More patients will be turning 40 in the next 4 years than ever before in history. As the size of the presbyopic population grows, optometrists need to make sure they have the technology and know-how to fit the visual needs of these patients.
"Current data show that of 100 million presbyopes in this country, only 1.3 million are wearing multifocal contact lenses. However, results of a Contact Lens Council survey of presbyopic patients showed that more than 83% of those polled would like to try contact lenses if they were available to satisfy their individual eye care needs," said Dr. Kading, a private practitioner from Specialty Eyecare Group in Seattle.
"Additionally," he continued, "results of a crossover study comparing monovision and multifocal contact lenses showed that three-fourths of patients preferred multifocal contact lens wear over monovision.
Getting the fit right
Dr. Kading presented the steps necessary to achieve success with multifocal contact lens fitting. Among the first factors to consider are the types of visual improvement aids used by the patient in the past, along with the individual's visual demands as they relate to occupation and hobbies. An honest doctor/patient discussion about patient expectations and the visual and mental adaptations they must make to these new lenses is also a necessity
"I tell patients that I will customize the fit based on their activities, prescription, pupil size, and topography," he said. "It is important that patients realize this is a process being specifically designed for them. However, they also need to accept that with multifocal contact lenses, their vision is not going to be the same as it was when they were 23."
Patients must be told there may be changes to their vision over time, that it may not always be crisp initially, and that they may experience some symptoms, such as shadows or halos, depending on their pupil size, lighting environment, and the design and fit of the lenses.
The fitting process
Patients who are being transitioned from monovision to a multifocal contact lens may need a washout period to regain binocularity. Eye dominance should be checked, Dr. Kading noted, because the lens power for the dominant eye should be favored for optimal distance vision. However, not all patients will manifest a strong eye dominance.
"Some patients appear to see equally well with both eyes," he said, "and they are the easiest to fit. During dominance testing, those who say they can't see anything clearly with either eye have strong binocular connectivity in their visual system, and that is difficult to break. Consequently, these patients are the most difficult to fit into multifocal lenses."
When fitting patients who need a soft toric multifocal contact lens, Dr. Kading said the first goal is to optimize the distance prescription. Therefore, he begins fitting these patients with the lowest add possible while he works to balance the cylinder and axis of the astigmatism correction.
"Making sure the patient has good distance vision at the end of the initial fitting is a critical goal," he said. "These patients walked into your office seeing well at distance, and they will be upset if you take that away. Patients who maintain good distance vision will wear their lenses into their follow-up exam. If not, you can expect them to carry their lenses in and ask for their money back."