Prescribing for Presbyopia
Is It the Eye or the Lens?
BY CRAIG W. NORMAN, FCLSA
This issue of Contact Lens Spectrum is dedicated to improving success in contact lens wearers who experience discomfort, whether it is from an existing dry eye condition or is induced by contact lens wear. When a wearer describes these symptoms, the challenge often boils down to a simple differentiation—is it the eye or the lens that is the key etiological factor?
Taking Steps Toward Comfort
The following steps can start the path toward improving patients’, particularly presbyopes’, ability to comfortably wear their lenses.
1. Establish a solid starting point. Always perform a detailed baseline ocular surface evaluation with emphasis on tear quality and volume (invasive or noninvasive tear breakup time [TBUT]), meibomian gland function, blinking cycle time and completeness, and tear meniscus height along with any other tear tests at your disposal). A new feature of the Oculus Keratograph 5M (Oculus, Inc.) can combine slit lamp and objective test findings with a patient dry eye survey, resulting in a comprehensive point of reference called the Jenvis Dry Eye Report (Figure 1). Without establishing a starting point, it will be more difficult to later compare how the eye is reacting to lens wear.
Figure 1. An example of a Jenvis Dry Eye Report.
2. Review the tasks that patients perform while wearing their lenses. At our facility, we see many presbyopic patients and carry out presbyopia-related studies. We’ve found that the biggest obstacle to both functional vision and lens comfort is computer use. With computers and other electronic devices being ubiquitous today, we must reinforce to patients to “think about blink” as a reminder to look away from their device every 15 to 20 minutes and to force blinking for a minute or two; they can also frequently use lubricating drops, if needed.
3. Ensure that you’ve chosen the most compatible lens material. The industry’s focus on increasing oxygen transmission over the past few years has resulted in a number of silicone hydrogel materials, but there’s also been a re-emergence of hydrogel-based designs.
Which material is better? The answer is patient-specific, and while either material is a good initial choice, patient symptoms may point you in a different direction. Some instruments may be helpful here by evaluating how quickly the tear film is breaking up on the front surface of the contact lens.
4. Choose a shorter replacement schedule. Most practitioners will agree that a shorter replacement cycle is better. Luckily, numerous single-use daily disposable multifocals have become available in both hydrogel and silicone hydrogel material options, with more on the horizon (Quinn, 2015; Cox and Nichols, 2015). Whenever possible, I believe that daily disposables are the best choice for soft lens wearers. Clean lenses are more deposit-resistant, potentially decreasing dryness or lens awareness symptoms. Even more importantly, single-use means no lens care, so no need to worry about care solution-related irritation or patient noncompliance.
Follow these steps and use the latest technology to help you answer the question—is it the lens or the eye? CLS
For references, please visit www.clspectrum.com/references and click on document #236.
Craig Norman is Director of Research, Michigan College of Optometry at Ferris State University. He is an advisor to the GP Lens Institute and has received lecture or authorship honoraria from B+L and TruForm Optics. You can reach him at CraigNorman@ferris.edu.