Are Entry Criteria for Cataract Surgery Justified?

PURPOSE: The German Ophthalmological Society (GOS) recently proposed surgical entry criteria, i.e. 300 cataract surgeries. We herein correlate the surgical hands-on experience with the risk of posterior capsule ruptures in order to assess whether this number is appropriate. METHODS: We identified all cataract operations that had been performed at the University Eye Hospital Freiburg since 1995. For each surgeon, we assigned a running number to his/her procedures in the order they had been performed. Thereafter, we excluded all combined procedures and the second eyes. We then selected the 5475 surgical reports between November 2008 and November 2012 for detailed review. We additionally classified each surgery into low- vs. high- à priori risk for posterior capsule ruptures. We fitted a multifactorial logistic regression model to assess the GOS recommendation of 300 surgeries under supervision. In the low-risk group, we additionally visualized the 'typical' learning curve by plotting the posterior capsule ruptures against the respective rank numbers. RESULTS: The odds ratio for posterior capsule ruptures of 'learning-mode' (one of the respective surgeon's 300 first procedures) vs. the non-learning-mode was 3.8 (p<0.0001). By contrast, classification into the low-risk group lowered the risk of posterior capsule ruptures three fold (p<0.0001). According to the low-risk plot, the surgeons started with a complication rate of 4% and continuously improved towards 0.5% after 1500 operations. Thereafter, the rate increased again and stabilized around one percent. CONCLUSION: The learning curve with respect to posterior capsule ruptures is surprisingly flat. The GOS entry criterion of 300 cataract procedures is therefore most likely justified. Careful selection of low-risk patients for the training surgeons may help in reducing the rate of posterior capsule ruptures during training.