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

University of California, Berkeley95 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Presbyopia

Interventions

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

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 spectaclesDEVICE

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

Eligibility

Sex: ALLMin age: 39 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

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

Berkeley, California, United States

Outcomes

Primary Outcomes

Visual Acuity, High Contrast, Distance Chart

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.