In the consideration of using multifocal contact lenses for those patients who are not yet old enough to have reached presbyopia, most of the dialogue and clinical research literature discusses the use of center-distance aspheric multifocal lenses in children in an effort to slow myopia progression. Though this is a widely discussed and well-researched area around the world, there are additional possible uses of other multifocal lens designs in non-presbyopic patients. In fact, several posters at last year’s American Academy of Optometry meeting discussed the utilization of center-near aspheric soft multifocal lenses.

Hoang and colleagues from Southern College of Optometry (2017) presented a poster titled “Fitting Daily Multifocal Contact Lenses for Near Point Problems in Non-Presbyopes.” The purpose of the poster was to utilize the “response AC/A” ratio and the change in near phoria through a one-day multifocal to determine the near add power actually utilized by non-presbyopic wearers. The study included 19 subjects aged 18 to 35 years with 20/25 or better monocular distance and near acuity. Subjects wore a plano/“low add” multifocal (center-near aspheric design) under habitual spectacle Rx. Phorias were measured at 40cm both via Von Graefe and prism cover test.

All subjects maintained 20/25 or better acuity at distance, and there was no significant difference between Von Graefe phoria and prism cover test in calculating multifocal add utilization.

According to the authors, 80% of subjects become more exophoric at near, showing that they were utilizing the multifocal correction. Those subjects who responded to the add within the multifocal accepted on average one-third of a diopter of the +1.00D present, but ranged to the full +1.00D being utilized. It should be noted that some subjects did not utilize the plus at near. However, clinicians can utilize individuals’ response AC/A ratio and near phoria while wearing center-near multifocal soft contact lenses to identify those individuals who would benefit from multifocal contact lenses and the add required.

Visual Acuity and Peripheral Defocus

Also presented at the 2017 Academy meeting were several posters discussing the more traditional multifocal design utilized and studied around the world in non-presbyopic individuals, namely the center-distance aspheric design. One such poster was presented by a group from the University of Houston College of Optometry.

Steffensen and Berntsen (2017) reported on two commercially available center-distance multifocal soft lenses and their optical profiles for possible myopia control. Twenty-five non-presbyopic adults were selected and fitted with both of the multifocals with a +2.50D add. Cycloplegic autorefraction was measured centrally and at 20°, 30°, and 40° nasally and temporally. Both lenses provided similar high- and low-contrast visual acuity. In addition, both options caused significant myopic shifts relative to the uncorrected eye. However, one of the multifocal lenses caused a significant myopic shift at more locations. Both lenses were deemed options for myopia control.

Looking Forward

Thankfully, we have many manufacturers today providing different multifocal designs in various materials and recommended replacement schedules. Additionally, it is through innovative research such as these studies and others that eyecare practitioners can translate the results into real-world clinical practice. CLS

For references, please visit www.clspectrum.com/references and click on document #271.