Cognitive Protection After Cataract Surgery: Examining Ketamine and Dexmedetomidine in the Elderly

Abstract Background: Cataract surgery has risen dramatically in the US as a reflection of the growing geriatric population. Despite its safety and efficacy, elderly patients remain vulnerable to postoperative cognitive dysfunction (POCD). Previous studies have shown ketamine and dexmedetomidine to have neuroprotective effects. This study aims to examine its association with POCD using the TriNetX database, mirroring a prior randomized trial and assessing outcomes at 1 week, 3 months, and 1 year postoperatively. Methods: We conducted a retrospective cohort study using the TriNetX US Collaborative Network, analyzing patients aged 65-85 who underwent cataract surgery prior to June 2025. Using ICD 10 codes, POCD was defined as the new onset diagnosis of delirium, dementia, encephalopathy, or depressive disorders at 1 week, 3 months, and 1 year post surgery. Exclusion criteria included pre-existing cognitive impairment, psychiatric illness, psychotropic use, anesthesia allergies, and severe visual impairment. Propensity score matching adjusted for demographics and ASA II/III risk profiles based on common comorbidities. Outcomes were compared using risk difference, risk ratio, and odds ratio metrics. Results: In matched ketamine cohorts (n = 3,733 each), POCD occurred in 0.308% vs. 0.705% at 3 months (p = 0.0182; RR = 2.29) and in 1.315% vs. 2.312% at 1 year (p = 0.0016; RR = 1.76), favoring ketamine. In matched dexmedetomidine cohorts (n = 8,569 each), 1-year POCD was 1.797% vs. 2.389% (p = 0.0094; RR = 1.33), also favoring the treatment group. Conclusion: These findings suggest that both ketamine and dexmedetomidine may reduce the risk of POCD in elderly patients undergoing cataract surgery. While short-term effects were not significant, reductions in POCD incidence became apparent by three months and persisted through one year. This supports prior evidence of potential neuroprotective effects of these agents and highlights their relevance in perioperative planning for older adults. Further prospective studies are warranted to validate these associations and clarify underlying mechanisms. Summary: This retrospective TriNetX study examined ketamine and dexmedetomidine use during cataract surgery in patients aged 65–85. Only ketamine was associated with reduced POCD at 3 months, but both agents were associated with reduced POCD at 1 year. Findings suggest an added cognitive benefit of these anesthetics in geriatric patients.