TOPICAL ANTIBIOTICS

Surgeons who use topical antibiotics as a prophylaxis against endophthalmitis following cataract surgery should restrict their use to less than a day before surgery and to no more than a week after surgery, in order to prevent the proliferation of antibiotic-resistant organisms, said Yonca Aydin Akova MD, FEBO, Bayindir Hospital, Ankara, Turkey.

“Cataract surgery is the most commonly performed surgical procedure in ophthalmology. Fortunately the advances in technology have transformed the outcomes in cataract surgery tremendously, but postoperative endophthalmitis remains a significant concern,” Dr Akova told the 19th ESCRS Winter Meeting in Istanbul, Turkey.

She noted that the ESCRS Endophthalmitis Study demonstrated that the use of intracameral antibiotics can reduce the incidence of endophthalmitis several-folds after cataract surgery. As a result many surgeons, particularly in Europe, have adopted that practice. However, many surgeons remain reluctant to switch from the topical antibiotics regimens they currently use. Moreover, it is not clear whether topical antibiotics, applied before or after surgery, can provide an additional prophylactic effect when used in addition to intracameral antibiotics.

She noted that a 2014 survey of ASCRS members showed that, although half of respondents were using intracameral antibiotics, 96 per cent were also using topical antibiotics.

The efficacy of topical antibiotics for endophthalmitis prophylaxis after cataract surgery has yet to be demonstrated in a randomised controlled study. However, the findings of a case-control study carried out in Canada provide some evidence in favour of this practice.

The study involved 23 cases of endophthalmitis cases among 75,000 eyes that had undergone cataract extraction by 26 different surgeons. A multivariate analysis indicated that postoperative topical second- and fourth-generation fluoroquinolones applied postoperatively had a statistically significant prophylactic effect.

“Mainly, we use topical antibiotics not because of the microorganisms going into the eye during the surgery, but because of those going in after surgery. That is why it might be wise to use topical antibiotics until the epithelium is healed, after three days to seven days, and we should not taper antibiotics due to the risk of developing antibiotic-resistant bacteria,” Dr Akova added.

There is less evidence in support of the use of preoperative antibiotics. The current standard for sterilising the ocular surface preoperatively is povidone iodine solution applied to the conjunctiva for at least three minutes prior to cataract surgery.

Some advocate the use of fourth-generation fluoroquinolones applied for a day or more before surgery. Research shows that topical moxifloxacin can reach therapeutic concentrations in the aqueous humour. The downside of that is that it can increase the number of fluoroquinolone-resistant bacteria in the eye.

Yonca Aydin Akova: yoncaakova@yahoo.com