Accommodation Disorders (AD)

This study has been completed.
Southern California College of Optometry
Information provided by (Responsible Party):
Christopher Chase, Western University of Health Sciences Identifier:
First received: April 4, 2011
Last updated: December 23, 2014
Last verified: December 2014

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.

Accommodative Insufficiency
Ill-sustained Accommodation

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Using Accommodative Lag to Diagnose Accommodation Disorders

Further study details as provided by Western University of Health Sciences:

Primary Outcome Measures:
  • Accommodation Lag 5D [ Time Frame: 3 week period ] [ Designated as safety issue: No ]
    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.

Secondary Outcome Measures:
  • Conlon Symptom Survey [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    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.

Enrollment: 83
Study Start Date: December 2010
Study Completion Date: August 2013
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
discomfort symptoms
level of discomfort symptoms while performing near work

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.


Ages Eligible for Study:   18 Years to 30 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Graduate students from Western University of Health Sciences


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.
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Please refer to this study by its identifier: NCT01329848

United States, California
Western University of Health Sciences
Pomona, California, United States, 91766
Sponsors and Collaborators
Western University of Health Sciences
Southern California College of Optometry
Principal Investigator: Chris Chase, PhD Western University of Health Sciences
  More Information

No publications provided

Responsible Party: Christopher Chase, Professor of Optometry, Western University of Health Sciences Identifier: NCT01329848     History of Changes
Other Study ID Numbers: 1R15EY021021
Study First Received: April 4, 2011
Results First Received: December 8, 2014
Last Updated: December 23, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Western University of Health Sciences:
Autorefraction processed this record on October 08, 2015