American Journal of Ophthalmology, November 2021
Although there is no FDA-approved treatment for adenoviral conjunctivitis, in vitro testing has shown that povidone-iodine (PVP-I) has virucidal activity against adenovirus. Although PVP-I has been used off-label for many years to treat adenoviral conjunctivitis, there have been few clinical trials of its use as monotherapy. In a pilot, double-masked, randomized study, Than et al. compared safety and efficacy for 5% PVP-I and artificial tears in the treatment of patients with adenoviral conjunctivitis. They found that 5% PVP-I was well tolerated and that it reduced viral load for patients who presented within several days of symptom onset.
For this study, the authors recruited patients presumed to have adenoviral conjunctivitis who were screened at one of nine participating clinics in the United States. Candidates were required to be at least 18 years old, with symptoms lasting four or more days and a positive AdenoPlus test result. Excluded from participation were patients with iodine allergy, thyroid disease, recent ocular surgery, and ocular findings that did not suggest early-stage adenoviral conjunctivitis.
Study participants were assigned randomly to receive a single administration of 5% PVP-I or artificial tears (control) in one eye. They were examined within two days of treatment and again on days 4, 7, 14, and 21. Conjunctival swabs were obtained at each visit and analyzed by polymerase chain reaction. The main outcome measure was the percentage of reduction from peak viral load. A key secondary outcome was improvement of clinical signs and symptoms of adenoviral conjunctivitis, as assessed by patients and clinicians. Evaluated symptoms included tearing, edema, redness, and mucoid discharge.
Among 212 screened participants, 56 met the inclusion criteria and were entered into the study. Half the enrollees (n = 28) had detectable viral titers at baseline. By day 4 following treatment, viral titers were 2.5% ± 2.7% of peak in the PVP-I group and 14.4% ± 10.5% of peak in the control group (p = .020). In addition, patient-reported symptoms were significantly milder for the 5% PVP-I group at this point (p < .05 vs. control group), and clinician-evaluated discharge, bulbar redness, and bulbar edema improved significantly by this time (all p < .05 vs. controls). After day 4, both groups had marked declines in viral titers and sign/symptom severity, and there were no meaningful differences between the groups.
The authors acknowledged that larger studies are needed to confirm these findings. Even so, they said, the data suggest that a single in-office administration of 5% PVP-I may speed viral-load reduction, leading to faster resolution of symptoms in patients who are treated promptly.
The original article can be found here.