Bausch & Lomb PureVision Multi-Focal Contact Lenses - Manual (Page 6)

eration. The eye care professional must take care in selecting, examining and
instructing contact lens patients. Patient hygiene and willingness to follow
practitioner instructions are essential to their success.
A detailed history is crucial to determining patient needs and expectations.
Your patient should be questioned regarding vocation, desired lens wearing
time (full or part time), and desired lens usage (reading, recreation or hobbies).
Initial evaluation of the trial lens should be preceded by a complete eye exam-
ination, including visual acuity with and without correction at both distance
and near, keratometry and slit lamp examination.
It is normal for the patient to experience mild symptoms such as lens aware-
ness, variable vision, occasional tearing (watery eyes) and slight redness dur-
ing the adaptation period. Although the adaptation period varies for each indi-
vidual, generally within one week these symptoms will disappear. If these
symptoms persist, the patient should be instructed to contact his or her eye
care professional.
FITTING PROCEDURE:
1. Pre-Fitting Examination
A pre-fitting patient history and examination are necessary to:
• determine whether a patient is a suitable candidate for daily wear contact
lenses (consider patient hygiene and mental and physical state),
• make ocular measurements for initial contact lens parameter selection,
and
• collect and record baseline clinical information to which post-fitting
examination results can be compared.
A prefitting examination should include spherocylinder refraction and VA,
keratometry, and biomicroscopic examination.
2. Initial Lens Power Selection
A. Perform a preliminary evaluation to determine distance refraction and
near add requirements.
B. Determine patient’s spherical equivalent refractive error corrected to the
corneal plane.
C. For each eye, select a lens of the power closest to the patient’s spherical
equivalent distance Rx.
D. 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
E. Measure binocular near and distance VA
F. Make adjustments in power as necessary. The use of hand held trial
lenses will simplify fitting and minimize lens changes. To improve near
vision, add plus in +0.25D increments to both eyes. If distance vision
becomes unacceptable with this change, add plus to the non-dominant
eye only. Measure near, then distance VA binocularly then monocularly.
To improve distance vision, add minus in –0.25 increments in both eyes.
If near vision becomes unacceptable with this change, add minus to the
dominant eye only. Measure distance, then near VA, binocularly then
monocularly.
G. Make final lens changes and confirm acuity. Attempt to minimize any
resultant binocular imbalance.
Demonstrate vision:
a. under normal conditions c. in decreased illumination
b. at near in any position of gaze d. at intermediate distances
3. Initial Lens Evaluation
a. To determine proper lens parameters observe the lens relationship to
the eye using a slit lamp.
• Movement: The lens should provide discernible movement with:
– Primary gaze blink – Upgaze blink
– Upgaze lag
• Centration. The lens should provide full corneal coverage.
b. Lens evaluation allows the contact lens fitter to evaluate the
lens/cornea relationship in the same manner as would be done with any
soft lens. If after the lens has settled on the eye, the patient reports
lens sensation, or if the lens is moving or decentering excessively, the
lens should not be dispensed. Alternatively, if the patient reports vari-
able vision, or if the lens shows insufficient movement, the lens should
not be dispensed.
4. Criteria of a Well-Fitted Lens
If the initial lens selection fully covers the cornea, provides discernible
movement after a blink, is comfortable for the patient and provides satis-
factory visual performance, it is a well fitted lens and can be dispensed.
5. Characteristics of a Tight (Steep) Lens
A lens which is much too steep may subjectively and objectively cause dis-
tortion which will vary after a blink. However, if a lens is only marginally
steep, the initial subjective and objective vision and comfort findings may
be quite good. A marginally steep lens may be differentiated from a prop-
erly fitted lens by having the patient gaze upward. A properly fitted lens
will tend to slide downward approximately 0.5mm while a steep lens will
remain relatively stable in relationship to the cornea, particularly with the
blink.
6. Characteristics of a Loose (Flat) Lens
If the lens is too flat, it will:
– Decenter, especially on post-blink.
– Have a tendency to edge lift inferiorly and sit on the lower lid, rather
than positioning between the sclera and palpebral conjunctiva.
– Have a tendency to be uncomfortable and irritating with fluctuating vision.
– Have a tendency to drop or lag greater than 2.0mm on upgaze post-blink.
7. Follow-up Care
a. Follow-up examinations are necessary to ensure continued successful
contact lens wear. From the day of dispensing, the following schedule
is a suggested guideline for follow up:
• 24 hours, 10 days, 1 month, 3 months, then every 6 months
thereafter.
At the initial follow-up evaluations the eye care professional should again
reassure the patient that any of the previously described adaptive symp-
toms are normal, and that the adaptation period should be relatively brief.
Depending on the patients prior experience with contact lenses and/or
continuous wear, the eye care professional may consider prescribing a one
week period of daily wear adaption prior to beginning continuous wear.
b. Prior to a follow-up examination, the contact lenses should be worn for at
least 4 continuous hours and the patient should be asked to identify any
problems which might be occurring related to contact lens wear. If the
patient is wearing the lenses for continuous wear, the follow-up exami-
nation should be conducted as early as possible the morning after
overnight wear.
c. With lenses in place on the eyes, evaluate fitting performance to assure
that CRITERIA OF A WELL FITTED LENS continue to be satisfied. Examine
the lenses closely for surface deposition and/or damage.
d. After the lens removal, instill sodium fluorescein [unless contraindicated]
into the eyes and conduct a thorough biomicroscopy examination.
1. The presence of vertical corneal striae in the posterior central cornea
and/or corneal neovascularization may be indicative of excessive
corneal edema.
2. The presence of corneal staining and/or limbal-conjunctival hyper-
emia can be indicative of an unclean lens, a reaction to solution
preservatives, excessive lens wear, and/or a poorly fitting lens.
3. Papillary conjunctival changes may be indicative of an unclean
and/or damaged lens.
If any of the above observations are judged abnormal, various profes-
sional judgments are necessary to alleviate the problem and restore
the eye to optimal conditions. If the CRITERIA OF A WELL FITTED LENS
are not satisfied during any follow-up examination, the patient should
be re-fitted with a more appropriate lens.
PRACTITIONER FITTING SETS:
Lenses must be discarded after a single use and must not be used from patient
to patient.
WEARING SCHEDULE:
The wearing and replacement schedules should be determined by the eye care
professional. Regular checkups, as determined by the eye care professional,
are extremely important.
Daily Wear:
There may be a tendency for the daily wear patient to over wear the lenses
initially. Therefore, the importance of adhering to a proper, initial daily wear-
ing schedule should be stressed to these patients. The wearing schedule
should be determined by the eye care professional. The wearing schedule
chosen by the eye care professional should be provided to the patient.
Continuous Wear (Greater than 24 hours or while asleep):
The wearing schedule should be determined by the prescribing eye care pro-
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