Article Date: 1/1/2014

Contact Lenses
SPECIALTY EYE CARE
contact lenses

Don’t Forget GP Options

Multifocal GP designs remain a viable option for many patients who require good vision at all distances.

MELISSA BARNETT-ERICKSON, O.D., F.A.A.O., SACRAMENTO, CALIF.

Although the Simple Minds song “Don’t You (Forget About Me),” made famous by the 80s’ film The Breakfast Club, isn’t about multifocal GP options, it easily applies, given all the recent press about soft multifocal contact lenses. Yes, the soft lens designs deserve accolades, but the corneal GP multifocal lenses remain viable options for many patients. In addition, scleral multifocal lens designs are a feasible choice for normal cornea patients. Here, I discuss the “classic” GP multifocal lenses and the “modern” scleral designs.

The classics

Corneal GP multifocal lenses remain a great option for lens wear in patients who require good vision at all distances.

For existing GP contact lens wearers, transitioning from single vision to multifocal lenses can be smooth. For patients who have not worn multifocal lenses previously, it’s important to tell them there’s a period of adaptation regarding the feeling of the lens and their brain, in terms of the vision the lenses provide. I tell patients this adaptation period may take two to six weeks.

To review, two types of corneal GP multifocal lenses are available:

(1) Aspheric, or simultaneous, multifocals. These are similar to progressive spectacle lenses. Patients who require lower add powers and use computers make excellent candidates.

(2) Translating bifocals. These are similar to lined bifocal lenses. Patients who require higher adds (+2.50D to +3.00D) and those who need critical near vision make excellent candidates.

Fitting advice: It is important to measure pupil size and lower eyelid position when fitting corneal GP lenses, as these measurements affect the fit and vision of the lenses. Fitting with diagnostic lenses and using trial lenses for over-refraction enhances the success rate with corneal GP multifocal lenses.

In segmented lenses, the position of segmented designs to the lower lid should be evaluated. Ideally, the segment line should be at or near the lower pupil margin. Aspheric lenses require “good” (not temporal or nasal decentered) centration and may benefit from the lens sitting under the upper lid to enable the wearer to obtain easy access to the add power. With all designs, it is helpful to use laboratory consultants for valuable fitting advice.

Just like a single vision lens, it is important to make sizeable changes when altering the fit of a corneal GP multifocal lens. It is helpful to change the base curve by at least 0.50D and the diameter by at least 0.3mm. If the changes are too small, it becomes difficult to evaluate the changes. If one multifocal design is not working, reevaluate the fit of the lens, and consider changing to another design.

Scleral designs

Although the largest group of scleral multifocal lens wearers continues to be those who have corneal ectasias, scleral lens use for presbyopic ocular surface disease patients who have regular corneas is escalating at a rapid pace. This is because this patient population tends to have concomitant ocular surface disease, and scleral lenses serve two purposes: (1) to provide outstanding vision and (2) to afford comfortable wear throughout the entire day.

Many well-designed multifocal scleral lenses are on the market today for regular and irregular cornea patients. (See “Multifocal Scleral Lens Designs,” page 35.) Multifocal scleral lenses are simultaneous vision designs, as these lenses move minimally on the eye. Most designs are center near, with the exception of the AVT scleral multifocal and Essilor’s Jupiter Plus lenses, which are center distance designs.

I recently fit a scleral multifocal lens design on a 57-year-old Hispanic female who presented for a contact lens examination. The patient works full time as an architect and reports spending 10 hours per day on reading and/or computer work. She complained of dry eyes with her current soft lenses, prompting her to wear the lenses for just four hours per day. When not wearing lenses, she said she noticed “slight” dryness. For intermediate and near vision, the patient wore reading glasses over her current soft lenses and reported a decrease in distance vision.

Ocular history was significant for dry eyes; she used bottled artificial tears in the morning and as needed. Her medical history was significant for allergic rhinitis and symptomatic menopause. The patient used estradiol and progesterone. Exam findings revealed a manifest refraction OD +0.50 + 0.25 x 174 20/20-1, OS +0.25 + 0.50 x 009 20/20-1. Keratometry values without distortion were OD 44.00/44.25 @ 096 OS 43.75/44.50 @ 072. Anterior segment examination showed meibomian gland dysfunction and dry eyes. Posterior segment was essentially normal except for large cup-to-disc ratios. Baseline glaucoma testing, including pachymetry, gonioscopy, visual field, optic nerve photographs and an optic nerve ocular coherence tomography were performed.

The patient was diagnosed with meibomian gland dysfunction, dry eyes and deemed a glaucoma suspect. I prescribed topical cyclosporine 0.05% (Restasis, Allergan) b.i.d. OU, non-preserved artificial tears as needed and lubricant ointment at night. Daily Omega 3 fatty acids and eyelid hygiene were recommended.

Multifocal Scleral Lens Designs

Company Lens Base curves Diameters Distance Power Near Add power Toric Option Design Cornea Type
Acculens Maxim Plus 38.00D to 57.00D can customize 15.7mm to 20.5mm +20.00 to -20.0D +1.00 to +3.50 Yes Center Near Irregular Corneas
Acculens Comfort SL Plus 38.00D to 57.00D can customize 15.7mm to 16.7mm +20.0 to -20.0D +1.00 to +3.50 Yes Center Near Regular Corneas
Art Optical / Dakota Sciences / Metro Optics So2Clear Progressive 51.00D to 35.00D 13.0mm to 15.0mm +20.00 to -20.0D +1.00 to +3.50 Will be released in 2014 Center Near Regular and Irregular Corneas
Advanced Vision Technologies AVT 40.00D, 45.00D, 50.00D can customize 16.1mm, 16.6mm, 17.1mm can customize +20.00 to -20.0D +1.00 to +3.00 Yes Center Distance Regular and Irregular Corneas
Blanchard Onefit P+A 61.00D to 45.00D 13.7mm, 14.0mm, 14.3mm, 14.6mm +20.00 to -20.0D +1.75 and +2.25D Yes Center Near Regular and Irregular Corneas
Essilor Jupiter Plus 39.00D to 54.00D 16.6mm to 17.6mm +25.00 to -25.0D +1.50D to +1.75D No Center Distance Regular and Irregular Corneas
Lens Dynamics Dyna Semi-Scleral Any flat base curve to 61.00D 13.5mm to 16.0mm +30.00 to -30.0D +1.00 to +2.50D Yes Center Near Regular and Irregular Corneas
Truform Digiform Multifocal 75.00D to 34.00D 15.0mm (range 13.5mm to 16mm) and 18.0mm +20.00 to -30.0D +0.25 to +4.00D Yes Center Near Regular and Irregular Corneas
Valley Contax Stable Near 56.25D to 37.50D 15.0mm and 16.0mm +20.00 to -30.0D +1.00 to +3.50 Yes Center Near Regular and Irregular Corneas

The patient was fit with soft multifocal contact lenses. Although binocular vision was 20/20 for distance and J1+ for near, she returned complaining her distance and near vision was not clear enough.

Next, I fit her in hybrid multifocal contact lenses. Binocular vision again was 20/20 for distance and J1+ for near, however she returned complaining lens comfort was not ideal. At this point, scleral multifocal lenses became available, so I prescribed them: OD 43.00 / +1.50 / +2.25 /16.5 Sag 4.65 2.5 add zone and OS 43.00 / +1.50 / +2.25 / 16.5 Sag 4.75 2.0 add zone. The patient reported good vision at distance, computer and near and “incredible” comfort with the multifocal scleral lenses — she said she was able to wear the lenses for 10 hours each day. However, she said she noticed some “ghosting” of vision when reading.

Monocular vision was 20/20+1 in the right eye and 20/20+2 in the left eye for distance; near vision was J3 in the right eye and J1 in the left eye. No over-refraction was present in either eye. A hydrogen peroxide-based and non-preserved 0.9% sodium chloride inhalation solution was used.

By reducing the add zone of the right lens to 2.0, monocular vision in the right eye improved to 20/20+1, J1. Binocular vision improved to 20/15-2, J1+. The patient said she noticed improvement of near vision with the new left lens. In addition, she remarked that both multifocal scleral lenses continued to be extremely comfortable.

These are exciting times for presbyopic patients, as numerous companies are in the process of releasing or have recently released designs.

Will you walk on by?

To paraphrase a lyric from “Don’t You (Forget About Me), “Won’t you come see about multifocal GP options?” Now that an array of GP multifocal contact lenses are available for you, the practitioner, to choose from, presbyopic patients have multiple options to provide excellent vision while retaining good eye heath and comfort. OM

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Dr. Barnett-Erickson is a principal optometrist at the University of California, Davis, Department of Ophthalmology & Vision Science, where she performs primary and medical eye examinations and fits contact lenses, including specialty contact lenses, in addition to teaching optics and contact lenses to ophthalmology residents. She has worked with Acculens and Essilor. E-mail her at drbarnett@ucdavis.edu, or send comments to optometric management@gmail.com.



Optometric Management, Volume: 49 , Issue: January 2014, page(s): 34 35 36