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Accommodation Disorders (AD)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01329848
Recruitment Status : Completed
First Posted : April 6, 2011
Results First Posted : January 5, 2015
Last Update Posted : January 5, 2015
Southern California College of Optometry at Marshall B. Ketchum University
Information provided by (Responsible Party):
Christopher Chase, Western University of Health Sciences

Brief Summary:
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.

Condition or disease
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.

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Study Type : Observational
Actual Enrollment : 83 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Using Accommodative Lag to Diagnose Accommodation Disorders
Study Start Date : December 2010
Actual Primary Completion Date : December 2012
Actual Study Completion Date : August 2013

discomfort symptoms
level of discomfort symptoms while performing near work

Primary Outcome Measures :
  1. Accommodation Lag 5D [ Time Frame: 3 week period ]
    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 :
  1. Conlon Symptom Survey [ Time Frame: 3 weeks ]
    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.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 30 Years   (Adult)
Sexes Eligible for Study:   All
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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01329848

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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 at Marshall B. Ketchum University
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Principal Investigator: Chris Chase, PhD Western University of Health Sciences
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Responsible Party: Christopher Chase, Professor of Optometry, Western University of Health Sciences Identifier: NCT01329848    
Other Study ID Numbers: 1R15EY021021 ( U.S. NIH Grant/Contract )
First Posted: April 6, 2011    Key Record Dates
Results First Posted: January 5, 2015
Last Update Posted: January 5, 2015
Last Verified: December 2014
Keywords provided by Christopher Chase, Western University of Health Sciences: