Accommodation Disorders (AD)

Using Accommodative Lag to Diagnose Accommodation Disorders

This project will develop clinically useful, objective measurements of accommodative insufficiency and fatigue using continuous autorefraction recordings. The development of these procedures will help vision care professionals diagnose and treat accommodative anomalies.

Study Overview

• Status: Completed
• Conditions: Accommodative Insufficiency; Ill-sustained Accommodation

Detailed Description

This project studies accommodative function, the ability to focus while doing near work. Visual discomfort symptoms, such as headaches, sore eyes, and blurred vision are commonly associated with prolonged reading or other near work. Researchers have long suspected accommodative dysfunction was involved but most clinical studies have failed to establish a relationship between weak accommodation and symptoms or reading impairments. Recent research, however, has found that clinical measure overestimate accommodative function and encourage the use of objective, autorefraction methods to measure and study accommodative weakness. This project will accomplish three goals. First, using autorefraction objective reliable procedures will be developed for measuring accommodative lag, the difference between the target location and where the eye is focused. Second, experiments will measure in real-time the impact of accommodative lag on reading fluency and visual discomfort systems. Third, studies will explore the role of the slow adaptive component in accommodative weakness. This work will lead to better methods for diagnosing and treating accommodative disorders.

• Study Type: Observational
• Enrollment (Actual): 83

Contacts and Locations

Study Locations

• United States
  • California
    • Pomona, California, United States, 91766
      • Western University of Health Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Graduate students from Western University of Health Sciences

Description

Inclusion Criteria:

• older adolescent and young adult
• skilled readers who attend school
• are skilled readers
• have heavy reading demands

Exclusion Criteria:

• Age > 30.
• Abnormal vergence system.
• Dry-eye.
• Uncorrected visual defects or significant ocular pathology.
• Learning disability or low IQ
• Medical conditions that might cause uncomfortable visual symptoms (e.g., migraine headaches, epilepsy, head trauma); sensory defects (e.g., deafness), or neurological conditions (e.g., stuttering) that could impair reading development or oral reading fluency.
• Somatosensory amplification.
• Systemic illness or medication associated with accommodative dysfunction.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
discomfort symptoms; level of discomfort symptoms while performing near work

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accommodation Lag 5D	Lag will be measured at different viewing distances and durations using autorefraction. Accommodation error refers to the difference between the distance where the target is located and where the eyes focus. Lag refers error that is under focussed; lead is error that is over focussed. This distance is measured in diopters, or 1/meter.	3 week period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Conlon Symptom Survey	Measures visual discomfort symptoms while doing near work. 23 item survey using a 4-point rating scale (never, occasionally, often, almost always). Total raw score reported on a range from 0 to 69 with higher scores indicating more frequent symptoms.	3 weeks

Collaborators and Investigators

• Sponsor: Western University of Health Sciences
• Collaborators: Southern California College of Optometry at Marshall B. Ketchum University
• Investigators: Principal Investigator: Chris Chase, PhD, Western University of Health Sciences

Study record dates

Study Major Dates

• Study Start: December 1, 2010
• Primary Completion (ACTUAL): December 1, 2012
• Study Completion (ACTUAL): August 1, 2013

Study Registration Dates

• First Submitted: April 4, 2011
• First Submitted That Met QC Criteria: April 4, 2011
• First Posted (ESTIMATE): April 6, 2011

Study Record Updates

• Last Update Posted (ESTIMATE): January 5, 2015
• Last Update Submitted That Met QC Criteria: December 23, 2014
• Last Verified: December 1, 2014

More Information

Terms related to this study

• Keywords: Reading; Accommodation; Autorefraction
• Other Study ID Numbers: 1R15EY021021 (NIH)