Techniques for the Presbyopic Patient
MARY JO STIEGEMEIER, OD, FAAO
Streamlining over-refraction can decrease chair
time when fitting presbyopes. I modify techniques for presbyopic contact lens patients
and adapt them even further for a monovision approach, a standard binocular
bifocal approach, or a modified bifocal approach. approach,
a standard binocular bifocal approach or a modified bifocal approach.
When the option is monovision, first do a good manifest refraction
with balance. Note the most plus, least minus correction for the distance and least
amount of add for acceptable near. Select the dominant eye as the distance eye and
insert the most plus, least minus correction. On the nondominant, or near eye, select
the least plus that will achieve adequate near acuity to begin.
Over-refract binocularly and record binocular vision using this
modified technique. Show the patient the Snellen chart with both eyes open. Over
the distance eye, show +0.50D and then –0.75D. If your distance sphere is
correct, both of those will be rejected; if accepted, demonstrate the change by
only 0.25D. Then over that lens, again show +0.50D and then –0.75D. Again,
when both are rejected you'll be at your final sphere.
With the best distance sphere in place, present the reading chart
at the appropriate distance for that patient. Begin the over-refraction at near
by showing –0.75D over the reading eye. If the vision is good and –0.75D
makes it worse, stop. If vision isn't adequate and –0 .75D doesn't improve
it, add plus in 0.25D steps until you achieve adequate vision. Changes for distance
and near should be small and infrequent with an excellent manifest refraction.
When over-refracting with the standard bifocal approach, it's
helpful to consider whether the patient is wearing a distance-center or near-center
For distance-center designs, on both eyes apply the most plus,
least minus correction for distance with the least amount of add acceptable for
near. Again, take binocular acuities and use your retinoscope to see if you scope
plus or minus. If you scope any plus, show that to the patient in +0.25D intervals
binocularly to see if he'll accept it. You should need to adjust the distance power
by only 0.25D either way with a correct manifest refraction.
Once you establish the distance power, take binocular near acuities.
If the acuity is acceptable for near, stop there. If it's not acceptable, show small
amounts of plus on the non-dominant eye initially and adjust either the add power
or distance power accordingly. Again, make changes in as small an increment as possible
and in only one eye to help maintain maximum acuity and binocularity. Recheck distance
acuity if changes are made for near. You may need to repeat the process.
If the design is near center, again apply on both eyes the most
plus, least minus correction for distance with the minimal add. Use the retinoscope
and the ophthalmoscope to view the add in the pupil and to evaluate the retinoscopy
reflex in the periphery of the pupil. Next, over-refract the patient, keeping in
mind that the patient may take a lot more minus than necessary for distance. The
patient will "eat minus" to negate his add if he is looking through the wrong zone
of the lens.
Modified Bifocal Approach
When prescribing a modified bifocal approach, make changes based
on binocular vision and the over-refraction technique described in the monovision
approach. Over-refract the dominant eye for distance and the non-dominant eye for
near in 0.25D steps.
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: March 2006