 
ACCENT TRANSLATING PROGRESSIVE
Pre-Fitting Examination
Assuming there are no contraindications, begin by determining the flatter K reading ("FlatK") and amount of corneal astigmatism. In addition, you want to observe pupil size, the limbal size of the cornea and especially the lower lid position in relationship to the limbus. Caution: A superior lid position may cause the distance optic zone to be too high.
Selecting Lens Size
The recommended lens size is 9.4mm. On rare occasions a larger 9.6mm or smaller 9.2mm may be used.
Choosing Base Curve
Accent is a back surface translating progressive. Its back surface consists of two zones, a central distance aspheric zone that is 3.5mm to 4.0mm in diameter and a spherical near zone. The near zone base curve is the fitting curve. Accent is fit on "K" or slightly steeper than "K". The chart below is an easy reference for base curve design.
| LENS SIZE
|
| CORNEAL CYL, D |
9.2 (8.0 O.Z.) |
9.4 (8.0 O.Z.) |
9.6 (8.0 O.Z.) |
| 0.00 |
On K |
0.25 D flatter to on K |
0.25 flatter to on K |
| 0.25-0.75 |
0.25 D stepper |
On K to 0.25 steeper |
On K to 0.25 D steeper |
| 1.00-1.75 |
0.50 D steeper |
0.25 D steeper |
0.25 D steeper |
| 2.00-2.75 |
0.75 D steeper |
0.50 to 0.75 D steeper |
0.50 steeper to 0.75 steeper |
|
Calculating Lens Power
Lens power is calculated the same as any single vision lens. If you fit steeper than "K" add minus to the distance manifest sphere power. If you fit flatter add plus. In addition, your patients add power need to be indicated. Note: Since Accent has two base curves, the central distance and the peripheal near, lens verification will not match the ordered parameters. It is recommended that you call our laboratory if you desire more detailed parameter information.
Fluorescein Pattern
Since Accent is a translating progressive with prism; its distance zone is displaced superior to the geometric center of the lens. The ideal pattern shows a steep fluorescein pattern in the central distance zone superimposing the pupil. Perfect papillary coverage is not necessary. A slight inferior decentration will work very well. An alignment pattern should be present in the near zone.
The Ideal Fit
The lens should move freely with the blink and settle to an inferior position on the cornea. Upon downward gaze the lens should translate up on the superior limbus. The ideal fluorescein pattern should show a steep pattern over the pupil with an alignment pattern throughout the rest of the lens.
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