Transcript Title

Lifestyle and Refractive
Factors Associated with
Progressive Addition Lens
Preference
The Center for Ophthalmic Optics Research, The Ohio
State University
Priya Ramamoorthy, BS Optom., MS
Jim Sheedy, OD, PhD
John Hayes, PhD
Introduction

Gaining popularity since 1950’s
– Acceptance & Satisfaction Studies
• Acceptance rate - 86% to 99%
• Satisfaction rate - 72% to 92%

Research on PALs
– PAL Preference Studies
• Numerous product comparison studies
• Few studies on true design preference
– Fowler et al. (1994), Preston et al. (1998)
Introduction

Current PAL designs have significant differences in
their optical characteristics (Sheedy, 2004; Sheedy,
Hardy et al. 2006)

PAL designs differ significantly in far, intermediate,
near zone and astigmatism characteristics

“One-for-all” design researched so far
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What about differences in the preference
characteristics of the population?

Visual needs of patients may differ
Study Objective

Test patient preference for PAL design based upon
their daily visual requirements

Test if lifestyle, refractive status, visual correction
history and/or other characteristics of the patient are
related to the lens design that best suits him/her
Overall study design
Patient Selection
Determining lifestyle needs
Subjects fitted with far and near PAL designs
Phase 1
Lens A/B x 2 weeks
Phase 2
Lens A/B x 2 weeks
Phase 3
Simultaneous comparison of lenses A and B x 1 week
Final preference assessment
Patient selection
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Patient Inclusion criteria
Clinical
– Corrected visual acuity of at least 20/20 in each eye
– No history of significant ocular disease (except
cataract)
– Previous PAL Wear > 1 year
Optical Criteria
– Distance prescription: < 3.50 D spherical equivalent
– Near add: Between +1.75 D and +2.50 D
– Cylinder prescription: < 1.75 D
– Anisometropia (spherical equivalent): <1.50 D
– Minimum fitting height: 18 mm
Screening
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Individual Factors
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Satisfied PAL wearers
Clarity of vision through the subject’s spectacles
PAL wear for at least half the waking hours
Demonstration of a clear lifestyle preference for distance
or near viewing requirements
Clear Distant
Viewing
Areas of Blur
Clear Near
Viewing
(a)
Far > Near
Viewing area
(b)
Near > Far
Viewing area
Selection of PALs
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Top-rated pools of distance and near vision lenses
Based on:
– Distance and near ratings by Sheedy, Hardy et al. 2006
– Maximal difference between the two ratings
– Equalized astigmatism ratings
Ratings for Distance & Near Viewing
Zones (Sheedy, Hardy et al. 2006)
Fitting Height 18
Distance Rating
PAL Design
Shamir Genesis (D)
Vis Ease Outlk (D)
Rdnstk Life AT poly
Younger Image
Zei Gradal Top (D)
Sig Kodak
Sig Kod Precise
Varlx Comfort
Varlx Liberty
Vis Ease Illumina
Varlx Panamic
Zei Gradal Brevity
AO Easy
Rdnstk Life XS
Varlx Ellipse
AO Compact (N)
Sig Kod Concise (N)
SolaMax
SOLA One
Sig Nav Short
Shamir Piccolo (N)
Pentx AF
Pentx AF Mini
Mean
Mean
77.8
70.7
67.5
57.5
57.2
45.9
42.1
39.0
34.8
34.2
32.5
30.2
27.1
26.9
25.2
21.0
20.5
19.0
18.2
15.5
13.5
-4.2
-4.6
33.8
SD
13.1
13.8
17.7
15.5
11.8
14.1
13.3
14.9
10.5
18.3
7.7
13.7
6.6
11.7
6.2
12.7
11.3
11.0
5.9
15.5
7.4
19.7
17.7
25.7
Ranges of non-significant differences
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PAL Design
Shamir Piccolo (N)
Sig Kod Concise (N)
Sig Nav Short
AO Compact (N)
Rdnstk Life XS
Varlx Ellipse
Vis Ease Illumina
SolaMax
SOLA One
Younger Image
AO Easy
Vis Ease Outlk (D)
Pentx AF Mini
Sig Kod Precise
Sig Kodak
Shamir Genesis (D)
Varlx Comfort
Rdnstk Life AT poly
Varlx Panamic
Varlx Liberty
Pentx AF
Zei Gradal Brevity
Zei Gradal Top (D)
Mean
Mean
50.1
48.5
48.2
45.1
43.7
40.0
38.3
38.2
34.8
32.7
32.5
32.3
31.9
31.5
28.6
27.8
27.4
27.2
27.1
26.2
23.5
17.3
15.3
33.3
Ranges of non-significant
differences
SD
2.5
4.0
10.0
4.5
1.7
2.3
3.6
4.0
3.8
4.9
3.2
3.1
4.1
2.8
7.5
6.6
5.7
6.5
3.3
9.3
15.2
15.9
8.5
11.5
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Preference Assessment - Final
Questionnaire

Evaluates preference between the 2 PALs for a variety of
functional visual aspects
•Clarity of vision
- Far (distant), intermediate & near
- Viewing straight-ahead and
through lens periphery
•Clarity of vision during driving,
viewing moving objects

Sample question:
– Response scale
•Ease of lens use
while performing
specific activities
•Ease in adaptation
•Overall Lens
Preference
Results
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Subjects
– 34 completed study
– Average age 54.21 ± 5.91 years
– 64.7% female
Refractive correction
Refractive
component
Sphere
Cylinder
Spherical
equivalent
Near add
n = 34
Mean
SD
Minimum
Maximum
0D
-0.58 D
1.50
0.38
-3.13
0
3
-1.5
-0.27 D
+2.24 D
1.54
0.28
-3.5
1.75
2.75
2.75
Results – Initial vs. Final PAL
Preference
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Comparison Of Subjects’ Initial And Final PAL Preference
PAL Preference
Initial preference Far
Near
Total
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Final preference, count (%)
Far
Near
11 (32.4%)
2 (5.9)
10 (29.4)
11 (32.4)
21 (61.8)
13 (38.2)
Initial PAL preference based on lifestyle visual needs
matched final PAL preference in 22 of 34 subjects
Χ21 = 4.65, P =0.03
Total
13 (38.2)
21 (61.8)
34 (100)
Final Overall Preference Scores

Overall Preference Scores
– Far group (mean = 8.08) indicating preference for
the far lens
– Near group (mean = 5.71) - no preference for either
lens
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Far group
– Initial and final preference of 11 of 13 subjects was
the far PAL

Near group
– 11 of 21 subjects preferred the near PAL design
– 10 subjects switched final preference to far PAL
PAL Preference Prediction

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Logistic regression analysis to predict PAL
preference
Significant predictors
– Cylindrical spectacle prescription significantly
associated with far PAL preference (p=0.01)
– Interaction term between myopia, initial near PAL
preference and amount of sphere in prescription (p =
0.03)

88% accuracy in prediction of PAL preference
Prediction of Model for Current Data
Far
PAL
Near
PAL
Far
Near
PAL
PAL
Final Overall Preference Scores

Other Final Questionnaire responses*
– Far group rated high far PAL preference
• For almost all perceived far vision tasks
• Combination tasks
• General factors
– Near Group
• Preference not significant for either lens
• Increased variability in scores
Results – Clear vision extent

Clear vision extent at far, intermediate and near distances
– Paired t test analyses
– Near PAL > Far PAL at near (p=0.03)
– Far PAL > Near PAL at far (p=0.04)

Summary statistics
Test distance PAL type
Far (4m)
Intermediate
Near
Near
Far
Near
Far
Near
Far
Extent of clear vision, in degrees
Average
SD
26.47
31.49
4.76
3.54
9.11
7.05
14.99
15.53
5.73
5.66
8.68
5.25
Discussion

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Significant association between initial PAL preference
based on lifestyle visual needs and final PAL preference
Far group more consistent
– Reflected in final preference score
– Strong preference for the far PAL in several of their lens
comparison responses
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Greater variability observed in the near group
Inferences from the regression model
– Cylinder in glass prescription

Optical Properties of far and near PAL designs
– Near width in near PAL
– Intermediate zone properties
• Int. ratings of far & near PALs, Need for accurate fitting, PD
Tolerance

Potential limitations
– Screening tool inadequacy
– Subjects’ judgment & far vision requirement
Conclusions

Based on individual visual requirements, there exist
differences in the PAL preference characteristics of
the population.
– Subjects with far visual needs clearly prefer PAL
designs
– Near group needs better designs and more assessment

Implications of findings
– Industrial implications: Need better lens designs for
segmented populations
– Clinical implications: Customized care for patients
based on their specific needs
Acknowledgement

This research was supported by the Center
for Ophthalmic Optics Research
Reference
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Sheedy JE. Progressive addition lenses – matching the specific
lens to patient needs.Optometry 2004; 75:83-102.
Sheedy et al.Progressive addition lenses – measurements and
ratings. (In press)
Hays et al. Psychometric properties of the National eye
institute-Refractive error quality of life instrument.
Ophthalmology 2003;110:2292:2301.
Preston, J. (1998). Progressive Addition Spectacle Lenses:
Design Preferences and Head Movements while Reading.
Optometry/ Physiological Optics. Columbus, OH, The Ohio State
University: 222.
Fowler CW, B. A., Bench BP, Kempster AJ. (1994). A wearer
comparison of two progressive addition spectacle lenses.
Vision Science and its Applications 1994. Washington DC,
Optical Society of America. Technical Digest Series Vol 2: 6-9.