Diagnoses of post-operative vision loss (POVL), although rare, rose significantly after 2008 compared with previous years, according to study results presented at the 2015 Annual Meeting of the Canadian Anesthesiologists’ Society (CAS).
“Patients are concerned about complications that are common and severe,” explained lead author Cameron Goldie, MD, University of Manitoba, Winnipeg, Manitoba, Canada, speaking here on June 22. “This is a complication that can be severe. If someone becomes blind following surgery, for example, that can be devastating.”
Analysing an administrative database from the province of Manitoba that covers the years 1987 through 2013, Dr. Goldie and colleagues identified surgeries considered to be at high risk for POVL, such as cardiac, lung, spine, and head and neck surgery, as well as surgeries considered to be at low risk for POVL, such as ambulatory orthopaedic, gynaecologic, and general surgeries. The incidence in low-risk surgeries served as baseline incidence of vision loss.
Investigators excluded patients with pre-existing diagnoses consistent with vision loss or a comorbidity like diabetes that could confound the diagnosis of POVL.
The team examined visual defects that occurred in patients up to 14 days after surgery. “We suspect we would not add large numbers of cases of POVL if we looked at the incidence [of POVL] beyond 14 days,” he noted.
They found that the incidence of POVL in high-risk surgeries is decreasing, but that the incidence overall is increasing. The researchers observed 242 POVL cases in 184,263 high-risk surgeries and 236 cases in 402,509 cases in low-risk surgeries.
In high-risk surgeries, the team found that the risk of POVL decreased after 2008, compared with previous years (P = .05). That was not the case for low-risk surgery (P = .68); post-discharge diagnoses of POV rose significantly after 2008 compared with previous years (P = .01).
“The incidence in high-risk surgery is trending downward over time, but the number of cases of POVL being discharged from hospital is increasing,” Dr. Goldie said. He postulated that some changes in anaesthesia management may explain why the incidence of POVL in high-risk surgeries is decreasing.
The next step may be to liaise with ophthalmologists about these data and the risk of POVL, and to suggest that ophthalmologists ask patients in their offices who report a recent visual defect whether they have undergone surgery recently.