contact lens case reports
Translating Bifocal Lenses: Top Pick for Presbyopes
BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO
When it comes to the optics of presbyopic contact lenses, it's tough to beat GP materials and lens designs. We believe that a major advantage of rigid lenses over their soft lens counterparts is the correction of any and all underlying corneal astigmatism.
Problems, Pluses of Design
Currently, there are a wide range of GP lens options for presbyopic patients (Figure 1). Often over-looked is GP lens monovision for patients who have corneal astigmatism. These lenses provide a number of optical advantages over toric soft lenses in the monovision modality. Additionally, as previously reported, hyperopic monovision has been an exciting option for some of our emmetropic presbyopes.
However, when it comes to the crème-de-la-crème of presbyopic contact lens optics, it's often the translating bifocal that stands alone at the top of the mountain.
Figure 1. Some of the common GP and hybrid lens designs for presbyopia.
No one will argue that these lenses aren't without their problems. They require ballasting to position the near segment in its inferior position and they must interact with the lower lid to facilitate translation. Determining the appropriate segment height (for all photopic and scotopic conditions) can be a challenge. Despite these obstacles, when the stars (and the lenses) are in perfect alignment, nothing seems to provide better optics and long-term patient satisfaction quite like a translating bifocal lens design.
A case in point is our patient who at age 57 we fit with a pair of Tangent Streak translating trifocal lenses (Fused Kontacts). Lost to follow up, this now 62-year-old executive returned to our practice with 20/20 distance acuity OD and OS and perfect 20/20 near acuity.
He works at a computer five to six hours a day and states that his trifocals with their +1.25D power serve him well (Figure 2). His reason for returning to our clinic was for a routine follow-up examination, a new glasses prescription and a back-up pair of contact lenses. We ordered new lenses with no changes in the current lens parameters.
Clinical experience has taught us that once these individuals are successfully fitted with translating lens designs, they often continue to flourish with the modality for years. If ocular health and long-term patient satisfaction are the benchmarks of fitting success, then in our experience translating GP lenses may be an ideal choice for many advancing presbyopes. CLS
Figure 2. Patient's translating trifocal GP lenses.
Patrick Caroline is an associate professor of optometry at Pacific University. He is also a consultant to Paragon Vision Sciences and SynergEyes, Inc. Mark André is an associate professor of optometry at Pacific University. He is also a consultant for CooperVision and SynergEyes, Inc.