IN THE DESIGN and prescribing of soft contact lenses, the eyecare practitioner is challenged with understanding the patient’s ocular surface shape and unique refractive error. This provides the basis for aligning the ocular surface with the sagittal height profile of the contact lens and to optimize the optics of the contact lens to ideally correct their refractive error.

For individuals who have presbyopia, this design and prescribing challenge is elevated due to their near visual demands and add need as well as managing the patient’s expectations and how to best incorporate the multifocal soft lens into the patient’s lifestyle. Along with the increasing number of multifocal contact lens options available, the task can feel overwhelming.

The soft multifocal marketplace landscape is broadly separated into two categories: those provided by the large molded commodity manufacturers and those product offerings provided by custom manufacturers fabricated via lathe cutting. But how does one choose which product more ideally suits one patient than another?

In terms of refractive error, the amount of sphere and cylinder correction needed can quickly eliminate some of the molded products, as the parameter availability is less than the patient’s refractive error dictates at the corneal plane. The most obvious example of this is astigmatism, as currently there are very few molded soft multifocal contact lenses and practitioners have historically needed to reach for custom soft multifocal lenses when the cylinder power exceeds 0.75D to 1.25D. Once a custom soft lens has been decided upon, the cylinder power range greatly increases with some manufactures offering lenses up to 8.00D of cylinder in addition to offering cylinder axis increments as fine as 1º.

Other considerations for choosing a custom soft lens are related to the add power desired in the lens, as most of the commodity lenses end with add powers around +2.25D to +2.50D, where custom soft multifocal manufacturers offer add powers up to +4.00D. Also, uniquely as it relates to custom soft lenses, the practitioner is given control of optic zone size. This can be immensely valuable to customize the zone size relative to pupil size (Figure 1). The type of zone can be customized as well.

 Custom soft lens manufacturers offer center-near and center-distance multifocals. Depending on the pupil size, the central zone can be optimized as well as the intermediate zone to best balance distance, intermediate, and near vision for the patient (Figure 2). More recent innovations related to custom soft multifocals include the ability to offset the multifocal optics depending on lens position related to the patient’s visual axis resulting in a true custom aligned optical profile.

 To complete the rationale for selecting a custom soft multifocal relates to the patient’s underlying ocular surface profile. The more extreme anatomical features the patient has, the greater likelihood a custom soft lens will be needed relative to their corneal size, central corneal curvature, and eccentricity.

Custom soft lens manufacturers offer a range of base curve and diameter options to satisfy those unique ocular surfaces for optimal lens fitting. This customization allows the practitioner and patient to optimize the vision distance, intermediate, and near. CLS

Full references are available with the online version of this article.