StrabismusNCT03450980
Mobile Medical Application for Cost-effective Strabismus Screening
An observational study of Strabismus, run by Massachusetts Eye and Ear Infirmary at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 88 yearsHealthy volunteers can take part
- Conditions the study is for
- Strabismus
- How many people
- 91 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2018to 30 Jan 2025
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 88 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Normal vision participants with simulated strabismus and participants with strabismus.
Who may be able to join
- Ground Truth Aim Study:
- Age 18 to 88 years
- 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
Who cannot join
- Ground Truth Aim Study:
- Age less than 18 years 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
Trial locations and contacts
1 site in 1 country.
United States1 site
Ophthalmology of Clinical Research Office, Mass Eye and Ear
Boston, Massachusetts, 021141
About this study
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.
Read the 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
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).
AIM 2:
Evaluate the strabismus app accuracy and feasibility in participants with strabismus tested with both the app and clinical methods and analyzed for levels of agreement.
Primary Hypothesis: For strabismus ranging from 1 to 30 prism diopters (target range), the optimized version of the app will provide measurements which are highly correlated with the ground truth (simulated strabismus) or clinical tests of eye alignment.
- Conditions
- Strabismus
- Keywords
- Double Vision, Amblyopia
- Medical subject headings
- Strabismus, Diplopia, Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Strabismus | Participants with strabismus had measurement with the app and compared to the cover test with prism neutralization (gold standard) or eye turning to know eccentricity. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of App-measured Eye Deviation Angles to Gold Standard
Linear regression analysis was used to compare the app measurements of strabismus angle to ground truth and gold standard measures. The outcome measure is the difference between the two methods, in terms of least square mean (LSM).
Measured: 15 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2018
- Study start1 Feb 2018
- Primary completion30 Dec 2019
- Study completion30 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (14)Papers the sponsor has linked to this study.
- Other trials for StrabismusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 91 participants (actual)
Sponsor and investigators
- Lead sponsor
- Massachusetts Eye and Ear Infirmary
- Sponsor type
- University, hospital or other
- Collaborators
- National Eye Institute (NEI)
- Responsible party
- Principal investigator, Gang Luo, Ph.D., Massachusetts Eye and Ear Infirmary
- Investigators
- Gang Luo, PhD, Principal investigator, Massachusetts Eye and Ear
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03450980
- Sponsor's protocol ID
- 15-061H
- Other IDs
- 2R44EY025902-02
- Status last verified
- Jun 2025
- First submitted
- 7 Feb 2018
- Last updated
- 14 Jul 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Brodie SE. Photographic calibration of the Hirschberg test. Invest Ophthalmol Vis Sci. 1987 Apr;28(4):736-42.
PubMed 3557878Rowe, F.J., Clinical Orthoptics. 3rd ed. 2012: Wiley and Sons. 486.
Taylor K, Elliott S. Interventions for strabismic amblyopia. Cochrane Database Syst Rev. 2011 Aug 10;(8):CD006461. doi: 10.1002/14651858.CD006461.pub3.
PubMed 21833955Cotter SA, Tarczy-Hornoch K, Song E, Lin J, Borchert M, Azen SP, Varma R; Multi-Ethnic Pediatric Eye Disease Study Group. Fixation preference and visual acuity testing in a population-based cohort of preschool children with amblyopia risk factors. Ophthalmology. 2009 Jan;116(1):145-53. doi: 10.1016/j.ophtha.2008.08.031. Epub 2008 Oct 29.
PubMed 18962921Loudon SE, Rook CA, Nassif DS, Piskun NV, Hunter DG. Rapid, high-accuracy detection of strabismus and amblyopia using the pediatric vision scanner. Invest Ophthalmol Vis Sci. 2011 Jul 7;52(8):5043-8. doi: 10.1167/iovs.11-7503.
PubMed 21642624Barnard, S. and E. Johnson, Detecting strabismus. Optician, 2013.
Klaver P, Marcar V, Martin E. Neurodevelopment of the visual system in typically developing children. Prog Brain Res. 2011;189:113-36. doi: 10.1016/B978-0-444-53884-0.00021-X.
PubMed 21489386Williams C, Northstone K, Harrad RA, Sparrow JM, Harvey I; ALSPAC Study Team. Amblyopia treatment outcomes after screening before or at age 3 years: follow up from randomised trial. BMJ. 2002 Jun 29;324(7353):1549. doi: 10.1136/bmj.324.7353.1549.
PubMed 12089090Epelbaum M, Milleret C, Buisseret P, Dufier JL. The sensitive period for strabismic amblyopia in humans. Ophthalmology. 1993 Mar;100(3):323-7. doi: 10.1016/s0161-6420(13)32170-8.
PubMed 8460000Eibschitz-Tsimhoni M, Friedman T, Naor J, Eibschitz N, Friedman Z. Early screening for amblyogenic risk factors lowers the prevalence and severity of amblyopia. J AAPOS. 2000 Aug;4(4):194-9. doi: 10.1067/mpa.2000.105274.
PubMed 10951293Lions C, Bui-Quoc E, Bucci MP. Postural control in strabismic children versus non strabismic age-matched children. Graefes Arch Clin Exp Ophthalmol. 2013 Sep;251(9):2219-25. doi: 10.1007/s00417-013-2372-x. Epub 2013 May 9.
PubMed 23657730Scheiman MM, Hertle RW, Beck RW, Edwards AR, Birch E, Cotter SA, Crouch ER Jr, Cruz OA, Davitt BV, Donahue S, Holmes JM, Lyon DW, Repka MX, Sala NA, Silbert DI, Suh DW, Tamkins SM; Pediatric Eye Disease Investigator Group. Randomized trial of treatment of amblyopia in children aged 7 to 17 years. Arch Ophthalmol. 2005 Apr;123(4):437-47. doi: 10.1001/archopht.123.4.437.
PubMed 15824215Hertle RW, Scheiman MM, Beck RW, Chandler DL, Bacal DA, Birch E, Chu RH, Holmes JM, Klimek DL, Lee KA, Repka MX, Weakley DR Jr; Pediatric Eye Disease Investigator Group. Stability of visual acuity improvement following discontinuation of amblyopia treatment in children aged 7 to 12 years. Arch Ophthalmol. 2007 May;125(5):655-9. doi: 10.1001/archopht.125.5.655.
PubMed 17502505Lukman H, Kiat JE, Ganesan A, Chua WL, Khor KL, Choong YF. Negative social reaction to strabismus in school children ages 8-12 years. J AAPOS. 2011 Jun;15(3):238-40. doi: 10.1016/j.jaapos.2011.01.158. Epub 2011 Jun 16.
PubMed 21683635
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mobile Medical Application for Cost-effective Strabismus Screening
- ClinicalTrials.gov ID
- NCT03450980
- Acronym / sponsor ID
- 15-061H
- Conditions
- Strabismus
- Keywords
- Double Vision, Amblyopia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 91 participants (actual)
- Lead sponsor
- Massachusetts Eye and Ear InfirmaryUniversity, hospital or other
- Collaborators
- National Eye Institute (NEI)
- Study start
- 1 Feb 2018 (actual)
- Primary completion
- 30 Dec 2019 (actual)
- Study completion
- 30 Jan 2025 (actual)
- First posted
- 1 Mar 2018 (actual)
- Results
- Posted 14 Jul 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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
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).
AIM 2:
Evaluate the strabismus app accuracy and feasibility in participants with strabismus tested with both the app and clinical methods and analyzed for levels of agreement.
Primary Hypothesis: For strabismus ranging from 1 to 30 prism diopters (target range), the optimized version of the app will provide measurements which are highly correlated with the ground truth (simulated strabismus) or clinical tests of eye alignment.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Strabismus | – | –Participants with strabismus had measurement with the app and compared to the cover test with prism neutralization (gold standard) or eye turning to know eccentricity. |
Who may qualify
- Ages
- 18 to 88 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Normal vision participants with simulated strabismus and participants with strabismus.
Key inclusion criteria (7 listed)
- Age 18 to 88 years
- Normal or corrected to normal vision
- Ages 18 to 88
- Strabismus
- Able to keep looking at a visual target for 30-60 seconds
Key exclusion criteria (5 listed)
- Age less than 18 years or greater than 88.
- Age less than 18 or greater than 88
- Inability to keep looking at a visual target for 30-60 seconds
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Comparison of App-measured Eye Deviation Angles to Gold Standard
Time frame: 15 minutes
Linear regression analysis was used to compare the app measurements of strabismus angle to ground truth and gold standard measures. The outcome measure is the difference between the two methods, in terms of least square mean (LSM).
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jul 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 3557878Brodie SE. Photographic calibration of the Hirschberg test. Invest Ophthalmol Vis Sci. 1987 Apr;28(4):736-42.
- BackgroundRowe, F.J., Clinical Orthoptics. 3rd ed. 2012: Wiley and Sons. 486.
- Background: PubMed 21833955Taylor K, Elliott S. Interventions for strabismic amblyopia. Cochrane Database Syst Rev. 2011 Aug 10;(8):CD006461. doi: 10.1002/14651858.CD006461.pub3.
- Background: PubMed 18962921Cotter SA, Tarczy-Hornoch K, Song E, Lin J, Borchert M, Azen SP, Varma R; Multi-Ethnic Pediatric Eye Disease Study Group. Fixation preference and visual acuity testing in a population-based cohort of preschool children with amblyopia risk factors. Ophthalmology. 2009 Jan;116(1):145-53. doi: 10.1016/j.ophtha.2008.08.031. Epub 2008 Oct 29.
- Background: PubMed 21642624Loudon SE, Rook CA, Nassif DS, Piskun NV, Hunter DG. Rapid, high-accuracy detection of strabismus and amblyopia using the pediatric vision scanner. Invest Ophthalmol Vis Sci. 2011 Jul 7;52(8):5043-8. doi: 10.1167/iovs.11-7503.
- BackgroundBarnard, S. and E. Johnson, Detecting strabismus. Optician, 2013.
- Background: PubMed 21489386Klaver P, Marcar V, Martin E. Neurodevelopment of the visual system in typically developing children. Prog Brain Res. 2011;189:113-36. doi: 10.1016/B978-0-444-53884-0.00021-X.
- Background: PubMed 12089090Williams C, Northstone K, Harrad RA, Sparrow JM, Harvey I; ALSPAC Study Team. Amblyopia treatment outcomes after screening before or at age 3 years: follow up from randomised trial. BMJ. 2002 Jun 29;324(7353):1549. doi: 10.1136/bmj.324.7353.1549.
- Background: PubMed 8460000Epelbaum M, Milleret C, Buisseret P, Dufier JL. The sensitive period for strabismic amblyopia in humans. Ophthalmology. 1993 Mar;100(3):323-7. doi: 10.1016/s0161-6420(13)32170-8.
- Background: PubMed 10951293Eibschitz-Tsimhoni M, Friedman T, Naor J, Eibschitz N, Friedman Z. Early screening for amblyogenic risk factors lowers the prevalence and severity of amblyopia. J AAPOS. 2000 Aug;4(4):194-9. doi: 10.1067/mpa.2000.105274.
- Background: PubMed 23657730Lions C, Bui-Quoc E, Bucci MP. Postural control in strabismic children versus non strabismic age-matched children. Graefes Arch Clin Exp Ophthalmol. 2013 Sep;251(9):2219-25. doi: 10.1007/s00417-013-2372-x. Epub 2013 May 9.
- Results publication: PubMed 15824215Scheiman MM, Hertle RW, Beck RW, Edwards AR, Birch E, Cotter SA, Crouch ER Jr, Cruz OA, Davitt BV, Donahue S, Holmes JM, Lyon DW, Repka MX, Sala NA, Silbert DI, Suh DW, Tamkins SM; Pediatric Eye Disease Investigator Group. Randomized trial of treatment of amblyopia in children aged 7 to 17 years. Arch Ophthalmol. 2005 Apr;123(4):437-47. doi: 10.1001/archopht.123.4.437.
- Individual participant dataSharing planned: No
Related trials for Strabismus
Not yet recruiting
Comparative Study Of Combined Recession-Resection And Fenestration of Superior Rectus Muscle for Treatment of Dissociated Vertical Deviation
Dissociated Vertical Deviation
RecruitingObservational study
Intraoperative OCT Guidance of Intraocular Surgery II
Macular Holes, Epiretinal Membrane
Not yet recruitingPhase 4
Effect of Ketamine-Propofol Total Intravenous Anesthesia Versus Sevoflurane-Based Anesthesia on Postoperative Vomiting in Children Undergoing Strabismus Surgery
Postoperative Vomiting, Postoperative Nausea and Vomiting
Not yet recruiting
Attention-based Binocular Training for Impaired Stereopsis (BRAVE)
Amblyopia, Strabismus
Not yet recruitingObservational study
Japanese Strabismus Outcomes Assessment and Research Group Study
Strabismus
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Gang Luo, PhD principal investigator
Massachusetts Eye and Ear
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Strabismus, run by Massachusetts Eye and Ear Infirmary at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 14 Jul 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison of App-measured Eye Deviation Angles to Gold Standard (time frame: 15 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03450980, which also lists 14 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Jul 2025; AzTrials last refreshed its copy on 30 Oct 2026.