(Reuters Health) - Late-career surgeons perform a large proportion of cataract operations, and they do it with an overall low rate of adverse events, a Canadian study suggests.

In recent years, researchers have analyzed whether surgeons’ age affects their skills, dexterity and risk for mistakes in the operating room, the study authors note in JAMA Ophthalmology.

“Our overall population is continuing to age, creating a demand for healthcare that can’t be met by younger surgeons alone,” said lead study author Dr. Robert Campbell of Queen’s University in Kingston, Ontario.

Cataract surgery is the most common operation in the U.S., Canada and many other developed countries, the study team notes, and the average surgeon age for the procedure continues to climb.

“We’re reliant on late-career surgeons to provide a large portion of surgical care,” Campbell told Reuters Health by email. “Understanding how that affects quality of care is very important.”

In cataract surgery, the lens of the eye - which has become clouded over, obstructing vision - is removed and replaced with an artificial lens.

Campbell and colleagues defined surgeons’ career stages based on how long it had been since they completed medical school: early (less than 15 years), mid (15 to 25 years) or late (more than 25 years). They examined records for 499,650 cataract surgeries performed in Ontario between 2009 and 2013.

In particular, they looked at four complications that can happen during the surgery and require further surgery or other treatment to correct.

These complications occurred in 2,800 cataract operations, with 2,000 involving just one of the four adverse events, known as posterior capsule rupture.

Late-career surgeons performed about 143,000, or 29 percent, of all the operations. Being in a later career stage wasn’t associated with any increased risk of complications. When the research team removed surgeon volume from the equation, meaning the number of cases a surgeon handles, being a late-career surgeon still wasn’t associated with more adverse events.

However, when researchers looked at each of the adverse events individually, the risk did increase for two complications. Late career stage was associated with higher odds of dropped lens fragments and suspected endophthalmitis, though in both cases, this translated to an actual increase in incidents of about one tenth of one percent, the authors note.

“These findings likely stem from a few factors, including that surgeons are staying up-to-date with technical innovations in the field and older surgeons are retiring at appropriate stages, before issues arise,” Campbell said.

Future studies should look at other adverse events that occur later after surgery, rather than during or immediately after surgery, as well as other measures of the quality of surgical care, he added.

Previous studies of surgeon age and surgery outcomes have found mixed results, the study team notes. The complexity of the procedure being performed and how frequently surgeons perform it are probably important variables that explain these findings, the authors write.

For example, one of the current paper's authors found in a 2007 study of cataract surgeries in Ontario that adverse event rates dropped steadily the more procedures a surgeon did yearly (bit.ly/2NY779f).

Similarly, greater experience was tied to higher odds of patient survival in a 2009 study that found older surgeons performed better than younger ones during a heart operation known as coronary artery bypass surgery (bit.ly/2OLrc86).

“Patients who underwent (the heart surgery) performed by surgeons under 40 years old had significantly higher in-hospital mortality rates,” said that study’s senior author Herng-Ching Lin of Taipei Medical University in Taiwan. “We concluded that older surgeons are more likely to achieve better clinical performance because of their greater clinical experience,” said Lin, who wasn’t involved in the current research.

SOURCE: bit.ly/2JevG10 JAMA Ophthalmology, online October 11, 2018.