Hybrid Multifocal (Previous Soft or Monovision Wearer): Roxanna T. Potter, OD, FAAO, FSLS
L. M., a 49-year old teacher and marathon runner presented for routine exam and contact lens evaluation. She was a soft multifocal lens wearer for many years, but has noticed a steady decline in her near vision over the last few. She had tried OTC readers over her contact lenses but didn’t think they were very helpful, and disliked needing to find/use them throughout the day.
Test Procedures, Fitting/Refitting, Design and Ordering
L.M. was previously wearing a soft, center near monthly multifocal design that gave her 20/20 DVA OU and 20/40 NVA OU. She was happy with the comfort but noted mild blur while driving at night and excessive blur when trying to work/teach, particularly while reading and using her computer.
OD: -3.75 – 0.75 x 178 20/20 ADD +2.00
OS: -4.75 – 0.75 x 148 20/20 ADD +2.00
OD: 43.70@180 / 44.60@090
OS: 44.20@160 / 44.90@070
Slit lamp evaluation:
Lids, lashes, cornea and conjunctiva were within normal limits OU. Her tear film was adequate in quantity and she had a tear break-up time of at least 10 seconds. Meibomian gland function appeared to be quite good. Other examination findings were unremarkable OU.
Due to the matching corneal and refractive cylinder, and the need for presbyopic correction, a GP lens was desirable. However, her active lifestyle with frequent running, traveling and marathons made her uneasy about losing lenses and lens decentration during wear. It was then decided that a hybrid design would allow for GP lens correction but with better stability. As such, the Duette Progressive design by SynergEyes was chosen.
A hybrid multifocal design is ideal for:
- Presbyopic patients with astigmatism (when corneal cylinder matches refractive cylinder)
- Up to 3.00D of corneal astigmatism
- Intermediate distance requirements
- Monovision failures
- Soft bifocal failures
- GP lens wearers that struggle with comfort or lens displacement issues
The Duette Progressive can be fit very simply using empirical data and the online Duette Calculator. Generally, the initial base curve of the GP should be approximately 0.50D steeper than flat K, and a skirt curve of 8.4 (Flat) is chosen to start. For L.M., a steeper skirt curve was used due to the somewhat higher minus GP lens in attempt to prevent decentration.
Trial lens parameters for Duette Progressive (hybrid design from SynergEyes), with a center near add zone OU.
OD: Base Curve: 7.6mm, Skirt Curve 8.1mm. Power -4.50D. Distance VA: 20/25+1; Near VA: 20/20
OS: Base Curve: 7.6mm, Skirt Curve 8.1mm. Power -5.25D. Distance VA: 20/25+1; Near VA: 20/20
The lenses were centered well with an aligned to slightly steep GP lens. The soft skirt was aligned well with the sclera and showed good movement, with no edge fluting noted. The patient noted good initial comfort and no difficulties with insertion, though she struggled slightly learning to remove the lenses.
Over-refraction revealed OD: +0.75DS which gave 20/20-2 Distance VA, and OS: -0.25DS which gave 20/20-1 DVA. Near VA OU was 20/20 and the patient was very pleased with the improvement noted when using her phone and looking at a desktop computer in the examination room.
Patient Consultation and Education
The patient was taught appropriate insertion/removal techniques and the importance of lens care and compliance was emphasized. She practiced lens removal in-office a few times to make sure she would be comfortable with this at home. She was educated that it might still be necessary to use OTC readers on occasion, depending on print size and lighting.
Follow-Up Care/Final Outcome
L.M. was seen one week later for follow-up and she reported good comfort and excellent vision at all distances. She noted that she was able to run without any concern of losing her lenses, and that her vision while teaching was so good she no longer needed to use OTC readers.
The fit of the lenses was found to be good, with GP lens and skirt alignment and excellent lens centration and movement. Over-refraction was found to be the same +0.75DS OD, and plano OS. The final lens power was adjusted to a -3.75DS OD with all other parameters left the same.
Discussion/Alternative Management Options
Hybrid multifocal designs are a great option for patients whose exam data suggests good candidacy for GP lenses but whose lifestyle does not allow for full adaptation to GP lens wear. They can also provide better lens security and centration in many instances, particularly in higher prescriptions or in the presence of abnormal lid positioning or tension where GP lenses are prone to decentration or dislocation.
The Duette Progressive is a dual aspheric design that can be ordered as either center near or center distance. The center distance design is of particular current interest in potentially being used for myopia control; young patients that have corneal cylinder and are unable to use other myopia control contact lens options such as soft multifocals or overnight orthokeratology may benefit from this design. The center near option is usually recommended for multifocal fitting to start. If centration issues arise, skirt curvature can be adjusted to improve overall fit. The size of the add zone can also be adjusted, as well as center thickness if flexure is a concern. Diameter and material is fixed. The GP lens material has a Dk of 130, and the SiHy skirt of 84, and the lens is classified as a Class II UVA/UVB blocker.
Insertion of the lenses is similar to that of a soft contact lens, but removal can be difficult. It is recommended that the wearer have dry fingers and use a V-shaped first finger and thumb pinching method to grasp and pull the lens off the lower part of the eye and then out, in a J-shaped movement. This can be a struggle for many patients, and requires thorough training and practice before the lenses are dispensed.
Alternatively, L.M. may have found success in a custom soft toric multifocal or a scleral multifocal. However, she found great optics and comfort, along with reasonable cost and convenience in this hybrid design.
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