Refractive ErrorsNCT07891897
Evaluation of the Agreement Between Automated Program-Operated Phoropter Subjective Refraction and Optometrist-Performed Subjective Refraction
A study testing Optometrist-Performed Subjective Refraction in people with Refractive Errors, run by Zhongshan Ophthalmic Center, Sun Yat-sen University.
Trial summary
This study aims to evaluate the performance of an automated subjective refraction system that operates a digital phoropter. By comparing its results with those obtained through conventional subjective refraction performed by an optometrist, the study will assess the agreement in refractive prescriptions and examine… Read more about this study
- Who is it for?
- Ages 7 years and olderHealthy volunteers can take part
- Conditions the study is for
- Refractive Errors
- What is being tested?
- Optometrist-Performed Subjective Refraction
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 508 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 28 Feb 2027
- Phase
- Interventional
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 7 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Children aged 7-16 years or adults aged 18 years or older, of either sex.
- Astigmatism magnitude of 1.50 D or less. ③ Children must be able to undergo cycloplegia. ④ Voluntary participation in the study with written informed consent.
Who cannot join
- Concomitant ocular diseases causing opacity of the ocular media, such as cataract, glaucoma, or fundus disease.
- History of ocular trauma or intraocular surgery.
- Manifest strabismus or significant binocular vision dysfunction.
- Inability to follow and respond to system instructions. ⑤ Only one eye meeting the eligibility criteria.
- Considered unsuitable for participation by the investigator.
About this study
This study aims to evaluate the performance of an automated subjective refraction system that operates a digital phoropter. By comparing its results with those obtained through conventional subjective refraction performed by an optometrist, the study will assess the agreement in refractive prescriptions and examine examination efficiency, repeatability, and participant experience, thereby providing evidence for the further application of automated subjective refraction technology.
- Conditions
- Refractive Errors
- Being tested
- Automated Program-Controlled Subjective Refraction, Optometrist-Performed Subjective Refraction
- Medical subject headings
- Refractive Errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Automated Program-Controlled Subjective RefractionDiagnostic test
Subjective refraction is performed using an automated program operating a standard phoropter to determine sphere, cylinder, and axis. The system incorporates an in-house AI algorithm that has not been registered as a medical device. Its results are used for research purposes only and do not guide spectacle prescription or other clinical decisions. The first 50 adult participants undergo a second automated measurement for repeatability assessment.
Optometrist-Performed Subjective RefractionDiagnostic test
Subjective refraction is independently performed by a qualified optometrist according to a standardized operating procedure to determine sphere, cylinder, and axis. The optometrist is unaware of the results generated by the automated refraction system when performing the examination.
| Study group | Role | What they receive |
|---|---|---|
| Automated Refraction First | Experimental | Participants first undergo subjective refraction using the automated program-controlled refraction system, followed by a rest interval of at least 20 minutes and then subjective refraction performed by an optometrist. Pediatric participants undergo cycloplegia before both examinations. The first 50 adult participants undergo an additional automated refraction examination for repeatability assessment. Receives: Diagnostic Test: Automated Program-Controlled Subjective Refraction; Diagnostic Test: Optometrist-Performed Subjective Refraction |
| Optometrist Refraction First | Experimental | Participants first undergo subjective refraction performed by an optometrist, followed by a rest interval of at least 20 minutes and then subjective refraction using the automated program-controlled refraction system. Pediatric participants undergo cycloplegia before both examinations. The first 50 adult participants undergo an additional automated refraction examination for repeatability assessment. Receives: Diagnostic Test: Automated Program-Controlled Subjective Refraction; Diagnostic Test: Optometrist-Performed Subjective Refraction |
What is being measured
The primary outcome is the main question the study is designed to answer.
Agreement in refractive prescriptions between automated and optometrist-performed subjective refraction
Agreement between automated subjective refraction and optometrist-performed subjective refraction will be evaluated using measurements from the right eye as the primary analysis eye. The paired differences in spherical power and cylindrical power, measured in diopters (D), and cylinder axis, measured in degrees, will be analyzed using Bland-Altman analysis to estimate the mean difference (bias) and 95% limits of agreement. Intraclass correlation coefficients (ICCs) will also be calculated. The prespecified clinically acceptable limits are ±0.25 D for spherical and cylindrical power and ±5 degrees for cylinder axis.
Measured: Day 1, after completion of both subjective refraction examinations.
Secondary outcomes (4)
Examination time for each subjective refraction method
The duration of each subjective refraction examination will be recorded in minutes, from the start of the refraction procedure to completion of the final refractive prescription. The paired examination durations for automated subjective refraction and optometrist-performed subjective refraction will be compared within each participant.
Measured: Day 1, during each subjective refraction examination.
Repeatability of the automated subjective refraction system
Among the first 50 adult participants who undergo two automated subjective refraction measurements, test-retest repeatability will be evaluated for spherical power and cylindrical power, measured in diopters (D), and cylinder axis, measured in degrees. Repeatability will be quantified using the intraclass correlation coefficient (ICC), within-subject standard deviation (Sw), and coefficient of repeatability.
Measured: Day 1, after completion of both automated subjective refraction measurements
Agreement between the two subjective refraction methods under cycloplegic and non-cycloplegic conditions
Agreement between automated subjective refraction and optometrist-performed subjective refraction will be evaluated separately in participants examined under cycloplegic conditions and those examined under non-cycloplegic conditions. Children will undergo both examinations after cycloplegia, whereas adults will undergo both examinations without cycloplegia. For each subgroup, paired differences in spherical power and cylindrical power, measured in diopters (D), and cylinder axis, measured in degrees, will be assessed using Bland-Altman analysis and intraclass correlation coefficients (ICCs).
Measured: Day 1, after completion of both subjective refraction examinations.
Participant acceptance, comfort, and satisfaction with the automated refraction procedure
The seven-item questionnaire assesses three aspects: understanding and operation, comfort and visual fatigue, and acceptance and willingness to use. Each item is rated on a 5-point Likert scale from 1 ("strongly disagree") to 5 ("strongly agree"), with higher scores indicating a more favorable evaluation.
Measured: Day 1, immediately after completion of both subjective refraction examinations.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Oct 2026
- Study start1 Nov 2026 (estimated)
- Primary completion31 Dec 2026 (estimated)
- Study completion28 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Refractive ErrorsStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 508 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07891897
- Sponsor's protocol ID
- 2026KYPJ109
- Status last verified
- Sep 2026
- First submitted
- 11 Oct 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No external sharing of individual participant data is currently planned.