Povidone-iodine is safe and effective against adenoviral conjunctivitis, study says

Primary Care Optometry News, September 1999

WILMINGTON, Del. — Povidone-iodine, which has long been used as a disinfectant to reduce bacterial colony counts, can be used for presumed adenovirus and many other external ocular infections, a study says. Although confirmatory culture results and further clinical studies are needed, povidone-iodine researcher Robert Abel Jr., MD, has had success with using a 5% and 10% solution off-label for the treatment of presumed adenoviral conjunctivitis.

“The disease is apparently superficial on the conjunctiva,” Dr. Abel said. “Therefore it can be treated with such a solution for a short duration.”

SEE ALSO

• New therapies target dry eye, conjunctivitis, redness...
• Exfoliate the lid margin to prevent meibomian gland clogging
• Excess iodine increases hypothyroidism risk in infants with...

Antiseptic for the eye

---Adenoviral keratoconjunctivitis:The use of povidone-iodine to treat this condition mimics the surgical use of the solution, Dr. Abel says.

According to Dr. Abel, his use of povidone-iodine is mimicking the surgical uses of the solution. Povidone-iodine is one of the most common forms of preoperative antiseptics for eye surgery in the United States. “The current technique is done by putting a drop or two of 5% iodine in the eye, having the patient close their eye, and then the periocular area is swabbed with the same povidone-iodine solution. It is washed off, and then the eye is irrigated,” Dr. Abel said.

Dr. Abel performed a retrospective analysis of povidone-iodine for the treatment of sporadic cases of presumed adenoviral keratoconjunctivitis. From research, Dr. Abel concluded that povidone-iodine was well accepted, safe and effective as a prophylactic and therapeutic medication against a variety of bacteria, chlamydia and viruses. Dr. Abel recommends either swabbing with a 5% solution on all four lids and leaving the eye for 30 seconds to 60 seconds, followed by irrigation, or using a 5% ophthalmic solution three times per day for several days until symptoms subside.

“The swab accomplishes something that eye drops may not,” Dr. Abel said. “[Swabbing] gets to the target tissue in an adequate concentration.”

Additionally, according to Dr. Abel, there is no risk associated with keeping the povidone-iodine in the eye longer than 60 seconds. The reason for the quick irrigation is to prevent the staining that is related with iodine. The other side effect associated with this use of povidone-iodine is mild burning, which lasts 5 to 10 minutes.

“What happens is the inflamed conjunctiva picks up the iodine and then it is sloughed,” Dr. Abel said. “The underlining tissue is presumably healthy. The bottom line is povidone-iodine is well tolerated and it resolves a problem that either has been, or may be, a long-term convalescent as well as a public nuisance.”

With the different solution strengths, povidone-iodine showed to be useful in the treatment of presumed or proven adenoviral keratoconjunctivitis. The study demonstrated an improvement in 34 of 36 patients within 24 hours to 48 hours with no other treatment. “I currently use a 5% solution and we are experimenting with 2.5%,” Dr. Abel said. “The 2.5% should be enough and there should be less discomfort.”

Treatment route

Thirty-nine eyes of 30 patients were treated by swabbing three lids or four lids with sterile 10% Betadine (povidone-iodine, Escalon Ophthalmics) surgical scrub solution. Each lid was gone over twice, and the eye was irrigated 30 seconds after the Betadine application. The last 10 eyes of six patients were treated with 5% povidone-iodine solution prepared from a 10% solution diluted equally with GenTeal (hydroxypropyl methylcellulose, CIBA Vision, Duluth, Ga.) ophthalmic solution. These drops were used three times per day for 2 days and patients were instructed to irrigate the solution 1 minute following povidone-iodine instillation.

Patient follow-up

The study patients were directed to report within 24 hours and were to be seen 2 days following treatment if symptoms were not significantly better. Thirty patients did not require a follow-up examination and reported feeling significantly better, with decreased lid swelling and decreased crusting 1 day after povidone-iodine instillation. Four patients totaling seven eyes confirmed that they felt better and established clinical improvement when examined 2 days later.

Two patients (involving two eyes) still complained of symptoms after 2 days. One patient demonstrated no change in papillary conjunctival hyperemia, which consequently resolved by day 4. The other patient’s symptoms improved; the patient continued to show corneal opacities in the first eye. The opacities cleared up about a month later, following the administration of topical fluorometholone acetate ophthalmic suspension 0.1%, which was applied three times per day and then successfully tapered during the next 15 days.

For Your Information:

• Robert Abel Jr., MD, can be reached at Concord Plaza Naamans Building, 3501 Silverside Road, Wilmington, DE 19810; (302) 479-3937; fax: (302) 477-2650. Dr. Abel has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.