prescribing for presbyopia
Fitting
Emmetropic Presbyopes
BY MARY JO
STIEGEMEIER,
OD, FAAO
Many practitioners shy away from fitting
emmetropic presbyopes, most of whom have never before needed visual correction and
have difficulty accepting near correction because it can
blur
their exceptional distance vision. Although this patient population can prove difficult
to fit, doing so can grow your contact lens practice because 25 percent of patients
age 40 or older who need correction are emmetropic presbyopes.
Start by listening to your patients'
needs. Explore their motivation for contact lenses, as well as their occupational
and hobby-related visual needs. This strategy will help you select the correct modality
of correction.
A Tale of Three Patients
Following are three cases
of emmetropic presbyopes and the approaches you can take for each.
Patient A is a 47-year-old
female non-lens wearer whose habitual correction was +1.00 OU reading glasses. Her
manifest refraction is OD plano 20/20 add +1.75, OS plano 20/20 add +1.75. She hates
her spectacles and complains about needing to put them on and losing them when she
takes them off.
Monovision could work for this patient.
Start with no lens on the dominant eye and a lower power lens on the non-dominant eye (+1.25D or +1.50D) for near.
After adaptation, increase the power of the nondominant eye for better near vision.
You could also use a simultaneous
vision multifocal lens such as Bausch & Lomb's SofLens 66 Multifocal or
Unilens Corp.'s C-Vue 55 Multifocal OU with plano distance power and a lower add.
This doesn't blur the distance and offers improved mid-range and near vision. You
could achieve a similar effect using CooperVision's Frequency 55 Multifocal in plano
OU and +1.50D add using two D lenses. Later, consider increasing the reading prescription
by fitting a plano +1.50D D lens on the nondominant eye and a plano +1.50D N lens
on the dominant eye.
Patient B is a 62-year-old
male non-lens wearer whose habitual correction was +2.00 OU reading glasses. His
manifest refraction is OD +1.50 20/20 add +2.50, OS +1.50 20/20 add +2.50. His chief
complaints are that he can't see golf balls anymore and that when he wears his reading
glasses and looks up, some distance objects are more in focus. He doesn't want to wear glasses full time and
especially not for driving.
For this patient, the slam dunk
approach is to push plus OU with single vision lenses. If you push at least +0.50D
OU, then he achieves 20/25+ with great intermediate vision and a great improvement
overall. He keeps the +2.00 readers to use over his lenses, and he's back in his
vision "comfort zone." His final prescription was +2.00 sphere OU.
Patient C
is a 52-year-old
female non-lens wearer whose habitual correction is full-time progressive addition
lenses. Her manifest refraction is OD –0.50 sphere 20/20 add +2.00, OS –0.75
sphere 20/20 add +2.00. She's acutely aware of both distance and near vision quality.
My initial approach is a simultaneous
vision multifocal lens. Assuming that the right eye is the dominant eye, apply diagnostic
lenses of –0.50D with "low" add OD and –1.00D with "high" add OS. If
distance vision is uncompromised and near vision isn't adequate, then try –0.75D
with "high" add OD and –1.00D with "high" add OS.
Another option is a modified bifocal
approach. If distance vision is most critical, then use a right single vision distance
lens with a left simultaneous multifocal. Conversely, if near vision is
most critical, use a simultaneous vision multifocal OD and a spherical near lens
OS.
Dr. Stiegemeier
is in private practice in Beachwood, Ohio. She lectures throughout the country
on the subject of contact lenses and performs clinical research.
Contact Lens Spectrum, Issue: July 2005