Citrus Spray as Antiseptic before Intravitreal Injections?

Denver, CO — A citrus-extract spray (Oftasecur) could reduce the risk for endophthalmitis from intravitreal injections and cataract surgery, researchers say.

After patients sprayed their eyes at home, researchers measured a reduction in bacteria often associated with the infections.

The citrus extract could be used in addition to iodopovidone, the antiseptic currently applied at the time of most intravitreal injections to prevent endophthalmitis, Lorenzo Ferro Desideri, MD, a resident at the University of Genoa in Italy, told Medscape Medical News. "Our aim is to further decrease the incidence of endophthalmitis."

He presented the finding at the Association for Research in Vision and Ophthalmology (ARVO) 2022 Annual Meeting. It was previously published in Ophthalmology and Therapy .

Desideri cited estimates that endophthalmitis occurs in about 1 in 2500 injections. "In our department we do 4,000 intravitreal injections every year, and sadly we see at least two patients with endophthalmitis,” Desideri said. "In our experience, the usual outcomes are devastating."

Topical antibiotics have shown little efficacy, and their repeated use might increase the evolution of antibiotic-resistant strains, Desideri said.

As an alternative, researchers turned to flavonoids extracted from the peels of citrus fruits that have broad-spectrum antimicrobial activity against many Gram-negative and some Gram-positive bacteria.

The flavonoids were developed in a liposome form and originally marketed as Biosecur for the food processing industry. The researchers combined this with hypromellose and other compounds to create an ophthalmic spray.

To test its potential in preventing endophthalmitis, Desideri and colleagues swabbed both eyes in 30 patients to measure the presence of microbes often associated with endophthalmitis, such as Staphylococcus epidermidis.

They trained the patients to spray one of their eyes four times a day starting 4 days before their injections.

The spray delivers droplets to the eyelid margin where it mixes with the tear film. Citing previous studies, the researchers said this delivery system is easier to use than traditional eye drops, which could be a particular advantage in incapacitated patients.

The fellow eyes served as controls. The percentage of treated eyes that were positive for the microbes dropped significantly: from 70.4% before the treatment to 29.6% after (P = .003).

Most of the microbes the researchers isolated before the treatment were Gram-positive coagulase-negative micrococci. They detected S epidermidis in 54% of the samples.

In control eyes, the number of positive swabs changed from 81.5% to 55.6%, and that difference was not statistically significant (P = .070).

All the patients took a Brief Ocular Discomfort Inventory questionnaire, based on an 11-point scale (0 for no discomfort and 10 for maximum discomfort). Their average score was 1.2. All of them adhered to the treatment schedule and none complained of discomfort.

Responding to a question from the audience, Desideri said the citrus spray has the potential to kill the fungi that are often isolated in endophthalmitis cases in tropical countries as well.

The results looked promising to session moderator Suzanne Fleiszig, OD, PhD, a professor of optometry and vision science at the University of California, Berkeley.

"If it is effective in reducing the microbial burden, if it's non-toxic, and comfortable to use, then it could have the potential possibly also for other things like eyelid inflammation as well," she told Medscape Medical News. "Particularly since it's sprayed on the eyelids, I could see some other applications and possibly for mild infections of the ocular surface of the eye."

She said she would like to see clinical trials showing that the citrus spray can actually prevent endophthalmitis.

Association for Research in Vision and Ophthalmology (ARVO) 2022 Annual Meeting. Presented May 2, 2022.

Desideri reports no relevant financial relationships. Fleiszig reported having three patents for antimicrobials. The study was independently supported.

Laird Harrison writes about science, health, and culture. His work has appeared in national magazines, in newspapers, on public radio, and on websites. He is at work on a novel about alternate realities in physics. Harrison teaches writing at the Writers Grotto. Visit him at www.lairdharrison.com or follow him on Twitter: @LairdH

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