Authors: Harold W. Climenhaga

Author Disclosure Block: H.W. Climenhaga: None.

Abstract Body:
Purpose: to establish a reference complication rate for cataract surgery when performed by an experienced surgeon and adjusting for known pre-operative risk factors 

Study Design: Prospective Cohort Study 

Methods: Between 31 July 2009 and 27 May 2016 all cataract surgeries carried out by one surgeon (n=16,984) were pre-operatively classified by risk factor(s) and all adverse surgical outcomes were recorded. (Health Research Ethics approval was obtained - #Pro00061598.) 

Results: Posterior Capsular Tear with or without vitrectomy occurred at the following rates: No risk factors - 0/13,241 (0.0%); Resident (no other risks) - 3/66 (4.5%); Tamsulosin use - 0/1144 (0.0%); “Small” pupil - 1/1144 (same case as the next two lines) (0.09%); Mechanical pupil expanders (subset of small pupils) - 1/542 (0.18%); Pseudoexfoliation/PXF other eye -1/691+131=822 (0.12%); “Dense” nuclear sclerosis - 0/614 (0.0%); Prior Vitrectomy/trauma - 6/230+81=311 (1.9%); Mature white cataract - 4/222 (1.8%); Posterior Polar Cataract - 2/27 (7.4%). Anterior Capsular Tears occurred in nine cases, three of which had no risk factors. In 8/9 cases the IOL was placed in the capsular bag and in 1/9 in the sulcus. Zonular loss without capsular damage occurred in five pseudoexfoliation cases, four trauma cases and one idiopathic lens subluxation visible pre-operatively. 

Conclusions: The normal complication rate for cataract surgery in the absence of identifiable risk factors approaches zero. All complications should be considered avoidable. New technologies in cataract surgery need to be evaluated based on the quality of the visual outcome - there can be no safety advantage. Reporting complication rates in the absence of sorting by risk factor is of limited utility. I suggest classifying risk factors by the associated surgical skills: small pupil, weak zonules, dense nuclear sclerosis, mature white, other.