Image of senior receiving eye exam
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When the macular layer of an older adult’s right eye retina becomes thicker, the person is more likely to experience postoperative delirium, a study shows. That was the case for older patients who underwent surgery under general anesthesia, according to a study published Tuesday in General Psychiatry.
Knowing about this correlation could help clinicians better identify those at risk for postoperative delirium, as there is no single, simple test, the authors pointed out.
Researchers evaluated data from 169 older adults who were 65 and older. All participants were having hip or knee replacements, or kidney or prostate surgery under general anesthesia at Shanghai 10th People’s Hospital. Before their operations, the participants received an eye imaging test called optical coherence tomography (OCT). They then were screened for delirium using the Confusion Assessment Method (CAM) algorithm each day for the first three days after their operations. The method measures delirium characteristics such as disorientation, reduced quality and amount of sleep, inability to sit still, and slowed movements.
Among participants, 24% developed postoperative delirium. Those participants had a greater mean macular thickness (283.35 micrometers) of the right eye at their preoperative assessment than the patients who did not experience postoperative delirium. The latter exhibited a macular thickness of 273.84 micrometers.
After the team adjusted for age, sex and mental state, they found that higher preoperative macular thickness of the right eye was linked with 1.593 higher odds of developing postoperative delirium and delirium with greater severity.
Thickening of the macular layer in the left eye was not associated with a greater risk of postoperative delirium, the data showed.
Older adults often experience postoperative delirium after surgery compared to younger adults, and it can affect their long-term outcomes. The condition often extends hospital stays and tends to require support at home. People who experience it have a higher risk of cognitive decline and dementia.
Researchers aren’t sure why there were differences in thickness between both eyes, but the authors said their findings were consistent with previous research. Studies on healthy individuals showed that the average macular thickness of the right eye was thicker than the left eye, and studies of neurodegeneration have reported asymmetrical neurodegeneration of both the retina and brain, the team wrote.