Influence of an Imaginary Target on the State of Accommodation Under Scotopic Conditions
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 39
- Locations
- 2
- Primary Endpoint
- Shift of accommodation in scotopic luminance (Dark focus)
Study Overview
Brief Summary
Shifts in accommodation at decreasing luminance levels are considered as principle cause for night myopia. Previous studies with laser optometers quantified the dark focus of accommodation up to 3 D. In addition to the measurement of dark focus, the aim of this study was to investigate the influence of an imaginary target at finite distances on the state of accommodation at scotopic luminance.
Detailed Description
Accommodation was measured by using an open-field autorefractor (WAM 5500, GRAND SEIKO). Full corrected right eyes of 39 subjects aged from 18 to 40 years were investigated in this randomized, cross-sectional study. Accommodation measurements in photopic luminance were taken for 6 m of empty field and for optotype fixation at 2 m, 1 m and 0.5 m. At scotopic luminance, dark focus of accommodation was examined directly after darkening and after 10 min of dark adaptation. After adaptation, subjects had to visualize imaginary targets in the four distances while accommodation was measured.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Single Group
- Primary Purpose
- Basic Science
- Masking
- None
Masking Description
Sequence of tests was randomized. It is no multi-arm study.
Eligibility Criteria
- Ages
- 22 Years to 39 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •age 18 - 44
- •visual acuity at least 0.8 (5/6)
Exclusion Criteria
- •medication with an impact on the visual system
- •visual disease or disease with an impact on the visual system
- •pregnancy or other hormonal variances
- •drug usage
- •overfatigue at the period of investigation
- •mental handicap
Arms & Interventions
Accommodation in scotopic luminance
Intervention: Accommodation Measurement (Diagnostic Test)
Outcomes
Primary Outcomes
Shift of accommodation in scotopic luminance (Dark focus)
Time Frame: Baseline only
Accommodative shift in scotopic luminance compared to photopic luminance for empty field (dark focus of accommodation)
Secondary Outcomes
- Difference of accommodation for 2 m target(Baseline only)
- Difference of accommodation for 1 m target(Baseline only)
- Difference of accommodation for 0.5 m target(Baseline only)
Investigators
Philipp Hessler
Principal Investigator
University of Applied Sciences Jena