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Eye Preps: When You Can't Use Povidone-Iodine
How to determine true iodine allergy and how to pick an alternative agent.
, Jean Hill, Lisa (Mary) Hill
Publish Date: October 10, 2007   |  Tags:   Ophthalmology

When it comes to prepping for eye surgery, povidone-iodine 5% is the solution of choice.[1, 2] But what if a patient presents with a known iodine allergy or has a reaction to the PVP? It's a tough call, as many of the alternatives either aren't as effective as PVP or are toxic to the cornea.

Is the patient really allergic?
Whether it's the surgeon, OR nurse or tech who performs the scrub, we rarely have the time for skin-testing or in-depth investigation. Further, patients - and often healthcare workers - use the term "allergy" for any type of adverse reaction, from skin rash to nausea and vomiting to anaphylaxis. When you also consider that manufacturers of povidone-iodine preparations list known sensitivity to iodine or its other components as a contraindication, it becomes all the more important that you understand allergy and sensitivity and ask the right follow-up questions when a patient reports an "allergy" to iodine, seafood or a skin cleanser.[3]

The American Academy of Allergy, Asthma and Immunology says that "contact dermatitis caused by topically applied iodine-containing antibacterials does not indicate an allergy to iodine. Anaphylaxis to these preparations is exceedingly rare and not proven to be due to iodine."[4] But does an allergy or hypersensitivity to iodine indicate sensitivity to PVP?

Often, "iodine allergy" is a reaction to radiocontrast media (RCM for short) or to seafood. If you can determine that a patient's stated allergy to iodine was to RCM or shellfish, it's unlikely he'd have a skin reaction to PVP. If in doubt, report to the physician as many details as possible and follow his orders or your facility's policy. If you've determined that the "allergy" was to PVP, ask about the specific reactive symptoms. Povidone-iodine combined with a detergent can cause corneal damage and should never be used.[5] Itching, burning, and chemosis may result from using a 10% solution rather than the diluted 5% PVP.[6] Conveniently available in the form of applicators, 10% PVP is reportedly used on lids and lashes. On the conjunctiva, 10% PVP may cause irritation - the 5% formula is much better tolerated and is recommended for use directly on the conjunctiva.[6,7]

A patient may report an "allergy" to a previous topical application of povidone-iodine without knowing sufficient details about the strength or if the detergent form of PVP had been used. If this is the case, you may want to conduct a patch test or a trial with a 5% PVP solution. But this isn't always practical or reasonable, so you need an alternate to 5% PVP to prepare the eye for surgery.

Peer practice
The American Society of Ophthalmic Registered Nurses asked its members (n=177) in January 2004 what they used in practice as an alternative to PVP. Here's a rundown of those products:

  • Baby shampoo. Soap-free, alcohol-free and hypoallergenic, this has the advantage of being well tolerated if it gets in the eyes and has been an effective treatment of choice for blepharitis.[9] But while this product and soaps mentioned in the survey (Castile or Phisoderm) remove normal skin flora, they aren't effective presurgical disinfectants.[10] Lid wipes used to remove makeup fall into the same category. The mechanical action of cleaning the lids and lashes is of some benefit in the pre-op preparation, but doesn't create a germ-free environment.
  • Poloxamer 188. Billed as "a wound cleaner specifically designed for use on acute non-surgical traumatic wounds," the main ingredient found in Shur-Clens (a non-toxic surfactant), is said to "not damage healthy tissue."[11] Product information says this product is "safe even around the eyes,"[12] but it wasn't designed as a pre-op cleanser.

  • Chlorhexidine gluconate. While this product was cited by 28 respondents, never use it to prep the eye. The product information clearly states, "do not use as a presurgical preparation on head or face."[13] Further, cases of corneal damage from using CHG have been reported, though the degree of corneal toxicity depends on the formulation.[14] Lower concentrations of the active ingredient may not pose the same risks to the eye, but they may not be as effective against all organisms. Many new antiseptics containing CHG and alcohol are appearing on the market in the form of waterless hand hygiene and scrub products. That's great for hand hygiene, but the material safety data sheets for many such products also warn that contact with the eye requires flushing with water for 15 minutes for a reason: They're not meant for eyes.[15,16]
  • Alcohol or alcohol prep pads. The survey returned 14 responses involving alcohol prep pads or "alcohol," which was presumed to be a 70% isopropyl alcohol swab. Alcohol in a 70% ethanol solution is known to be toxic to the cornea.[5] Some physicians instruct patients to perform lid scrubs at home and instill antibiotic drops for several days before surgery, then the periorbital area is cleansed with an alcohol swab just before surgery. Lower concentrations of an active ingredient may not pose the same risks to the eye, but you must take care not to get alcohol in the eye. Consider AORN recommendations regarding OR safety: Alcohol is a fire hazard in the presence of electrocautery.[17]
  • Green Soap Tincture. The material safety data sheet lists ethyl alcohol 30% as a chemical component (an alcohol-free formulation is not commercially available) and rates it flammable (the flash point is 82'F to 83'F), making it unsafe in the presence of electrocautery. If the product comes in contact with eyes, "flush with water for at least [15] minutes and get medical attention if irritation persists."[21]
  • Hexachlorophene. The main ingredient in Phisohex and Septisol is hexachlorophene. Together, they elicited 60 responses in the survey. The products are bacteriostatic skin cleansers with limited effectiveness against gram-negative bacteria, the tubercle bacillus, fungi or viruses.[22] Hexachlorophene shouldn't be used in or around the eye and mucous membranes, as it can damage the cornea after just one minute of exposure.[5] The FDA restricts the use of hexachlorophene in cosmetics "because of its neurotoxic effect and ability to penetrate human skin."[22]
  • 3% PCMX. One of the alternate products mentioned most frequently in the ASORN survey was Techni-care, whose active ingredient is para-chloro-meta-xylenol (or 3% PCMX). According to product literature, this cleanser has "broad spectrum antimicrobial activity against gram-negative and gram-positive vegetative bacteria, yeast, fungi, VRE, and MRSA" and is "safe and effective around the'eye."23 The anti-viral efficacy is not clear.
  • Benzalkonium chloride. Supplied as an aqueous solution of 1:750, the recommended dilution (with sterile distilled water) for eye irrigation using Zephiran is 1:5,000 to 1:10,000.[24] Although Zephiran solutions are "active against bacteria and some viruses, fungi, and protozoa," their efficacy is "bacteriostatic or bacteriocidal depending on the concentration."[24] You must store these solutions according to manufacturers' directions or risk contamination. In addition, "if solutions stronger than 1:3,000 enter the eyes, irrigate immediately and repeatedly with water."[24]

Put it to use
Povodine iodine 5% remains the pre-op periocular disinfectant of choice because of studies demonstrating superior antiseptic qualities and safe use in the eye.[1,2,5,6,7] Based on the survey results, it's obvious many products - not all of them good choices - are used as alternatives when patients have stated iodine allergies. Fortunately, the incidence of PVP sensitivity is infrequent. However, if you don't have enough information or time to validate PVP sensitivity, you must find a substitute. Based on our literature review, chloroxylenol 3% holds the most promise as a pre-op lid and lash cleanser. Unlike alcohol-based products, CHG or hexachlorophene, it's safe for use around the eye; it doesn't require dilution or special storage like benzalkonium chloride; and it's effective against many organisms, including some viruses.