Ocular Symptoms Are Not Exacerbated By Povidone Iodine Solution Use

Povidone iodine use for orthokeratology lenses does not increase ocular symptomatology.

Using a povidone iodine (PI) solution does not increase the frequency or severity of ocular signs and symptoms observed prior to orthokeratology (ortho-k) lens wear, according to a study published in Contact Lens and Anterior Eye. 

Researchers enrolled 80 children (mean age, 9.05±1.14 years; 66% girls) who wore ortho-k lenses in a study and randomized them to 1 of 4 groups using different cleaning regimes. All participants disinfected their lenses with the PI-based solution per the manufacturer’s instructions. Group 1 participants merely disinfected the lenses, but the remaining children all rubbed their lenses prior to disinfection. Group 2 individuals only rubbed their lenses with the PI-based solution. Children in group 3 used an additional daily cleaner and group 4 participants used both a daily cleaner and a weekly protein removal treatment. All participants rubbed and rinsed their lenses with the rinsing solution  and use unpreserved artificial tears to cushion the lenses. 

Study participants also completed a questionnaire to assess visual symptoms and symptoms related to lens wear, including discomfort, dryness, itchiness, burning sensation, redness, and tearing.

[T]here were no significant differences between the groups with respect to symptoms, indicating that the disinfecting solution adequately removed deposits without additional cleaning steps, probably due to the presence of a surfactant in the solution and/or a proteolytic enzyme incorporated in the neutralizing tablet.

Investigators report no significant differences in signs and symptoms between the 4 groups before and after lens wear (P >.07). Prior to lens wear, itchiness (69%) and dryness (53%) were the most reported symptoms. A total of 8 children reported a burning sensation before lens wear, but it improved in 4 participants. The frequency and severity of all symptoms remained similar after lens wear (P >.10). 

Follicles in the lower tarsal conjunctiva (22%) and conjunctival injection (15%) were commonly observed, but reduced following lens wear (P <.01). Mild corneal staining was observed in 13% of children at baseline, and did not change over time (P =.17).  

“[T]here were no significant differences between the groups with respect to symptoms, indicating that the disinfecting solution adequately removed deposits without additional cleaning steps, probably due to the presence of a surfactant in the solution and/or a proteolytic enzyme incorporated in the neutralizing tablet,” according to the researchers. ”However, as deposits do tend to accumulate over time and ortho-k lenses are routinely replaced only on an annual, or even longer, basis, practitioners may wish to err on the side of caution and advise their patients accordingly.”

Study limitations include a short study duration, small sample size, and lack of a control group using an alternative solution.

References:

Cho P, Boost MV, Cheung SW. Ocular signs and symptoms of orthokeratology patients associated with povidone iodine-based disinfecting solution. Cont Lens Anterior Eye. doi:10.1016/j.clae.2022.101742