- Cataract surgery is commonly performed in elderly patients who are at high risk for
developing postoperative cognitive dysfunction. Most cataract surgeries are performed
under peribulbar or retrobulbar anesthesia, however, most of the patients require
sedation to relieve the perioperative anxiety and induce amnesia. So, many sedative
agents can be used especially benzodiazepines which may increase the risk of developing
postoperative cognitive dysfunction.
- Ketamine can be used as a sedative and analgesic agent in a dose of 0.25 -0.5 mg/kg with
certain studies suggesting that it may decrease the risk of postoperative cognitive
dysfunction. Similarly, dexmedetomidine can be used as a sedative and analgesic agent
with the possibility of decreasing the incidence of postoperative cognitive dysfunction.
- this controlled study will compare the effect of ketamine or dexmedetomidine on the POCD
of patients undergoing cataract surgery.