GP lens eye Rounds

PRESBYOPIA: Segmented Translating Multifocal Case

Roxanna Potter OD, FAAO, FSLS

History

• A 46 year-old white female presented wearing spherical corneal GP lenses, complaining of near blur. She stated she was unable to wear spectacles due to discomfort and blur. She reported a long history of amblyopia OS.

Examination

• Entering visual acuities (VAs) were OD: 20/20 and OS: 20/50-2.
  • Her habitual pair of GP lenses were verified to be the following parameters:

OD: 8.22mm/7.40mm/+3.50D Fit: slightly steep fluorescein (NaFl) pattern, lid attached
OS: 8.22mm/7.40mm/+7.75D Fit: alignment NaFl pattern, lid attached

• Refraction and Keratometry:

OD: +3.50 -0.25 x 040, 20/20 40.25 @ 006/41.00 @ 096
OS: +6.75 -0.50 x 035, 20/50-2 39.75 @ 009/41.25 @ 099

• Examination:
  • Pupils, EOM and CVF all WNL
  • Slit lamp examination findings

1. 1. 1. Lids/lashes clear/normal, with lower eyelid sitting at inferior limbus OU
      2. Conjunctiva/sclera/cornea clear/normal OU
      3. Tear film healthy, TBUT > 10 seconds and no notable MGD
      4. Iris/AC clear/normal
      5. Fundus findings unremarkable OU

Decision-Making Process

• The patient had successfully adapted to GP lens wear, but was noting near blur and preferred not to have to use OTC readers overtop. She has mild-to-moderate amblyopia OS which could make it difficult to get acceptable vision in an aspheric/simultaneous design GP multifocals. Her refractive anisometropia caused difficulty with aniseikonia symptoms in spectacles, especially through an add (even with reverse slab-off). A translating GP multifocal design will provide best visual acuity in both eyes, particularly her dominant OD.

Fitting and Evaluation

• Translating progressive GP multifocal lenses were ordered empirically using refraction and keratometry readings.
• Lenses were ordered larger and slightly flatter to allow them to center more inferiorly/rest on lower eyelid OU, although still smaller in OAD than many GP’s due to the higher plus power Rx:

OD: BCR: 8.30mm; OAD: 9.00mm; Power: +7.25D; Add: +1.75D add; Seg Height: 3.6mm; Prism: 1.50
OS: BCR: 8.25mm; OAD: 9.00mm; Power: +3.50D; Add: +1.75D add; Seg Height: 3.6mm; Prism: 1.50

• First dispense: lenses fit well, with slight nasal rotation OU. They exhibited good lower lid apposition after quickly settling post-blink OU. Translation on down gaze was sufficient. VA was 20/20 OD and 20/50 OS at distance, and 20/20 OU at near. Slit lamp examination findings were WNL OU without corneal staining or conjunctival injection.
• One-week follow-up visit: The patient was complaining of a delay in her ability to focus at distance after blinking. The OD lens showed excessive upward movement after blink. A remake for the OD was ordered with a small change in power (over-refraction of +0.25D) and increased prism to 2.00 allowed the lens to settle faster post-blink. No changes were made to the left lens.
• One-month follow-up visit: The patient was happy with vision and comfort. Lenses were finalized OU.

Clinical Pearls

• Translating GP multifocal lenses are a good option for patients requiring the best visual acuity possible (in this case a functionally monocular patient).
• The easiest patients to fit in translating GPs are those that are already adapted to GP lens wear, although soft lens wearers can do so successfully when they are willing to go through an adaptation period of a few weeks.
• Translating GP multifocal lenses are most successful when the patient’s lower lid is aligned with the inferior limbus; any higher or lower position can make successful translation (movement into the reading zone) difficult.
• Higher ametropia may require pre-emptive adjustments to the fit to allow for centration of lenses with increased CT, edge thickness, or weight (depending on the type of Rx).
• Following the fitting guide of the specific design will aid in troubleshooting translating GP multifocal fits.