Aberrations, Peripheral Defocus Vary Among Myopia Control Contact Lenses

Different contact lenses designed to provide myopia control may exhibit differences in relative peripheral defocus, myopic refractive astigmatism with cylinder power set orthogonally or at oblique angles (J₀ and J₄₅, respectively), accommodative amplitude, and spherical aberration, according to a study published in Optik. However, researchers have not yet determined the clinical relevance of these findings with respect to myopia control. 

Researchers included 34 patients with myopia (eyes, 68; mean age, 21.86 years; 23 women) in the single-blinded, randomized, prospective study. Participants underwent comprehensive eye examinations and were assigned to treatment with progressive multifocal, multifocal center distance, dual focus, or single vision (control) soft contact lenses. Participants wore each contact lens design for 6 hours per day for a 4-day period. 

Investigators measured participants’ visual acuity, stereoacuity, accommodative amplitude, accommodative posture, spherical aberration, horizontal coma, and non cycloplegic central and relative peripheral refractions at 10, 20, 25, and 30° along the nasal and temporal meridians of the horizontal visual field while wearing each lens design.

Myopic defocus and myopic J₀ astigmatism were highest in the progressive multifocal and dual focus designs, the report shows. Accommodative amplitude was slightly reduced with the dual focus design and spherical aberration was significantly higher with the progressive multifocal lens compared with the other lenses. Horizontal coma was higher and varied more with the progressive multifocal design.

No significant differences were noted in stereoacuity or distance and near visual acuity between baseline and while wearing all 4 lens types.

While all 3 myopia control contact lenses have demonstrated myopia control efficacy in other studies, the study authors stress the importance of minimizing aberrations.  

“Spherical aberration and horizontal coma are higher-order aberrations with analytical importance in eyes wearing contact lenses, according to the literature,” the researchers note. “Therefore, consideration should be given to how soft contact lenses affect spherical aberration and horizontal coma of the eye when assessing their optical performance.”

Study limitations include a short duration, the use of non cycloplegic peripheral refractions, and single center design.