Although postoperative vision loss is exceedingly rare, it is far more common in children undergoing neurosurgery.
A database analysis by a team of Texas researchers has helped characterize the nature and incidence of pediatric postoperative vision loss, an undertaking they said would provide valuable insight for clinicians working with children.
“Perioperative vision loss in any patient is obviously one of the most devastating complications that we can encounter,” said Erin S. Williams, MD, an assistant professor of anesthesiology at Baylor College of Medicine, in Houston. “Thankfully, it is rare. However, because of its devastating characteristics—meaning that it is largely irreversible—we find it important to look at this potential complication and try to better understand its causes, and hopefully thereby prevent it.”
The pathogenesis of postoperative vision loss has been attributed to numerous factors, including optic nerve ischemia, central retinal artery occlusion and cortical ischemia.
Despite its often devastating effects, postoperative vision loss has been rarely studied in children. As such, Dr. Williams and her colleagues set out to elucidate the prevalence of the adverse event among all pediatric patients undergoing surgery and the risk factors that may contribute to the disorder.
The researchers used 2012 data from the Healthcare Cost and Utilization Project’s Kids’ Inpatient Database (KID). KID contains data from approximately 3 million pediatric discharges each year from more than 4,100 community hospitals in the United States. The investigators used ICD-9-CM diagnosis codes for sudden visual loss, ischemic optic neuropathy, retinal vascular occlusion and cortical blindness to identify patients with postoperative visual loss. Surgeries were identified using ICD-9-CM procedure codes and grouped into abdominal, cardiac, spinal, orthopedic, neurologic and transplant operations.
As Dr. Williams reported at the 2017 annual meeting of the American Society of Anesthesiologists (abstract BOC01), a total of 157,331 patients of the 3,038,451 unweighted discharges underwent the surgeries of interest. Of these, postoperative vision loss occurred in 128 children (0.10%). These patients were predominantly more than 1 year of age (mean, 6.43 years), male and white.
When specified by type of surgery, the investigators found the highest rate of postoperative visual loss in children who underwent neurosurgery (0.48%; odds ratio [OR], 4.14; P<0.001), followed by transplant (0.25%) and spinal surgeries (0.25%). The majority of the cases in neurosurgery were attributed to cortical blindness, whereas cases from transplant and spinal surgeries were attributed to retinal vascular occlusion.
Surprisingly, the incidence of ischemic optic neuropathy, which is the most common cause of perioperative visual blindness in adults, was extremely rare in children. “We also found that elective cases were 3.3 times more likely to actually have perioperative visual loss compared to emergent cases,” Dr. Williams said. The odds of developing postoperative vision loss are shown in the Table.
|Table. Odds Ratios of Developing Postoperative Vision Loss|
|Odds Ratio (95% CI)||P Value|
|1-5 years||1.66 (0.91-3.03)||0.09|
|6-10 years||1.67 (0.95-2.92)||0.07|
|11-17 years||0.72 (0.41-1.26)||0.25|
Despite the strength of the findings, Dr. Williams noted that the study had limitations, beginning with its retrospective design. “It is a database, which frankly makes it difficult to know the specifics of the perioperative care, so a lot of granular medical information is limited. Another thing to consider is that it’s not clear which technique was used to diagnose the perioperative visual loss. Typically, we encourage anyone who awakens with visual loss to get an ophthalmology consult.
“Our conclusion from this database study is that cortical blindness appears to be a more common cause of perioperative visual loss in the pediatric population than either retinal vascular occlusion or ischemic optic neuropathy,” Dr. Williams said. “Some of the mosaic of events where we see increased incidence of perioperative visual loss included neurosurgical procedures, patients with preexisting anemia and perioperative hypotension.
“Given this information, we do need to continue delving into this,” Dr. Williams added. “This will also help us with decision tools to prevent or decrease the risk of perioperative visual loss in patient populations that have this increased risk profile.”
“You have found some possible associations with risk factors and outcome, although in a very limited number of cases,” said Nathan L. Pace, MD, a professor of anesthesiology at the University of Utah School of Medicine, in Salt Lake City. “So you’re not saying that any of these possible associations are actionable yet; that is, we don’t know when we can change care.”
“That’s correct,” Dr. Williams replied. “We’re not saying this is a direct association yet and aren’t yet recommending any actions to prevent postoperative visual loss.”
“Do any of these children recover from the perioperative visual loss?” asked Gilbert Blaise, MD, a professor of anesthesiology at the University of Montreal Hospital. He also asked about treatment.
“There can be some improvement with cortical blindness, but it is rare to recover fully from visual deficit,” Dr. Williams said. “Treatment for the cause of cortical blindness can be supported with excellent oxygenation, maintenance of adequate perfusion pressure, and making sure the patients have adequate cerebral perfusion pressure.”