Estifying the macular layer of the retina of the eye is associated with a greater risk of postoperative delirium for older patients undergoing surgery under general anesthesia, reveals an online study published online in the Open Access Journal General psychiatry.
Postoperative Delirium is one of the most common complications for older patients after surgery and can have in -depth implications for health and well -being in the long term.
Patients with postoperative delirium need a longer stay in the hospital and are more likely to require support at home to help with daily tasks such as washing, dressing and eating or being fired in a nursing home. They also run a greater risk of cognitive decline and dementia.
Although there are no simple tests to identify patients who are at risk of developing postoperative delirium, visual impairments is a risk factor, so the authors have assumed to determine whether a thickened retinal layer is called the macular, a potential biomarker of the condition can be.
The study included 169 patients of 65 years or more planned for hip or knee replacements, kidney or prostat surgery under general anesthesia in the Shanghai 10th People’s Hospital who received an eye image test called Optical Coherence Tomoscy (oct) as part of their pre-operative assessment. Patients were screened for delirium using the confusion method (CAM) algorithm every day during the first three days after the operation.
The severity of each delirium was measured using the CAM-SEVERITY (CAM-S) assessment of ten delirium characteristics, including inattention, unorganized thinking, disorientation, reduced quality and amount of sleep, inability to still be accompanied by anxiety, or delayed movement and thinking processes.
Forty patients (24%) developed postoperative delirium and these patients had shown a larger average macular thickness (283.35 µm) of the right eye in their preoperative assessment than the patients who did not experience a postoperative delirium (273.84 µm). After correction for age, gender and mental state, a larger preoperative macular thickness of the right eye was associated with 1,593 higher chances of developing postoperative delirium and the experienced delirium was of greater severity.
The thickness of the macular in patients with postoperative delirium was greater in the right eye and the thickening of the macular of the left eye was not associated with a greater risk of postoperative delirium.
The reasons for the differences in association between the right and left eye are unclear, the authors say, but are consistent with findings from earlier studies. Studies of healthy individuals have found the average macular thickness of the right eye thicker than that of the left eye, and studies of neuro degeneration have reported asymmetrical neurodegeneration of both the retina and the brain.
This is an observational study and as such, no strong conclusions can be drawn about cause and effect. The authors also acknowledge that the study has some limitations, including the small size and that potential confusing factors, such as existing eye dominance, were not investigated.
The authors conclude: “Our findings suggest that macular thickness measured by OCT can serve as a non-invasive marker and identify that are vulnerable to developing postoperative delirium after anesthesia and surgery in geriatric patients.”
They add: “Further large -scale validation studies must be carried out to confirm these results.”
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Journal Reference:
Shi, Z., et al .. (2025). Association between the thickness of the retinal layer and postoperative delirium in older patients. General psychiatry. doi.org/10.1136/gpsych-2024-101740.