Bausch & Lomb PureVision Multi-Focal Contact Lenses - Manual (Page 7)

fessional for each individual patient, based upon a full examination and
patient history as well as the practitioner's experience and professional judg-
ment. Bausch & Lomb recommends beginning continuous wear patients with
the recommended initial daily wear schedule, followed by a period of daily
wear, and then gradual introduction of continuous wear one night at a time,
unless individual considerations indicate otherwise.
The practitioner should examine the patient in the early stages of continuous
wear to determine the corneal response. The lens must be removed, cleaned
and disinfected or disposed of and replaced with a new lens, as determined by
the prescribing eye care professional. (See the factors discussed in the
Warnings section.) Once removed, a lens should remain out of the eye for a
period of rest overnight or longer, as determined by the prescribing eye care
professional.
MULTI-FOCAL FITTING GUIDELINES:
1. Patient Selection
A. Good motivation
B. Realistic expectations
2. Lens Selection
A. Select the patient’s distance spectacle sphere (must be in minus cylin-
der form, ignore the cylinder) and vertex, if necessary.
B. Select the appropriate ADD.
• Bausch & Lomb PureVision® Multi-Focal Low Add: +0.75D to +1.50D.
• Bausch & Lomb PureVision® Multi-Focal High Add: +1.75D to +2.50D.
3. Lens Fitting
A. Equilibrate for 10 minutes.
B. Lens should center well with 0.5 – 1.0mm movement in primary gaze,
1.0 – 1.5mm upward gaze.
C. Check distance acuity monocularly in normal room illumination.
D. Over-refract if necessary in 0.25D steps to 20/25.
E. Check distance acuity binocularly. Over-refract if necessary in 0.25D
steps to 20/20.
F. Check near acuity binocularly, with distance over-refraction still in place.
4. Symptom Resolution
A. Acuity – 0.25D makes a significant difference in acuity, re-check near and
distance acuities with over-refraction in place.
B. Distance visual acuity not acceptable –
If patient is wearing two Low ADD lenses:
1. Add –0.25D to the dominant eye.
If patient is wearing two High ADD lenses:
1. Add –0.25D to the dominant eye.
2. Use a Low ADD in the dominant eye and a High ADD in the
non-dominant eye.
C. Near visual acuity not acceptable –
If patient is wearing two Low ADD lenses:
1. Add +0.25D to the non-dominant eye
2. Use a Low ADD in dominant eye and High ADD in non-dominant eye
3. If near vision is still not acceptable, use High ADD in both eyes
If patient is wearing two High ADD lenses:
1. Add +0.25D to non-dominant eye.
5. Patient Education
All patients do not function equally well with multifocal correction. Patients
may not perform as well for certain tasks with this correction as they have
with multifocal reading glasses. Each patient should understand that multi-
focal correction can create a vision compromise that may reduce visual acu-
ity and depth perception for distance and near tasks. During the fitting
process it is necessary for the patient to realize the disadvantages as well
as the advantages of clear near vision in straight ahead and upward gaze
that multifocal contact lenses provide.
MONOVISION FITTING GUIDELINES:
1. Patient Selection
A. Monovision Needs Assessment
For a good prognosis the patient should have adequately corrected dis-
tance and near visual acuity in each eye. The amblyopic patient or the
patient with significant astigmatism (greater than one [1] diopter) in one
eye may not be a good candidate for monovision with the PureVision
Multi-Focal Contact Lenses. Occupational and environmental visual
demands should be considered. If the patient requires critical vision
(visual acuity and stereopsis) it should be determined by trial whether
this patient can function adequately with monovision. Monovision con-
tact lens wear may not be optimal for such activities as:
(1) visually demanding situations such as operating potentially danger-
ous machinery or performing other potentially hazardous activities;
and
(2) driving automobiles (e.g., driving at night). Patients who cannot
pass their state drivers license requirements with monovision correc-
tion should be advised to not drive with this correction, OR may
require that additional over-correction be prescribed.
B. Patient Education
All patients do not function equally well with monovision correction.
Patients may not perform as well for certain tasks with this correction as
they have with multifocal reading glasses. Each patient should under-
stand that monovision can create a vision compromise that may reduce
visual acuity and depth perception for distance and near tasks. During
the fitting process it is necessary for the patient to realize the disadvan-
tages as well as the advantages of clear near vision in straight ahead
and upward gaze that monovision contact lenses provide.
2. Eye Selection
A. Ocular Preference Determination Methods
Generally, the non-dominant eye is corrected for near vision. The follow-
ing test for eye dominance can be used.
Method 1 - Determine which eye is the "sighting dominant eye." Have
the patient point to an object at the far end of the room. Cover one eye.
If the patient is still pointing directly at the object, the eye being used is
the dominant (sighting) eye.
Method 2 - Determine which eye will accept the added power with the
least reduction in vision. Place a trial spectacle near add lens in front of
one eye and then the other while the distance refractive error correction
is in place for both eyes. Determine whether the patient functions best
with the near add lens over the right or left eye.
B. Refractive Error Method
For anisometropic corrections, it is generally best to fit the more hyper-
opic (less myopic) eye for distance and the more myopic (less hyperopic)
eye for near.
C. Visual Demands Method
Consider the patient's occupation during the eye selection process to
determine the critical vision requirements. If a patient's gaze for near
tasks is usually in one direction correct the eye on that side for near.
Example:
A secretary who places copy to the left side of the desk will usually
function best with the near lens on the left eye.
3. Special Fitting Considerations
Unilateral Lens Correction
There are circumstances where only one contact lens is required. As an
example, an emmetropic patient would only require a near lens while a
bilateral myope may require only a distance lens.
Example:
A presbyopic emmetropic patient who requires a +1.75 diopter add
would have a +1.75 diopter lens on the near eye and the other eye left
without a lens.
A presbyopic patient requiring a +1.50 diopter add who is -2.50 diopters
myopic in the right eye and -1.50 diopters myopic in the left eye may
have the right eye corrected for distance and the left uncorrected for
near.
4. Near Add Determination
Always prescribe the lens power for the near eye that provides optimal near
acuity at the midpoint of the patient's habitual reading distance. However,
when more than one power provides optimal reading performance,
prescribe the least plus (most minus) of the powers.
5. Trial Lens Fitting
A trial fitting is performed in the office to allow the patient to experience
monovision correction. Lenses are fit according to the directions in the
general fitting guidelines.
Case history and standard clinical evaluation procedure should be used to
determine the prognosis. Determine which eye is to be corrected for dis-
tance and which eye is to be corrected for near. Next determine the near
add. With trial lenses of the proper power in place observe the reaction to
this mode of correction.
Immediately after the correct power lenses are in place, walk across the
room and have the patient look at you. Assess the patient's reaction to dis-
tance vision under these circumstances. Then have the patient look at
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