Participants who achieved good vision with both lens types preferred toric ortho-K over soft toric multifocal lenses. Click image to enlarge.
Toric orthokeratology (ortho-K) lenses and soft toric multifocal lenses are options for myopia management of patients with moderate to high astigmatism, but there are quite a few differences between them. In a recent study, researchers evaluated objective and subjective clinical differences between toric ortho-K and soft toric multifocal contact lenses in the same group of myopic adult wearers with moderate to high astigmatism.
A total of 30 adults with refractive myopia (plano to -5.00D) and astigmatism (1.25D to 3.50D) were fitted empirically with both toric ortho-K and soft toric multifocal contact lenses. Participants wore the lenses for 10 days in random order, separated by a 14-day washout period. Since the lenses were ordered empirically and no refitting was performed, the eyes that had good vision (20/40 or better) with the initial lens were classified as successful.
The first lens fit success rate was much greater with soft toric multifocal than toric ortho-K lenses (95% vs. 63%). “This difference in success rates highlights the need for ongoing effort to improve empirical fitting; however, one of the main drivers of decentration with orthokeratology lens wear is lid interaction, which cannot be accounted for with empirical fitting,” the authors noted.
High contrast and glare acuity were reduced with toric ortho-K compared with soft toric multifocal lenses. The participants indicated a noticeable decrease in comfort, vision and handling with toric ortho-K lenses and a decrease in vision with soft toric multifocal lenses compared with their habitual single vision correction. When forced to choose between lens types, toric ortho-K was preferred for vision and overall, which the authors suggest may be due to patient preference for the more “stable” blur associated with ortho-K correction over the unstable blur associated with blinking with soft toric multifocal lenses.
“Almost all the participants were habitual single vision toric soft lens wearers, so they were likely more critical of the vision in soft toric multifocal lenses compared with their habitual and perhaps less critical of the handling since they were already familiar with care, application and removal,” the authors explained.
Tomiyama ES, Richdale R. Clinical outcomes of a randomized trial with contact lenses for astigmatic myopia management. Optom Vis Sci. December 6, 2022. [Epub ahead of print].