GP Lens Case Grand Rounds Troubleshooting Guide – 21

Advanced Presbyopia (Low Lower Lid): Doug Benoit, OD, FAAO

Background

Patient VR, a 60-year-old retiree, presented for a complete eye examination. He had no complaints with his eyes or vision, but found glasses bothersome for golf and cycling, as well as other activities. He had always been told he was not a candidate for contact lenses due to his astigmatism and his need for a bifocal. His general health was normal and he took only a multivitamin on a daily basis.

Test Procedures, Fitting/Refitting, Design and Ordering

Manifest Refraction:

OD: +2.50 -1.75 x 114
OS: +1.75 -1.50 x 45
Add +2.50 OU

Keratometry:

OD: 41.50 @ 005; 42.75 @ 095
OS: 41.25 @ 170; 42.75 @ 080

This patient was right eye dominant. Slit lamp examination revealed mild meibomian plugging and early nuclear sclerosis. The tear meniscus was of average height and width, without debris. Palpebral fissure height was 11.5mm OU. The upper lid overlapped the superior limbus by 2mm while the lower lid was 1.5mm below the inferior limbus with normal lid tension. The pupil diameter was 3.5mm in normal room illumination.

Despite the patient’s high add requirement, he was a better candidate for an aspheric multifocal than a segmented /translating design due to the position of the lower lid. Being positioned well below the inferior limbus, this might pose a problem for keeping the segment properly positioned in primary gaze as well as allowing proper translation on down gaze.

The Diagnostic Lenses Were the Following:

Essential GP Multifocal (Blanchard)
Base Curve Radius: 8.10mm OU
Overall Diameter: 9.5mm OU
Power: +2.00D OU
Add: +2.00D
Minus Lenticular OU

A topical anesthetic was applied immediately prior to initial lens application. Distance vision: OD 20/20 with a -0.50D over-refraction; OS 20/20 with a -0.75D over-refraction. His near vision was 20/20 OU with a +0.50 OR over the trial lens / distance OR combination. Each lens positioned in a superior-central, lid attachment manner. Movement was good in all positions of gaze with good translation on down gaze. With fluorescein application, a central alignment pattern with good peripheral clearance was exhibited OU. By this point in time, the anesthetic had worn off and comfort was reasonable good.

The Following Lenses Were Ordered:

Essential GP with CSA (a concentric front surface add)

Essential GP Series 2 Multifocal (Blanchard)
Base Curve Radius: 8.10mm OU
Overall Diameter: 9.5mm OU
Power: +1.50D OD, +1.25D OS
Additional Information: +0.50D CSA with a 4.30mm central zone OU
Minus Lenticular OU

The CSA design consists of a paracentral annular zone with additional add power on the front surface of the lens. Any add power can be provided in this zone which relies on the lens naturally shifting upward or translating on downward gaze. As with spherical designs, the use of a minus lenticular will assist in centration with plus power designs by increasing the edge thickness and, therefore, assisting in lid interaction with the superior edge.

Patient Consultation and Education

While he waited for his lenses, the patient was advised to use warm compresses each night for about 5 minutes to help reduce the meibomian plugs and improve the quality/quantity of his tear film. At dispensing, the lenses were inserted without anesthetic. Comfort was good and tearing minimized after about 5 minutes. The distance vision was 20/20 OD, OS, OU. The near vision was only 20/25-, and required an additional +0.50 OU to obtain 20/20 vision.

Each lens had a central to superior-central position in primary gaze. Movement was good but each lens decentered slightly inferiorly after the blink in primary gaze. Translation up was marginal on down gaze. Fluorescein evaluation showed central alignment with adequate peripheral clearance. The patient was eager to try the lenses in the real world so insertion and removal were demonstrated and practiced.

Proper care using the Boston Advance Comfort Formula solution system was reviewed. The patient was reminded of the need to gradually increase wear time, starting at no more than 4 hours the first day, and adding 2 hours per day up to a maximum of 14 hours. The patient was also reminded that changes in lens parameters might be necessary.

Follow-Up Care/Final Outcome

At the one week follow-up, the patient was satisfied with the comfort and distance vision, but found the near vision blurred. Distance vision was 20/20 OD ,OS, OU. Near vision was 20/30 OD, OS, OU. An over-refraction of +0.50D again improved the near vision to 20/20. Both lenses had a central to superior-central position in primary gaze, and feel slightly inferior after the blink. Translation was adequate with downward gaze.

The application of fluorescein showed central alignment with adequate peripheral clearance. In order to correct the near vision problem and enhance the fit, each lens was reordered using a Series 3 Add and leaving everything else unchanged. The Series 3 has a flatter posterior aspheric geometry than the Series 2, which should increase lid attachment and increase peripheral clearance,
while also helping the near vision via a higher effective add. The patient was allowed to continue wearing the first pair until the new pair arrived.

The new lenses were dispensed and resulted in good subjective comfort OU. The distance and near vision were OD 20/20; OS 20/20. Each lens had a superior-central position in primary gaze and good movement in all positions of gaze. Translation on down gaze was very good, positioning the near area in front of the pupil OU. With fluorescein application, central alignment with good peripheral clearance was present OU. At the next progress evaluation 10 days later, the patient was very happy with the vision at all distances. Vision and physical fit remained unchanged from the dispensing visit.

Discussion/Alternative Management Options

If the patient drops the head too much, they are always looking through the distance portion of the lens and near vision is compromised. This patient was not really a good candidate for a segmented/translating GP design due to the low lower lid position. In such cases it is difficult to get a segment height that will provide good near vision. If the lid tension was low, the lens may not translate properly either, which further complicates efforts to obtain good near vision.

A soft toric bifocal or multifocal could have been used for this patient, although vision may have been less at all distances and it may be unstable as soft lenses tend to be torqued by the lids more than GP lenses. In this patient, the mild dry eye might also have made soft lenses a poor choice due to their greater dependence on the tear film for fluid.

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