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Understanding why ophthalmologists should be using intracameral antibiotics to lower the risk of postoperative endophthalmitis after cataract surgery.
Listen to Christina R. Prescott, MD, PhD, discuss the role of intracameral antibiotics to lower the risk of postoperative endophthalmitis after cataract surgery during the annual Current Concepts in Ophthalmology meeting at the Wilmer Eye Institute/Johns Hopkins University.
Take home: Understanding why ophthalmologists should be using intracameral antibiotics to lower the risk of postoperative endophthalmitis after cataract surgery.
By Liz Meszaros; Reviewed by Christina R. Prescott, MD, PhD
Baltimore, MD-Postoperative endophthalmitis after cataract surgery is rare, but ophthalmologists can still take steps to alleviate its risk even further, according to Christina R. Prescott, MD, PhD.
“As (physicians) all know, cataract surgery is a remarkably successful surgery,” said Dr. Prescott, assistant professor of ophthalmology, Wilmer Eye Institute, Johns Hopkins Medicine, Baltimore, MD. “The complication risk is so incredibly low that we often focus primarily on discussions of refractive outcomes. We get so caught up in trying to meet our patients’ refractive goals that we can forget that cataract surgery is still a surgery and every surgery does have some risks, however low.”
Endophthalmitis can occur months and even years after surgery, but Dr. Prescott said postoperative endophthalmitis could occur 1 to 2 weeks after surgery. The rates of postoperative endophthalmitis are low (less than 1% in the United States), though the exact incidence of these infections is unknown, she noted.
“Approximately 3 million cataract surgeries are performed in the United States annually, so even if the infection rate is 0.1%, that is a significant number of patients. Approximately 4,000 cases of endophthalmitis are recorded annually,” she explained, adding that most of these infections are bacterial, although fungal infections can occur.
Can we do better?
To improve outcomes, ophthalmologists should be aware that some contributing factors are out of their control, while others are not, continued Dr. Prescott. She reviewed some of the controllable factors ophthalmologists should be aware of, which include:
· Patient selection. Some patients are at higher risk for infection, including those with additional ocular and systemic illnesses, and those who have trouble adhering to follow-up care. “For these patients, you may want to take extra steps to help reduce their risk,” she said.
· Location of surgery. Some studies have shown that surgical centers confer a lower risk of endophthalmitis than hospital settings. Dr. Prescott noted, however, “It is difficult to determine whether this is related to the fact that patients with more health problems are more likely to have surgery in a hospital setting.”
· Surgeon experience. The more surgeries an ophthalmologist has performed and performs on a regular basis, the lower the risk of infection.
· Case complications. Increase the risk of endophthalmitis by about 4.9%.
· Type of corneal incision. Scleral tunnel incisions carry a 5.88-fold decreased risk of endophthalmitis versus clear corneal incision. “In some of my higher risk patients, I do a scleral tunnel incision for this reason,” Dr. Prescott said.
· IOL type. Acrylic lenses are more commonly implanted, but silicone lenses are still used and carry a 3.13-fold increase in the risk of endophthalmitis versus acrylic lenses.
The use of antibiotics pre-, intra-, and postoperatively is common, continued Dr. Prescott. There are, however, no protocols or antibiotics specifically approved for this indication.
“There is no specific antibiotic or specific antibiotic protocol that is approved for prophylaxis in ophthalmic surgery,” she said. “Every antibiotic that is approved in this country is only approved for bacterial conjunctivitis. The most recently approved antibiotic was besifloxacin, which was only approved for bacterial conjunctivitis based on superiority to placebo alone.”
Antiseptic use is also a controllable factor in the battle against infection. For example, preoperative betadine has been shown by multiple studies to decrease the rate of bacterial flora on the eye preoperatively, Dr. Prescott said.
Intraoperatively, some surgeons are using anterior chamber antibiotics, while others use antibiotics in the irrigating bottle, and some use subconjunctival antibiotics. Postoperatively, most ophthalmologists in the United States use the fourth generation fluoroquinolones, she added.
“Depending upon what country you are in, this protocol changes quite a bit,” Dr. Prescott commented. “Over 50% of European ophthalmologists use intracameral antibiotics, whereas in this country, about 80% of ophthalmologists use topical antibiotics instead of intracameral.”
Topical versus intracameral
Topical antibiotics are the standard of care in the United States, she continued. They have a longer duration, which can be beneficial, as well as a low risk of side effects. A disadvantage to topical antibiotics, however, is the high costs they may cause the patient. Other disadvantages are that the use of topical antibiotics is patient dependent, and that the intraocular concentrations achieved are quite low, noted Dr. Prescott.
With intracameral antibiotics, most studies show a 3- to 5-fold decrease in the rate of endophthalmitis. Other advantages of intracameral antibiotics include the high intraocular concentrations that can be achieved, the fact that their use is patient independent, and that they cost less than topical antibiotics. Disadvantages of intracameral antibiotics include issues with compounding, concerns for sterility, and toxicity-although no side effects of currently used intracameral antibiotics have been reported.
“The main issue in this country is that intracameral antibiotics need to be obtained from compounding pharmacies and there is still no consensus on how to administer these medications,” said Dr. Prescott, adding that some ophthalmologists are now using both topical and intracameral antibiotics in tandem.
“We have a lot of good options,” she said. “If there were a way to reduce our already low infection rates 3- to 5-fold, I think it would be worth doing.”
Christina R. Prescott, MD, PhD
P: (410) 836-7010 or (410) 893-0480
F: (410) 893-9796
Dr. Prescott has no financial interest in the subject matter.