Contact Lens Practice Pearls
When Multifocals Don’t Succeed
BY GREGORY J. NIXON, OD, FAAO
With the proliferation of smart phones, tablets, e-readers, and laptops, the near visual demands of our patients are higher than they have ever been. This can create significant challenges for our emerging and established presbyopic patients, whose blurred near vision can interfere with daily tasks. Thankfully, the expansion of new multifocal designs in recent years has helped meet the needs of this growing demographic. With so many tools to work with, presbyopic fitting has become increasingly fun since we are able to celebrate success with more new multifocal lens wearers. However, we still need to be prepared for the times when multifocals don’t meet our patients’ needs.
Case in Point
The most common cause of multifocal failure is lack of achieving an adequate balance of distance and near clarity. I recently saw a busy working mother who inquired about a contact lens fitting to help with her hectic lifestyle. She is a 45-year-old emmetropic presbyope who has succumbed to wearing reading glasses in the last year. While they provide her adequate near clarity, putting them on and taking them off throughout the day is not conducive to her demanding work environment. We attempted to fit her in a variety of multifocal lens designs that included center-distance lenses in both eyes, center-distance in her dominant eye and center-near in her nondominant eye, and center-near lenses in both eyes. Despite obtaining 20/20 acuity at distance and near, each combination of multifocals lacked the adequate distance clarity when driving and watching her kids’ sporting events. By going uncorrected in her dominant eye and using a low-add, center-near multifocal with an additional +0.25D correction in her nondominant eye, her optimal balance of distance and near clarity was achieved.
Weighing the Options
While some automatically choose monovision as the preferred mode of correction for early presbyopes, it is my experience that patients enjoy the more natural vision at all distances provided by a multifocal lens. This is supported by studies in which early presbyopes have compared the modalities. Studies by Richdale et al (2006) and Woods et al (2009) highlight subjects choosing multifocals over monovision as their preferred mode of correction.
While I regularly find this to be the case in practice, there are times that I have found it particularly challenging for multifocals to maintain distance clarity in emmetropic presbyopes or those who have nominal refractive error. Instead of resorting to traditional monovision, employing a modified monovision approach with a multifocal lens in the nondominant eye rather than a single-vision near lens is a nice alternative. This helps provide a better range of clarity at intermediate and near targets, and it sets the patient up for transitioning into wearing multifocal lenses in both eyes in future years.
For your most sensitive patients who cannot tolerate any compromise from a monovision or multifocal modality, a variety of spectacles can be worn over distance-correcting contact lenses. Prefabricated over-the-counter reading glasses are an inexpensive, convenient option that works well most of the time. But prescribing plano progressive over-spectacles provides patients more freedom and flexibility to leave their glasses on and maintain functional distance, intermediate, and near vision throughout the work day.
Be sure to offer your presbyopic patients multifocal contact lenses. Even though we work with these lenses every day, they still are a well-kept secret among the general public. Let them know about the great advances in technology that can help them keep pace with their busy lives. CLS
For references, please visit www.clspectrum.com/references and click on document #239.
Dr. Nixon is the associate dean for Clinical Services and professor of clinical optometry at The Ohio State University College of Optometry. He is also in a group private practice in Westerville, Ohio. You can reach him at firstname.lastname@example.org.