Effect of Lens Presentation on the Clinical Oculomotor Assessment at Near

Not Applicable

Completed

• Conditions: Vision Disorders
• Interventions: Device: Phoropter

• Registration Number: NCT02679313
• Lead Sponsor: 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).

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.

Study Timeline

• Study Start: 2016-02
• Study First Submitted: 2016-02-01
• Study First Submitted QC: 2016-02-09
• Study First Posted: 2016-02-10
• Primary Completion: 2016-09
• Study Completion: 2016-09
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-31
• Last Update Posted: 2025-01-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Phoropter	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).

Primary Outcome Measures

Name	Time	Method
Horizontal near vergence ranges	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.
Minus lens amplitude of accommodation	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.
Near horizontal heterophoria	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.
Accommodative convergence to accommodation (AC/A) ratio	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.

Secondary Outcome Measures

Name	Time	Method
Negative and Positive Relative Accommodation (NRA and PRA)	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.

Trial Locations

Locations (1)

SUNY College of Optometry; 🇺🇸 New York, New York, United States