PHMB-containing antiseptics ‘may offer alternative’ to iodine
perioperative agents, say researchers

Stefanie Petrou-Binder MD
in Ludwigshafen, Germany

A NOVEL antiseptic biguanide agent with good preoperative short-term germicidal capabilities may in the long run offer better protection than established agents, say researchers at the annual DGII conference in Germany.

The new antiseptic agent, Lavasept, contains poly-hexa-methyl-biguanide (PHMB). Researchers compared the effects of Lavasept 0.02% (Fresenius), PVP-iodine (poly-vinyl-pyrolidone) and Ringer solution (boiled distilled water containing 8.6g sodium chloride, 0.3g potassium chloride and 0.33g calcium chloride per litre) in a three-arm prospective randomised controlled double-blind clinical study.

“A PHMB-containing antiseptic agent may offer an alternative to iodine-containing perioperative antiseptics. It works just as effectively as polyvinyl-pyrolidone, without the occurrence of contact allergic reactions or thyrotoxic crises, which sometimes accompany the application of substances containing iodine,” Fabian Hansmann MD reported.
Thirty patients participated in the study. They received eye drops containing one of the three substances before cataract surgery.

The researchers took a connective tissue swab before adding the test drops and then measured the germ count using quantitative microbiologic methods.
They took swab samples again after the application of test drops, before, during and after cataract surgery.

The researchers also observed the eyes for hyperaemia, an indication of a potential reaction of the drops with the connective tissue. They also documented discomfort afforded by the drops, according to a pain analogue scale.
Lavasept revealed good short-term antiseptic efficacy in the eyes receiving it preoperatively. The antisepsis provided was quite similar to the protection given by PVP-iodine. It was well tolerated by patients, with low tissue response and patient discomfort.

As Lavasept tends to bind with mucous membranes for two to three days, Dr Hansmann explained that this binding property may render a longer-lasting antiseptic protection in the eye following surgery, an effect lacking in PVP-iodine.
Although the postoperative infection rate following intraocular procedures in quite low (0.01% to 1.7%) thanks to the efficacy of PVP-iodine 1.25% solution, iodine carries a small risk of inducing allergic reactions and more rarely, thyrotoxic crisis.
Lavasept 0.02% solution is therefore an interesting option for surgeons to consider, especially in more allergy-prone patients.

“Lavasept has revealed itself as a harmless antiseptic. It can be employed along side standard antiseptic solutions to reduce germs, prolong antisepsis in post-surgical patients, or as an alternative to iodine-containing solutions,” he noted.
Previous studies with Lavasept appear to support the findings in this study. Lavasept has demonstrated potent activity against numerous microorganisms, including both methicillin-susceptible and methicillin-resistant bacteria.

However, Swiss researchers did report two cases of severe anaphylaxis following contact of surgical wounds with the disinfectant during orthopaedic interventions (Schweiz Med Wochenschr 1998;128:1508–11).
Endophthalmitis remains one of the most feared complications of cataract surgery. Yet there is little consensus about the best method of prophylaxis.
Approaches within Europe range from no preoperative prophylaxis at all to combinations of preoperative drops antibiotic infusions, subconjunctival mitomycin and postoperative topical antibiotics.

One reason for this lack of consensus is the dearth of well-designed clinical trials examining the issue. The ESCRS will this year launch a large multicentre controlled trial, designed to reduce the rate of endopthalmitis following cataract surgery to less than 0.01% and identify the natural history and true incidence of the disease.
The study will involve 35,000 patients undergoing phaco cataract surgery in 16 centres in eight European countries. Its principal aim is to show whether intraocular/intracameral antibiotics reduce endophthalmitis in patients undergoing phaco.
The first patients will enter the trial on June 16, 2003 and the final follow-up visit of the last patient will be on May 30, 2005. The researchers will complete their analysis of the information in time for the XXIII ESCRS Congress in Lisbon in 2005.

Fabian Hansmann MD
University Eye Clinic, Lübeck, Germany
Email: fhansmann@ophtha.mu-luebeck.de