Assessment of Three Basic Progressive Lens Designs

Study Overview
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Brief Summary
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This clinical trial investigates the differences between three different progressive addition lens designs. It is a non-invasive double-masked randomized clinical investigation. For this study, 80 participants will be recruited.

Detailed Description
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The purpose of the study is to evaluate the preference, adaptability, and visual performance of three progressive lens designs. The difference in these lens designs is a variation of zone sizes for intermediate and near vision. The clinical trial helps manufacturers and eye care practitioners to give detailed suggestions to patients. Study participants will be experienced progressive addition lens wearers, which will be recruited by advertisements, by email, and with direct person-to-person solicitation. The study will be conducted at the Eye Care Institute at the Patient Care Center Western University of Health Sciences, Pomona, CA, 91766. For each participant, the study is completed in around two months and requires three separate visits.

Official Title
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Assessment of Three Basic Progressive Lens Designs

Conditions
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Presbyopia

Intervention / Treatment
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* Device: Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 45 to 70 years old. Visual Acuity: far & near monocular: cc ≥ 20/20 (decimal cc ≥ 1.0) Normal binocular vision (at distance & near: no strabismus on cover testing, aligning prism of less than 2Δ horizontally or vertically, stereoacuity of 2' or better at distance and near). Prescription is in the range: Spherical power: less than +/-6.00 D Cylindrical power: less than -2.75 D Addition: 1.50 D - 2.50 D Difference in power (spherical equivalent) between eyes: less than 2.00 D Exclusion Criteria: Have never worn any progressive lens design. First prescription for progressive lenses. Prescription found during visit#1 varies from current prescription more than 0.50 D in any meridian. Currently wearing single vision lenses with accommodative support. Double vision or prismatic prescription in current glasses. Known ocular disease including strabismus, any pathology, any eye surgeries that may affect visual acuity. Use of systemic or ocular medications that are likely to affect vision. Balance problem/vertigo problem. Concurrent participation in other vision-related research.

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental: The specified PAL design wearers<br>Subjects who have been already wearing any from specified design type of PAL | Device: Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating<br>* Subjects will be wearing three different PAL designs with different geometries of the optical progression.<br>|
| Active Comparator: The other PAL design wearers<br>Subjects who have been already wearing any from the other design type of PAL | Device: Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating<br>* Subjects will be wearing three different PAL designs with different geometries of the optical progression.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the adaptation to progressive lens designs. | Evaluate the adaptation to progressive lens designs through a Satisfaction questionnaire after 1 week of use of each of the 3 progressive addition lenses. The Satisfaction questionnaire assesses: visual comfort, visual acuity at far distances, intermediate, and near distances, and visual fields at far distances, intermediate, and near distances. Each is evaluated on a 5-point scale from 5 (very comfortable) to 1 (very uncomfortable). | Entire study duration (approx. 4 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the preference among progressive lens designs. | Evaluate the preference among progressive lens designs through a Final comparison questionnaire. The survey asks to rank the three pairs of glasses (The best, Good, The worst) with respect to which provides a better distance visual acuity (seeing clear and sharp), wider field of view, and having the least perceived swaying/floating effects. The ranking is conducted for distance, intermediate, and near vision. | Entire study duration (approx. 4 weeks) | 
| Evaluate the fast impression of progressive lens designs. | Evaluate first impression of progressive lens designs through a First impression questionnaire after 10-15 minutes of wearing each of the 3 PALs. The First impression questionnaire scale is (a) very comfortable, (b) comfortable, (c) adequate, (d) slightly uncomfortable, (e) uncomfortable. | 10-15 minutes of wearing time. |