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Effect of Lens Presentation on the Clinical Oculomotor Assessment at Near

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ClinicalTrials.gov Identifier: NCT02679313
Recruitment Status : Completed
First Posted : February 10, 2016
Last Update Posted : May 17, 2017
Sponsor:
Information provided by (Responsible Party):
State University of New York College of Optometry

Brief Summary:
This study will compare near clinical oculomotor parameters (heterophoria, vergence ranges, AC/A and accommodative findings) measured when lenses and/or prisms are introduced using three different instruments namely: (i) a standard manual phoropter, (ii) an electronic phoropter and (iii) a wearable adaptive refractor (VisionFit).

Condition or disease Intervention/treatment Phase
Vision Disorders Device: Phoropter Not Applicable

Detailed Description:
Previous studies have demonstrated differences in a number of near oculomotor parameters [e.g., heterophoria, accommodative convergence to accommodation (AC/A) ratio] when measured in a manual phoropter versus a trial frame. These differences may be due to variations in proximal vergence, differences in head and eye position and restriction of the peripheral visual field. Further, a number of standard clinical oculomotor procedures require the use of Risley rotary prisms. While prism is typically introduced in a smooth, ramp-like fashion with manual phoropters, step changes in prism are created with electronic phoropters. The precise effect of these variations on clinical measurements is unclear. Accordingly, after a routine refractive examination, a standard clinical near assessment (comprising near heterophoria, AC/A ratio, horizontal vergence ranges, amplitude of accommodation and negative and positive relative accommodation) will be carried out on the same individuals through: (i) a standard manual phoropter (American Optical model 11625), (ii) an electronic phoropter (Topcon CV-5000) and (iii) a wearable adaptive refractor (VisionFit). The latter resembles a trial frame mounted on a helmet carrier (similar to a binocular indirect ophthalmoscope headset) but includes adaptive lenses that can be changed electronically.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 30 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Effect of Lens Presentation on the Clinical Oculomotor Assessment at Near
Study Start Date : February 2016
Actual Primary Completion Date : September 2016
Actual Study Completion Date : September 2016

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: Phoropter
Each subject will be tested on 3 separate occasions using either the manual phoropter (American Optical 11625), electronic phoropter (Topcon CV-5000) or the wearable adaptive refractor (VisionFit).
Device: Phoropter
Each subject will be tested on 3 separate occasions using either the manual phoropter (American Optical 11625), electronic phoropter (Topcon CV-5000) or the wearable adaptive refractor (VisionFit). Oculomotor measurements, i.e., heterophoria, vergence ranges, AC/A and accommodative findings will be measured at each session using the different devices. Each session will be separated by a minimum of 24 hours and a maximum of 14 days.




Primary Outcome Measures :
  1. Near horizontal heterophoria [ Time Frame: approximately 15 minutes ]
    Near horizontal heterophoria (measured in prism diopters) will be recorded using both the Von Graefe and Modified Thorington techniques using each of the three lens presentation devices. The single set of measurements will be recorded approximately 15 minutes after the start of the trial.

  2. Accommodative convergence to accommodation (AC/A) ratio [ Time Frame: approximately 15 minutes ]
    The AC/A ratio will be calculated from measurements of near horizontal heterophoria (quantified in prism diopters) will be recorded using the Modified Thorington technique at 3 different accommodative stimulus levels (1.5D, 2.5D and 3.5D). Measurements will be obtained using each of the three lens presentation devices and calculated in units of prism diopter per diopter accommodation.The single set of measurements will be recorded approximately 15 minutes after the start of the trial.

  3. Horizontal near vergence ranges [ Time Frame: approximately 15 minutes ]
    Near base-in and base-out vergence ranges will be measured (in prism diopters) while the subject fixates a near target. Measurements will be expressed in terms of the blur point, break point and recovery measurement .The single set of measurements will be recorded approximately 15 minutes after the start of the trial.

  4. Minus lens amplitude of accommodation [ Time Frame: approximately 15 minutes ]
    Minus lens amplitude of accommodation (measured in diopters) will be recorded using each of the three lens presentation devices.The single set of measurements will be recorded approximately 15 minutes after the start of the trial.


Secondary Outcome Measures :
  1. Negative and Positive Relative Accommodation (NRA and PRA) [ Time Frame: approximately 15 minutes ]
    NRA and PRA (measured in diopters) will be recorded using each of the three lens presentation devices.The single set of measurements will be recorded approximately 15 minutes after the start of the trial.



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Ages Eligible for Study:   18 Years to 30 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Corrected visual acuity of at least 20/20 (logMAR = 0.0) or better in each eye

Exclusion Criteria:

  • Strabismus, amblyopia, manifest ocular disease.

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 ClinicalTrials.gov identifier (NCT number): NCT02679313


Locations
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United States, New York
SUNY College of Optometry
New York, New York, United States, 10036
Sponsors and Collaborators
State University of New York College of Optometry
Investigators
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Principal Investigator: Mark Rosenfield, MCOptom, PhD State University of New York College of Optometry
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Responsible Party: State University of New York College of Optometry
ClinicalTrials.gov Identifier: NCT02679313    
Other Study ID Numbers: Phoropter Study
First Posted: February 10, 2016    Key Record Dates
Last Update Posted: May 17, 2017
Last Verified: May 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Additional relevant MeSH terms:
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Vision Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Eye Diseases