Defocus Induced Changes on Choroidal Thickness

Effects of Defocus on Choroidal Thickness

The goals of this study are to assess the short-term (10-60 minutes) effects of different magnitudes of myopic and hyperopic optical defocus on the transient thickness of the choroid in children and adults, as well as to assess the recovery period. Choroidal thickness will be measured non-invasively following 10-60 minutes of monocular exposure to -5 diopters to +5 diopters of optical defocus induced by spectacle lenses. The hypothesis is that choroidal thickness will increase with increasing myopic defocus and decrease with increasing hyperopic defocus. The relationship between the magnitude of defocus and the magnitude and direction of choroidal thickness change will be assessed.

Study Overview

• Status: Completed
• Conditions: Induced Defocus to the Retina
• Intervention / Treatment: Device: Plus powered optical lens

Detailed Description

The purpose of this study is to determine modifying factors inducing or protecting against the development or progression of myopia, or nearsightedness. Myopia has reached epidemic levels in urbanized countries, reaching up to 90% of the teenage and young adult population in urban Asia. Myopia represents a significant socioeconomic burden and poses a risk for associated ocular diseases such as retinal detachment, choroidal neovascularization, and glaucoma. The economic and public health burden of myopia are growing disproportionately to the population, spurring interest in the development of therapies to prevent occurrence or progression. Myopia generally occurs because the eye grows too long, with onset and progression occurring from about ages 6 to 20. Though much is known about factors that influence eye growth, the exact mechanisms by which they do so have not been elucidated.

The goals of this study are to assess the short-term (10-50 minutes) effects of different magnitudes of myopic and hyperopic optical defocus on the transient thickness of the choroid in children and adults, as well as to assess the recovery period. Choroidal thickness will be measured non-invasively following 10-50 minutes of monocular exposure to -5D to +5D of optical defocus induced by spectacle lenses. The hypothesis is that choroidal thickness will increase with increasing myopic defocus and decrease with increasing hyperopic defocus. The relationship between the magnitude of defocus and the magnitude and direction of choroidal thickness change will be assessed.

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77004
      • University of Houston College of Optometry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 years to 45 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 6 to 45 years of age (preliminary studies indicate that children under 6 cannot sit for imaging, and subjects over 45 do not respond to the optical defocus with expected choroidal thickness changes)
• Best corrected visual acuity of 20/25 or better in better-seeing eye

Exclusion Criteria:

• Age younger than 6 years or older than 45
• Best corrected visual acuity worse than 20/25 in better-seeing eye
• Ocular pathology or prior ocular injury
• Heavily-pigmented choroid that precludes accurate measurement of choroidal thickness

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Induced myopic defocus; Subjects will view a television through a lens that induces blur to the retina for one hour. Images of the eye will be captured every 10 minutes	Device: Plus powered optical lens; A plus powered optical lens will be placed in front of one eye.
No Intervention: No defocus; Subjects will view a television through a lens that induces no blur to the retina for one hour. Images of the eye will be captured every 10 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Choroidal thickness	Changes in choroidal thickness following induced myopic defocus	1 hour

Collaborators and Investigators

• Sponsor: University of Houston

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2018
• Primary Completion (Actual): September 1, 2021
• Study Completion (Actual): December 31, 2021

Study Registration Dates

• First Submitted: May 15, 2019
• First Submitted That Met QC Criteria: May 15, 2019
• First Posted (Actual): May 17, 2019

Study Record Updates

• Last Update Posted (Actual): March 17, 2022
• Last Update Submitted That Met QC Criteria: March 15, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: Retina; Myopia; Choroid; Blur; Defocus; Eye growth
• Other Study ID Numbers: STUDY00000852

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: IPD will be provided by request once published
• IPD Sharing Time Frame: At any point after completion of the study and publication
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP); Informed Consent Form (ICF)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes