Study: Cataract complication rates of residents lower than expected

Oct 23, 2018

Improvement was seen with experience gained, show data from comparative study

Cataract surgeries performed by resident surgical trainees do not appear to be associated with more complications than surgeries performed by staff surgeons.

Reviewed by Rosa Braga-Mele, MD

Cataract surgeries performed by resident surgical trainees do not appear to be associated with more complications than surgeries performed by staff surgeons. That is the conclusion reached by a large study that evaluated almost 9,000 procedures of phacoemulsification cataract surgery. This was the first large comparative study performed in North America.

Considering the estimated 3 million cataract surgeries performed annually in the US, that study was certainly warranted. However, before the study was undertaken, no large comparative studies had been performed to establish definitely the intraoperative complication rates of novice surgeons compared with staff surgeons in North America.

Only smaller, retrospective non-comparative surveys had been performed, according to Rosa Braga-Mele, MD, emphasizing the importance of such a study.

Phacoemulsification cataract surgery is by far the most commonly performed surgery in the developed world and it is an important part of ophthalmology surgical training, she pointed out.

“The complication rates have decreased with new technology and refined techniques.”

The published posterior chamber rates of rupture and vitreous loss rates for residents range from 2.0% to 14.7% and for staff surgeons from 0.19% to 2.7%.

Comparative study

Dr. Braga-Mele and colleagues performed a prospective, observational study that compared the intraoperative complication rates in phacoemulsification cataract surgery performed by resident trainees and staff ophthalmologists at a Canadian academic center.

The investigators included consecutive cases of primary phacoemulsification cataract surgery and intraocular lens (IOL) implantation with residents present in the operating room.

The data collected included case tracking forms and intraoperative complication tracking forms completed by residents following each case. The variables included the levels of resident training, case complexity, resident participation, and intraoperative complications.

The last included the following categories: no complication, wound burns, anterior chamber tears, posterior chamber tears, vitreous loss, dropped lens/fragment, iris prolapse, other iris complication, central Descemet’s membrane damage, hyphema, dislocated IOL, zonular loss, and choroidal hemorrhage, she explained.

She is professor of ophthalmology, University of Toronto, and director of the Cataract Surgery at Kensington Eye Institute, Toronto.

The study covered the period from January 2016 to December 2016; 8,738 procedures were included. Of the 3,775 cases in which residents were involved, most involved residents who were in postgraduate year 5.

In most cases (83%) when residents were involved, they were completing the entire case. Two-thirds of the cases were considered simple. The one-third of cases that were complex involved patients with small pupils/intraoperative floppy iris syndrome, 8.4%; corneal issues, 5.3%; hypermature cataracts, 4.2%; and zonular issues/pseudoexfoliation syndrome, 3.3%.

Some cases had a combination of challenges, most often the presence of a hypermature cataract with mature pupillary and zonular issues.

She noted that complications developed in 233 (2.7%) cases. When broken down by residents and staff surgeons, the rate of any complication was 2.7% in each group. The analysis identified a significant difference in vitreous loss between staff and residents; interestingly the chances of vitreous loss occurring were lower when a resident was involved in the case.

“This was likely the effect of the complexity and higher degree of complexity of the case. It is not surprising that complex cases have higher odds of having a complication develop, and this is statistically significant. The staff surgeons perform more complex cases and are likely doing cases of higher complexity,” she said.

When the investigators evaluated only simple cases, there were no significant differences in the complication rates between the staff surgeons and residents.

When they evaluated only cases in which residents were involved, there was an increase in the complication rates during a 5- to 8-week training period and then a subsequent trend was seen toward decreasing complication rates as the residents gained experience.

How the results stacked up

When Dr. Braga-Mele and colleagues compared their results to previously published studies, no startling differences were found.

In an Australian study by Fong et al. (Clin Exp Ophthalmol 2012;40: 597-603) that included 1,851 patients, surgical audit data were available for fewer than a third of cases and excluded the challenging cases. The study found no significant difference in the overall complications tracked, or in the rates of posterior chamber rupture, i.e., staff surgeons, 2.7% and residents 3.9%, P=0.7.

Randleman et al. (Arch Ophthalmol 2007; 125: 1215-1219) evaluated the resident surgeon phacoemulsification learning curve based on a retrospective review of 680 cases and found a significant reduction in the rates of vitreous loss after the residents had completed their first 80 cases (51% to 1.9% P=0.03), a result that was similar to the current trend identified toward decreased complication rates after 8 weeks.

A third study by Hashemi et al. (Cataract Refract Surg 2013; 39: 1377-1382) found when residents were unsupervised in the operating room, the odds of vitreous loss increased markedly compared with residents who were supervised.

The current study findings were that the intraoperative complication rates in cataract surgery are low, resident involvement in cataract surgery does not increase the complication rates, the complexity of the case is associated with higher complication rates, and the resident surgical experience is associated with lower complication rates, she said.

“The current results are based on findings at an institutional level. Individually, there likely are surgeons who have higher rates of posterior capsular rupture and those who have lower rates. There is a good chance that among those surgeons with the lowest rupture rates, having residents increases their rupture rates, but all is well below what we consider acceptable. In addition, some surgeons might perform more complex cases and have a higher complication rate as a result,” she said.

Disclosures:

Rosa Braga-Mele, MD
E: rbragamele@rogers.com
Dr. Braga-Mele has no financial interest in any aspect of this report

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