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OpenTrials
Completed

NCT Number: NCT01234207

Clinical Assessment of a Customized Free-form Progressive Addition Lens Spectacle

The purpose of this study was to compare objective clinical measures of visual performance and subjective measures of satisfaction and preference between standard progressive addition lens (PAL) spectacles and a new type of free-form surfaced, optically customized PAL spectacle.

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Key information

Conditions

Presbyopia Eye Diseases Refractive Errors

Age range

39 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clinical Research Center, School of Optometry, University of California, Berkeley

Berkeley, California, 94720-2020, United States

About this study

In a double-masked crossover trial, 95 experienced wearers wore customized free-form PAL spectacles (Test) and standard non-free-form PAL spectacles (Control) for one week each. All subjects wore both Test and Control spectacles, and the pair to be worn first was randomly assigned. At dispensing and after 1 week of wear, subjects were tested for distance and near visual acuity (VA) under both high and low contrast; in addition, 30 degree off-axis VA was measured using a novel apparatus, as was the horizontal extent of undistorted vision at reading distance. Subjects also completed a set of questionnaires detailing their satisfaction levels, adaptation times, and preferences for Test or Control spectacles for different visual tasks.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Presbyope
  • Experienced PAL spectacle wearer
  • Correctable to at least 20/25 in both eyes
  • Able and willing to use Test and Control spectacles for 1 week each as primary form of presbyopia correction
  • Able and willing to complete all laboratory measurements and questionnaire batteries

Exclusion criteria

  • Purchasing free-form PAL spectacles from the UC Berkeley Eyewear Center
  • Having eye conditions or diseases that could potentially cause a decrease in visual acuity over the course of participation in the study
  • Having eye conditions or diseases that could potentially interfere with ability to use Test and Control spectacles as primary form of presbyopia correction

Treatment and study plan

Standard, non-free-form, non-customized PAL spectacles

Device

Control spectacles include several different PAL brands as selected by patients in the UC Berkeley Optometry Clinic and purchased in the Eyewear Center; after successful fitting and purchase, potential subjects were recruited for the trial.

Individually customized free-form surfaced PAL spectacles

Device

Test spectacles are Zeiss Individual, free-form surfaced, and customized using the iTerminal device to account for individual back vertex distance, wrap angle and pantoscopic tilt

Other names: Zeiss Individual, Carl Zeiss Vision, Inc., Germany

Primary outcomes

  1. Visual Acuity, High Contrast, Distance Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Standard assessment of high contrast visual acuity at distance, as in normal clinical practice, using Baily-Lovey charts and the M&S Technologies Smart System II visual acuity projection system.

  2. Visual Acuity, Low Contrast, Distance Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Standard assessment of low contrast visual acuity at distance, as in normal clinical practice, using Baily-Lovey charts and the M&S Technologies Smart System II visual acuity projection system.

  3. Visual Acuity, High Contrast, Near Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Standard assessment of high contrast visual acuity at near, as in normal clinical practice, using Baily-Lovey charts and the M&S Technologies Smart System II visual acuity projection system.

  4. Visual Acuity, Low Contrast, Near Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Standard assessment of low contrast visual acuity at near, as in normal clinical practice, using Baily-Lovey charts and the M&S Technologies Smart System II visual acuity projection system.

  5. 30-degree Off-axis Distance Visual Acuity, High Contrast Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Measured with subject immobilized in specially designed apparatus, keeping head pointed straight forward and moving only the eyes to left or right to view the off-axis chart

  6. 30-degree Off-axis Distance Visual Acuity, Low Contrast Chart

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Measured with subject immobilized in specially designed apparatus, keeping head pointed straight forward and moving only the eyes to left or right to view the off-axis chart

  7. Horizontal Extent of Undistorted Vision at Reading Distance

    Time frame: Post-1 week of wear of Test Spectacles and post-1 week of wear of Control Spectacles

    Novel apparatus designed to immobilize head and allow subject to indicate point of peripheral optical distortion on a modified Amsler-type grid

  8. Questionnaire Battery

    Time frame: At study exit, after both Test and Control spectacles had been worn for 1 week each

    Forced-choice Likert scale preference questionnaire

Sponsors and collaborators

Lead sponsor

University of California, Berkeley

Other

Collaborators

  • Carl Zeiss Meditec, Inc.

Registry information

Acronym: CZV_PAL1

Important dates

Study start
2009
Primary completion
2009
Study completion
2009
First posted
Nov 4, 2010
Registry last updated
Apr 18, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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