prescribing for presbyopia
From
GPs to GP Multifocals — A Natural Progression
BY
MARY JO STIEGEMEIER, OD, FAAO
Resbyopic patients are often perfect candidates
for GP multifocal lenses. For many patients these lenses offer an opportunity
to have uncompromised distance and near acuity. GP multifocallenses are avcals
are available in two general categories: Simultaneous and translating or alternating.
Simultaneous lenses present distance and near optics at the same time. You can control
the proportion of distance and near optics to some extent, and these lenses translate
slightly upward in downgaze, improving near performance. Alternating designs can
fit "on alignment" and are designed to have one optic in front of the pupil at a
given time. During downgaze the lens must translate superiorly so the pupil can
access the near segment. Alternating designs are available in a wide parameter range
with high adds.
Progressing Through the Years
Current GP lens wearers are excellent candidates for GP multifocal
contact lenses. You can "age enhance" these lenses to help your patients transition
through emerging presbyopia to mature presbyopia. Take the following case, for example.
Patient LD, presently age 62, was an adapted GP contact lens wearer
when she became presbyopic, making her a great candidate for the transition into
GP multifocals.
In 1985 at age 42, she successfully wore Polycon lenses with a
prescription of OD 7.40 9.5 –5.75 20/20 distance and near, OS 7.50 9.5 –4.75
20/20 distance and near. Her manifest refraction was OD –6.25 –0.75
x 085 20/20 no add, OS –5.25 –0.75 x 095 20/20 no add, and she had keratometry
readings of OD 45.50/46.00, OS 45.00/45.50.
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Figure 1. Fluorescein pattern of LD's translating
GP design. |
In
1990 at age 47 we successfully refit her into VFL II simultaneous vision lenses
(Conforma Contact Lens) manufactured in Fluoroperm 30 (Paragon Vision Sciences)
in the following parameters: OD 7.20 9.5 –8.25 20/25 +2 Jaeger 1, OS 7.10
9.5 –8.00 20/25 Jaeger 1. Her manifest refraction was OD –6.00 –1.00
x 075 20/20 +1.75 add Jaeger 1, OS –5.50 –1.50 x 105 20/20 +1.75 add
Jaeger 1, and she had Ks of OD 45.00/46.00, OS 45.00/
46.25.
LD wore this simultaneous vision lens design for nine years, until
her add progressed to full +2.50D. She complained of slightly blurred distance acuity,
but good near acuity; when we improved distance acuity, we couldn't achieve adequate
near acuity.
In 1999 we switched LD into a GP translating design originally
in Boston ES, now in Boston EO (Bausch & Lomb) material in the following prescription:
OD 7.50 –5.50 9.5/9.2 4.5 segment height 1.5 prism +2.50 add 20/20 distance
and near, OS 7.50 –4.75 9.5/9.2 4.5 seg. ht. 1.5 prism +2.50 add 20/20 distance
and near (Figure 1). Her manifest refraction was OD –6.00 –1.00 x 075
20/20 +2.75 add Jaeger 1, OS –5.25 –1.25 x 105 20/20 +2.75D add Jaeger
1. Her Ks and topography were OD 45.25/46.00, OS 45.00/46.00, clear mires.
Best Vision for Presbyopes
Both simultaneous multifocal GP designs and translating GP designs
can provide excellent visual capabilities and healthy physiology. Today's high-Dk
contact lens materials and improved designs will ensure visual and physiological
success.
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: November 2005