May 01, 2004

Oregon Clinic Has Infectious Outbreak for Years: Blames Surgical Gloves

After years of high-incidence DLK at surgical clinic, gloves found to be instigator

Matt Young
EyeWorld Staff Writer

Outbreaks of diffuse lamellar keratitis plagued Drs. Fine, Hoffman, & Packer LLC, Eugene, Ore., from 2000-2003, with the incidence as high as 37% in one three-month period and 85% on one day.

After trying to eliminate the problem by switching sterilizers, changing their pre-operative and intra-operative regimen, and troubleshooting in other ways, surgeons there switched glove brands during refractive surgery and the DLK vanished.

"I have a very strong suspicion that silicone oil on those gloves was the cause for our high incidence of DLK," said Richard S. Hoffman, M.D., clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland.

Hoffman was expected to further explain why he suspected surgical gloves as the DLK causes, and discuss prevention of the pathologic condition at the ASCRS?ASOA Symposium & Congress, San Diego.

Evolution of the outbreak

The notion that surgical gloves could cause DLK was dubious to Hoffman at first. A nurse at his clinic had suggested gloves as a cause after remembering a presentation given by Diane Hatsis, RN, who implicated a glove contaminant as a cause for some DLK problems.

"The idea that the surgical gloves are somehow associated with DLK didn't seem to make a lot of sense because, for the most part, the gloves aren't really touching the interface or instruments that are touching the interface," Hoffman said. "But we tried it and switched from one brand of gloves to another."

The clinic switched from using Encore MicrOptic (Ansell Healthcare Products, Red Bank, N.J.) gloves to using Protegrity (Cardinal Health, Dublin, Ohio) gloves.

"The next day that we had surgery, we had a substantial number of surgical cases - about 25 - and we were used to seeing anywhere from 10% to 25% DLK," Hoffman said. "But on the first post-operative day after using the new gloves, we didn't have any DLK, so it was a pretty remarkable decrease."

In fact, the clinic has had no cases of DLK since the switch, Hoffman said.

Now a fervent believer in the possibility of glove-induced DLK, Hoffman said he knows why gloves are a potential cause.

He had both gloves analyzed and found substantial amounts of silicone oil on the Encore MicrOptic gloves, while only insignificant amounts on the Protegrity gloves.

"Oils from the microkeratome have been implicated in DLK," Hoffman said. "Even though silicone oil is a relatively benign substance, in my opinion, it caused the DLK."

Silicone oil is used to help remove gloves from their molds during manufacturing and also used as a donning agent.

Upon closer clinical examination, Hoffman noticed that he and his colleagues touch the blade with gloves while inserting them into the microkeratome. He also found that before wiping the keratectomy interface with a sponge, they wet it and rung it dry wearing the gloves.

"So there's silicone oil that is potentially getting on the sponge at that point, and then being wiped directly on the interface," Hoffman said.

Informed consent and post-DLK care

For patients that developed DLK, Hoffman and his colleagues used frequent topical steroids and oral steroids. None of the patients lost any vision as a result of the DLK and all were happy with their result, he said.

"But it's a major hassle," Hoffman said. "On the first post-operative day if you had 20% of the eyes with DLK, you had to see those patients back more frequently."

He and the other surgeons never considered stopping refractive surgery, he said.

"If there was definite morbidity and patients were losing vision, then yes, we would think about it," Hoffman said. "The DLK was a nuisance complication, not a serious sight-threatening complication."

Still, if DLK is not treated appropriately, patients can develop interface scarring, a hyperopic shift, and a loss of best spectacle corrected visual acuity, Hoffman said.

As part of the patient consent process in 2003, Hoffman did inform patients that there was an increased chance that they might develop some benign inflammation that requires more frequent topical or oral steroid use.

The incidence of DLK during the outbreaks ranged from 16% to 85% per surgical day but the surgical volume on these days tended to be low so the overall number of DLK cases was not out of control, Hoffman said.

Editors' note: Hoffman has no financial interests related to his comments.

Contact Information
Hoffman: 541-687-2110, 541-484-3883, Posted by Admin at May 1, 2004 12:16 AM