Cognitive Dysfunction After Cataract Surgery

  • participants needed
  • sponsor
    Tanta University
Updated on 7 May 2021


  • 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.


  • Postoperative cognitive dysfunction is a common postoperative complication in elderly patients. Despite the role of the risk of anesthesia and/or surgery in developing postoperative cognitive dysfunction, it can be developed even with surgeries performed under local or regional anesthesia.
    • Ageing is the most common risk factor for developing postoperative cognitive dysfunction that can affect memory and speech. Also, impaired vision may be another important risk factor.
    • Cataract surgeries can be considered the most common surgery performed in elderly patients. It is usually performed under local anesthesia (peribulbar, retrobulbar, or sub-tenon blocks), however, sedation is usually required to relieve the anxiety of the patients and induce amnesia.
    • there are many sedative agents that can be used with such patients, the most commonly used are benzodiazepines. However, benzodiazepines use may increase the incidence of postoperative cognitive dysfunction.
    • Ketamine, the dissociative anesthetic, acts mainly through inhibition of NMDA receptors that reduce the neuronal loss of the cortex. it may attenuate the postoperative cognitive dysfunction and induce neuroprotective effect through suppressing the inflammatory response and minimizing cerebral ischemia.
    • dexmedetomidine is a sedative and analgesic agent that have the advantage of minimal respiratory depression and can be used as a sedative agent in cataract surgery. Studied revealed that its sedative analgesic effect is not associated with changes in memory.
    • This randomized controlled double-blinded study will be carried upon 90 elderly patients undergoing cataract surgery under peribulbar anesthesia where they will be classified into 3 groups: - Group I (Placebo Group). Where the patients will receive normal saline as a placebo.

Group II (Ketamine group). Where patients will receive ketamine in a dose of 0.3 mg/kg in physiological solution.

Group III (Dexmedetomidine group). where patients will receive dexmedetomidine in a dose of 0.5 ug/kg in a physiological solution.

-Primary outcome will be the incidence of POCD, the secondary outcomes will be the hemodynamic changes and the changes in the intraocular pressure.

Condition POCD - Postoperative Cognitive Dysfunction
Treatment Dexmedetomidine, Ketamine, Normal saline
Clinical Study IdentifierNCT04730596
SponsorTanta University
Last Modified on7 May 2021

Similar trials to consider


Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note