Forget the Humble GP Sphere
JOHN MARK JACKSON, OD, MS, FAAO
Sometimes it's the obvious things in life that
elude us. Recent reports show that new cosmetic GP lens fits are on the decline.
I've made it my personal mission to see that our graduates are comfortable
fitting GP lenses, but I realized recently that I'm guilty of not always offering
them to patients when I should.
1. GP lens with even alignment and good lid attachment.
Soft Lens Woes
I recently saw a patient who had a long history of soft toric
lens wear and wasn't satisfied with her lenses. She's in her mid-30s and stated
that her vision had always been "good enough," but not crisp with her contact lenses.
She also noted that previous practitioners had tried numerous lenses with only moderate
success. Her manifest prescription was OD –7.00 –1.25 x010 and OS –6.50
–1.25 x170. Her K values were OD 46.00/47.00 @ 102 and OS 46.00/47.00 @ 090.
Her ocular tissues were all unremarkable.
We tried several brands of soft toric lenses over time, and she
experienced problems with all of them: Excessive rotation, borderline acuity, discomfort
from dryness and a "film" that developed on the lenses within a few days. Changing
cleaning regimens and makeup didn't help, either.
A Simple Solution
We were all getting frustrated when a student asked, "Why don't
we try a pair of GP lenses?" Even though I know better, I inwardly sighed and began
a mental list of reasons not to try them (patient nonacceptance and adaptation difficulties
being the main ones). I then realized that the student was correct and we hadn't
offered the patient the obvious solution to her problem. She had a textbook-perfect
situation for successful GP lens wear: About 1.00DC of with-the-rule corneal and
refractive astigmatism and an upper lid that covered the limbus, allowing for good
lid attachment. We also believed that she would find the lenses easier to care for
and to keep clean.
was eager to try something new, so we ordered a pair of lenses with the following
parameters: Starlens (X-Cel) design, Paragon HDS material, OD 7.58mm base curve,
9.6mm overall diameter (OAD), –6.00D power; OS 7.58mm base curve, 9.6mm
At the dispensing visit, she was a little unsure about the initial
lens awareness but claimed that her vision was better than with any lenses she'd
tried before (20/15 OU) and even better than with her glasses. The lenses fit well
(Figure 1) with even alignment and good lid attachment. We taught her application
and removal and lens care techniques, then scheduled her for a follow-up visit a
Like No Other (Soft) Lens
By the next visit, she was wearing the lenses for almost the whole
work day. She was thrilled with her vision and was adapting well. She was also pleased
with the ease of cleaning and that no "film" developed on the lenses. Her main question
was: "Why hasn't anyone offered these lenses before?"
Why indeed. This column regularly discusses GP lens fitting from
the simple to the complex, and while complicated fits are fun to read about,
sometimes the simple fits are the most rewarding for patients. Offer GP
lenses to your patients when they're appropriate - you'll be glad you did.
Dr. Jackson is an assistant
professor at Southern College of Optometry where he works in the Advanced Contact
Lens Service, teaches courses in contact lenses and performs clinical research.
Contact Lens Spectrum, Issue: August 2005