Povidone Iodine Solution Can Disinfect Rigid Contact Lenses

Woman putting cleaning dilution into contact lens case.
Woman putting cleaning dilution into contact lens case.
The absence of pathogens in a majority of conjunctival lens and case samples indicate povidone iodine can likely improve the safety of overnight lens wear.

Effectively disinfecting rigid contact lenses may be achieved by using a povidone iodine (PI) based solution, according to findings published in Contact Lens & Anterior Eye.

Researchers conducted a study to gauge the impact of PI solutions and various cleaning techniques on conjunctival colonization and contact lens and case contamination.

The study involved 76 participants ages 6 to10 years who used orthokeratology (OK) lenses. Researchers assigned participants to 1 of 4 lens cleaning routines, some utilizing daily or weekly cleaners, which were performed by their parents. The study analyzed conjunctival colonization, along with lens and case contamination, at baseline and at 1, 3, and 6 months after lens wear. Organisms were identified via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. 

Conjunctival colonization was present in 32% (n=24) of participants at baseline, while 34 of the 52 remaining participants yielded no growth. Participants who were positive at baseline had a higher likelihood of colonization after lens wear commencement (P =.02). The colonization rate was reduced to 15% (11/72 participants) after 6 months of lens wear, reaching significance for participants colonized at baseline (P <.001). There was no evidence of Pseudomonas aeruginosa, and few ocular pathogens were observed among all cultures. Contamination rates of lenses and lens cases were also low, with few isolations of ocular pathogens. The researchers did not observe any significant association between cleaning regimes and conjunctival colonization or contamination of lenses or cases.

The researchers note that little difference existed between the 4 groups, indicating that the contamination level was minimally impacted by the cleaning regime. 

”PI-based [solutions offer] a viable alternative system of disinfection for rigid and ortho-k lens wearers,” according to the researchers. “The absence of pathogens in the great majority of samples cultured and the dramatically reduced contamination rate compared with those previously reported indicate that use of PI-based solution can improve the safety of overnight lens wear.”

Study limitations include the inability to determine compliance with investigator instructions regarding correct rinsing procedures and intermittent cleaning. 


Cheung SW, Boost MV, Cho P. Effect of povidone iodine contact lens disinfecting solution on orthokeratology lens and lens case contamination and organisms in the microbiome of the conjunctiva. Cont Lens Anterior Eye. 2021;44(6):101412. doi:10.1016/j.clae.2021.01.007.