PROFESSIONAL
FITTING AND
INFORMATION
GUIDE
BOSTON® MultiVision
(enflufocon A) Contact Lens
Rigid Gas Permeable
Contact Lenses for Daily Wear
TABLE OF CONTENTS
Introduction
Product Description
Lens Parameters Available
Indications
Contraindications, Warnings, Precautions,
and Adverse Reactions
Selection of Patients
Pre-Fitting Examination
Fitting Guide
In-Office Care of Trial Lenses
Recommended Initial Wearing Schedule
Clinical Assessment
Criteria of a Well-fitted Lens
Optimizing Fitting Characteristics
Problem Solving
Modified Monovision Fitting Guidelines
Patient Lens Care Directions
Laboratory Lens Cleaner
Care for a Sticking (Non-Moving) Lens
Reporting of Adverse Reactions
How Supplied
INTRODUCTION
Boston® MultiVision (enflufocon A) Contact Lenses are made from the Boston ES® (enflufocon A) fluoro silicon acrylate material with a water content of <1% by weight.
For a complete listing of a vailable lens parameters, please refer to LENS PARAMETERS AVAILABLE.
PRODUCTDESCRIPTION
The Boston ES® (enflufocon A) is composed of aliphatic fluoroitaconate siloxanyl methacrylate copolymer including a color additive (D &C Green No . 6) with an ultraviolet absorber (Uvinul D-49).
The lenses described above can have a center thickness of 0.10 to ~0.69 mm that will vary with lens design and power.
The physical/optical properties of the lens are:
Specific Gravity |
1.22 |
|
Refractive Index |
1.443 |
|
Light Absorbance (640 nm) |
10.2 |
(absorbance units/inch) |
Surface Character |
Hydrophobic |
|
Wetting Angle |
52° |
|
Water Content |
<1% |
|
Oxygen Permeability |
36* (18**) |
|
{x 10-11 (cm3 O2 • cm)/(cm2 |
• sec • mmHg) @ 35° C} |
|
*gas to gas method |
|
|
**polarographic method (ISO/Fatt)
BOSTON® ES - 0.07 mm thick BOSTON ES (Blue)
CORNEA - Human cornea from a 24-year-old person as described in Lerman, S., Radiant Energy and the Eye, MacMillan, New York, 1980, p. 58.
CRYSTALLINE LENS - Human crystalline lens from a 25-year-old person as described in Waxler, M., Hitchins, V.M., Optical Radiation and Visual Health, CRC Press, Boca Raton, Florida, 1986, p. 19, figure 5.
NOTE
The effectiveness of wearing UV-absorbing contact lenses in preventing or reducing the incidence of ocular disorders associated with exposure to UV light has not been established at this time.
WARNING
UV-absorbing contact lenses are NOT substitutes for protective UV-absorbing eyewear such as UV-absorbing goggles or sunglasses. Persons should continue to use their protective UV-absorbing eyewear as directed.
INDICATIONS
The BOSTON® MultiVision (enflufocon A) Contact Lens is indicated for daily wear for the correction of refractiv e ametropia (myopia, hyperopia, astigmatism and presbyopia) in not aphakic persons with non-diseased eyes, who exhibit astigmatism of 4.00 diopters or less and can obtain satisfactory visual acuity. The lens provides a nomi - nal functional add of +1.50 diopters. The lens may be disinfected using a chemical disinfecting system only.
CONTRAINDICATIONS (REASONSNO T TO USE)
DO NOT USE the BOSTON® MultiVision (enflufocon A) Contact Lens when any of the following conditions exist:
•Acute or subacute inflammation or infection of the anterior chamber of the eye
•Any eye disease, injury, or abnormality that affects the cornea, conjunctiva, or eyelids
•Severe insufficiency of lacrimal secretion (dry eyes)
•Corneal hypoesthesia (reduced corneal sensitivity), if not aphakic
•Any systemic disease that may affect the eye or be exaggerated by wearing contact lenses
•Allergic reactions of ocular surfaces or adnexa that may be induced or exaggerated by wearing contact lenses or using contact lens solutions
•Allergy to any ingredient in a solution which is to be used to care for the BOSTON®MultiVision (enflufocon A) Contact Lenses
•Any active corneal infection (bacterial, fungal, or viral)
•Red or irritated eyes
WARNINGS
Patients should be advised of the following warnings pertaining to contact lens wear:
•Problems with contact lenses and lens care products could result in serious injury to the eye. It is essential that patients follow their eyecare practitioner’s directions and all labeling instructions for proper use of lenses and lens care products, including the lens case. Eye problems, including corneal ulcers, can develop rapidly and lead to loss of vision.
•Daily wear lenses are not indicated for overnight wear, and patients should be instructed not to wear lenses while sleeping.Clinical studies have shown that the risk of serious adverse reactions is increased when daily wear lenses are worn o vernight.
•Studies have shown that contact lens wearers who are smokers have a higher incidence of adverse reactions than nonsmokers.
Practitioner Note: BOSTON® MultiVision
(enflufocon A) Contact Lenses are not sterile when shipped from the Authorized BOSTONManufacturer. Prior to dispensing, clean and disinfect the lens(es) according to the appropriate lens care regimen.
•If a patient experiences eye discomfort, excessive tearing, vision changes, or redness of the e ye, the patient should be instructed to immediately remo ve lenses and promptly contact his or her eyecare practitioner.
PRECAUTIONS
•Special Precautions for Eyecare Practitioners:
•Due to the small number of patients enrolled in clinical investigation of lenses, all refractive powers, design configurations, or lens parameters available in the lens material are not evaluated in significant numbers. Consequently, when selecting an appropriate lens design and parameters, the eyecare practitioner should consider all characteristics of the lens that can affect lens performance and ocular health, including oxygen permeability, wettability, central and peripheral thickness.
•The potential impact of these factors on the patient's ocular health should be carefully weighed against the patient's need for refractive correction;therefore, the continuing ocular health of the patient and lens performance on the eye should be carefully monitored by the prescribing eyecare practitioner.
•Before leaving the eyecare practitioner’s office, the patient should be able to properly remo ve lenses or should have someone else available who can remove the lenses for him or her .
•Eyecare practitioners should instruct the patient to remove the lenses immediately if the e ye becomes red or irritated.
•The presence of the ultraviolet (UV) light absorber in the BOSTON® MultiVision (enflufocon A)l contact lens material may require equipment enhancement to visualize fluorescein patterns adequately. (Refer to the FITTING PROCEDURE for detailed instructions.)
Eyecare practitioners should carefully instruct patients about the following care regimen and safety precautions:
•Different solutions often cannot be used together, and not all solutions are safe for use with all lenses. Use only recommended solutions.
–Do not heat the conditioning/storage solution and lenses. Keep them away from extreme heat.
–Always use fresh unexpired lens care solutions .
–Always follow directions in the package inserts for the use of contact lens solutions.
–Use only a chemical (not heat) lens care system.Use of a heat (thermal) care system can warp the BOSTON® MultiVision (enflufocon A) Contact Lenses .
–Sterile unpreserved solutions, when used, should be discarded after the time specified in the labeling directions.
–Do not use saliva or anything other than the recommended solutions for lubricating or wetting lenses.
–Always keep the lenses completely immersed in the recommended storage solution when the lenses are not being worn (stored). If dry storage is desired to store the lenses for a longer period of time, they must first be
cleaned, rinsed with water and carefully dried by blotting with a soft lint-free tissue prior to being placed in a clean, dry lens storage case. Ideally, these lenses should be cleaned and disinfected prior to insertion.
•If the lens sticks (stops moving) on the e ye, follow the recommended directions on Care for a Sticking Lens. The lens should move freely on the eye for the continued health of the e ye. If nonmovement of the lens contin - ues, the patient should be instructed to immediately consult his or her eyecare practitioner.
•Always wash and rinse hands before handling lenses. Do not get cosmetics, lotions, soaps, creams, deodorants, or sprays in the eyes or on the lenses. It is best to put on lenses before putting on makeup. Water-based cosmetics are less likely to damage lenses than oil-based products.
•Do not touch contact lenses with the fingers or hands if the hands are not free of foreign materials, as microscopic scratches on the lenses may occur, causing distorted vision and/or injury to the eye.
•Carefully follow the handling, insertion, remo val, cleaning, disinfecting, storing and wearing instructions in the Patient Instructions for the BOSTON® MultiVision (enflufocon A) Contact Lens and those prescribed by the eyecare practitioner.
•Never wear lenses beyond the period recommended by the eyecare practitioner.
•If aerosol products such as hair spray are used while wearing lenses, exercise caution and keep eyes closed until the spray has settled.
• Always handle lenses gently and a void dropping them on hard surfaces.
•Avoid all harmful or irritating vapors and fumes while wearing lenses.
•Ask the eyecare practitioner about wearing lenses during water activities and other sports.
•Inform the patient to alert their health care practitioner (doctor) that they wear contact lenses.
•Never use tweezers or other tools to remo ve lenses from the lens case unless specifically indicated for that use. Pour the lens into the hand.
•Do not touch the lens with fingernails .
• Always contact the e yecare practitioner before using any medicine in the e yes.
•Always inform your employer that you wear contact lenses . Some jobs may require use of e ye protection equipment or may require that the patient not wear contact lenses.
•As with any contact lens, follow-up visits are
necessary to assure the continuing health of the patient’s eyes. The patient should be instructed as to a recommended follow-up schedule.
ADVERSE EFFECTS
The patient should be informed that the following problems may occur :
• Comfort is less than when lens was first placed on the eye
• Feeling of something in the e ye such as a foreign body, scratched area
• Excessive watering (tearing) of the eyes
If the patient notices any of the abo ve symptoms, he or she should be instructed to:
Immediately remove lenses
If the discomfort or problem stops, then closely inspect the lens. If the lens is in any way damaged, do not put the lens back on the eye. Place the lens in the storage case and contact the eyecare practitioner.
If the lens has dirt, an eyelash, or other foreign body on it, or the problem stops and the lens appears undamaged, the patient should thoroughly clean, rinse, and disinfect the lenses;then reinsert them. After reinsertion, if the problem continues, the patient should immediately remove the lenses and consult the e ye care practitioner.
The patient should be informed that the following problems may also occur:
•Eyes stinging, burning, itching (irritation), or other eye pain
•Redness of the eyes
•Reduced sharpness of vision (poor visual acuity)
•Blurred vision, rainbows, or halos around objects
•Sensitivity to light (photophobia)
•Dry eyes
If the patient notices any of the abo ve symptons, he or she should be instructed to:
Immediately remove lenses
When any of the above problems occur, a serious condition such as infection, corneal ulcer, neovascularization, or iritis may be present. The patient should be instructed to keep the lens off the eye and seek immediate professional identification of the problem and prompt treatment to avoid serious eye damage.
SELECTION OF PATIENTS
BOSTON® MultiVision (enflufocon A) Contact Lens is a rigid gas permeable lens for the daily wear patient who may require the correction of visual acuity for myopia, hyperopia, astigmatism or presbyopia.BOSTON® MultiVision (enflufocon A) Contact Lenses are suitable for patients who ha ve never worn contact lenses, for current PMMA wearers, for patients wanting to upgrade their current rigid gas permeable lenses, as well as for some patients who have been unsuccessful with soft contact lenses .
PRE-FITTING EXAMINATION
A pre-fitting patient history and examination are necessary to:
•determine whether a patient is a suitable candidate for daily wear presbyopic contact lenses (consider patient hygiene and mental and physical state),
•make ocular measurements for initial contact lens parameter selection,
•collect and record baseline clinical information to which post-fitting examination results can be compared,
A pre-fitting examination should include distance refraction, keratometry and slit lamp evaluation to rule out any contraindications to contact lens wear. Careful assessment of the cornea, lids, conjunctiva and precorneal
tear film establishes a baseline against which the practitioner can compare any changes resulting from contact lens wear.
FITTING GUIDE FOR THE BOSTON® MultiVision (enflufocon A) CONT ACT LENS
CAUTION: Federal Law Prohibits Dispensing Without a Prescription
Background Information
The BOSTON MultiVision (enflufocon A) Contact Lens consists of a back surface aspheric design intended to provide distance and intermediate correction with a reading addition of +1.50D. The base curves range from 7.3 mm to 8.3 mm, in 0.1 mm steps, with an overall lens diameter of 9.6 mm. The lens parameters and lens design were chosen to maximize the ease of fit.
Fitting Principles
Although these lenses may be empirically fit, the best success has been found when they have been fit using diagnostic (trial) lenses. There are no conversion requirements or special techniques required for fitting this multifocal design. The following guidelines have been provided to maximize the fitting success of the lens.
Initial Base Curve Selection:
If the patient’s corneal cylinder is less than or equal to 1.50D, then the initial base curve selected should corre - spond to the patient’s flat K reading. If the patient’s corneal cylinder is greater than 1.50D, the initial base curve selected should correspond to 0.1 to 0.2 mm steeper than the patient’s flat K reading. In general, the goal of the fit of this multifocal design is to achieve good centration of the lens over the pupil, although superior central posi - tion may also be acceptable. The lens must translate well with the blink (1-2 mm) ensuring that the reading portion of the lens moves over the pupillary area upon down gaze. The patient should be instructed to keep their head erect while moving their gaze to an inferior position (much like progressive addition multifocal spectacle lenses) to maximally utilize the reading portion.
Example:
Step one:
Measure central corneal cur vature and identify the Flat K (lowest dioptric power)
In this example – K = 42.75/44.75 @ 90;Flat K = 42.75D (7.90mm)
The “Flat K”is used as a reference point from which the Base Curve Radius is Chosen.
Step two:
Calculate the corneal astigmatism (difference between the flat and steep K).
In this example – K = 42.75/44 .75 @ 90;Corneal Astigmatism = 2.00D
Step three:
Calculate the Base Cur ve Radius.
In this example – K = 42.75/44.75 @ 90;
Flat K = 7.90D
Corneal Astigmatism = 2.00D |
|
|
Lens Diameter = 9.6 mm |
|
|
Initial Base Curve: |
|
|
Flat K |
42.75D |
7.90mm |
+ Corneal Astigmatism Factor |
0.50D steeper than Flat K |
|
= Initial Base Cur ve |
43.25D |
|
Base Curve Radius |
43.25D |
7.80 mm |
You may use the above method to select your initial base curve or you may refer to the chart below:
Note: Corneal astigmatism greater than 1.50D should be evaluated with a 0.1 mm steeper lens . Greater than 2.50D of corneal astigmatism may require a 0.2 mm steeper lens.
Determine Flat K |
Select Base Curve |
|
|
Recommendation (mm) |
|
Range (diopters) |
Corneal |
Corneal |
|
Astigmatism |
Astigmatism |
|
< 1.50D |
> 1.50D |
40.00 - 40.25 |
– |
8.3 |
40.50 - 40.75 |
8.3 |
8.2 |
41.00 - 41.25 |
8.2 |
8.1 |
41.50 - 41.75 |
8.1 |
8.0 |
42.00 - 42.25 |
8.0 |
7.9 |
42.50 - 42.75 |
7.9 |
7.8 |
43.00 - 43.50 |
7.8 |
7.7 |
43.75 - 44.00 |
7.7 |
7.6 |
44.25 - 44.50 |
7.6 |
7.5 |
44.75 - 45.25 |
7.5 |
7.4 |
45.50 - 45.75 |
7.4 |
7.3 |
46.00 - 46.50 |
7.3 |
– |
With this initial base curve selection evaluate the following:
A. Lens Movement:
The lens MUST move freely with the blink. Poor translation will not place the reading portion of the lens in front of the pupillary zone upon down gaze. If the lens does not translate well, try a flatter base curve. The greatest effect of the add is achieved when the lens interacts with the lo wer lid in down gaze which will facilitate upward translation.
B. Lens Centration:
The lens should center over the pupil in primary gaze and translate upward in down gaze. The greatest effect of the add is achieved when the lens interacts with the lo wer lid in down gaze which will facilitate upward transla - tion.If the lens is not well centered over the pupil in primary gaze (straight ahead) try a steeper base curve.
C. Fluorescein Pattern:
In evaluating the fluorescein pattern, divide the pattern into three zones: central, intermediate and peripheral. The ideal fluorescein pattern is one that demonstrates an aligned to slightly bearing central zone, an aligned intermediate zone and a peripheral zone that demonstrates a slightly high edge. This slightly high edge lift or flu - orescein pooling, is normal as long as there is not a excessive amount of edge lift, i.e., creating bubble formation at the edge or causing the lens to be unstable.
The presence of the UV-absorber in the BOSTON® MultiVision (enflufocon A) contact lens may require equip - ment enhancement to visualize fluorescein patterns adequately. A simple, inexpensive approach is the use of an auxiliary yellow Kodak Wratten #12 filter in conjunction with the cobalt blue filter of the biomicroscope.
Slit Lamp Application:
1.All customary light intensities and filter settings (Cobalt Blue) are left in place.
2.The Kodak Wratten Filter #12* (yellow) is secured on the patient side of the slit lamp microscope with a small piece of adhesive tape.
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