operation volume of individual surgeons and clinical units. The number of cataract procedures yearly per surgeon and clinical unit, proportion of capsule complications, and change over time in operation volume and complication rate. The proportion of high-volume (≥500 procedures yearly) and very high-volume (≥1000 procedures yearly) surgeons increased from 15.0% to 34.0% and 2.1% to 10.9%, respectively (P < 0.001 for both categories). The proportion of all cataract procedures performed by high-volume surgeons was 36.9% in 2007, increasing to 68.1% in 2016. The yearly incidence of capsule complications decreased with increasing number of procedures; from a mean of 2.15% (standard deviation [SD], 3.17) for low-volume surgeons (10-99 procedures/year) to 1.32% (1.28) for medium-volume (100-499 procedures/year) surgeons and 0.59% (0.49) for high-volume surgeons (P= 0.016). Preoperative best-corrected visual acuity was significantly better in eyes operated on by high-volume and very high-volume cataract surgeons; the median best-corrected visual acuity (BCVA) was 0.5 (decimal) compared with a BCVA of 0.4 for patients who had their surgery performed by low- or medium-volume surgeons (overall P < 0.001). No significant difference in rate of capsule complications was seen between clinical units with high or low operation volume (P= 0.804). The overall incidence of capsule complications decreased gradually from 1.5% in 2007 to 0.8% in 2016, and preoperative BCVA increased from 0.46±0.10 (logarithm of the minimum angle of resolution) to 0.40±0.05 (P= 0.030). There is a strong association of rate of capsule complications with operation volume of individual surgeons but not with operation volume of individual clinical units. The decreased rate of capsule complications seen between 2007 and 2016 may be explained in part by a dramatic increase in the proportion of high-volume cataract surgeons during the period.