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Erin Berg, O.D.
The Ohio State University
College of Optometry
Cornea and Contact Lens Advanced Practice Fellow
Abstract
A hybrid multifocal contact lens offers a promising solution to an astigmatic presbyope with a history of
contact lens dropout in both soft and gas permeable contact lenses.
I.
Case History
RG, a fifty-eight year old Caucasian male, presents for a multifocal contact lens fitting. RG has worn
progressive addition spectacles since noticing presbyopic symptoms about seven years ago. Before
entering presbyopia, the patient primarily wore soft toric contact lenses and recalls good overall
comfort. He notes his vision with spectacles is better than his vision was with soft contact lenses. He
trialed gas permeable (GP) contact lenses about 10 years ago to achieve crisper vision, but had poor
comfort secondary to his occupation. RG works as a restaurant cook. His daily job duties include
cleaning in environments that contain dust and small particles in the air which makes wearing GP’s
especially uncomfortable. The patient appreciated better peripheral vision and awareness when
wearing soft contact lenses and would like to pursue soft multifocal lenses to eliminate spectacle wear.
RG’s ocular history is unremarkable except for the presence of trace nuclear sclerotic cataracts OU. His
systemic health is significant for hypertension and high cholesterol which are well controlled with
amlodipine and simvastatin.
II. Pertinent Findings
Best corrected visual acuity with manifest refraction was 20/20 OD (-3.75-1.50x040 Add +2.00) and
20/20-2 OS (-4.25-1.50x150 Add +2.00) at distance and near. Simulated K values on corneal topography
were 45.4@012/46.6@112 OD and 45.4@175/46.6@085 OS.
III. Differential Diagnosis/Treatment
Several contact lens options are available for presbyopic patients with regular astigmatism. When
choosing a correction modality, one must consider the patient’s visual needs and lifestyle. GP lenses are
a good option for correcting spectacle astigmatism that is the result of and closely matches corneal
cylinder. The tear lens created between the cornea and back surface of the rigid lens corrects the
corneal astigmatism and results in crisp visual acuity. Although this patient’s corneal cylinder does
closely match his spectacle cylinder in both eyes, he has a history of GP lens dropout secondary to poor
comfort and did not wish to pursue a traditional GP multifocal contact lens fitting. The patient was
accustomed to excellent visual acuity at distance and near with his current progressive addition
spectacles. It was predicted the near and distance visual acuities produced by a soft toric multifocal lens
would not meet the patient’s visual expectations. In order to provide the best astigmatic and
presbyopic correction, while still maintaining good comfort and minimal lens awareness, a hybrid
multifocal contact lens fitting was pursued. This option would optimally correct the patient’s significant
corneal astigmatism and presbyopic needs while providing good lens comfort.
IV. Diagnosis and Discussion
Of all presbyopic contact lens options, GP designs (translating or simultaneous) have consistently been
shown to produce the best vision in a variety of environments. Patients generally prefer the vision
provided by multifocal GP’s when compared to other presbyopic contact lens options.1 GP contact
lenses are also a good option to correct corneal astigmatism. The rigid nature of the lenses causes
formation of a tear film between the back surface of the lens and front surface of the cornea. This
creates a regular, spherical surface and crisp visual acuity.2 While the vision produced by GP lenses is
quite reliable, comfort and lens awareness often lead to dropout.3 The patient in this report had a
history of GP dropout secondary to poor comfort, so a GP multifocal was not initially chosen for this
patient.
Soft contact lenses offer options to correct both astigmatism and presbyopia. These lenses have been
shown to be one of the most comfortable lens modalities.4 Commercially available soft toric lenses
employ a variety of designs to achieve stabilization and consistent vision on the eye. Still, patients
commonly report variable acuity.4 Multifocal soft contact lenses are also available in several design
strategies. Because these lenses don’t translate on the eye like GPs, these options are simultaneous
designs that often employ aspheric technology and/or concentric ring designs. Simultaneous vision
designs can involve a compromise in distance and near vision, and some patients have difficulty
accepting this compromise.5 The patient in this case stated that he wanted the crispest vision possible
at distance and near. Because vision can be variable and slightly reduced with both toric and multifocal
designs, soft contact lens modalities were not initially chosen for the patient.
Hybrid contact lenses involve a design that contains a rigid gas permeable center optic bonded to a soft
(usually hydrogel or silicone hydrogel) skirt. These lens designs initially gained popularity as a solution
for irregular cornea patients who had poor comfort or complications with GP lenses such as dry eye, 3
and 9 o’clock staining, and vascularized limbal keratitis.6 Since their emergence on the market, concern
has been raised about hybrid lens complications like decreased corneal oxygen uptake, lens seal off, and
corneal edema. Careful monitoring of the lens fit and ocular surface in the initial period of hybrid lens
wear can help avoid these adverse effects.7,8
Although hybrid lenses are traditionally fit on irregular corneas, new designs have emerged in recent
years to exclusively fit corneas with regular corneal astigmatism. While providing the patient with the
astigmatic correction and optics of a GP, these lenses provide comfort and lens awareness similar to a
soft contact lens. The lens used in this case report was the SynergEyes Duette Multifocal. This particular
lens contains a 130-Dk silicon acrylate GP central optic surrounded by a low modulus 84-Dk silicone
hydrogel skirt. The combination of these two materials is intended to help decrease complications
associated with oxygen transmissibility.6 A center-near, aspheric multifocal design is employed to
achieve presbyopic correction. Two add zones, small or large, are available.
As hybrid lenses and fittings become more common, data has emerged about visual performance and
patient preference with respect to comfort and vision. Nau compared the comfort and vision of irregular
cornea patients who were refit from traditional GP designs into a hybrid lens. 79.5% reported improved
comfort with the hybrid lens and the best corrected visual acuity of hybrid lenses was comparable to
that with GP lenses.2
Besides improving comfort, hybrid lenses offer stable GP-like correction of astigmatism while allowing
soft contact lens comfort. A cross-over study by Lipson compared vision-related quality of life of
patients with soft toric contact lenses and a hybrid lens designed for normal corneas. 44% preferred the
hybrid lens and 56% preferred the soft toric. While the soft toric lens had superior comfort, patients
reported better vision with the hybrid lens. 90% of the patients who preferred the hybrid lens said the
main reason was “sharper vision.” 50% of previous soft toric wearers preferred the hybrid lens.
Additionally, 71% of prior GP wearers preferred the hybrid in this study.2 This data is significant,
demonstrating a portion of current soft toric wearers aren’t completely satisfied with the quality of
their vision and would be willing to sacrifice some comfort to achieve better acuity. In the hybrid lens,
the data suggests GP wearers noticed similar vision quality with improved comfort and chose the hybrid
lens.
Patients choose to continue or discontinue contact lens wear for a variety of reasons. These reasons
and opinions are valuable economically and professionally to eye care practitioners. Although cost and
convenience factor into a patient’s decision to stay in contact lenses, data suggests that comfort is the
primary reason patients drop out of contact lens wear. A 2010 survey study showed that 50% of
patients in the United States who discontinued contact lens wear did so because of poor comfort. The
second most common reason for drop out (15.9%) was decreased vision when compared to glasses.9
When fitting patients in contact lenses, comfort is a key factor. Overcoming lens awareness and
irritation will aid in a successful fit. However, if a comfortable contact lens wearer requires well-defined
vision, they are likely to discontinue contact lens wear and return to spectacles. Hybrid contact lenses
allow patients to enjoy both soft lens comfort and GP vision.
In this case, the patient had high visual expectations secondary to longstanding spectacle correction and
a history of GP dropout. When the visual drawback of soft toric and multifocal contact lenses were
considered, a hybrid multifocal lens was determined to be the best initial choice to provide optimum
comfort and vision at all distances.
V. Treatment and Management
Initial Fitting Visit:
RG was referred to the contact lens clinic 2 weeks after receiving a comprehensive, dilated eye exam. At
the initial fitting appointment, the first base curve on each eye was chosen based on the patient’s
keratometry values and the nomogram provided in the Duette Multifocal fitting set. This nomogram
suggests initial base curve selection to be about 0.20 mm steeper than the flat K reading. For both eyes,
a 7.3 base curve with a medium skirt was indicated as the first diagnostic lens to trial on the eyes. The
appearance of the trial lenses suggested slightly steep fit OU (central pooling observed), so a lens one
step flatter was placed on the eyes to re-evaluate. This 7.5 BC lens with a medium skirt OU revealed a
better central fluorescein pattern (no pooling or touch OU). An over refraction was performed with the
-3.00 D trial lenses to determine the best power. The manufacture’s fitting guide states that final lens
power should be 0.25-1.00 D more myopic than the patient’s spectacle sphere power. A contact lens
power 1.00 D or more myopic than the spherical spectacle power suggests a steep fit. Base curve should
be flattened to compensate. Over refraction with this patient produced contact lens powers of -4.00
and -5.00, within these recommendations.
First Follow-Up Visit:
Upon inserting the first pair of trial lenses (OD -4.00D, BC 7.5, Medium skirt, Small add zone; OS -5.00,
BC 7.5, Medium skirt, Small add zone), the patient appreciated 20/25 acuity at distance and near. Initial
over refraction (after 3-5 minutes as suggested by manufacturer) OU revealed -0.50 D to achieve 20/20
distance acuity (without affecting near acuity). The fit appeared appropriate according to
manufacturer’s guidelines OU (thin central fluorescein layer, distinct fluorescein band at junction, 0.50
mm movement with the blink). However, after 20 minutes of wear time, the patient noticed distance
vision was reduced and the lenses appeared slightly decentered temporally. At this time, distance acuity
was 20/30- OU and the over refraction was -1.00 OU to achieve 20/20 distance acuity. Still, the patient
was impressed with his ability to achieve adequate vision at distance and near and said the comfort of
the hybrid lenses was like that of his previous soft lenses. Because of the fluctuating distance acuity, a
phone call was made to the lens lab consultant. The consultant suggested steepening the base curve OU
by one step to improve centration and ensure the patient is looking through the center of the lenses.
Based on empirical calculations of the base curve change, the following lenses were ordered: BC 7.5
mm, medium skirt, small add zones OU, -4.75 D OD, and -5.75 D OS. These lenses would achieve
improved centration and provide clear distance and near vision while maintaining the comfort the
patient requires.
VI. Conclusion
Hybrid contact lenses can serve as an effective tool to prevent soft or RGP contact lens dropout in
astigmatic and presbyopic patients. Patients who experience fluctuating or inadequate vision with soft
toric and/or multifocal lens can appreciate sharper vision with hybrid lenses, and traditional RGP
wearers may enjoy improved comfort.
References
1. Rajagopalan, A. S., Bennett, E. S., & Lakshminarayanan, V. (2006). Visual performance of subjects
wearing prebyopic contact lenses. Optometry and Vision Science, 83(8), 611-615.
2. Nau, A. C. (2008). A Comparison of Synergeyes versus Traditional Rigid Gas Permeable Lens Designs
for Patients with Irregular Corneas. Eye & Contact Lens: Science & Clinical Practice, 34(4), 198-200
3. Polse, K., Graham, A., Fusaro, R., Gan, C., Rivera, R., Chan, J., ... Sanders, T. (1999). Predicting RGP
Daily Wear Success. CLAO Journal, 25(3), 152-158.
4. Lipson, M. J., & Musch, D. C. (2007). Synergeyes versus Soft Toric Lenses: Vision-Related Quality of
Life. Optometry and Vision Science, 84(7), 593-597.
5. Bakaraju, R. C., Ehrmann, K., Falk, D., Ho, A., & Papas, E. (2012). Optical performance of multifocal
soft contact lenses via a single-pass method. Optometry and Vision Science, 89(8), 1107-1118.
6. Davis, R. L., Eiden, S. B., & Murphy, M. (2012). New concepts in combination lenses. Contact Lens
Spectrum, 27(May), 24-27
7. Pilskalns, B., Fink, B. A., & Hill, R. M. (2007). Oxygen Demands with Hybrid Contact Lenses.
Optometry and Vision Science, 84(4), 334-342.
8. Fernandex-Velazquez, F. J. (2011). Severe epithelial edema in Clearkone Synergeyes contact lens
wear for keratoconus. Eye and Contact Lens, 37(6), 381-385.
9. Rumpakis, J. (2010, January 15). New Data on Contact Lens Dropouts: An International Perspective.
Review of Optometry. Retrieved from
http://www.revoptom.com/content/d/contact_lenses___and___solutions/c/18929/