Endophthalmitis debate goes from conflict to consensus

Contention has slowly given way to consensus in the cross-Atlantic debate on the merits of intracameral antibiotic prophylaxis following cataract surgery, suggests a debate held at the 2015 American Society of Cataract and Refractive Surgery Symposium in San Diego.

The landmark ESCRS Endophthalmitis Study was a large prospective randomised, multicentre cataract surgery study that compared various antibiotic regimes. The essential conclusion of the study was that the use of intracameral cefuroxime at the end of surgery significantly reduced the occurrence of postoperative endophthalmitis from 0.35 per cent to 0.05.

Since the study appeared in the JCRS in 2007, its recommendations were taken up more quickly and enthusiastically in Europe than in the USA. David F Chang MD and Peter Barry MD took the stage, representing the US and Europe respectively, to discuss the effect the study has had on current practice.

Dr Chang began by citing nine studies in the literature since 2007 confirming the efficacy of intracameral cefuroxime prophylaxis. He highlighted a large US study conducted by the Kaiser health group showing a 22-fold decrease in endophthalmitis rates when its hospitals switched to the ESCRS study regimen. He noted that while the 2011 AAO guidelines and ASCRS white papers both stopped short of recommending this approach as standard of care, both concluded that the evidence supported the efficacy.

Dr Chang discussed how the original skepticism about the study expressed by many in the USA has evolved to increased acceptance with time. He compared the results of surveys of ASCRS members conducted shortly after the study (2007) with a similar study conducted in 2014.

In the initial survey, 77 per cent of respondents were not using intracameral antibiotics postoperatively. In the later survey, half of respondents were using intracameral antibiotics. The survey found that among US doctors not using the intracameral approach, two thirds stated they were not yet convinced of the merits. This was a significant decline from the 90 per cent who reported being unconvinced in the initial survey. Concern over the risk of mixing errors was also frequently cited as a reason for hesitation.

“Two thirds of US doctors surveyed say intracameral is important, and 84 per cent said they would use an intracameral antibiotic if one such as Aprokam were commercially available. But clearly the potential mixing risk is what is holding some people back. I don’t think the US and European surgeons are that different in how they think. The difference is who has a commercial intracameral preparation available to use,” commented Dr Chang.

Dr Barry offered the European perspective. He cited multiple studies conducted since the original ESCRS study results, providing further support for intracameral prophylaxis.

“The important thing to understand is that these studies represent countries where a decision was made at one point in time to switch to intracameral cefuroxime. Looking at collective data from almost one million patients, every study shows that when the switch was made where endophthalmitis rates were high, as in France, they became low; where they were low, as in Singapore, they got even lower,” said Dr Barry, chairman of the original ESCRS study.

ESCRS SURVEY

Dr Barry noted that acceptance of this approach was undoubtedly stymied by the lack of an approved, licensed commercially available product. This has now changed, with the European Medicines Agency (EMA) approval of Aprokam (Thea), a single dose preparation developed specifically for this purpose. A single 50mg cefuroxime powder is mixed with a single dilution of 5.0ml normal saline. It is now available in 23 European countries.

A 2012 ESCRS survey looking at uptake of intracameral cefuroxime use throughout Europe surgeons found that 74 per cent of correspondents always or usually use intracameral antibiotics. However, a more detailed look across Europe shows practice patterns to be inconsistent.

For example, in France, which does the most cataract surgery in Europe, intracameral antibiotics are used 90 per cent of the time. Similar numbers are also seen for Sweden, Denmark, Finland, Spain and Portugal. France and Denmark actually have official Government Health Agency guidelines supporting this approach, noted Dr Barry.

Intracameral prophylaxis is also used in more than 90 per cent of cataract surgeries in Italy. This is driven in part by concern over legal litigation. That country is currently the most litigious in the world for cataract surgery, Dr Barry explained.

However, in Germany, second only to France in terms of cataract volume, intracameral prophylaxis has yet to catch on, perhaps because of unresolved legal and budgetary issues.

A paper in the JCRS journal, authored by the clinical cataract committee of the ASCRS, concluded:

“Intracameral injection of antibiotics ultimately should improve the safety of cataract surgery by providing better endophthalmitis prophylaxis. We’re calling on pharmaceutical companies and US FDA to make development and approval of such an agent a high priority.”

“The debate is over, we are actually all in harmony. The difference is you in the US have a brick wall that we don’t,” Dr Barry concluded.

David F Chang: dceye@earthlink.net

Peter Barry: peterbarryfrcs@theeyeclinic.ie

Dr Chang is Clinical Professor at the University of California, San Francisco, and has no relevant financial interest in this subject