THE NUMBER of soft contact lenses available in the marketplace today may make the decision to select one lens over another seem overwhelming. The level of innovation and new product offerings is impressive, with companies introducing new lenses on a continual basis.

In managing patients who have presbyopia with soft lenses, patients are traditionally either placed in monovision or multifocal soft contact lenses. Once the decision has been made to place a patient in multifocal contact lenses, the next decision is to place them in one of two main multifocal designs, namely center-near or center-distance, or a combination of the two with one eye receiving center-distance and the other center-near. In terms of the number of multifocal soft contact lens product offerings, the overwhelming majority of soft multifocal contact lenses made today are center-near with the second most common being center-distance.

The general next step in the fitting process is to reference the manufacturer’s fitting guide for the selected product. If the patient is placed in a particular product and has success visually with the lens, yet the fit is unsatisfactory, the practitioner historically had the patient fit with another trial lens in the hope that a subsequent lens had a more optimal fit profile. However, the practitioner was left to almost guess what the fit profile of the next lens may be.

A recent publication intended to describe the sagittal height profiles of commonly commercially available soft contact lenses (van der Worp et al, 2021). With this information, the eyecare practitioner is now able to alter the fit profile of the contact lens more confidently to a particular patient’s eye.

In the previous example of the patient who is fitted with a soft multifocal contact lens and the vision is adequate but the fit is suboptimal, the practitioner is able to reference the sagittal height profiles in the study and move either deeper/tighter/steeper (to the right-hand side of the chart) or shallower/looser/flatter (to the left-hand side of the chart) (Figures 1-3 available online).

Another way to use these charts is when the patient is successfully wearing a lens with one type of recommended replacement schedule but is wanting to switch to another recommended replacement schedule (e.g., monthly to daily disposable) and the fit profile is not intended to change, the practitioner can identify the lens that the patient is currently wearing, find its associated sagittal height, and then identify the second lens and keep the fit profile similar.

Zheng and colleagues noted that if a soft multifocal contact lens decenters on the eye, patients have an increased likelihood to report poor visual quality (Zheng et al, 2016). It may also result in decreased visual acuity due to the small zone profiles for distance, intermediate and near vision in a multifocal soft contact lens. If decentration of a soft multifocal contact lens is noted and utilizing the sagittal height charts does not result in a superior fit, another option may be to place the patient in monovision. With that option, the optic zone in single vision sphere and toric soft contact lenses is much larger than multifocals and is not as affected by subtle amounts of decentration.

Utilizing these sagittal height charts can aid in clinical efficiency in selecting the most appropriate soft contact lens for individuals who have presbyopia. CLS

References

1. van der Worp E, Lampa M, Kinoshita B, Fujimoto MJ, Coldrick BJ, Caroline P. Variation in sag values in daily disposable, reusable and toric soft contact lenses. Cont Lens Anterior Eye. 2021 Dec;44:101386.
2. Zheng F, Caroline P, Lampa M, et al. Visual Effects of Centered and Decentered Multifocal Optics. Poster presented at the 2016 Global Specialty Lens Symposium, Las Vegas. January 2016.