Mobile Medical Application for Cost-effective Strabismus Screening

April 16, 2021 updated by: Kevin Houston, Massachusetts Eye and Ear Infirmary
Develop and evaluate a new smartphone based app to screen for and measure eye misalignment (strabismus). The investigators will validate the app against simulated strabismus of known magnitude and common clinical tests. They will evaluate the app as a screening tool in high risk populations, to determine the sensitivity and specificity. They hypothesize that the app can measure to within 2 units (prism diopters) of the ground truth, and that it will be correlated with gold standard tests.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The goal of the proposed project is the development and evaluation of a novel mobile medical application for the detection and monitoring of strabismus (eye misalignment). The image analysis technology necessary to measure strabismus using the corneal reflection technique (Photographic Hirschberg Test) has been available for many decades, however it has never been deployed using a smart phone. A smart phone platform will eliminate barriers of cost (since the hardware is maintained and updated by the smart phone industry), leading to rapid wide spread application and allowing the technology to finally reach its potential level of impact for children's eye care in the detection and management of strabismus. Strabismus causes visual confusion and double vision which ultimately results in the brain suppressing vision from the deviated eye. In children this results in under-development (amblyopia) with permanent vision loss in the deviated eye if not detected and treated at a young age. Strabismus in children is also associated with coordination problems such as postural instability and severe social disadvantages. Strabismus develops in an estimated 3-8% of children in the U.S. The prototype smart phone app (Referred to here as the Mobile Eye Alignment App - MEAA), uses photographic analysis of the corneal reflection (Purkinjie image) generated by the smart phone camera flash. The corneal reflection method uses the displacement of the reflection from the center of the pupil in the deviated eye to calculate the amount of eye misalignment. This measurement technique will be deployed for the proposed project using the hardware of the iPhone, a popular phone with an iOS operating system. Preliminary results suggest the app can measure differences in eye alignment of 1.6° (2.8 prism diopters). If successfully developed, the app has potential to be utilized to advance pediatric strabismus research by facilitating and reducing the cost of collecting enormous amounts of data from the general population and under-served or remote populations for epidemiological studies, and allowing researchers to capture eye alignment data much more frequently than is currently possible. Such a tool could better delineate the natural history of strabismus and perhaps help determine its causes. While devices are available which could make these measurements, the costs are prohibitively high (>$3,000 ea.) and will not reach the widespread availability of smart phones. Clinical goals for the app are to provide eye doctors with an objective measurement tool in the exam room, allow daily monitoring of treatment effects, and eventually to be used as a screening tool by school nurses, pediatricians, and parents. The barriers to market success of stand-alone devices is not the accuracy sensitivity or specificity of photographic analysis technique which has been reported with sensitivity from 53% to near 90% and specificity ranging from 76% to 94% for strabismus detection. Impact of strabismus screening for the young - Early detection for strabismus in young children, especially during the critical period up to 2 years of age, is important to ensure that treatment is administered as soon as possible. The success of amblyopia treatment depends on several factors, but principally on the age of onset and the age at which the treatment is initiated. Therapy for amblyopia is maximally effective if started before age 3 and can be initiated as early as 8 months, underscoring the critical need for early and widespread access to strabismus screening. Indeed, countries with long-standing early vision screening programs have reported significantly reduced rates of amblyopia. Access to strabismus screening is also important for older, school age children (age 7-17) suffering from amblyopia, for whom treatment can lead to significant improvements in visual acuity ranging from 20%-70% of patients, depending on their age bracket.

Aims Specific Aim 1: Develop and test key functionality of the strabismus app by comparing measurements with successive versions of the prototype app to known angles of eye deviation (non-strabismic volunteers will gaze at off axis targets of known eccentricity). Specific Aim 2: Evaluate the strabismus app accuracy and feasibility in a clinical environment.

Primary Hypothesis: For strabismus ranging from 1 to 30 prism diopters (target range), the optimized version of the app will provide measurements which are not significantly different from the ground truth (simulated strabismus) or clinical tests of eye alignment.

Study Type

Interventional

Enrollment (Anticipated)

190

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 86 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Ground Truth Aim Study (closed for recruitment):

  • Age 18 to 88
  • Normal or corrected to normal vision

Clinical Aim Study:

  • Ages 18 to 88
  • Strabismus
  • Able to keep looking at a visual target for 30-60 seconds
  • Able to report locations of visual targets during testing

Exclusion Criteria:

Ground Truth Aim Study:

  • Age less than 18 or greater than 88.

Clinical Study:

  • Age less than 18 or greater than 88
  • Inability to keep looking at a visual target for 30-60 seconds
  • Inability to report locations of visual targets during testing

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: EyeTurn App
All participants will have their eye alignment measured with both the experimental device (EyeTurn app) and the clinical gold standard tests or ground truth (simulated strabismus gaze angles).
Other: EyeTurn App
App software which analyzes the position of ocular surface reflections in a photograph to quantify eye misalignment (strabismus)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Strabismus angle with the app compared to ground truth and gold standard tests
Time Frame: 15 minutes
Strabismus angle is typically reported in prism diopters (PD) where 1PD = 0.57degrees.
15 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Perceived Value Survey
Time Frame: 5 minutes after completion of the tele-strabismus consult
A 10 point likert-type rating scale to quantify the perceived value (1 low value to 10 high value) of the app tele-strabismus consultation (a subaim in the clinical evaluation aim)
5 minutes after completion of the tele-strabismus consult
Test-Retest repeatability of the app
Time Frame: 3 app measurements taken over approximately 1 minute
Strabismus angle
3 app measurements taken over approximately 1 minute
Robustness
Time Frame: 1 year
calculation of the percentage of capture failures (capture failures/ total number of attempted image captures)
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Massachusetts Eye and Ear Infirmary

Collaborators

National Eye Institute (NEI)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 2018

Primary Completion (Actual)

December 30, 2019

Study Completion (Anticipated)

December 30, 2022

Study Registration Dates

First Submitted

February 7, 2018

First Submitted That Met QC Criteria

February 23, 2018

First Posted (Actual)

March 1, 2018

Study Record Updates

Last Update Posted (Actual)

April 19, 2021

Last Update Submitted That Met QC Criteria

April 16, 2021

Last Verified

April 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 15-061H
  • 2R44EY025902-02 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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