ENDOPHTHALMITIS

In an effort to reduce the number of cases that develop endophthalmitis following intravitreal anti-VEGF injections, Peter Barry FRCS has extended an invitation to retinal specialists across Europe to participate in the newly launched ESCRS Endophthalmitis Registry.

“The idea of the registry is that it will enable us to track any changing patterns of microbial susceptibility and antimicrobial resistance, which is just as important to retinal specialists who perform anti-VEGF injections as it is to cataract surgeons,” said Dr Barry, St Vincent’s University Hospital, Dublin Ireland, at the 13th EURETINA meeting in Hamburg.

Easy data entry

The ESCRS Endophthalmitis Registry is based on the Swedish Endophthalmitis Registry, and is operated through the ESCRS office in Dublin, Ireland. By and large, the information it requires of participating retinal surgeons performing anti-VEGF injections is the same as is required of cataract surgeons. Participating surgeons will make an anonymised entry into the registry when they first suspect that an eye may have endophthalmitis following a cataract procedure or an anti-VEGF injection. The entry will include a reference number for the patient, the name of the surgeon, the name and location of the hospital and the date of the tentative diagnosis of endophthalmitis.

“For data protection reasons we don't want the name of the patient, who is given an arbitrary number which will help you identify which case you're sending details from,” Dr Barry explained. Three months after entering a suspect case of endophthalmitis into the registry database, participating surgeons will receive a computergenerated form that will first inquire whether or not the case was confirmed.

In cases of confirmed endophthalmitis, additional information requested include the bacteria identified and the method used to confirm the infection, whether by Gram stain, culture, PCR or a combination of techniques. Other information requested include whether prophylactic topical and/ or intracameral antibiotics were used, and if so, which agent or agents were used, and also whether the patient used antibiotic eye drops postoperatively and finally the patient’s outcome in terms of visual acuity. Dr Barry noted that an important distinction between the Swedish Endophthalmitis Registry and the ESCRS registry is that it will not determine the rate at which the complication occurs, since it will not catch every case.

Instead, it will serve a purpose more similar to that of the TRUST (Tracking bacterial Resistance in the US Today) bacterial surveillance programme, in which an independent central laboratory performs in vitro susceptibility testing on bacterial isolates submitted from hundreds of clinical centres around the country. “The findings of the ESCRS registry could help EURETINA provide evidencebased guidelines regarding the prophylaxis of endophthalmitis following anti-VEGF injections,” Dr Barry added.

Registries yield results

Dr Barry noted that it was findings from the Swedish Cataract Registry that first put the ESCRS Endophthalmitis Study in motion. The subsequent drop in endophthalmitis following cataract surgery in centres using intracameral cefuroxime is therefore evidence of the type of result that can be achieved using a registry approach.

The ESCRS Prophylaxis of Endophthalmitis Study for its part showed that in cataract patients randomised to preoperative povidone iodine alone the rate of endophthalmitis was 0.35 per cent. That compared to a rate of 0.05 per cent among patients randomised to receive intracameral injections of cefuroxime. Critics of the study, particularly those in North America, said that the endophthalmitis rate in the control group was unduly high, making the results of the study irrelevant to their practice, Dr Barry said. “Some American colleagues actually told me that their conclusion from the ESCRS study was that European cataract patients should travel to the United States because Europe was dirty and that if they travelled to America all they would need is topical antibiotic drops to avoid endophthalmitis. However, I would argue that this figure of 0.35 per cent is very close to the reality on both sides of the Atlantic,” he added.

That conclusion is supported by a recent study from California, he noted. The study’s authors adopted the use of intracameral antibiotics in 2007 when they found that their previous prophylactic regimen, povidone iodine and postoperative antibiotic eye drops, was leaving them with an endophthalmitis rate of 0.31 per cent. When they switched to intracameral antibiotics the rate dropped to 0.014 per cent (Shorstein et al J Cataract Refract Surg 2013;39:8-14).

Furthermore, the recent introduction of a new single-dose preparation of cefuroxime (AprokamR, Thea) for intracameral use may remove an additional source of resistance to using intracameral cefuroxime – namely the potential medicolegal consequences of using a product in an off-label way. It is now approved in 14 European countries and more will be added this year.

“The ESCRS study has achieved most of its objectives, in that it has proved the safety and efficacy of intracameral cefuroxime in the prevention of endophthalmitis after cataract surgery. That, in turn has encouraged industry to provide a standard preparation which we now have, and we’re simply waiting for worldwide acceptance,” Dr Barry concluded.