• Posted April 2, 2025

Eye Exam Can Assess Risk Of Delirium Following Surgery

They say the eyes are the windows to the soul.

The eyes also might help detect seniors at risk for a common syndrome in which they emerge from surgery in a state of delirium, new research suggests.

Seniors who have thicker retinas are about 60% more likely to develop post-surgical delirium, researchers reported April 1 in the journal General Psychiatry.

The retina is the layer of cells along the back of the eye that translates light images into nerve signals to the brain.

In particular, a thicker macula – an oval-shaped set of sensors in the center of the retina that contribute to detailed vision – is associated with a risk of post-surgical delirium, researchers found.

“Our findings suggest that macular thickness … may serve as a non-invasive marker and identify individuals vulnerable to developing postoperative delirium after anesthesia and surgery among geriatric patients,” concluded a team led by senior researcher Dr. Yuan Shen, a professor with Tongji University School of Medicine in Shanghai, China.

About 26% of older patients develop post-surgical delirium, according to the American Medical Association (AMA).

In a 2023 AMA article, Michigan internist Dr. Amit Ghose recalled his own bout with post-surgical delirium following a four-hour heart procedure.

Ghose woke disoriented and confused. “I asked: ‘Why am I not in Lansing, rounding on my patients,’ ” the doctor, who is in his 60s, recalled.

Ghose couldn’t correctly answer questions posed by his family and opioid painkillers only made his delirium worse. It took him days to shake off his symptoms.

Patients with post-surgical delirium require longer hospital stays and are more likely to require support at home following their discharge, researchers said in background notes. They also face a greater risk of cognitive decline and dementia.

Unfortunately, there’s no simple test for identifying people at risk for post-surgical delirium, researchers said.

However, previous studies have identified vision problems as an independent risk factor for delirium following surgery. Retinal thickness has also been associated with cognitive impairment and risk for Alzheimer’s disease.

To see if the eyes could be used to find at-risk people, researchers recruited 169 patients 65 or older scheduled to undergo a knee or hip replacement, kidney or prostate surgery under general anesthesia.

Prior to their operation, the patients received an eye imaging test called optical coherence tomography (OCT), which uses light waves to create cross-sectional pictures of the retina.

For three days after their surgery, patients were screened for delirium.

About 24% developed post-surgical delirium, and these 40 patients had thicker-than-average maculas in their right eye, researchers found.

A thicker macula in the right eye was associated with 59% greater odds of delirium following surgery, results show.

This study can’t prove a direct cause-and-effect link between macular thickness and risk for post-surgical delirium.

But the results are powerful enough to warrant further review in larger studies, and could lead to a pre-surgical test for delirium, researchers said.

Post-surgical delirium can be prevented, according to the American Geriatrics Society.

Asking patients to walk multiple times daily, reminding patients of the time and their location, allowing overnight sleep without interruption, making sure they stay hydrated, keeping their glasses or hearing aids with them, and avoiding use of catheters all can help ward off delirium, the AGS says.

More information

The American Geriatrics Society has more on treating and preventing post-surgical delirium.

SOURCES: BMJ, news release, April 1, 2025; General Psychiatry, April 1, 2025